Usefullness of analysing ones own games with an engine

First of all it kind of depends on your playing strength, but every player can benefit at least a bit from an engine.

Personally I use the engine for the following analysis:

Opening preperation: I play out different variations of my opening with the engine running. I do this so I dont miss any critical good moves of my opponents. For myself I dont necessarily chose the best engine move, but the move I think fits my style the best. At the end I check if I like the position and what the engine says of it. I dont care about +- 0.2, as long as I feel the position is good for me.
Open issue control: If I play 10+0 or 15+15 online, I dont analyze every game by hand afterwards. But I will go for a quick engine run and check, what kind of mistakes I made (if there are any). This way, I get a overview about my typical mistakes and know where I can improve. I also check, if I followed my prepared opening ideas (if present) and how the position developed.
For club games, I will always first analyze them by hand. The time spent depends a lot about the position and how many ideas I find which are worth analyzing (or ideas I had in the game but could not calculate due to time). Of course I will analyze my mistakes I spot myself. Afterwards I will run the engine and check if I missed any mistakes. In addition I will play out some lines of the engine which I find intresting. Afterwards I think about, wheither I could have spotted it during the game and if it was something I could play myself, regarding the resulting position.

In general, I think an engine gives you intresting insights, but you should always remember, that you dont have to be able to play like the engine. So the engine will find some lines, which you should dismiss, because they are too hard for you.

For additional benefit, you can use a book to improve. I will sit down with a chess book go over some content and later on use the engine to double check the ideas I learned in the book.


In the Caro-Kann Panov-Botvinnik Attack 5... e6 6. Nf3, what are the differences between 6... Be7 and 6... Bb4 ? Which one is more solid and quiet?

As surprising as it sounds, 6...Bb4 is probably going to lead to the quieter game.  The reason is that with the bishop on b4, pieces will get traded off on c3.

As an example, the game Najdorf-Portisch 1-0, from 1962 shows some of these ideas.  Although the game begins as a 1. d4 game, the position transposes directly to the Panov Botvinnik.

[FEN ""]
[Event "Varna"]
[Site "Varna"]
[Date "1962"]
[EventDate "?"]
[Round "3"]
[Result "1-0"]
[White "Miguel Najdorf"]
[Black "Lajos Portisch"]
[ECO "B14"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "43"]

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.cxd5 Nxd5 6.e3 cxd4
7.exd4 Bb4 8.Qc2 Nc6 9.Bd3 Nxc3 10.bxc3 Nxd4 11.Nxd4 Qxd4
12.Bb5+ Ke7 13.O-O Qxc3 14.Qe2 Bd6 15.Bb2 Qa5 16.Rfd1 Rd8
17.Qh5 f6 18.Qxh7 Kf7 19.Be2 Qg5 20.Bc1 Bxh2+ 21.Kxh2 Qe5+
22.f4 1-0


How do top players use computers to improve their play?

How might players such as Nakamura use Rybka to improve their play against a computer opponent?

  ... check their own moves for blunders; check the computer's suggestions
  to see if there are some convoluted move sequences which lead to a
  huge advantage ...

I believe you said it yourself here. A computer would be used in order to check if the move that the GM thinks would be a good move is indeed the best move to exploit the existing position. I doubt that it would play the end game fully, I am positive that the GM thinks through every move of the game instead of trusting blindly the computer, but most likely definitely the opening would be played by the machine, at least till about move 5-7, until the position changes known book course.Additionally, the computer would most likely have some kind of a database of the previous games played between other players, so if the position played was already played by someone else a while back, it could be used to not make the same mistake or, vice-versa, to build a long term plan.

How have computers changed the way top players play today (when unassisted by computers)?

OK, I do understand that this might get a bit long, but bear with me. Ill bold the important points. Computers have made the modern top players much more tactically aware and ready than the chess players before them. This is what the quote about Fischer is talking about: Fischer did not have the opportunity to analyse his games and study lines to such a far extent as is done by the modern top players using computer technology. About the second quote: with the knowledge that there is a possible accurate move in virtually any position, top players would dedicate more time to thinking and finding that one single accurate move, than just assuming that the position was lost and thats it. This makes the game much more interesting and thrilling, because you know that the accurate move exists, its just the matter of finding it.

About how computers help top players prepare: so basically, theres 4 reasons why computers are used today for chess:

Playing against software program
Keeping track of games (Databases)
Using software to analyse your games
Using software to do chess problems

Out of those 4 points, the one that interest us are the bolded two.

Keeping track of games (Databases) is used usually to analyse the openings, and then comparing them to how they were played by other top-players in order to evaluate one's own position and/or learn something from others. You could've never thought that that move would bring any use, but if Kasparov's been whipping it out right and left for the past 5 years with great success, you might as well try giving it a go.

Using software to analyse your games is the primary use of computer engine by top-players. After every official game they play, the will analyse their games and see where they did wrong and where they could do better. The programs are usually proficient in tactics and opening theory, so for someone like Magnus Carlsen, whose opening is not as strong compared to other GM's like Kasparov and etc, a computer engine would be the best an fastest way to improve. And of course, if they find that what they did in game is not the strongest move in the position, next time they would be aware of it and follow the move that was suggested by the engine. Usually this would happen once again in the opening, because middle games repeat quite rarely if played against different opponents.


What's the best continuation for white here?

You're not down material, so just develop.

6.d4 allows both your bishops to get in the game while keeping strength in the center. After that, you can develop your minor pieces and castle very efficiently. You're going to have a swell game.

I wouldn't worry too much about 7... f6. That move weakens his Kingside. And since you're up a pawn, the best he can do is retake on e5 and give himself an isolated pawn. 8. Bf4 develops a piece and puts an eye on the under-defended c7 square.

Furthermore, after Bf4, you can plan for Nc3 followed by O-O-O (castling on the queenside) where your rook will thunder on the d file.


What are the pairing regulations for a single-elimination (knockout) tournament?

The participants were seeded by their FIDE rating: the highest rated player (Magnus Carlsen, 2822) got #1; Wesley So, rated 2810, got #2, all the way down to Oluwafemi Balogun (2255), seed #128.

In the first round, the player with number x plays against the opponent with number 129 - x. So 1 vs. 128, 2 vs. 127, and so on.

In the second round, assuming the stronger player (with the lower number) advances, the player with number x plays against the opponent with number 65 - x. So 1 vs. 64 (this actually happened) and 9 vs. 56 (but this became 9 vs. 73 since 73 beat 56).

The 'target sum' for the third round is 33, for the fourth round 17, and so on until the final where #1 is supposed to play against #2.

This all is a standard seeding mechanism used in many sports (sometimes with slight variations); actually, in most cases, only the top n% (25% is common) of the players is seeded and the rest are paired randomly. This tournament was 'completely' seeded, which is relatively rare.


Are two knights generally worth less than two bishops?

According to GM Larry Kaufman, who has worked on the chess engines Rybka and Komodo, and has done extensive database analysis of material imbalances,

The bishop pair has an average value of half a pawn (more when the opponent has no minor pieces to exchange for one of the bishops), enough to regard it as part of the material evaluation of the position, and enough to overwhelm most positional considerations. Moreover, this substantial bishop pair value holds up in all situations tested, regardless of what else is on the board.

although he goes on to note some exceptions. The whole article is worth reading.


Is it true that at any time only one piece can put king in check?

Double check is a fine tactic. An example would be a bishop lined up on the same diagonal as the king with a rook or knight in the way blocking the check. The rook or knight moves giving check to the king and also uncovering the check from the bishop. The king must move since there is no way to block two different lines or take two different pieces at the same time.


Earliest text which mentions the pawn promotion rule

According to H.J.R. Murray (in A History of Chess, 1913), the pawn promotion rule (specially named as 'shatpada' or six steps) is already found in the very first known ancestry of chess: chaturanga (an ancient indian four-handed dice game whose pieces were  King, Elephant, Chariot, Horse and Pawn for each one of the four armies). Chaturanga exists in this form at least since the 7th century of our era. The subsequent forms of games related to chaturanga, including our western chess, have employed several different ways to promote pawns through the centuries (only to queen - or similar, like vizir or counsellor; only if the pawn reaches the 8th row at selected ranks - for example not in the 'e', 'b' or 'g' files; only to a previously captured piece; only to the piece originally related to the rank; etc), but this feature has been always present.

A History of Chess - Page 70
A History of Chess - Cover


What is the longest checkmate problem a human has composed?

The longest known checkmate problem composed by a human is dependent on a few criteria that are generally used by chess composers. Namely, it is a question of whether or not you want the problem to have a unique solution, meaning that there is only one possible solution with Black defending optimally, and if you want the position to be legal or not, meaning that it is reachable from the starting position. Another consideration is whether or not promoted pieces are allowed, as most composers try to not use them. Finally, it is also debatable whether or not an illegal position must have only pieces from the chess box, with pawns being converted as needed.
Here is a selection of a few problems that fall along these lines.
This is the longest legal problem with a unique solution and no promoted pieces.
[Title "Walther Jørgensen, Thema Danicum 1982, Mate In 226"]
[fen "1N2Q3/p6n/p5n1/p1p2rpb/p4k1r/K1P4p/2PP4/6B1 w - - 0 1"]

1. Bh2+! Kf3 2. Qe3+ Kg2 3. Qg1+ Kf3 4. Qf1+ Kg4 5. Qe2+ Rf3 6. Qe6+ Rf5 7. Nd7 Kf3 8. Qe3+ Kg2 9. Qg1+ Kf3 10. Qf1+ Kg4 11. Qe2+ Rf3 12. Qe6+ Rf5 13. Kb2! Kf3 14. Qe3+ Kg2 15. Qg1+ Kf3 16. Qf1+ Kg4 17. Qe2+ Rf3 18. Qe6+ Rf5 19. Kc1! Kf3 20. Qe3+ Kg2 21. Qg1+ Kf3 22. Qf1+ Kg4 23. Qe2+ Rf3 24. Qe6+ Rf5 25. Kd1! a3! 26. Kc1 Kf3 27. Qe3+ Kg2 28. Qg1+ Kf3 29. Qf1+ Kg4 30. Qe2+ Rf3 31. Qe6+ Rf5 32. Kb1 Kf3 33. Qe3+ Kg2 34. Qg1+ Kf3 35. Qf1+ Kg4 36. Qe2+ Rf3 37. Qe6+ Rf5 38. Ka2 Kf3 39. Qe3+ Kg2 40. Qg1+ Kf3 41. Qf1+ Kg4 42. Qe2+ Rf3 43. Qe6+ Rf5 44. Kxa3 Kf3 45. Qe3+ Kg2 46. Qg1+ Kf3 47. Qf1+ Kg4 48. Qe2+ Rf3 49. Qe6+ Rf5 50. Kb2 Kf3 51. Qe3+ Kg2 52. Qg1+ Kf3 53. Qf1+ Kg4 54. Qe2+ Rf3 55. Qe6+ Rf5 56. Kc1 Kf3 57. Qe3+ Kg2 58. Qg1+ Kf3 59. Qf1+ Kg4 60. Qe2+ Rf3 61. Qe6+ Rf5 62. Kd1 a4! 63. Kc1 Kf3 64. Qe3+ Kg2 65. Qg1+ Kf3 66. Qf1+ Kg4 67. Qe2+ Rf3 68. Qe6+ Rf5 69. Kd1 a5! 70. Kc1 Kf3 71. Qe3+ Kg2 72. Qg1+ Kf3 73. Qf1+ Kg4 74. Qe2+ Rf3 75. Qe6+ Rf5 76. Kd1 a6! 77. Kc1 Kf3 78. Qe3+ Kg2 79. Qg1+ Kf3 80. Qf1+ Kg4 81. Qe2+ Rf3 82. Qe6+ Rf5 83. Kd1 a3 84. Kc1 Kf3 85. Qe3+ Kg2 86. Qg1+ Kf3 87. Qf1+ Kg4 88. Qe2+ Rf3 89. Qe6+ Rf5 90. Kb1 Kf3 91. Qe3+ Kg2 92. Qg1+ Kf3 93. Qf1+ Kg4 94. Qe2+ Rf3 95. Qe6+ Rf5 96. Ka2 Kf3 97. Qe3+ Kg2 98. Qg1+ Kf3 99. Qf1+ Kg4 100. Qe2+ Rf3 101. Qe6+ Rf5 102. Kxa3 Kf3 103. Qe3+ Kg2 104. Qg1+ Kf3 105. Qf1+ Kg4 106. Qe2+ Rf3 107. Qe6+ Rf5 108. Kb2 Kf3 109. Qe3+ Kg2 110. Qg1+ Kf3 111. Qf1+ Kg4 112. Qe2+ Rf3 113. Qe6+ Rf5 114. Kc1 Kf3 115. Qe3+ Kg2 116. Qg1+ Kf3 117. Qf1+ Kg4 118. Qe2+ Rf3 119. Qe6+ Rf5 120. Kd1 a4! 121. Kc1 Kf3 122. Qe3+ Kg2 123. Qg1+ Kf3 124. Qf1+ Kg4 125. Qe2+ Rf3 126. Qe6+ Rf5 127. Kd1 a5! 128. Kc1 Kf3 129. Qe3+ Kg2 130. Qg1+ Kf3 131. Qf1+ Kg4 132. Qe2+ Rf3 133. Qe6+ Rf5 134. Kd1 a3 135. Kc1 Kf3 136. Qe3+ Kg2 137. Qg1+ Kf3 138. Qf1+ Kg4 139. Qe2+ Rf3 140. Qe6+ Rf5 141. Kb1 Kf3 142. Qe3+ Kg2 143. Qg1+ Kf3 144. Qf1+ Kg4 145. Qe2+ Rf3 146. Qe6+ Rf5 147. Ka2 Kf3 148. Qe3+ Kg2 149. Qg1+ Kf3 150. Qf1+ Kg4 151. Qe2+ Rf3 152. Qe6+ Rf5 153. Kxa3 Kf3 154. Qe3+ Kg2 155. Qg1+ Kf3 156. Qf1+ Kg4 157. Qe2+ Rf3 158. Qe6+ Rf5 159. Kb2 Kf3 160. Qe3+ Kg2 161. Qg1+ Kf3 162. Qf1+ Kg4 163. Qe2+ Rf3 164. Qe6+ Rf5 165. Kc1 Kf3 166. Qe3+ Kg2 167. Qg1+ Kf3 168. Qf1+ Kg4 169. Qe2+ Rf3 170. Qe6+ Rf5 171. Kd1 a4 172. Kc1 Kf3 173. Qe3+ Kg2 174. Qg1+ Kf3 175. Qf1+ Kg4 176. Qe2+ Rf3 177. Qe6+ Rf5 178. Kd1 c4! 179. Kc1 Kf3 180. Qe3+ Kg2 181. Qg1+ Kf3 182. Qf1+ Ke4! 183. Qxc4+ Kf3 184. Qf1+ Kg4 185. Qe2+ Rf3 186. Qe6+ Rf5 187. Kd1 a3 188. Kc1 Kf3 189. Qe3+ Kg2 190. Qg1+ Kf3 191. Qf1+ Kg4 192. Qe2+ Rf3 193. Qe6+ Rf5 194. Kb1 Kf3 195. Qe3+ Kg2 196. Qg1+ Kf3 197. Qf1+ Kg4 198. Qe2+ Rf3 199. Qe6+ Rf5 200. Ka2 Kf3 201. Qe3+ Kg2 202. Qg1+ Kf3 203. Qf1+ Kg4 204. Qe2+ Rf3 205. Qe6+ Rf5 206. Kxa3 Kf3 207. Qe3+ Kg2 208. Qg1+ Kf3 209. Qf1+ Kg4 210. Qe2+ Rf3 211. Qe6+ Rf5 212. Kb2 Kf3 213. Qe3+ Kg2 214. Qg1+ Kf3 215. Qf1+ Kg4 216. Qe2+ Rf3 217. Qe6+ Rf5 218. Kc1 Kf3 219. Qe3+ Kg2 220. Qg1+ Kf3 221. Qf1+ Kg4 222. Qe2+ Rf3 223. Qe6+ Rf5 224. Kd1 Nf8,Nf6 225. Nf6+ Kf3 226. Qe2#

Based off of an earlier mate in 292 with an illegal position, this mate in 257 has as legal position with some minor duals in the solution.
[Title "Ottó Titusz Bláthy, Vielzügige Schachaufg 1889, Mate In 257 Legal Version of the #292"]
[FEN "q5nn/1pk1p3/p3P1p1/P3rpP1/1Kp1pP1p/8/2PQ1PP1/8 w - - 0 1"]

1. Qd7+ Kb8 2. Qd8+ Ka7 3. Qd4+ Rc5 4. Qxc5+ Kb8 5. Qe5+ Kc8 6. Qd5 Kc7 7. Qd7+ Kb8 8. Qd8+ Ka7 9. Qb6+ Kb8 10. c3 Kc8 11. Qc5+ Kb8 12. Qe5+ Kc8 13. Qd5 Kc7 14. Qd7+ Kb8 15. Qd8+ Ka7 16. Qb6+ Kb8 17. Ka3 Kc8 18. Qc5+ Kb8 19. Qe5+ Kc8 20. Qd5 Kc7 21. Qd7+ Kb8 22. Qd8+ Ka7 23. Qb6+ Kb8 24. Kb2 Kc8 25. Qc5+ Kb8 26. Qe5+ Kc8 27. Qd5 Kc7 28. Qd7+ Kb8 29. Qd8+ Ka7 30. Qb6+ Kb8 31. Kc1 Kc8 32. Qc5+ Kb8 33. Qe5+ Kc8 34. Qd5 Kc7 35. Qd7+ Kb8 36. Qd8+ Ka7 37. Qb6+ Kb8 38. Kd1 Kc8 39. Qc5+ Kb8 40. Qe5+ Kc8 41. Qd5 Kc7 42. Qd7+ Kb8 43. Qd8+ Ka7 44. Qb6+ Kb8 45. Ke2 Kc8 46. Qc5+ Kb8 47. Qe5+ Kc8 48. Qd5 Kc7 49. Qd7+ Kb8 50. Qd8+ Ka7 51. Qb6+ Kb8 52. Kf1 Kc8 53. Qc5+ Kb8 54. Qe5+ Kc8 55. Qd5 Kc7 56. Qd7+ Kb8 57. Qd8+ Ka7 58. Qb6+ Kb8 59. Kg1 Kc8 60. Qc5+ Kb8 61. Qe5+ Kc8 62. Qd5 Kc7 63. Qd7+ Kb8 64. Qd8+ Ka7 65. Qb6+ Kb8 66. Kh2 Kc8 67. Qc5+ Kb8 68. Qe5+ Kc8 69. Qd5 Kc7 70. Qd7+ Kb8 71. Qd8+ Ka7 72. Qb6+ Kb8 73. Kh3 Kc8 74. Qc5+ Kb8 75. Qe5+ Kc8 76. Qd5 Kc7 77. Qd7+ Kb8 78. Qd8+ Ka7 79. Qb6+ Kb8 80. Kxh4 Kc8 81. Qc5+ Kb8 82. Qe5+ Kc8 83. Qd5 Kc7 84. Qd7+ Kb8 85. Qd8+ Ka7 86. Qb6+ Kb8 87. Kh3 Kc8 88. Qc5+ Kb8 89. Qe5+ Kc8 90. Qd5 Kc7 91. Qd7+ Kb8 92. Qd8+ Ka7 93. Qb6+ Kb8 94. Kh2 Kc8 95. Qc5+ Kb8 96. Qe5+ Kc8 97. Qd5 Kc7 98. Qd7+ Kb8 99. Qd8+ Ka7 100. Qb6+ Kb8 101. Kg1 Kc8 102. Qc5+ Kb8 103. Qe5+ Kc8 104. Qd5 Kc7 105. Qd7+ Kb8 106. Qd8+ Ka7 107. Qb6+ Kb8 108. Kf1 Kc8 109. Qc5+ Kb8 110. Qe5+ Kc8 111. Qd5 Kc7 112. Qd7+ Kb8 113. Qd8+ Ka7 114. Qb6+ Kb8 115. Ke2 Kc8 116. Qc5+ Kb8 117. Qe5+ Kc8 118. Qd5 Kc7 119. Qd7+ Kb8 120. Qd8+ Ka7 121. Qb6+ Kb8 122. Kd1 Kc8 123. Qc5+ Kb8 124. Qe5+ Kc8 125. Qd5 Kc7 126. Qd7+ Kb8 127. Qd8+ Ka7 128. Qb6+ Kb8 129. Kc1 Kc8 130. Qc5+ Kb8 131. Qe5+ Kc8 132. Qd5 Kc7 133. Qd7+ Kb8 134. Qd8+ Ka7 135. Qb6+ Kb8 136. Kb2 Kc8 137. Qc5+ Kb8 138. Qe5+ Kc8 139. Qd5 Kc7 140. Qd7+ Kb8 141. Qd8+ Ka7 142. Qb6+ Kb8 143. Ka3 Kc8 144. Qc5+ Kb8 145. Qe5+ Kc8 146. Qd5 Kc7 147. Qd7+ Kb8 148. Qd8+ Ka7 149. Qb6+ Kb8 150. Kb4 Kc8 151. Qc5+ Kb8 152. Qe5+ Ka7 153. Qd4+ Kb8 154. Qxh8 Kc7 155. Qe5+ Kc8 156. Qd5 Kb8 157. Qd8+ Ka7 158. Qb6+ Kb8 159. Ka3 Kc8 160. Qc5+ Kb8 161. Qe5+ Kc8 162. Qd5 Kc7 163. Qd7+ Kb8 164. Qd8+ Ka7 165. Qb6+ Kb8 166. Kb2 Kc8 167. Qc5+ Kb8 168. Qe5+ Kc8 169. Qd5 Kc7 170. Qd7+ Kb8 171. Qd8+ Ka7 172. Qb6+ Kb8 173. Kc1 Kc8 174. Qc5+ Kb8 175. Qe5+ Kc8 176. Qd5 Kc7 177. Qd7+ Kb8 178. Qd8+ Ka7 179. Qb6+ Kb8 180. Kd1 Kc8 181. Qc5+ Kb8 182. Qe5+ Kc8 183. Qd5 Kc7 184. Qd7+ Kb8 185. Qd8+ Ka7 186. Qb6+ Kb8 187. Ke2 Kc8 188. Qc5+ Kb8 189. Qe5+ Kc8 190. Qd5 Kc7 191. Qd7+ Kb8 192. Qd8+ Ka7 193. Qb6+ Kb8 194. Kf1 Kc8 195. Qc5+ Kb8 196. Qe5+ Kc8 197. Qd5 Kc7 198. Qd7+ Kb8 199. Qd8+ Ka7 200. Qb6+ Kb8 201. Kg1 Kc8 202. Qc5+ Kb8 203. Qe5+ Kc8 204.Qd5 Kc7 205. Qd7+ Kb8 206. Qd8+ Ka7 207. Qb6+ Kb8 208. Kh2 Kc8 209. Qc5+ Kb8 210. Qe5+ Kc8 211. Qd5 Kc7 212. Qd7+ Kb8 213. Qd8+ Ka7 214. Qb6+ Kb8 215. Kh3 Kc8 216. Qc5+ Kb8 217. Qe5+ Kc8 218. Qd5 Kc7 219. Qd7+ Kb8 220. Qd8+ Ka7 221. Qb6+ Kb8 222. g4 Kc8 223. Qc5+ Kb8 224. Qe5+ Kc8 225. Qd5 Kc7 226. Qd7+ Kb8 227. Qd8+ Ka7 228. Qb6+ Kb8 229. gxf5 gxf5 230. Kh4 Kc8 231. Qc5+ Kb8 232. Qe5+ Kc8 233. Qd5 Kc7 234. Qd7+ Kb8 235. Qd8+ Ka7 236. Qb6+ Kb8 237. Kh5 Kc8 238. Qc5+ Kb8 239. Qe5+ Kc8 240. Qd5 Kc7 241. Qd7+ Kb8 242. Qd8+ Ka7 243. Qb6+ Kb8 244. Kg6 Kc8 245. Qc5+ Kb8 246. Qe5+ Kc8 247. Qd5 Kc7 248. Qd7+ Kb8 249. Qd8+ Ka7 250. Qb6+ Kb8 251. Kf7 Kc8 252. Ke8 Kb8 253. Kd7 e3 254. fxe3 Nf6+ 255. gxf6 exf6  256. e7 Qa7 257. e8=Q#

Here is the longest problem that has a promoted piece and some minor duals in the solution.
[Title "Nenad Petrovic, Zagreb 1969, Mate In 271"]
[FEN "8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1"]

1. Bb1 h4 2. Ka4 Ka8 3. Ka3 Kb7 4. Ka2 Ka8 5. Ka1 Kb7 6. Ba2 Ka8 7. Kb1 Kb7 8. Kc1 Ka8 9. Kd1 Kb710. Ke1 Ka8 11. Bb1 Kb7 12. Kf1 Ka8 13. Kf2 Kb7 14. Ke1 Ka8 15. Kd1 Kb7 16. Kc1 Ka8 17. Ba2 Kb7 18. Kb1 Ka8 19. Ka1 Kb7 20. Bb1 Ka8 21. Ka2 Kb7 22. Ka3 Ka8 23. Ka4 Kb7 24. Ka5 f5 25. Ka4 Ka8 26. Ka3 Kb7 27. Ka2 Ka8 28. Ka1 Kb7 29. Ba2 Ka8 30. Kb1 Kb7 31. Kc1 Ka8 32. Kd1 Kb7 33. Ke1 Ka8 34. Bb1 Kb7 35. Kf1 Ka8 36. Kf2 Kb7 37. Ke1 Ka8 38. Kd1 Kb7 39. Kc1 Ka8 40. Ba2 Kb7 41. Kb1 Ka8 42. Ka1 Kb7 43. Bb1 Ka8 44. Ka2 Kb7 45. Ka3 Ka8 46. Ka4 Kb7 47. Ka5 f4 48. Ka4 Ka8 49. Ka3 Kb7 50. Ka2 Ka8 51. Ka1 Kb7 52. Ba2 Ka8 53. Kb1 Kb7 54. Kc1 Ka8 55. Kd1 Kb7 56. Bb1 Ka8 57. Ke1 Kb7 58. Kf1 Ka8 59. Kf2 Kb7 60. Ke1 Ka8 61. Kd1 Kb7 62. Kc1 Ka8 63. Ba2 Kb7 64. Kb1 Ka8 65. Ka1 Kb7 66. Bb1 Ka8 67. Ka2 Kb7 68. Ka3 Ka8 69. Ka4 Kb7 70. Ka5 f6 71. Ka4 Ka8 72. Ka3 Kb7 73. Ka2 Ka8 74. Ka1 Kb7 75. Ba2 Ka8 76. Kb1 Kb7 77. Kc1 Ka8 78. Kd1 Kb7 79. Ke1 Ka8 80. Bb1 Kb7 81. Kf1 Ka8 82. Kf2 Kb7 83. Ke1 Ka8 84. Kd1 Kb7 85. Kc1 Ka8 86. Ba2 Kb7 87. Kb1 Ka8 88. Ka1 Kb7 89. Bb1 Ka8 90. Ka2 Kb7 91. Ka3 Ka8 92. Ka4 Kb7 93. Ka5 f5 94. Ka4 Ka8 95. Ka3 Kb7 96. Ka2 Ka8 97. Ka1 Kb7 98. Ba2 Ka8 99. Kb1 Kb7 100. Kc1 Ka8 101. Kd1 Kb7 102. Ke1 Ka8 103. Bb1 Kb7 104. Kf1 Ka8 105. Kf2 Kb7 106. Ke1 Ka8 107. Kd1 Kb7 108. Kc1 Ka8 109. Ba2 Kb7 110. Kb1 Ka8 111. Ka1 Kb7 112. Bb1 Ka8 113. Ka2 Kb7 114. Ka3 Ka8 115. Ka4 Kb7. 116. Ka5 h3 117. Ka4 Ka8 118. Ka3 Kb7 119. Ka2 Ka8 120. Ka1 Kb7 121. Ba2 Ka8 122. Kb1 Kb7 123. Kc1 Ka8 124. Kd1 Kb7 125. Ke1 Ka8 126. Bb1 Kb7 127. Kf1 Ka8 128. Kf2 Kb7 129. Ke1 Ka8 130. Kd1 Kb7 131. Kc1 Ka8 132. Ba2 Kb7 133. Kb1 Ka8 134. Ka1 Kb7 135. Bb1 Ka8 136. Ka2 Kb7 137. Ka3 Ka8 138. Ka4 Kb7 139. Ka5 h2 140. Ka4 Ka8 141. Ka3 Kb7 142. Ka2 Ka8 143. Ka1 Kb7 144. Ba2 Ka8 145. Kb1 Kb7 146. Kc1 Ka8 147. Kd1 Kb7 148. Ke1 Ka8 149. Bb1 Kb7 150. Kf1 Ka8 151. Kf2 Kb7 152. Ke1 Ka8 153. Kd1 Kb7 154. Kc1 Ka8 155. Ba2 Kb7 156. Kb1 Ka8 157. Ka1 Kb7 158. Bb1 Ka8 159. Ka2 Kb7 160. Ka3 Ka8 161. Ka4 Kb7 162. Ka5 h6 163. Ka4 Ka8 164. Ka3 Kb7 165. Ka2 Ka8 166. Ka1 Kb7 167. Ba2 Ka8 168. Kb1 Kb7 169. Kc1 Ka8 170. Kd1 Kb7 171. Ke1 Ka8 172. Bb1 Kb7 173. Kf1 Ka8 174. Kf2 Kb7 175. Ke1 Ka8 176. Kd1 Kb7 177. Kc1 Ka8 178. Ba2 Kb7 179. Kb1 Ka8 180. Ka1 Kb7 181. Bb1 Ka8 182. Ka2 Kb7 183. Ka3 Ka8 184. Ka4 Kb7 185. Ka5 h5 186. Ka4 Ka8 187. Ka3 Kb7 188. Ka2 Ka8 189. Ka1 Kb7 190. Ba2 Ka8 191. Kb1 Kb7 192. Kc1 Ka8 193. Kd1 Kb7 194. Ke1 Ka8 195. Bb1 Kb7 196. Kf1 Ka8 197. Kf2 Kb7 198. Ke1 Ka8 199. Kd1 Kb7 200. Kc1 Ka8 201. Ba2 Kb7 202. Kb1 Ka8 203. Ka1 Kb7 204. Bb1 Ka8 205. Ka2 Kb7 206. Ka3 Ka8 207. Ka4 Kb7 208. Ka5 h4 209. Ka4 Ka8 210. Ka3 Kb7 211. Ka2 Ka8 212. Ka1 Kb7 213. Ba2 Ka8 214. Kb1 Kb7 215. Kc1 Ka8 216. Kd1 Kb7 217. Ke1 Ka8 218. Bb1 Kb7 219. Kf1 Ka8 220. Kf2 Kb7 221. Ke1 Ka8 222. Kd1 Kb7 223. Kc1 Ka8 224. Ba2 Kb7 225. Kb1 Ka8 226. Ka1 Kb7 227. Bb1 Ka8 228. Ka2 Kb7 229. Ka3 Ka8 230. Ka4 Kb7 231. Ka5 h3 232. Ka4 Ka8 233. Ka3 Kb7 234. Ka2 Ka8 235. Ka1 Kb7 236. Ba2 Ka8 237. Kb1 Kb7 238. Kc1 Ka8 239. Kd1 Kb7 240. Ke1 Ka8 241. Bb1 Kb7 242. Kf1 Ka8 243. Kf2 Kb7 244. Ke1 Ka8 245. Kd1 Kb7 246. Kc1 Ka8 247. Ba2 Kb7 248. Kb1 Ka8 249. Ka1 Kb7 250. Bb1 Ka8 251. Ka2 Kb7 252. Ka3 Ka8 253. Ka4 Kb7 254. Ka5 Kc8 255. Ka6 Kd8 256. b7 Nd7 257. Bxf3 h1=Q 258. Bxh1 d3 259. cxd3 f3 260. Bxf3 Ke7 261. b8=Q Nxb8+ 262. Bxb8 c2 263. Bxc2 Ke6 264. b6 Kf6 265. b7 Ke6 266. d4 h2 267. Bxh2 f4 268. b8=Q Kf7 269. Bxf4  Kg7 270. Bh5 Kf6 271. Qe5#

In regards to the longest known correct checkmate in an illegal position that uses just pieces from the chess box, as Blathy repurposed the the light squared bishop onto a dark square.
Note-Althogh Blathy is known to have composed to slightly longer dualed, illegal mate in 292 moves, that problem is cooked, meaning it is incorrect and has a shorter solution although I still searching for an exact mention of where in the problem are the moves that Blathy missed in his analysis.
[Title "Otto Blathy, Weihnachtsgrüße 12/1929, Mate In 290"]
[FEN "bBrb1B2/P1n1r2p/1Kp1Pb1p/2pk1P1p/5P2/1P2pP2/1pP1P3/1R4n1 w - - 0 1"]

1. Rd1+ Bd4 2. c4+ Kd6 3. Rxg1 Bc3 4. Rd1+ Bd4 5. Ka5 Bb7 6. Ka4 Ba8 7. Ka3 Bb7 8. Ka2 Ba8 9. Kb1 Bb7 10. Kc2 Ba8 11. Kd3 Bb7 12. Re1 Ba8 13. Rf1 Bb7 14. Rd1 Ba8 15. Kc2 Bb7 16. Kb1 Ba8 17. Ka2 Bb7 18. Ka3 Ba8 19. Ka4 Bb7 20. Ka5 Ba8 21. Kb6 h4 22. Ka5 Bb7 23. Ka4 Ba8 24. Ka3 Bb7 25. Ka2 Ba8 26. Kb1 Bb7 27. Kc2 Ba8 28. Kd3 Bb7 29. Rf1 Ba8 30. Re1 Bb7 31. Rd1 Ba8 32. Kc2 Bb7 33. Kb1 Ba8 34. Ka2 Bb7 35. Ka3 Ba8 36. Ka4 Bb7 37. Ka5 Ba8 38. Kb6 h3 39. Ka5 Bb7 40. Ka4 Ba8 41. Ka3 Bb7 42. Ka2 Ba8 43. Kb1 Bb7 44. Kc2 Ba8 45. Kd3 Bb7 46. Rf1 Ba8 47. Re1 Bb7 48. Rd1 Ba8 49. Kc2 Bb7 50. Kb1 Ba8 51. Ka2 Bb7 52. Ka3 Ba8 53. Ka4 Bb7 54. Ka5 Ba8 55. Kb6 h2 56. Ka5 Bb7 57. Ka4 Ba8 58. Ka3 Bb7 59. Ka2 Ba8 60. Kb1 Bb7 61. Kc2 Ba8 62. Kd3 Bb7 63. Rf1 Ba8 64. Re1 Bb7 65. Rd1 Ba8 66. Kc2 Bb7 67. Kb1 Ba8 68. Ka2 Bb7 69. Ka3 Ba8 70. Ka4 Bb7 71. Ka5 Ba8 72. Kb6 h5 73. Ka5 Bb7 74. Ka4 Ba8 75. Ka3 Bb7 76. Ka2 Ba8 77. Kb1 Bb7 78. Kc2 Ba8 79. Kd3 Bb7 80. Rf1 Ba8 81. Re1 Bb7 82. Rd1 Ba8 83. Kc2 Bb7 84. Kb1 Ba8 85. Ka2 Bb7 86. Ka3 Ba8 87. Ka4 Bb7 88. Ka5 Ba8 89. Kb6 h4 90. Ka5 Bb7 91. Ka4 Ba8 92. Ka3 Bb7 93. Ka2 Ba8 94. Kb1 Bb7 95. Kc2 Ba8 96. Kd3 Bb7 97. Rf1 Ba8 98. Re1 Bb7 99. Rd1 Ba8 100. Kc2 Bb7 101. Kb1 Ba8 102. Ka2 Bb7 103. Ka3 Ba8 104. Ka4 Bb7 105. Ka5 Ba8 106. Kb6 h3 107. Ka5 Bb7 108. Ka4 Ba8 109. Ka3 Bb7 110. Ka2 Ba8 111. Kb1 Bb7 112. Kc2 Ba8 113. Kd3 Bb7 114. Rf1 Ba8 115. Re1 Bb7 116. Rd1 Ba8 117. Kc2 Bb7 118. Kb1 Ba8 119. Ka2 Bb7 120. Ka3 Ba8 121. Ka4 Bb7 122. Ka5 Ba8 123. Kb6 h6 124. Ka5 Bb7 125. Ka4 Ba8 126. Ka3 Bb7 127. Ka2 Ba8 128. Kb1 Bb7 129. Kc2 Ba8 130. Kd3 Bb7  131. Rf1 Ba8 132. Re1 Bb7 133. Rd1 Ba8 134. Kc2 Bb7 135. Kb1 Ba8 136. Ka2 Bb7 137. Ka3 Ba8 138. Ka4 Bb7 139. Ka5 Ba8 140. Kb6 h5 141. Ka5 Bb7 142. Ka4 Ba8 143. Ka3 Bb7 144. Ka2 Ba8 145. Kb1 Bb7 146. Kc2 Ba8 147. Kd3 Bb7 148. Rf1 Ba8 149. Re1 Bb7 150. Rd1 Ba8 151. Kc2 Bb7 152. Kb1 Ba8 153. Ka2 Bb7 154. Ka3 Ba8 155. Ka4 Bb7 156. Ka5 Ba8 157. Kb6 h4 158. Ka5 Bb7 159. Ka4 Ba8 160. Ka3 Bb7 161. Ka2 Ba8 162. Kb1 Bb7 163. Kc2 Ba8 164. Kd3 Bb7 165. Rf1 Ba8 166. Re1 Bb7 167. Rd1 Ba8 168. Kc2 Bb7 169. Kb1 Ba8 170. Ka2 Bb7 171. Ka3 Ba8 172. Ka4 Bb7 173. Ka5 Ba8 174. Kb6 h1=Q 175. Rxh1 Bg7 176. Rd1+ Bd4 177. Ka5 Bb7 178. Ka4 Ba8 179. Ka3 Bb7 180. Ka2 Ba8 181. Kb1 Bb7 182. Kc2 Ba8 183. Kd3 Bb7 184. Rf1 Ba8 185. Re1 Bb7 186. Rd1 Ba8 187. Kc2 Bb7 188. Kb1 Ba8 189. Ka2 Bb7 190. Ka3 Ba8 191. Ka4 Bb7 192. Ka5 Ba8 193. Kb6 h2 194. Ka5 Bb7 195. Ka4 Ba8 196. Ka3 Bb7 197. Ka2 Ba8 198. Kb1 Bb7 199. Kc2 Ba8 200. Kd3 Bb7 201. Rf1 Ba8 202. Re1 Bb7 203. Rd1 Ba8 204. Kc2 Bb7 205. Kb1 Ba8 206. Ka2 Bb7 207. Ka3 Ba8 208. Ka4 Bb7 209. Ka5 Ba8 210. Kb6 h3 211. Ka5 Bb7 212. Ka4 Ba8 213. Ka3 Bb7 214. Ka2 Ba8 215. Kb1 Bb7 216. Kc2 Ba8 217. Kd3 Bb7 218. Rf1 Ba8 219. Re1 Bb7 220. Rd1 Ba8 221. Kc2 Bb7 222. Kb1 Ba8 223. Ka2 Bb7 224. Ka3 Ba8 225. Ka4 Bb7 226. Ka5 Ba8 227. Kb6 h1=Q 228. Rxh1 Bg7 229. Rd1+ Bd4 230. Ka5 Bb7 231. Ka4 Ba8 232. Ka3 Bb7 233. Ka2 Ba8 234. Kb1 Bb7 235. Kc2 Ba8 236. Kd3 Bb7 237. Rf1 Ba8 238. Re1 Bb7 239. Rd1 Ba8 240. Kc2 Bb7 241. Kb1 Ba8 242. Ka2 Bb7 243. Ka3 Ba8 244. Ka4 Bb7 245. Ka5 Ba8 246. Kb6 h2 247. Ka5 Bb7 248. Ka4 Ba8 249. Ka3 Bb7 250. Ka2 Ba8 251. Kb1 Bb7 252. Kc2 Ba8 253. Kd3 Bb7 254. Rf1 Ba8 255. Re1 Bb7 256. Rd1 Ba8 257. Kc2 Bb7 258. Kb1 Ba8 259. Ka2 Bb7 260. Ka3 Ba8 261. Ka4 Bb7 262. Ka5 Ba8 263. Kb6 h1=Q 264. Rxh1 Bg7 265. Rd1+ Bd4 266. Ka5 Bb7 267. Ka4 Ba8 268. Ka3 Bb7 269. Ka2 Ba8 270. Kb1 Bb7 271. Kc2 Ba8 272. Kd3 Bb7 273. Rf1 Ba8 274. Re1 Bb7 275. Rd1 Ba8 276. Kc2 Bb7 277. Kb1 Ba8 278. Ka2 Bb7 279. Ka3 Ba8 280. Ka4 Bb7 281. Ka5 Ba8 282. Kb6 Bb7 283. Kxb7 b1=Q 284. Rxb1 Be5 285. Rd1+ Bd4 286. Rxd4+ cxd4 287. Kb6 d3 288. a8=Q Rxb8+ 289. Qxb8 dxe2 290. Qxd8#

Lastly, if you allow any amount of illegal material, with no first/last rank pawns and one king per side of course, here is a mate in 415 that is an extension of Blathy's above mate in 290.
 [FEN "bBrb1B2/P1n1r1bp/pKp1P2p/2pk1P1p/5P1p/1P2pP1p/1pP1P2p/1R5n w - - 0 1"]

1. Rd1+ Bd4 2. c4+ Kd6 3. Rxh1 Bc3 4. Rd1+ Bd4 5. Ka5 Bb7 6. Ka4 Ba8 7. Ka3 Bb7 8. Ka2 Ba8 9. Kb1 Bb7 10. Kc2 Ba8 11. Kd3 Bb7 12. Rh1 Ba8 13. Rf1 Bb7 14. Rd1 Ba8 15. Kc2 Bb7 16. Kb1 Ba8 17. Ka2 Bb7 18. Ka3 Ba8 19. Ka4 Bb7 20. Ka5 Ba8 21. Kb6 h1=Q 22. Rxh1 Bc3 23. Rd1+ Bd4 24. Ka5 Bb7 25. Ka4 Ba8 26. Ka3 Bb7 27. Ka2 Ba8 28. Kb1 Bb7 29. Kc2 Ba8 30. Kd3 Bb7 31. Rh1 Ba8 32. Rf1 Bb7 33. Rd1 Ba8 34. Kc2 Bb7 35. Kb1 Ba8 36. Ka2 Bb7 37. Ka3 Ba8 38. Ka4 Bb7 39. Ka5 Ba8 40. Kb6 h2 41. Ka5 Bb7 42. Ka4 Ba8 43. Ka3 Bb7 44. Ka2 Ba8 45. Kb1 Bb7 46. Kc2 Ba8 47. Kd3 Bb7 48. Rh1 Ba8 49. Rf1 Bb7 50. Rd1 Ba8 51. Kc2 Bb7 52. Kb1 Ba8 53. Ka2 Bb7 54. Ka3 Ba8 55. Ka4 Bb7 56. Ka5 Ba8 57. Kb6 h3 58. Ka5 Bb7 59. Ka4 Ba8 60. Ka3 Bb7 61. Ka2 Ba8 62. Kb1 Bb7 63. Kc2 Ba8 64. Kd3 Bb7 65. Rh1 Ba8 66. Rf1 Bb7 67. Rd1 Ba8 68. Kc2 Bb7 69. Kb1 Ba8 70. Ka2 Bb7 71. Ka3 Ba8 72. Ka4 Bb7 73. Ka5 Ba8 74. Kb6 h4 75. Ka5 Bb7 76. Ka4 Ba8 77. Ka3 Bb7 78. Ka2 Ba8 79. Kb1 Bb7 80. Kc2 Ba8 81. Kd3 Bb7 82. Rh1 Ba8 83. Rf1 Bb7 84. Rd1 Ba8 85. Kc2 Bb7 86. Kb1 Ba8 87. Ka2 Bb7 88. Ka3 Ba8 89. Ka4 Bb7 90. Ka5 Ba8 91. Kb6 h5 92. Ka5 Bb7 93. Ka4 Ba8 94. Ka3 Bb7 95. Ka2 Ba8 96. Kb1 Bb7 97. Kc2 Ba8 98. Kd3 Bb7 99. Rh1 Ba8 100. Rf1 Bb7 101. Rd1 Ba8 102. Kc2 Bb7 103. Kb1 Ba8 104. Ka2 Bb7 105. Ka3 Ba8 106. Ka4 Bb7 107. Ka5 Ba8 108. Kb6 h6 109. Ka5 Bb7 110. Ka4 Ba8 111. Ka3 Bb7 112. Ka2 Ba8  113. Kb1 Bb7 114. Kc2 Ba8 115. Kd3 Bb7 116. Rh1 Ba8 117. Rf1 Bb7 118. Rd1 Ba8 119. Kc2 Bb7 120. Kb1 Ba8 121. Ka2 Bb7 122. Ka3 Ba8 123. Ka4 Bb7 124. Ka5 Ba8 125. Kb6 h1=Q 126. Rxh1 Bc3 127. Rd1+ Bd4 128. Ka5 Bb7 129. Ka4 Ba8 130. Ka3 Bb7 131. Ka2 Ba8 132. Kb1 Bb7 133. Kc2 Ba8 134. Kd3 Bb7 135. Rh1 Ba8 136. Rf1 Bb7 137. Rd1 Ba8 138. Kc2 Bb7 139. Kb1 Ba8 140. Ka2 Bb7 141. Ka3 Ba8 142. Ka4 Bb7 143. Ka5 Ba8 144. Kb6 h2 145. Ka5 Bb7 146. Ka4 Ba8 147. Ka3 Bb7 148. Ka2 Ba8 149. Kb1 Bb7 150. Kc2 Ba8 151. Kd3 Bb7 152. Rh1 Ba8 153. Rf1 Bb7 154. Rd1 Ba8 155. Kc2 Bb7 156. Kb1 Ba8 157. Ka2 Bb7 158. Ka3 Ba8 159. Ka4 Bb7 160. Ka5 Ba8 161. Kb6 h3 162. Ka5 Bb7 163. Ka4 Ba8 164. Ka3 Bb7 165. Ka2 Ba8 166. Kb1 Bb7 167. Kc2 Ba8 168. Kd3 Bb7 169. Rh1 Ba8 170. Rf1 Bb7 171. Rd1 Ba8 172. Kc2 Bb7 173. Kb1 Ba8 174. Ka2 Bb7 175. Ka3 Ba8 176. Ka4 Bb7 177. Ka5 Ba8 178. Kb6 h4 179. Ka5 Bb7 180. Ka4 Ba8 181. Ka3 Bb7 182. Ka2 Ba8 183. Kb1 Bb7 184. Kc2 Ba8 185. Kd3 Bb7 186. Rh1 Ba8 187. Rf1 Bb7 188. Rd1 Ba8 189. Kc2 Bb7 190. Kb1 Ba8 191. Ka2 Bb7 192. Ka3 Ba8 193. Ka4 Bb7 194. Ka5 Ba8 195. Kb6 h5 196. Ka5 Bb7 197. Ka4 Ba8 198. Ka3 Bb7 199. Ka2 Ba8 200. Kb1 Bb7 201. Kc2 Ba8 202. Kd3 Bb7 203. Rh1 Ba8 204. Rf1 Bb7 205. Rd1 Ba8 206. Kc2 Bb7 207. Kb1 Ba8 208. Ka2 Bb7 209. Ka3 Ba8 210. Ka4 Bb7 211. Ka5 Ba8 212. Kb6 h1=Q 213. Rxh1 Bc3 214. Rd1+ Bd4 215. Ka5 Bb7 216. Ka4 Ba8 217. Ka3 Bb7 218. Ka2 Ba8 219. Kb1 Bb7 220. Kc2 Ba8 221. Kd3 Bb7 222. Rh1 Ba8 223. Rf1 Bb7 224. Rd1 Ba8 225. Kc2 Bb7 226. Kb1 Ba8 227. Ka2 Bb7 228. Ka3 Ba8 229. Ka4 Bb7 230. Ka5 Ba8 231. Kb6 h2 232. Ka5 Bb7 233. Ka4 Ba8 234. Ka3 Bb7 235. Ka2 Ba8 236. Kb1 Bb7 237. Kc2 Ba8 238. Kd3 Bb7 239. Rh1 Ba8 240. Rf1 Bb7 241. Rd1 Ba8 242. Kc2 Bb7 243. Kb1 Ba8 244. Ka2 Bb7 245. Ka3 Ba8 246. Ka4 Bb7 247. Ka5 Ba8 248. Kb6 h3 249. Ka5 Bb7 250. Ka4 Ba8 251. Ka3 Bb7 252. Ka2 Ba8 253. Kb1 Bb7 254. Kc2 Ba8 255. Kd3 Bb7 256. Rh1 Ba8 257. Rf1 Bb7 258. Rd1 Ba8 259. Kc2 Bb7 260. Kb1 Ba8 261. Ka2 Bb7 262. Ka3 Ba8 263. Ka4 Bb7 264. Ka5 Ba8 265. Kb6 h4 266. Ka5 Bb7 267. Ka4 Ba8 268. Ka3 Bb7 269. Ka2 Ba8 270. Kb1 Bb7 271. Kc2 Ba8 272. Kd3 Bb7 273. Rh1 Ba8 274. Rf1 Bb7 275. Rd1 Ba8 276. Kc2 Bb7 277. Kb1 Ba8 278. Ka2 Bb7 279. Ka3 Ba8 280. Ka4 Bb7 281. Ka5 Ba8 282. Kb6 h1=Q 283. Rxh1 Bc3 284. Rd1+ Bd4 285. Ka5 Bb7 286. Ka4 Ba8 287. Ka3 Bb7 288. Ka2 Ba8 289. Kb1 Bb7 290. Kc2 Ba8 291. Kd3 Bb7 292. Rh1 Ba8 293. Rf1 Bb7 294. Rd1 Ba8 295. Kc2 Bb7 296. Kb1 Ba8 297. Ka2 Bb7 298. Ka3 Ba8 299. Ka4 Bb7 300. Ka5 Ba8 301. Kb6 h2 302. Ka5 Bb7 303. Ka4 Ba8 304. Ka3 Bb7 305. Ka2 Ba8 306. Kb1 Bb7 307. Kc2 Ba8 308. Kd3 Bb7 309. Rh1 Ba8 310. Rf1 Bb7 311. Rd1 Ba8 312. Kc2 Bb7 313. Kb1 Ba8 314. Ka2 Bb7 315. Ka3 Ba8 316. Ka4 Bb7 317. Ka5 Ba8 318. Kb6 h3 319. Ka5 Bb7 320. Ka4 Ba8 321. Ka3 Bb7 322. Ka2 Ba8 323. Kb1 Bb7 324. Kc2 Ba8 325. Kd3 Bb7 326. Rh1 Ba8 327. Rf1 Bb7 328. Rd1 Ba8 329. Kc2 Bb7 330. Kb1 Ba8 331. Ka2 Bb7 332. Ka3 Ba8 333. Ka4 Bb7 334. Ka5 Ba8 335. Kb6 h1=Q 336. Rxh1 Bc3 337. Rd1+ Bd4 338. Ka5 Bb7 339. Ka4 Ba8 340. Ka3 Bb7 341. Ka2 Ba8 342. Kb1 Bb7 343. Kc2 Ba8 344. Kd3 Bb7 345. Rh1 Ba8 346. Rf1 Bb7 347. Rd1 Ba8 348. Kc2 Bb7 349. Kb1 Ba8 350. Ka2 Bb7 351. Ka3 Ba8 352. Ka4 Bb7 353. Ka5 Ba8 354. Kb6 h2 355. Ka5 Bb7 356. Ka4 Ba8 357. Ka3 Bb7 358. Ka2 Ba8 359. Kb1 Bb7 360. Kc2 Ba8 361. Kd3 Bb7 362. Rh1 Ba8 363. Rf1 Bb7 364. Rd1 Ba8 365. Kc2 Bb7 366. Kb1 Ba8 367. Ka2 Bb7 368. Ka3 Ba8 369. Ka4 Bb7 370. Ka5 Ba8 371. Kb6 h1=Q 372. Rxh1 Bc3 373. Rd1+ Bd4 374. Ka5 Bb7 375. Ka4 Ba8 376. Ka3 Bb7 377. Ka2 Ba8 378. Kb1 Bb7 379. Kc2 Ba8 380. Kd3 Bb7 381. Rh1 Ba8 382. Rf1 Bb7 383. Rd1 Ba8 384. Kc2 Bb7 385. Kb1 Ba8 386. Ka2 Bb7 387. Ka3 Ba8 388. Ka4 Bb7 389. Ka5 Ba8 390. Kb6 a5 391. Kxa5 Bb7 392. Ka4 Ba8 393. Ka3 Bb7 394. Ka2 Ba8 395. Kb1 Bb7 396. Kc2 Ba8 397. Kd3 Bb7 398. Rh1 Ba8 399. Rf1 Bb7 400. Rd1 Ba8 401. Kc2 Bb7 402. Kb1 Ba8 403. Ka2 Bb7 404. Ka3 Ba8 405. Ka4 Bb7 406. Ka5 Ba8 407. Kb6 Bb7 408. Kxb7 b1=Q 409. Rxb1 Be5 410. Rd1+ Bd4 411. Rxd4+ cxd4 412. Kb6 d3 413. a8=Q Rxb8+ 414. Qxb8 d2 415. Qxd8#


Is there any website that generates and hosts board position with PGN as input?

Found one, after googling for quite a while!

Here is the diagram I just generated at the URL
http://www.chessvideos.tv/bimg/3etzqdenimww8.png

Anand vs Gelfand Game 1 Grunfeld Defence, WCC 2012

The website to generate the diagram is http://www.chessvideos.tv/genboard.php

[Edit]
Found another one, this one is far better, it generates Animated gifs

Anand vs Gelfand Game 2 Queen's Gambit Declined Semi-Slav, WCC 2012

This can be done here http://www.caissa.com/chess-tools/pgn-editor.php


A question on psychology / strategy in Chess opening

There are many ways of looking at this depending on one's strength. Super Grandmasters are able to shift between openings with ease and still play them well at a very high level and with deep understanding. As for middling players, it is good to stay with one opening line for long and there are several advantages to that;

Experience is a very important aspect in the road to mastery and there's no shortcut to acquiring experience. The great martial artist, Bruce Lee once said,

  I fear not the man who has practiced 10,000 kicks (chess openings) once, but I fear the man who has practiced one kick (chess opening) 10,000 times.

The same could also be said about chess and sticking with one (or a few) opening lines for long time, acquiring more experience, deepening your understanding in strategic & tactical ideas behind the opening and both the resulting middlegames and endgame positions.

Don't play against the player but play against the pieces. Most great masters of the past including Bobby Fischer himself have stayed with one opening repertoire for long and playing fearlessly against all their opponents. Fischer played just a few openings, Ruy Lopez, Sicilian Najdorf, King's Indian Attack & Defense, Grunfeld Defense, and others in between. Some openings and variations have been named after masters simply because they remained loyal for long and built indepth understanding in those lines.
The desire to win quickly and the creeping in of last minute doubt in one's opening repertoire is what has led many players to run away from their main weapons, hoping that the new unknown opening will yield better results in their favor. More often than not, it is the same players that end up surprising themselves with their own lack of experience in the new unusual opening than surprising their opponents. The sad is thing is that after the game, there isn't much to analyse or to add to your experience in that surprise opening.

For serious tournament games, I would strongly recommend sticking with one's main opening repertoire and using surprise openings for blitz and casual chess. As for beginners, I would recommend that they should stay with simple openings that adhere to basic opening principles (develop your pieces quickly, knights first, king safety, etc) like the Italian Game before trying to surprise anyone.


Is my representation of the Pirc Defense correct?

If you are aiming to use this tree for practical use at 2000 level, you should start in the Pirc tabiya position after 1.e4 d6 2.d4 Nf6 3.Nc3 g6. That's where it all starts, with main choices being 4.f4, 4.Be2, 4.Be3, 4.Nf3, 4.f3. (edit: Also 4.Bg5, 4.Bc4 and even 4.Bf4 as pointed in comments. And also 4.g3 and 4.h3)

That way, you will not be confused by games without ...g6 at all, like the Philidor 3...e5 or some moderns with 3...c6, 4...Qa5.

I don't think the 1.e4 d6 2.d4 e6?! branch will ever be useful to you. With Black, you won't ever want to play this. With White, if you face it you can tackle it by following general rules, and in any case a tree is not useful there. Also, I wonder how this very obscure sideline appeared in your tree. If you use popularity to select lines, have you consider how far 2...e6 lies behind 2...Nf6 ? Have you restricted your base to tournament play, if possible above a certain level (say, 1800) ?

If need be, you can build a separate tree for early deviations, like 2.Nf3, 2.Nc3 or 2.f4 - keeping in mind that they will often transpose later in your main tree in case of d2-d4. But if you have practical purposes, you want to get rid of parasitic information. That will also allow you to go deeper that move 5 - which is mandatory at 2000 level !


What are the hardest pawnless endgames that go over the 50-move rule?

If you mean "hardest" == "longest": There are 7-man table bases available and it is said that the longest pawnless ending takes 549 moves. It is KQB vs. KRBN.

Resources: http://tb7.chessok.com/articles/Top8DTM_eng

And in case you are too lazy to go through the moves by yourself :-): http://tb7.chessok.com/probe/745/61

I think that is what is known today. I would not be surprised if even longer pawnless endings exists with 8 pieces on the board.


In the Ruy Lopez, does White play on the queenside or King side?

In most variations of the Ruy Lopez, White, with the Bishop on b3, has better chances playing on the kingside.  In the Marshall gambit, White counterattacks on the Queenside.  In the Exchange variation, White normally has better chances in the kingside in the endgame.

Fischer-Spassky
Ninth Match Game
Sveti Stefan 1992

[fen ""]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. O-O f6 6. d4 exd4 7. Nd4 c5 8. Nb3 Qd1 9. Rd1 Bg4 10. f3 Be6 11. Nc3 Bd6 12. Be3 b6 13. a4 O-O-O 14. a5 Kb7 15. e5 Be7 16. Rd8 Bd8 17. Ne4 Kc6 18. axb6 cxb6 19. Nbc5 Bc8 20. Na6 fxe5 21. Nb4

In this famous game, White did attack on the queenside.  The reason for the exception is the placement of the King.  Opposite side castling throws most chess rules out the window and the only thing that matters is an attack.


Has any chess player ever been banned because of doping?

The short answer is "No". The long answer is "Don't be silly!"

About a year ago I asked elsewhere if the English GM Mickey Adams (the only English player at the time comfortably over 2700) had to go through the WADA style rigmarole of informing the chess anti-doping officials of a time and exact location for every day of the year where he could be found if they wanted to test him as required by FIDE's anti-doping policy.

A prominent member of the FIDE Qualification Committee replied "I'm not saying you're wrong, but that's news to be. Where can I find it?"

This 73-page FIDE document - FIDE Anti-Doping Rules based on Wada’s Models of Best Practice for International Federations and the World Anti-Doping Code - from 2015 spells out in painful detail what FIDE's "intentions" are.

When I sent him the link this was his response -  "I think the International-Level part refers only to things that FIDE Anti-Doping can do if they want to and in practice don't, but still worth knowing."

So, at the moment FIDE has a suitable IOC-friendly policy on the books but they are only likely to actually implement it if the vast Olympic money bags are opened for chess.


Is always possible to win King + Queen vs. King + Rook?

Mate is always possible, except in the cases you've outlined already. From Wikipedia:

  A queen wins against a lone rook, unless there is an immediate draw by stalemate or due to perpetual check (Nunn 2002a:49) (or if the rook or king can immediately capture the queen). ... With perfect play, in the worst winning position, the queen can win the rook or checkmate within 31 moves (Müller & Lamprecht 2001:400).


Way to Logically Predict Approximate Chess Rating in Pop-Culture Games

You will need statistics to estimate playing strength from a single game. It's of course possible, but you will be need to read journal articles.

  https://ailab.si/matej/doc/Using_Heuristic-Search_Based_Engines_for_Estimating_Human_Skill_at_Chess.pdf

"Using Heuristic-Search Based Engines for Estimating Human Skill at Chess" is considered as a baseline for estimating human skills from a single game. The idea is simple; assume a computer engine plays much stronger chess than humans; we should be to use the difference in evaluations for statistical inference.

I have personally implemented this paper for a chess company. The system is working.


Why is the definition of check not circular?

A move can be illegal because the opponent could "take" the king. This "taking the king" move does not need to be "legal". See Can a piece pinned to my king put the opponent's king in check? and Is the king actually in check if the attacking piece cannot be moved?


Vitamins to improve memorizing of variations in chess

There is no credible evidence that supplements benefit cognitive functioning in people who don't have clinical disorders.  The only people making those claims are people trying to sell you something.  As mentioned above, the only indicated rationale for such treatment is with a nutritional disorder, or some other type of clinical problem.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3311304/

"Dietary supplements are one of the most common forms of complementary and alternative medicine that patients use and although limited, evidence for their potential interactions with other treatments has been documented. Considering the insufficient evidence for their efficacy, potential for interaction with other therapies and costs to patients, physicians should be aware of the use of dietary supplements among their patients so that they can advise their patients on the potential benefits and harms."


Where can I watch Carlsen - Karjakin with video + commentaries?

There's live commentary from two GMs on Chess24's youtube channel:
https://www.youtube.com/user/chess24media

They have video, but only of the commentators (not the players), together with an analysis board


Tablebases for variant where stalemate is a win?

What I'm wondering is whether anyone has created tablebases for this variant of chess,

Interesting proposal, but nobody has done the works to my knowledge. If you would like to participate, you may modify source code of https://github.com/syzygy1/tb.


What is the average number of legal moves per turn?

Whilst acknowledging the comment by @SmallChess that this is pointless, it is also relatively straightforward to do. I analysed 2,539,871 games from a ChessBase mega database counting the number of moves for the next player to move before each move was played. I did not include the number of moves available after the final move of the game had been played. The total number of moves played was 194,389,820 (76.5 per game) and the total number of available moves was 6,039,013,721 giving an average of about 31.1 per move.

Here is an analysis of the average number of moves available for each colour at each move point for the first 100 moves of each. Move 0 is prior to the first move of each colour. It is interesting to observe that, on average, black has fewer options than white. I am not sure why this would be-hopefully, it isn't an error in the analysis (!) but I don't think it is.


does anyone use OSX Xboard app in Mavericks?

Winboard is what can run in wine. Though macwine is limited to 32bit executables.   Xboard on the other hand always could be compiled in OSX just fine!  I created an .app package ready for use and I'm told works fine in 10.10-10.6

It is a GTK2 app running through Quartz, so no X11 server app is needed.

http://www.open-aurec.com:8080/wbforum/viewtopic.php?f=19&t=53274&p=200662#p200662


It seems that

   Qa3

is mate in one. It is indeed harder than it looks at first sight, because there are so many pins.


One reason the set-up with Re1 is less popular could be that it loses a pawn in a certain quite common variation:

[FEN ""]
[Title "KIA with Re1"]
[Startply "15"]

1. Nf3 d5 2. g3 c6 3. Bg2 Nf6 4. O-O Bf5 5. d3 h6 6. Nbd2 e6 7. Re1 Be7 8. e4?

Do you see black's tactic?

   After 8. ... dxe4 9. dxe4 Nxe4 10. Nxe4, white has opened the file allowing for Qxd1!, forcing the Rook to abandon the Knight and black ends the exchange sequence up a pawn.


Why do people say today's chess is dominated by computers?

Masters use computers as training tools.  They allow a master to quickly check the viability of variations and understand why some moves are good or bad.  Further, they afford searchable instant access to millions of positions and countless openings to the master.

In short, the computer is your sparring partner, second, and librarian, and who works for cheap.


Is there a rule that doesn't allow adjustment during the opponents time?

I think this FIDE rules section explains that:

  Article 6.2

  d. Only the player whose clock is running is allowed to adjust the
  pieces.

According to Article 4.2, a player should announce "j’adoube" (I adjust) before adjusting pieces on the board, providing only the player having the move may adjust one or more pieces on their squares (i.e. player in turn with clock still running).

In actual games usually the arbiter only issues verbal warning about adjusting pieces only in respective player's turn. But keep in mind you should avoid distracting the opponent, i.e. obstructing their view on the board when it's opponent's turn to make a move, since Article 4.8 applies if a player decides repeating disruptive behavior from his/her opponent, without announcing to adjust the pieces first:

  A player forfeits his right to claim against his opponent’s violation
  of Articles 4.1 – 4.7 once the player touches a piece with the
  intention of moving or capturing it.

Related issue:

Adjusting in ones turn only


Which free chess (learning) programme would you recommend?

Take a look at Lucas Chess.

http://www-lucaschess.rhcloud.com

From its web:

Play: The program has 21 engines prepared to play from the start, and with very different levels, from 1300 to 3000 elo.

Train:
You have an extensive list of trainings with which to try to improve your chess:

Training positions
Play like a grandmaster
Training mates

Compete: In Lucas Chess there are several competitions, and in two of them you can publish the results.


How good is 1. e3 2. c4 as an opening for White?

Overall, I wouldn't suggest it, especially for a beginner. There are better ways to fight for an advantage.
By playing e3 first, you are allowing your opponent to do almost whatever they like on their first move. Are you OK with them playing 1...d5? Is that going to prevent you from playing c4? If that's going to be a problem, you may want to play 1.c4 first instead (which is the much more reputable English opening.)
With a pawn on e3, your c1 bishop has limited scope. Perhaps you want to fianchetto it to b2? Otherwise, it's either stuck on d2 where it doesn't do much, or you need to play e4 to free it, which perhaps means that e3 was a waste of a tempo.
Castling on opposite sides seems like it's something you need to decide later - don't do it if you aren't in the right position. If your opponent castles kingside (which they usually do), then castling queenside means that you're putting your king on the c-file, behind a pawn you've moved two squares (and if you've fianchettoed the c1 bishop, the b-pawn has also moved.) Depending on what your opponent has been doing and how open the game has become, this may be a bad idea.


The most comprehensive and recent publication I've found related to this question is The relationship between cognitive ability and chess skill: A comprehensive meta-analysis. It's behind a paywall, but you may be able to find copies of the PDF by googling the title. Also here's a less technical overview of the article from ScienceDaily.

The bottom line is that according to a meta-analysis of numerous studies, there is clearly a correlation between chess skill and cognitive ability, but cognitive ability explains only about 6% of the variance in chess skill (12% if you only consider numerical ability only). There must be other factors as well (e.g., training), some of which could be more important than cognitive ability.

An interesting observation was that intelligence plays a bigger role among lower-level players; here's a relevant quote from the ScienceDaily article.

  The study found that intelligence was linked to chess skill for the
  overall sample, but particularly among young chess players and those
  at lower levels of skill. This may be because the upper-level players
  represent a winnowed distribution of cognitive ability -- in other
  words, they all tend to be fairly bright. (By way of comparison,
  Burgoyne said, consider the world's best basketball players. Although
  there is essentially no correlation between height and points scored
  at that level, that doesn't mean height isn't important in
  basketball.)

I don't have an answer specifically regarding the IQ of GMs or world champions, but this page has an interesting, if unsourced, factoid:

  International team of psychologists have attempted to measure IQ score of Garry Kasparov and after many tedious tests has concluded Kasparov’s IQ to be 135, making him fall into ‘moderately gifted’ category.

(I later found the same claim in other websites, some of which say that the testing was organized by Der Spiegel in the 1980s.)

If this is true, it would mean Kasparov is perhaps in the top 1% in terms of IQ, which is certainly not bad, but seems almost nothing compared to the percentile he occupies in terms of chess skill (top 0.0001% or whatever, depending on how you define "chess player").


Edit: Using the chessgames Opening Explorer, I confirmed the move is playable, here is the list of possible replays:

Move     #games
---------------
4.Nxe5   175
4.Bc4    151
4.d3     52
4.a3     14
4.Nd5    12 <- my option
4.Be2    2
4.d4     2
4.Bd3    1
4.g3     1

4.Nd5 looks viable and easily prevents that double pawn.

It also pushes the game into an aggressive one, which can be good or bad depending on your play-style.

Final position after 4.Nd5:

rnbqk2r/pppp1ppp/5n2/3Np3/1b2P3/5N2/PPPP1PPP/R1BQKB1R b KQkq - 5 4

He will most likely do NxN, I don't see many other choices here as both the Bishop and the e Pawn are attacked:

4...Nxd5
4...Bd6 (weak move)
4...a5 (weak move)


What is the correct pawn promotion procedure?

The procedure is (FIDE rules): move the pawn to its promotion square, then replace it with the piece you want. You can take it from the captured pieces yourself, your opponent does nothing. If the piece isn't readily available, you can stop the clock and ask the arbiter to bring one. Your choice of piece is only finalized when it touches the promotion square. See the Laws of Chess

An upside down rook is a rook. A pawn on its side is a pawn, and thus an illegal move.

The FIDE rules will be changed a bit in the upcoming July 2014 Laws of Chess, see e.g. this ChessCafe "Arbiter's Notebook" column by Geurt Gijssen, who is involved in the rules changes. From July, it will also be legal to remove the pawn from the board without moving it to the promotion square (followed by putting the piece on the promotion square), and it will also be legal to place the piece first and then remove the pawn. Those used to be illegal moves.

And also from July, if you move the pawn to the promotion square and then press the clock, you've made an illegal move (that's already the case now), and as usual the pawn counts as touched and you will have to promote it in the legal way, but you will be forced to promote to queen. Apparently people were using this illegal move and the delay it will bring as extra thinking time to decide which piece to promote to.

As you can see there are some fiddly details that may be different with USCF rules, but I don't know those.


Chess variation where the goal is to lose all pieces

I played black and lost all the matches. Does white have a decisive advantage since he can play d4 followed by bh6 and lose a piece and stay one move ahead?

According to Dr Mark Watkins of The University of Sydney, losing chess has been solved and White can force a win with 1. e3:

  The move 1. e3 has been solved as a win for White under both FICS and
  International Rules. The final leg was actually much easier than expected,
  as I wasted around a year on false leads. In fact, the not-too-deep idea
  1. e3 b6 2. a4 e6 3. Ra3 Bxa3 4. Nxa3 Qh4 5. a5 bxa5 6. Qh5! leads to
  some queen races where White just needs a bit deeper search to show
  a good score


Is Whale Variation a successful opening?

The Whale variation
[FEN ""]
1.e4 e5 2. c4

is quite an offbeat opening. It shares obvious similarities with the English opening, and it sometimes transposes, but it has some serious drawbacks. The obvious one is the gaping hole it leaves on d4. Another one is that it leads to very closed positions, which intermediate players usually do not fin comfortable. This leads to inaccurate plans and rushing, which because of the dubious setup from white, usually ends up favoring black. The main one is that white does not have a threat, allowing black to immediately seize the initiative with Nf6.
Let's address first the hole on d4. There are several setups to play around it, the most straightforward plan is to play d3, Be3, and Ne2. This overprotects the weakness and ensures better center control, but is awfully slow since Bc5 essentially blocks everything, and severely neglects king safety (white's not gonna castle anytime soon). Another setup is to kingside fianchetto, and another is with Be2. They all have big drawbacks, since essentially white is playing an English opening with a way too early e4 push. With somewhat accurate play for black (Nf6 and Bc5, which are natural moves that they should consider), there really is no good solution for this.
Here you have several sample lines that give an idea of why this opening should be avoided. For example, 1. e4 e5 2. c4 Nf6 3. Nc3 Bc5 4. d3 d6 is more than fine for black, with easy plans and development. This seems like a closed Sicilian gone wrong. Also, 1. e4 e5 2. c4 Nf6 3. d3 Bc5 4. Be2 is pitiful, with white's only "developed" piece being completely shut behind the pawns. Black still has easy plans.
Finally, let's address the issue of giving up the initiative. Since white is no making any threats with 2.c4, black is completely free to just play Nf6 and Bc5 in virtually all variations. Moreover, d6 and Bg4 is a very standard plan, as well as Nc6 aiming for the hole in d4. Since the dark squared bishop is now outside the chain pawn, black has e7 free for a knight, with Nf6-Ne7-Ng6 being a common reroute.
This makes it a difficult variation to play if black makes reasonable moves. I would suggest to play the English opening, and steer the game into closed positions that will benefit from a timely e4 push. For example: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3 Nf6 6. e4, followed by d3.


Could Karpov defend against Kasparov in 1990 championship?

Nf6 is followed by e.g.:

[FEN "r4b1k/1b4p1/p2r1n2/8/Pnp1Q3/6RP/1B3PP1/1B4K1 w - - 0 1"]

1. Qh4+ Kg8 2. Bxf6 Rxf6 3. Qxf6

with not only huge material advantage for white, but also some very nasty threats that are ultimately not defendable. So in short, there is not much to gain with Nf6.


What is the maximum number of checked squares on a board that delivers checkmate without a draw?

It's going to be hard for any position to be "natural" if the king is out and roaming about, so I presume that you mean that the position must be legal. Also, as far as I understand it, the king may only teleport in a checkmate position, and not while in check, because otherwise, it would be nigh impossible to give a mate.
Firstly, it is entirely possible to get eight queens on a board for checkmate without drawing, like so, with a little help from other White pieces. While this can be done with just the pawns alone, the extra pieces are needed to do it in exactly eight moves.
[FEN "8/PPPPPPPP/8/8/8/8/k7/1RN1K3 w - - 0 1"]

1. a8=Q+ Kxb1 2. c8=Q Kb2 3. d8=Q Kb1 4. e8=Q Kb2 5. f8=Q Kb1 6. g8=Q Kb2 7. h8=Q+ Kb1 8. b8=Q#

But it is also possible to achieve this effect with just White's eight starting pieces. I remembered this old problem by Josef Kling that does it. The stipulation reads: White checkmates in 14 moves but only after attacking all 64 squares." I would suppose that this position is more "natural" than one with eight White queens.
Do note that while the stipulation reads “64 squares,” it has been proven, that with opposite-colored bishops, the starting pieces can only control 63 squares. Kling knew that for sure, so it's just a minor discrepancy that he used “64” to have a better sounding stipulation in my opinion.
[Title "Josef Kling, The Chess Player's Companion 1849, 'Fancy Sketch'"]
[FEN "4k3/8/8/8/8/8/8/RNBQKBNR w - - 0 1"]

1. Qd6 Kf7 2. Rh8 Kg7 3. Bb2+ Kf7 4. Qa6 Ke7 5. Bh3 Kf7 6. Ke2 Ke7 7. Kd3 Kf7 8. Bd4 Ke7 9. Nd2 Kf7 10. Ne2 Ke7 11. Rg1 Kf7 12. Nc3 Ke7 13. Nd5+ Kf7 14. Be6#


Reason(s) to play 5. Nf3 in the stonewall dutch opening?

A couple thoughts:

After Bxf4, taking gxf4 is acceptable.  The g-file is open, black's ideas of g5 are prevented, you have a lock on e5, and can fix the pawn structure with f3+e4.
After a g5-g4 push, h4 is often a better square for the knight than f4, to stop h5-h4.
f3 points at e5, a better square than f4.  f4 is vulnerable to an e5 push, and the e6 pawn is rarely weak.


Does taking tranquilizers count as cheating in chess?

The World Chess Federation (FIDE) uses the list of prohibited substances published by the World Anti-Doping Agency.
I did not see tranquilizers on the list, although I can't say I'm familiar enough with the names of medications to know for sure.
Tranquilizers would seem to be a rather counterproductive way to cheat in most sports, which might explain why they're not on the list.


Is it possible to reach master level without studying theory?

Anything is possible.  The real question is how likely are you and most people to do it that way.

And it depends on what you call 'theory'.

I read NO theory. But I read a lot of practical books on openings, tactics, end games, pawn structure, positional play, yada yada.

They claim that an AI program learned to play Go by playing itself.  I do not know anyone humans that have done that.  We might if we lived millions of years but in reality humans can't do it that way.  Most humans learn by seeing how others,  who win doing it, have done it;  and try to improve on that if possible using the basic tools they learned from practical books.


What is right way to set up King & Queen In the beginning of game?

It starts with the board being setup correctly, and that means a light square in the right-hand corner. Then, the queens each go on their own color.

 [FEN ""]


Output whether the best move is "much better" or only "slightly better" than the other moves

I don't think Stockfish gives you the information as it's not useful to anybody other than programmers for debugging. The best way is just run MultiPV=2, and subtract the best two moves. Is there any reason why you can't do that?

If you insist you'll have to modify the source code yourself. It's not a very hard change. But why would you do that?


Can a player capture en passant two times in a row?

Yes, given that the opponent helps the capturing side, it is possible to capture en passant two times or more in a row
Here is a famous example from a real game. The score came from chessgames.com
You can find more such games here on Chess Stack Exchange.
[Title "Sergey Gennadyevich Kudrin-Rudy C Douven, GMA Baleares op, Palma de Mallorca Spain, 1989"]
[startply "59"]
[FEN ""]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5  Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bf4 Qa5+ 12. Bd2 Qc7 13. O-O-O Ngf6 14. Ne4  O-O-O 15. g3 Nxe4 16. Qxe4 Nf6 17. Qe2 Bd6 18. Ne5 c5 19. Rh4 Bxe5 20. dxe5 Nd7  21. Rg4 Rhg8 22. Re1 Qc6 23. Qe4 Nb8 24. Rf4 Rd7 25. Qh7 Rgd8 26. Ba5 b6 27. Bc3  Qd5 28. b3 b5 29. Kb1 b4 30. Bb2 f5 31. exf6 g5 32. hxg6 Rxh7 33. gxh7 e5 34. Rxe5 Qf7 35. Re7 Qf8 36. f7 Qxe7 37. f8=Q Rxf8 38. Rxf8+ Qxf8 39. h8=Q Qxh8 40. Bxh8 h5 41. Kc1 Kd7 42. Kd2 Ke6 43. Ke3 Kf5 44. f3 Nd7 45. Kd3 Nb6 46. Bg7 a5 47. Bf8 Nd7 48. Bd6 Ke6 49. Bc7 Kd5 50. c4+ bxc3 51. Kxc3

For an extreme showcase, here is a chess problem that features 7 en passant captures in a row! My source for it is Yet Another Chess Problem Database.
[Title "Milan Velimirovic, Novi Temi 1979, 1st Prize, Mate In 10"]
[FEN "r7/pppppppN/8/1PPPPPPP/1n5k/R5N1/3n2K1/8 w KQkq - 0 1"]

1. Ra4! a5 2. bxa6 b5 3. cxb6 c5 4. dxc6 d5 5. exd6 e5 6. fxe6 f5 7. gxf6 g5 8. hxg6 Ne4 9. Rxb4 Kg4 10. Rxe4#


Can I move a piece protecting the king if it keeps protecting on its new location?

Yes, that's legal.  For example:

[FEN "6k1/6r1/8/8/8/6R1/8/6K1 w - - 0 1"]
[SetUp "1"]
[CurrentPosition "6k1/6r1/8/8/8/8/6R1/6K1 b - - 1 1"]

1.Rg2

The rook can move along the g-file.  This is known as a "partial pin" - the rook is somewhat limited in its movement (and can't go to a3, for example) but it can still move if it still protects the king.


What is the consequence of removing the two-square first move rule?

The purpose of the two space first move rule was to speed up the game, and the (military) theory behind it was that soldiers leaving "camp" and marching to the "battlefield" could march at double "time" (speed) before the actual fighting began.

The one thing that could prevent this was an enemy pawn on his fifth rank (your fourth) adjacent to the marching pawn (soldier). Think of your soldier as being "ambushed" by the enemy en passant on the way to taking up his designated position on the battlefield. He never arrives there, even though his marching orders tell him to march two squares in one move.

Not having these rules would make for a slower game.


What does it mean when a position is "complicated"?

Well, according to Merriam Webster:

  difficult to analyze, understand, or explain

Unfortunately, you have to trust the GM on this (unless you are a strong player yourself). There is no way of using a chess engine to determine this. What is complicated for a human (positions with a lot of tactics, with a lot of possible capture sequences) might be very easy for a computer, and complicated positions for a computer (strategic battles) might be a lot easier for humans to judge.


With the time you say you have to spend on chess, of course it's possible to improve. You should remember that chess should never come first though, and it's just a game you enjoy. If you're not aiming to be a professional, don't spend hours on end every day studying it.

Here's a list of chess literature I think would benefit you, at your skill level:

Grandmaster Preparation series by Jacob Aagard. If you can work through all the books in it (I believe there are 5) you'll definitely improve.
My Great Predecessor series by Garry Kasparov. He annotates games of all the world champions (as well as many other strong players), and it's incredibly instructive. I also learned a huge amount of chess history from the series.

Other than that, it's good to continue playing online and doing tactics training. Even if you did only 1/2 hours per day of reading/playing/tactics, you'll start to see improvement. Also, since school should come first, I'd recommend not exceeding 1/2 hours per day, unless you're absolutely set on becoming a GM / professional (which I don't recommend).


Do users of chess-db get informed when you play against their computer simulation of themselves?

No, they are not. Chess-db has no good way of contacting those people anyway.


How to offer a draw when the opponent is not present

The correct way of offering a draw is, as you probably know:

Make a move
Make an offer
Press the clock

When your opponent is not present:

Make a move
Stop the clock (or you can leave your time running)
Call an arbiter and say that you want to offer a draw, and your opponent isn't here
Start the opponent's time
You are free to go now - if you run into your opponent on the way, you can mention the offer
When you're back at the board, make your offer.

Note that the draw-offer is perfectly valid at any given time. The reason why you call an arbiter to explain the situation is to avoid being accused of distracting your opponent when you offer it in "incorrect" way.

Edit: Adding information from official FIDE rules:

  9.1.b.1: A player wishing to offer a draw shall do so after having made a move on the chessboard and before pressing his clock. An offer at any other time during play is still valid but Article 11.5 must be considered. No conditions can be attached to the offer. In both cases the offer cannot be withdrawn and remains valid until the opponent accepts it, rejects it orally, rejects it by touching a piece with the intention of moving or capturing it, or the game is concluded in some other way.

And

  11.5: It is forbidden to distract or annoy the opponent in any manner whatsoever. This includes unreasonable claims, unreasonable offers of a draw or the introduction of a source of noise into the playing area.


Stockfish, at depth 20, evaluates Rfe1 with a score of -8.5, while cxd4 has one of -2.6. With so large a difference, the explanation is that
you were playing against a weak computer. There is usually
a gradient (e.g. from 1 to 10) of difficulty to choose from
when playing against a computer, so you have probably chosen something
far from 10. Chess.com (guessing from the screenshot) also has
adaptative opponents that will grow stronger/weaker according to your
performance.
For what it's worth, shortly after cxd4 White gives up a rook and a pawn
for Black's knight and has an exposed king and piteous pawn structure —so Black wins anyway—, as follows.
4r1k1/1pp2pp1/p6p/4q3/P2rPn2/2P1QP1P/1P4P1/R4RK1 w - - 0 6

1. cxd4 Qg5 2. Kf2 Qxg2+ 3. Ke1 Qxb2 {Double threat: Qxa1+ and Ng2+ (a royal fork)} 4. Qxf4 Qxa1+ 5. Ke2 Qxd4


There is an app called Dark Chess:
Dark Chess for Android

I know it's not exactly the variation you asked for, but I thought it could be useful in some way.


When to give up on winning a game e.g. due to material

There are very few positions in which it is actually impossible to win although you are up material. Basically only KN vs K or KB vs K.

Then there are positions which can be won, but this would require such egregious errors by your opponent, that in practice a draw will inevitably be agreed. Examples are KNN vs K, KBB vs KB, KR vs KB.

And then there are theoretically drawn positions which give you very real winning chances even against strong players. KR vs KN, KRB vs KR, KQ vs KNN.

There are also known "fortresses" where the stronger side cannot break through once the weaker side has achieved a certain setup. Here is one famous (and relevant) example:

   [White "The wrong"]
   [Black "bishop"]
   [FEN "k7/8/8/PK2B3/8/8/8/8 w kq - 0 13"]


I leave a partial answer for interested parties:

Scidb (Scidb is a Chess Information DataBase) is a chess information database. (Great sentence.)

It supports some variants (3-check, King of the Hill, Anti/Suicide/Giveaway/Losers, and Crazyhouse), as well as 960 starting. It is currently still in development, and is available only for Linux systems at the moment, requiring a build from source. (It might work on Windows with an appropriate environment configured.)

Unfortunately, it doesn't support the variant I'm interested the most in (Atomic) and is limited to Linux (I do run Linux, but would prefer not to grapple with it as mine runs from an external HDD).

Further answers would be appreciated.


How to avoid falling into unfamiliar traps in the opening stage?

As a practical matter, if you're playing to win, and you encounter a gambit you haven't seen before, don't take the material. Play defensively. This will be sub-optimal by engine standards, but will usually lead to a position that is easier to play. This is particularly true in your case, where you expect to outplay your lower rated opponent given enough time on the board.
That said, personally, at ~2100 Lichess Rapid, I almost always accept gambits, even if I'm unfamiliar with them, because it gives me good experience trying to stubbornly hang onto the material or punish my opponent's shaky position, And then, when I inevitably lose to some silly line that I never studied, I analyze it after the game, and try to remember the refutation next time. This is how I've treated the King's Gambit, and I'm slowly getting better at refuting it. I don't care much about winning or losing a single game, if I can learn from it and improve.


Analysing Positions in Databases with a program

I am the author of pgn-extract and, as has been pointed out, it doesn't hook up directly with a chess engine. However, if you would like to try out something I recently wrote that does interface with an engine then there is a description of a UCI-based analyser that can output annotated PGN via its --annotatePGN option. It is still a little experimental and you will need to compile from source but it might provide something close to what you are looking for.


What would happen if multiple GMs played on both sides of a chess match?

I think that the draw rate does not have to be higher than games between individual Grandmasters. In a team versus team game, a small mistake will be severely punished. Most probably, grabbing the initiative will become more or less decisive. The opening battle will be very interesting and shape the rest of the game in a decisive manner. The type of positions that will arise in the games will depend to the team composition (the playing style of the players in each team). A team with players that prefer sharp and complex middlegames will probably have good chances to win the match. Adding a time control to the mix will make sure that a draw will not be a simple task for either team.

The probability of making a mistake will become lower. At the same time, the probability of noticing a mistake made by the opponent team will become higher. The ability to keep an initiative will increase. The ability to win endgames with a small advantage will increase. At the same time, having a time control will have an important effect. Also the exact rules will have an important effect, concerning the use of helping materials (books and engines). If using books and engines will be forbidden, the risk of making mistakes or becoming surprised in the opening will increase. It would be very exciting to see such a game with the normal time controls (90 min / 40 moves, 30 min / the rest of the game with a 30 second increment / move). The teams would have to show an excellent ability to communicate efficiently and make solid decisions at short time intervals. Probably they would not be allowed to have a demo board and would have to discuss the position in their heads. This should also increase the risk of making mistakes. All in all, longer time controls => less mistakes and higher quality of play.


How do you want to do it?

I know that sounds flippant, but that's pretty much the only good answer to questions along the lines of "How do I create something that no one has created?"

Chess endgame theory developed by people starting from very simple positions and identifying commonalities among them. Typically, endgames get classified by the pieces involved (Rook endings, minor piece endings, etc.) so I'd start with elemental positions that are clearly won/lost, see what leads to them, try and see common maneuvers to create them, etc.

From simple positions you create the building blocks for understanding more complex positions.

Rinse. Lather. Repeat.

An example is pawn endings. We started with simple concepts like the queening square, moved on to techniques like opposition, and kept building until we ended up with a theory of co-ordinate squares, which covered all pawn endings. Opposition, Triangulation, all of that stuff boiled down to being special cases, subsets within that theory. But it all started with atoms, from which we built molecules, and so on until we eventually arrived at an impressive, comprehensive, edifice.

There's no single uniform best way to approach something that's never been done. You try something, if it seems helpful you keep using it; if not, try another way.

By definition, there is no mapped out course to get you safely through uncharted waters.


Bishop's Opening, Berlin Defense, white goes Qf3; how to exploit with Black?

This opening is not dangerous.

You have no weaknesses.

White's Queen is doing nothing useful while blocking the best square for White's King's Knight.

Once you develop your Queen's Knight to c6 White has to worry about Nc6-d4 with a big gain of time.

Your f6 is fine – your knight masks it for now, and once you castle kingside it's well-defended and easily reinforced, while White will have trouble bringing up anything else to attack it.

Castling queenside is probably not indicated, although the White pawn-storm you mentioned is both premature and far too slow.

It's not like you're winning here, but White is not going to wrest any advantage out of this position without being given a gift. Whatever problems you're running into are not due to this opening.


Why is it a good idea to retreat the bishop into the pawn chain in this variation of the Caro Kann?

The immediate point of Bd7 versus Bg6 is to prevent White from playing 6 e6 which could give Black's King a lot of trouble.

Generally, Black cannot entirely avoid White's g4 anyway (it's always a move to keep in mind in the advance variation).
However, the question is: Does that move actually help White in the long run? Yes, it gains the short-term advantage you mention (free tempo + space), but at the same time it also comes with the long-term disadvantage of fracturing White's kingside pawn structure. Black can then try to play around this and later free the Bishop via e8 & f7-h5 (after that pawn has moved to f6 to attack White's center).


Is 22..., Nf6 a good alternative move to accepting the rook sacrifice by 22..., Kxf7 in Yi's recent "Immortal Game"?

After 22. ... Nf6, white will reply 23. Qe6!, threatening a nasty discovered check. 23. ... Bf8 won't work because it is mate after 24. Re7+ Kh8 25. Qxf6+ Kg8 26. Qxg6+ Kh8 27. Qxh7#, and 23. ... Kh8 loses to 24. Bg5! and Black's position will collapse.


Is this the correct behaviour?

Yes it is.

Consider the FIDE Rating Regulations -

  1. Rate of Play
  1.1 For a game to be rated each player must have the following minimum periods in which to complete all the moves, assuming the game lasts 60
  moves. Where at least one of the players in the game has a rating 2200
  or higher, each player must have a minimum of 120 minutes.

The standard time control used in the vast majority of FIDE rated competitions is game in 90 minutes with a 30 second increment starting from move 1.

Suppose the increment is added after the player presses the clock and he starts with 90 minutes. After 59 moves his clock will show -
90 minutes + 59x30 seconds - time taken to make 59 moves
= 119 minutes 30 seconds - time taken to make 59 moves

In other words he is going to have less than 120 minutes to make 60 moves because the 30 second increment doesn't get added until he has completed 60 moves. If he takes 119 minutes 31 seconds to make 60 moves then his flag will have fallen before he presses the clock and gets the increment.

Adding 30 seconds before the first move corrects this.


How could I have extracted an opening advantage in this Owen's defence game?

Black's opening play doesn't look good. This is more passive and dubious than a normal Owen's.

The suggestion of 10. Nf1 followed by 11. Ng3 is a good one and should give white a nice advantage.

But I believe black should be punished harder for their passive play. Perhaps 8. e5 Nd5 9. a3!?.

[FEN ""]
[StartPly "17"]

1. d4 e6 2. e4 b6 3. Nf3 Bb7 4. Bd3 Nf6 5. Qe2 Bb4+ 6. c3 Be7 7. O-O h6 8. e5 Nd5 9. a3!?

Black has to worry about the knight on d5 getting trapped. After 9... c5 10. c4 Nc7 11. dxc5 bxc5 12. Nc3, white obtains a better position than they usually get in Owen's.

[FEN ""]
[StartPly "23"]

1. d4 e6 2. e4 b6 3. Nf3 Bb7 4. Bd3 Nf6 5. Qe2 Bb4+ 6. c3 Be7 7. O-O h6 8. e5 Nd5 9. a3!? c5 10. c4 Nc7 11. dxc5 bxc5 12. Nc3

Black's kingside looks really weak.


What are the qualification criteria for the world team championship?

From the FIDE Handbook:

  1.4.1 Teams
   Qualification for the FIDE World Team Championship according to the following criteria:
   a.The previous event's World Chess Team Champion
   b.The three highest-placed teams in the FIDE Olympiad prior to the event.
   c.The four Continental Champions. The qualifiers will be the winners of the ultimate, respective Continental Championship organised at least six months prior to the World Team Championship.
   d.A team from the organizing federation.
   e.A team to be nominated by FIDE President.

  If any team would have already qualified according to one of these criteria, this place will be given to the next highest ranked country, in the Olympiad preceding the World Team Championship.


Just to get started, of the top of my head:

Magnus Calsen worked with Jon Ludvig Hammer,  Laurent Fressinet, Ian Nepomniachi, Peter Heine Nielsen, Michael Adams, Simen Agdestein, Garri Kasparov. He also had training sessions with Ding Liren and Wesley So. Also, this were his seconds for WCC 2016.
Vishy Anand worked with Peter Heine Nielsen, Rustam Kasimdzhanov,Radoslaw  Wojtaszek, Grzegorz Gazewski, Krishnan Sasikiran, Peter Leko, Surya Ganguly and Sandipan Chanda. He also had at least one training session with Magnus Carlsen.
Kramnik worked with Peter Svidler, Miguel Illescas, Evgeny Bareev, Peter Leko, Sergey Rublevsky, Alexander Motylev, Efimenko.
Veselin Topalov worked with Cheparinov, Paco Vallejo, Dominguez Perez, Romain Edouard.

As you can see the rating of these seconds is generally in the 2650-2750 range. (A notable exception would be Kris Littlejohn, a 2100 player who used to assist Hikaru Nakamura). It is quite common for seconds to work for different top players, at different points in time. (Leko, Motylev, Nielsen, Kasimdzanov … from the list above.)
As for the strength of a second, they are typically very strong theoreticians. And often a new second is hired because he is a specialist in a particular opening.This is the main reason why his name might be kept a secret. For example Dominguez is an expert in the Grunfeld and the Najdorf. Michael Adams was clearly hired because of his expertise in the Berlin Defence. Gajewsky introduced a strong counter gambit in a line of the Ruy Lopez …


What are the most common squares to be overworked?

Prior to castling, f2/f7 are the most exploitable squares in the game, because they are defended by only one piece: the king. That's why so many king-stuck-in-the-center games are rounded off by a piece sacrificing itself on those squares.

On the queenside, the c2 and c7 squares also have problems, because of a tactical sequence like this:

1. Bf1-b5+ Qb6xb5
2. Nd5-c7 (forking the queen with either a king on e8, or a rook on a8)

But these tactics happen less often than tactics on f2-f7, because the queen is usually a better defender than the king.


Traps and tricks for White in the 4.Bf4 variation vs the Grunfeld

https://www.youtube.com/watch?v=BX9Ax29jZ1k is video 1 of 4 explaining this system.  Mike Virgo has the links to the rest of the series.
One of the comments is:  "It is a good video, however, Roman makes one mistake. at 15:45, he forgot to place pawn on h3 back to h2."  Many minor errors show in most chess videos, so ensure you understand the moves.


Adams - Torre comes to mind. It does not fully answer your requirements - some sacs are not side by side, some are not in the middle of the board - but still...

[fen "2r1r1k1/1p1q1ppp/3p1b2/p2P4/3Q4/5N2/PP2RPPP/4R1K1 w - - 1 0"]

1. Qg4 Qb5
2. Qc4 Qd7
3. Qc7 Qb5
4. a4 Qa4
5. Re4 Qb5
6. Qb7 1-0


Just for completeness, I would like to add more explicit instructions for using stockfish in Scid, because sometimes it is a little confusing how to get stockfish to function in an actual chess program.

sudo apt-get install scid
sudo apt-get install stockfish

Load Scid
In Scid Click:

Tools -> Analysis Engine (click twice) -> New
    Set Name to ‘stockfish’
    Command is /usr/games/stockfish (use ‘which stockfish’ if not)
    Directory : Click the ~/.scid button
    Hit OK and select the stockfish engine

Hopefully this is straightforward enough that anybody could replicate it.


Kasparov said human+computer beats just computer. What does human bring to the table in such teams?

Experienced human correspondence chess players with a strong chess engine definitely play better chess than just the engine itself.

If you think about it, the human player could always simply follow the engine moves without any thinking.  However, you're not going to win the world correspondence title if you don't do your own analysis. You have an engine, but your opponent also have an engine! You just can't win a game unless you guide the engine.

A strong International Correspondence Chess Grandmaster know how to analyze a chess position with a chess engine. They can make a move on a board, and evaluate the new positions again with the engine. There is no way the engine by itself can beat this human+engine perfect combination - tactics + long-term strategic thinking.

Human can make some moves on the board, that simplifies the search process (searching at depth x is not equivalent to x+1)
Human understands drawn endgames. They can guide the engine not to choose a line that wins a pawn but draw 50 moves later in a rook ending
Human can try the engine lines, play some training games, test the new positions etc. Chess engines can't do that by itself!


Here is a fun puzzle:

Construct a legal chess game where

white starts with 1. a3,
white delivers checkmate on move 5, and
the last move is made with the rook that started on a1.

   Hint: Black takes the pawn on a3.


The Maroczy System is covered from white's point of view in Opening for White according to Kramnik, Vol 3 (2001) by Khalifman. This book contains around 70 pages about the Maroczy. In the new edition (2011), the Maroczy System is moved to Volume 4 for some reason.

There is also a small chapter about the Maroczy in Wojo's Weapons, Volume 3 by Hilton and Ippolito. Here the focus is more on ideas for white than on concrete lines.


I'm not that old (yet), but I do know how it feels. I even showed a few of my games to GMs asking for feedback, and it turns out that very often I have seen the (good) move recommended by them, pondered about it, but could not calculate properly and played another move instead. Too bad.
The solution I came up with is largely based on Dvoretsky books (not the latest ones but those from maybe 80-s or 90-s): calculation is overrated. Calculating is for engines; for humans it is very inefficient in terms of energy consumption and error costs. Instead, you should avoid calculating as much as possible, and only do it when absolutely necessary. With your experience, you should trust your intuition and know which move is good and which not before starting to calculate lines. In your example, you already knew that Nxb5 was the move; there was no need to calculate it before you actually had the position after Qxb5+ Nd7. Dvoretsky actually has quite a few examples how to solve studies using this method.
This is not going to be a popular opinion due to the recent progress of engines chess; a lot of noobs will think that if computers play better than humans, they should try thinking just like engines do. I suppose if you're 15 this might indeed work for you.


Is there software which generates novel chess opening traps?

I am sorry, but you can not create any novel chess opening traps because all were already discovered in a certain range of moves.
Also, I want to mention @RemcoGerlich's comment that even if there was an undiscovered opening trap then a computer couldn't recognize that it is a trap.
Instead, you could try to use an engine to look up moves that lose but are difficult to comprehend by humans.


Why is it a good idea to teach chess in schools?

What are the advantages of teaching chess at schools?

That depends. If you like chess, the advantage of having chess classes for free from good teachers (assuming they are good) is that you play your favourite game / learn something you like / have people to play with / all of this is free. It is really good for average chess players (who will be able to find steady income by teaching others).

But knowing this you have to understand that there are people who do not like chess. How will you feel if right now you will be forced  to learn how to play the triangle (kind of funny musical instrument that I by myself find kind of lame). What would you think if your child instead of math/biology/whatever subject you find important would be wasting his time learning triangle/chess which in my opinion will not help his career (assuming he will not become pro triangle / chess player)?

Also forcing a child to do something is not a good way for him to like this something. I enjoy playing chess, but if when I was child I would be forced to go study chess - most probably I would hate this game. There are a lot of places for a person to play chess in his free time enjoying it, so why spoil the fun with compulsory things?

  What "life skills" will the students learn by learning chess

What life skills will you gain by swimming / playing the triangle? You will not drown fast in case of flood. You will become a good swimmer. You will learn how to play the triangle and will be able to properly hear/understand music. People can argue that music will make you a better person, swimming will make you more fit, organized, but I am not aware of the proper studies conducted. What skills will you gain by training to solve IQ tests every day? Will you perform well in physics, economy, history, programming? Highly doubtful, and average person who spends 1/10 of your time learning one of these things will perform better. IQ tests will make you a better IQ test solver.

The same way with chess - by learning chess you will learn how to play chess, maybe will learn abstract thinking, thinking ahead and analyzing your options.

I by myself was speaking with some of the top 200 grandmasters and based on their discussion, chess is hard to make money on. You spend thousands of hours on learning preparation, dedication to mastery. And if you are not in top 20 it is really hard to get normal money out of it. Yes, you can publish books, create videos, participate in paid tournaments (which requires a lot of time and effort), but after this amount of time spent in economy you can secure a steady good income.


Native French speaker and regular tournament-goer (pre-Covid) here. The comments under the other answer are correct.
Some background tournament etiquette (probably not France-specific but necessary for what follows):

Calling the arbiter: stop the clock, raise your hand and say "arbitre" (once, but loud enough to be heard). Do not leave your place.
(pre-Covid, this may have changed) You shake hands with your opponent before and after the game.

Now for the French sentences:

Offering a draw: see Evargalo's comment, "je propose (la) nulle" is IMO best; just "nulle ?" sounds quite rough to me but it is not offensive either. Refusing such as offer: "non" (no); accepting: "oui" (yes); or any other non-verbal variant (for instance, extending the hand over the board after such an offer = let's shake on it = yes).
Claiming a draw by repetition: "nulle" (as an affirmation, not a question). Should the opponent disagree (I have never seen that happen), call the arbiter: "la même position a été répétée trois fois" (the same position has been repeated three times). "Je réclame la nulle par répétition" (I claim a draw by repetition) is correct, but formal.
Illegal move: if you feel nice, you can point out that the move is illegal and allow the opponent to retract it ("ce coup est illégal", this move is illegal, or something more precise, for instance "on ne peut pas laisser le roi en échec", you cannot leave the king in check). The officially-correct thing to do is to call the arbiter who will apply whatever the rules say (if memory serves, in longer time controls, the opponent gets extra time for the first two offenses).
Resigning: "j'abandonne" (I resign). Common non-verbal alternatives: tipping the king over (which some people consider mildly rude, but IMO it is not if you do it calmly and with a smile), or extending the hand over the chessboard (to shake it, implying the game is over).
Reminding someone of the touch-move rule: "pièce touchée, pièce à jouer" (a touched piece must be played). Less useful: "pièce lâchée, pièce jouée" (a dropped piece has been played = you cannot change the square you put it on). (Only for intentional contact - if the opponent reaches for their glass across the board and accidentally touches a piece, it does not apply.)
Adjusting pieces: "j'adoube" (must be said before touching a piece)
Pairings: "appareillement(s)"
Leaderboard: "classement"

Game notation is algebraic, with the following abbreviations: R=roi (king), D=dame (queen, literally "lady"), T=tour (rook, lit. "tower"), F=fou (bishop, lit. "fool"), C=cavalier (knight, lit. "rider"). For instance Alekhine's defense is written 1.e4 Cf6 instead of 1.e4 Nf6.


If you ask only about the R+2p vs R endgame then no, it was drawn. In serious engine tournaments the stronger engines usually have access to 6-men tablebases, so they play these endgames perfectly.

If you ask about the whole rook endgame, then 45.Kh3 looks like a good winning attempt, as black has no easy way to transpose to the game, e.g. 45...g2 46.Ra1 Rc3+ 47.Kxg2 Rc2+ 48.Kg1 and there is no counterplay which was possible in the game.


Is it beneficial to play chess against yourself?

Depending on exactly what you mean by "playing chess against yourself," I would say it can be extremely beneficial, and that yes, strong players do this quite a lot.

Consider what you do when you have to decide what move to make when you're playing a normal game against an opponent distinct from yourself: you analyze the position as best as you can in your head, which means needing to figure out what possibilities are available to both players in order to get to the truth of the position. In essence, you play some portion of a game against yourself starting from the position you're at. But you don't just play straight through; you have to consider sidelines and various ideas and pitfalls that might pop up along the way.

Because this is such a fundamental part of playing the game, analyzing positions or entire games on one's own, freely exploring moves and ideas while trying to determine best play, is a fantastic way to improve at chess. Not only does this endeavor have the simple potential to open your mind by exposing you to more and more types of positions and ideas, but it also offers practice at just the kind of thought process that you continually need to engage in internally during a game. One can anylyze existing games, of course, be they grandmaster games or your own past games, but games initiated on the spot serve just as well to offer up new positions in which you have to figure out how to play for each side.

So if, when you play a game against yourself, you don't merely play an alternating sequence of moves until you get a result, but instead do some stopping, backtracking and general meandering, digging deeply to figure out how and why things could proceed differently, then really you're working to develop your analysis skills, and so it could definitely prove beneficial.


How do I spend time on chess in boring meetings?

One posibility is to concentrate in problems.
Write on paper the posicion description, using a notation like the following:
This fen:
r1bqk2r/pppp2pp/2n1pn2/5p2/2PP4/5NP1/PP1NPPBP/R2QK2R b KQkq - 0 7

Corresponds to:
W-Ke1,Qd1,Ra1,Rh1,Bg2,Nd2,Nf3,Pa2,b2,c4,d4,e2,f2,g3,h2
B-Ke8,Qd8,Ra8,Rh8,Bc8,Nc6,Nf6,Pa7,b7,c7,d7,e6,f5,g7,h7
Black to move.

Annotate your answer as a continuous line of moves without the move numbers to simulate note taking.


What is the percent of players in the top X that are women for different values of X?

What I would suggest you do which will allow you to get these statistics for yourself is to go to the FIDE ratings advanced search page. There you can choose options like:

rating 2400 - 3000

sex: both

exclude inactive: tick

and you will get the answer "2184" followed by a list of players and their details. Repeat this with "sex: female" and you will get 66 followed by the list.

Repeat this for 2300 and you get total: 5073, female: 185, so percentage is 3.65%.

For 2000 you get 1473 / 31866 = 4.62%

For 1500 you get 7167 / 100730 = 7.12% and so on.

This way you can go as far as you want and in whatever detail you want.


Because the queen is protected by the bishop on A3. Therefore its checkmate.


Rook and bishop vs. opposite color bishop

Definitely not a theoretical draw, this should be easily winning for White. The strategy to win would be:

Advance with your king and rook to push back Black's king. If Black's light-squared bishop blocks your rook's check, then this means the Black king is on a dark square. Thus, you can use your dark-squared bishop to check the king and push it back.
Eventually you'll have pushed Black's king to either a light-squared or dark-squared corner.

If it's in a light-squared corner like a8, the light-squared bishop isn't able to act as a blockader from your rook. In the diagram you posted, here's one example of how to win:  1...Kb7 2.Bb6 Bh5 3.Ra7+ Kb8 4.Kd6 Bf3 5.Rc7 Bg2 6.Ba7+ Ka8 7.Kc5 Bf3 8.Kb6. Now all you need to do is maneuver your rook to the 8th rank to checkmate, which can be accomplished in as little as 2 moves.
If it's in a dark-squared corner like h8: Put your king on h6 and move your rook to the 8th rank, checking the Black king. If Black manages to block the check with ...Bg8, then you can checkmate immediately by moving your bishop onto the a1-h8 diagonal.


Why do players think after they have made a plan?

I had the same thought myself. For a couple tournaments, I started playing lines which I had calculated out with about 10 seconds of thought on each move. My results were terrible.

The reason, I think, is that the extra move being played on the board gives you quite a bit of added calculation power. I now take more time on the moves following a long think and I frequently encounter errors in my previous analysis, which I either have to find fixes for or find a new move.


Is allowing takebacks in friendly games a bad practice?

Getting too used to playing with takebacks could be somewhat detrimental if you were to transition to tournament chess at some point, since it downplays the importance of keeping your guard up and being vigilant about tactical possibilities in positions. Nevertheless, I think that in the setting you indicate playing with occasional takebacks (especially for really major blunders) is an instructive way to go, and so can be a good short-term practice for your long-term understanding of the game.

When some terrible blunder happens in your friendly games, there are basically three choices:

Resign and start anew.
Play on in a very lopsided (and probably not so instructive) position.
Take the blunder back and pick a different way to proceed.

Only the third option forces you to return to the position where the mistake was made and figure out something better to do, which in turn requires you to determine the nature of the mistake that was made in the first place. This is a good thing to do, at least if you want to emphasize learning over the competitive results of your friendly games.


Why do modern Grandmasters prefer playing quiet openings?

Aggressive openings often rely too much on preparation and most top players would rather play something "quieter", trying to outplay their opponent later on, rather than exposing themselves to being surprised by a novelty thier opponent spent hours or even days analyzing at home.
Also note that the theory of some of those "sharper" openings is so deep these days that sometimes they're just "known to be a draw". Take the Poisoned Pawn variation of the Najdorf Sicilian for instance.
That being said, it's worth noting that lots of interesting and even "chaotic" ideas are appearing all the time in openings that used to be considered "quiet".


A book on the Lasker - Capablanca World Championship Match (1921)

Capablanca's comments about the match can be found in this book.


What is the best way to continue the game in this situation and maintain my advantage?

I will expand a bit on the statements above. Just look objectively into the position:

There is no threat to either king. Q+N can be a weapon of mass destruction, but nothing happens here.
Everything is hanging: your Q and N, his Q and R.
Thus the position is very "hot" and you just have to calculate the most urgent things: check, capture, or God save the queen.
1.Nxf8+ and you are an exchange up. After that, you retreat your queen (1...Rxf8 2.Qd4, preferably, or 2.Qd3) and especially hang on to your weak pawns on c4 and e4 until you come to playing Rc1/b3 and Re1/f3. Technically easily won, note that Ba6 does nothing after you consolidated.
1.Nxe7 cxd5 and unlucky recapturing cxd5 hangs your rook, thus 2.Nxd5 Bxc4 3.Rfd1, about += (you are still a pawn up and have the better structure).
1.Qh5 and Black loses the exchange anyway, since he must go out of the fork. 1...Qxe4 2.Nxf8+ Rxf8. Same as variant 1, still won, only Pe4 will write "I hate you" on his tombstone, as you wasted him for nothing. Arguably, call it a sacrifice to quickly invade with your rooks via the e-file, but I'm a materialist.

In blitz I'd play Nxf8+ in a second.


Is it legal to play a move without hitting the clock?

Is this a breach?

No. Article 4.7 of the FIDE Laws of Chess defines when a move has been "made". Basically when your hand loses contact with the piece moved/captured/promoted etc. Once the move has been made the opponent may make a move. This applies whether clocks are being used or not.

If clocks are being used then the move is "completed" when the player presses the clock. If the player did not press the clock then it is completed when he makes his next move - article 6.2.1 -

  6.2.1 During the game each player, having made his move on the chessboard, shall stop his own clock and start his opponent’s clock
  (that is to say, he shall press his clock). This “completes” the move.
  A move is also completed if:
  6.2.1.1 the move ends the game (see Articles 5.1.1, 5.2.1, 5.2.2, 9.6.1 and 9.6.2), or
  6.2.1.2 the player has made his next move, when his previous move was not completed

When increments are used it is important that a player making a move should have the opportunity to press the clock and gain the increment. This is covered in article 6.2.2 -

  6.2.2 A player must be allowed to stop his clock after making his move, even after the opponent has made his next move.

Hence if the opponent makes his move before the player has pressed the clock then the player may press the clock without making a move and it is up to the opponent to press the clock back which most opponents would do immediately in a blitz game.

So, there is no breach, no penalty.


Where can I find details of future tournaments?

One of the options is Chess Results, but even though there are some future events, probably most of the listed events will be already finished tournaments (like now).

But you can try it in the future. Just search by your federation and do the tournament selection:

Another possibility is ChessMix Calendar. There seem to be a lot of events but the problem is that most of the search (almost everything) is available only for subscribers (who paid the $25/year fee).

My next try would be The Week in Chess (TWIC) calendar, althought it is not searchable at all and most of the events are located in Europe.

You might also consider giving a "Like" to some Facebook sites like Africa Chess Confederation that announce some competitions every now and then.