Why has the number of games decreased over time in WCC?

I don't think there's going to be a definitive answer for this: Terms are decided largely by FIDE with a small amount of input from the incumbent champion and challenger, meaning that people like us can't really know. I can however highlight a few factors that I think play a role.

As GuRoux hinted at, not running over other tournaments is a plus. Not just because of divided attention of the community, but because it means that at least two (and likely more, considering the role of seconds) of the worlds top players won't be able to compete in any other tournament while the WCC is ongoing.
Attention span. As an extreme example, the 1984 championship went for 48 (not a typo) games before the match was called off by the president of FIDE. It's hard to expect players or spectators to put aside such large amounts of time when there's no garuantee of a result, and people who are not really 'into' chess will likely stop watching quite quickly.
Increased costs. Aside from the high costs that are present in all post-Fischer-era matches (venue, hotels, prize pool, etc). there are a number of other expenses that have come up in recent years. To give only one example, the current (2014) match between Carlsen and Anand is being streamed live to the internet, which requires a production crew (streaming like that is harder than it looks) and commentators (I can't imagine the experience and quality of a top player and commentator such as Svidler coming cheap). It's true that this allows for advertising possibilities which might cover those costs, but that means that you need to find even more sponsors to cover both new and traditional expenses, and with more sponsors you can ask for less money as they share less of the limelight.
The format promotes attacking chess, in much the same way that 20/20 cricket promotes high-risk/high-reward play over the traditional test match format. The aforementioned Karpov-Kasparov match went for 48 games, but at the conclusion the score was 5-3 (five times as many draws as wins, and the ratio was even worse but for the last two games). Even people already interested in chess would likely lose interest with continual draws, not to mention attempting to attract new players. In a shorter format, you are forced to go on the offensive, because there is less time to make up a mistake arising from a mistake after passive play. Tiebreaks with decreasing time controls also means that the luck factor increses there, and so both players will likely want to avoid that.

In general I agree that 12 games is very short, but it's almost inconcievable that at 24-game match would occur these days, and even 16-18 would likely be stretching things considering the chess world's continued problems with finding and maintaining sponsorship.


Chess games ownership, databases to use in app to sell

Nobody has copyright to raw PGN games, so you are free to distribute it. You may pack it to your own format, you may offer it as a free download, or you may sell it.

However, you can't sell annotation. You may use Chessbase's 2017 Mega Database, get the games, remove annotation (if any) and use the games for your app.


I have practiced this technique since I was 10 years old. My very first chess coach emphasized the importance of analyzing the chess position from different angles - it doesn't necessarily help me understand threats or traps, but rather assists me in understanding the game from my opponent's perspective. My opponent will be considering the position and potential plans, and it's usually easier to realize a valid plan for the other side when viewing the board from that side.

Furthermore, this behavior does tap into the psychological aspect of chess. If your opponent is unaware of this tactic, he or she may be uncomfortable that you are standing behind them as they are unused to such actions. This can play to your advantage as you can break their train of thought. Of course, you shouldn't try to distract them - it's simply an unusual act that may warrant a second glance.


This is not a book review, nor is it an opinionated account of the method. I've never really used this method per se, but have read/heard about it,
so hopefully my rough summary here doesn't do disservice to the merits of the method.

The Dorfman method is a two-fold scheme for finding good moves.

The static elements

The first fold is the static elements of the position. These are 4 elements in decreasing priority:

The king position: whose king is better positioned and protected.
Material correlation: material balance, and combination of pieces. For instance, Dorfman considers 2 knights + bishop as being often more effective than 2 bishops + knight since the former can triply coordinate on the colour of the bishop.
Which side will stand better after a potential trade of queens. This depends on which side has a more active queen, and whose endgame play is favourable.
Pawn structure. Central outposts, number of pawn islands, pawn weaknesses, pawn majority, doubled-pawns, domination of light/dark squares such as the grip provided with the Moraczy bind, etc.

Dynamic play

The second fold is short-term play provided by dynamic play, which roughly constitutes:

Being ready to opt for extreme measures, such as piece sacrifices,
Create threats,
Preventing a king from getting castled,
Drastic change of pawn structure, and liquidations,
Quick pawn advances on either flanks.
etc.

Critical moments of a game

The scheme then is basically: At each critical moment of the game, each player has to decide whether to play statically, i.e. to improve their longterm play, or play dynamically
for short-term advantages to possibly stir up the static balance of the position.

Critical moments are defined as moments when there can be:

a possible exchange of pieces,
a change in the pawn structure,
and the existence of forced sequences of moves.

The Method

At each such critical juncture in the game, the method says:

Study the static balance of the position in order to decide whether to play dynamically or not.
The balance constitutes comparing the 4 elements one-by-one between the two sides, starting from highest priority.
One side is deemed statically better if it stands better in any of the higher priority elements. For instance, if king positions are about the same, but one side has a stronger material correlation, then that side stands statically better even though they might be worse in the 3rd and 4th elements of the static balance.
The side with a favourable static balance should play slowly and find moves that further improve their longterm static advantages.
Conversely, the side being statically worse, should opt for dynamic play and establish a short-term advantage, in order to ultimately stir up the static balance in their favour.
Ideally, the dynamic play should aim to establish an advantage in terms of a higher priority static element. For instance, if we are statically worse because our material correlation (2nd element) is worse, then by playing dynamically we should try to worsen our opponent's king position relative to ours, i.e., establish an edge in a static element higher in priority than the one we're doing worse in. So in this example that higher priority would be the king position (1st element).

Related material and further reading:

The two books: The Method in Chess, and The Critical Moment.
A review by Chess Today of the I. Dorfman books, also containing discussed examples from the book.
An article on the method by Iryna Zenyuk on chess.com.
English and French video series on chess24.com with I. Dorfman, Laurent Fressinet and Jan Gustafsson explaining the method.


What's the maximum number of moves that can result in a threefold repetition from an arbitrary position?

Twelve moves is the maximum:

[FEN "5K1k/6p1/6pp/8/8/8/b7/Q7 w - - 0 1"]

1. Qxa2 Kh7 2. Qa3 Kh8 3. Qa4 Kh7 4. Qa5 Kh8 5. Qa6 Kh7 6. Qa7 Kh8 7. Qg1 Kh7 8. Qf1 Kh8 9. Qe1 Kh7 10. Qd1 Kh8 11. Qc1 Kh7 12. Qb1 Kh8 13. Qa2 Kh7 14. Qa3 Kh8 15. Qa4 Kh7 16. Qa5 Kh8 17. Qa6 Kh7 18. Qa7 Kh8 19. Qg1 Kh7 20. Qf1 Kh8 21. Qe1 Kh7 22. Qd1 Kh8 23. Qc1 Kh7 24. Qb2 Kh8 25. Qa3 Kh7 26. Qa4 Kh8 27. Qa5 Kh7 28. Qa6 Kh8 29. Qa7 Kh7 30. Qg1 Kh8 31. Qf1 Kh7 32. Qe1 Kh8 33. Qd1 Kh7 34. Qc1 Kh8 35. Qb1 Kh7 36. Qa2 Kh8 37. Qa3 Kh7 38. Qa4 Kh8 39. Qa5 Kh7 40. Qa6 Kh8 41. Qa7 Kh7 42. Qg1 Kh8 43. Qf1 Kh7 44. Qe1 Kh8 45. Qd1 Kh7 46. Qc1 Kh8 47. Qb1 Kh7 48. Qa1 Kh8

Moving the Queen to a2, a3, a4, a5, a6, a7, b1, c1, d1, e1, f1 or g1 all lead to threefold repetition.

As @RemcoGerlich explained the Black pieces have to reset for the positions to be the same.  Black is resetting after every other move (on moves 2, 4, ..., 48) in the example above which is the quickest possible.

Thirteen moves would require the Black pieces to reset at least 26 times however Black can reset at most 25 times in 50 moves.


Two Knights of the Caro-Kann: 2.Nc3 vs 2.Nf3

One thing I can think of is that after 2. Nc3 you still have a chance to transpose to main lines after 2 ... d5 3. d4, so it's a tad more flexible. I know it's a stretch, but if your opponent is (for whatever reason) afraid of the two knights variation, they might not play 2. .. d5 and opt for 2. ... g6 or other inferior move.


Only the king remains, but he is stuck, can't move

If you mean he can't move his king anywhere because if he does his king will be in check, but none of your pieces are attacking him at the moment, and it's his turn, then yes, it's called a stalemate because he has nothing to play but his king isn't attacked by any one of your pieces, and this is a draw.

P.S. that is if none of his pieces are able to move, if he has another piece which he can play with it's not a stalemate. xD


What are the differences between Chess and Go from the perspective of computers?

Chess:

Chess programming pretty much consists of optimising the tree search. All attempts at introducing "human like knowledge" into the engines have been dropped for more and more sophisticated search heuristics.
The ultimate goal in chess programming has been reached. In fact one could argue that chess programming overshot it's goal by a mile or two. Since the mid-2000s no human player stands a chance against the top engines.

Go:

Apart from searching a search tree of possible variations the latest advances in go programming have included such divers techniques as Monte Carlo simulations and neural networks.
The best human players are still stronger than the engines, so arguably there is still more to accomplish.


Why black is happy with slow development?

I do not know that I would say "happy", but in chess, there are pluses and minuses to every move we make, and on top of that, there are exceptions to many positional concepts. We see GMs move pieces twice in the opening all the time when there is a good reason.

Now, as to that specific position, black is, indeed, somewhat behind in development, but has compensating factors. In particular, black has traded the bad bishop for white's good bishop, and the exchange of light-squared bishops makes most kingside attacks very difficult to execute, and in the Caro, with less space, that is a concern. The c6 and e6 pawns are well-placed to help control the light squares since the bishop was traded. Black's remaining bishop is probably a little better than white's, and contributes well to the defense.

In addition, black is incredibly solid, so black has the time to finish development safely, and then to break back with c5. It is almost impossible to prevent c5 later.

Lastly, black is normally down one tempo, but here it is two. Black had no choice but to play Bh7 when white played Ne5. How is being behind in development normally punished? By opening the position. That is virtually impossible here, so black is content (the word I would use instead of "happy") to be behind en development temporarily.

Edit: I am going to move a few more things from my comments below to the answer.

One more thing that compensates is that the Ng3 is not well-placed, and often goes to e4 later, giving back a tempo. You also might look at h4 as a potential weakness, but it is rare in practice that it is a factor in that sense...it usually is not weak, but cramps black's kingside.

Development is not the overriding factor in this line, or similar lines...it is that white has more space, which is why black must eventually chip away at the center with c5. If not, it will probably be a slow strangulation.


Is a wasted tempo with an early ...a6 or ...h6 by Black in the opening really compromising?

At such an early stage, there is plenty of room for speculation, but the answer is that it can be dangerous in some positions, and not so dangerous in others. I will go into detail in a moment. The biggest drawback of playing those moves so early is that you are not yet sure if they will fit into, and if they will be useful (very important), as the position develops. A good rule of thumb is to play moves that you know you will need earlier, and then see what other moves fit in with your plan as the game has developed.

In the first position, you have a double-king-pawn opening, aka an open game. It is called an open game for a reason...because the position will be very open. Very open positions often rely on tactics and tempo, so losing a tempo on move three could easily evolve into a lost game by move 15. I would say in that position, it is the most dangerous.

In the second and third positions, both are closed games, and thus, losing a tempo is not as likely to be fatal. Again, whether you can make a6 valuable in those positions, it is not clear. In either case, even if it does not lead to an immediate win, I would expect white to have a MUCH better chance at obtaining a solid +/- out of the opening, instead of the more typical +/= or =.


In SCID, from the Game List you can select the "Change filter" icon followed by the "Search for material or board patterns" icon. In the window that pops up, you can select the location of up to ten pawns. Although ten is not enough to specify the pawns of both sides, you can also separately specify the number of pawns each side has.

You can also select just the file and not the rank (for example, you might care that your a-pawn exists, but not about its exact location.) And you can specify that a particular file doesn't have any pawns of a particular color. Here's what the screen can look like:

In this example, for a game to match the filter, Black must have pawns on b7, c6, e6, f7, and g7, no pawn on the d-file, and exactly seven pawns. Additionally, White must have pawns on c2, d4, and f2, with no pawn on the e-file, and exactly seven pawns.


Brainteaser: What is the one thing a queen cannot do that all other pieces can do?

I'll have a go at saying the queen is the only piece that cannot reveal a discovered check.


Can you really learn from playing against computers just like when playing against humans?

I read an article in chess life about a man who won an significant open tournament even though he was unrated when he entered. He had practiced only against the computer.

I myself have learned a lot of what I know from computer programs. It is very difficult to find good players here and the computer is always available. From what I have read you learn most when you play against a player who is just a little better than you are. The computer allows you to control the level of play of your opponent. This is most effective when you opponent can tell you afterward what you did wrong and what you did right, so you will want to have the computer analyze the game afterward.

I would recommend also using books of games (or a database of games) where you can go over the analyzed games from players about your own strength. I have one of my grandfathers books which is a collection of games by Capablanca called "The Immortal Games of Cabablanca" the games early in his life helped me a great deal. I couldn't understand his later games enough to get much out of them.

To conclude I you can learn from playing a computer. They will play at the set level of play and can analyze your games, however use other sources to help you advance as well.


Why move bishop first instead of queen in this puzzle?

After Qa4 Black can reply ...Kf8 if you capture there's ...Qd7 (pinning your knight and regaining it later)
A continuation would be 1.Qa4 Kf8 2.Nxc6 Qd7 3.Bb5 a6 4.Nxe7 axb5


For now, I am going to assume that you are a somewhat weaker player.

If that is the case, virtually 90% of your time should be spent on tactics for now, but you want to find them grouped by category, so you are constantly solving similar problems. Try to do 50 per day, spending no more than two minutes per problem.

In addition to that, you want to find a good endgame course, like "Silman's Complete Endgame Course". At times, when you want a break from the tactics, start reading through that book page by page. Frankly, do not try to deeply study it at first. You should prefer to just see many, many, examples played out, and try to absorb as much as you can by osmosis, rather than deeply studying at first. There are a few things that need to be memorized, like how to draw K+P vs. K when your lone king is in front of the pawn, or the Lucena position to win certain rook endgames, or Philidor's position to draw certain rook endgames.

Lastly, you can also spend some time with opening pawn structure books, like Soltis' "Pawn Structure Chess". There are analysis mistakes in it galore, but the overall ideas are sound, and will teach you HOW to play chess rather than trying to memorize opening theory.

Spend most of your time on the tactics, but take breaks, and dabble in the other two. As you get stronger, things will change.

You can also read my answer here for more advice.


Game analysis - Understanding the potential of this queenside expansion

I am not trying to be hard on you, but to be blunt, this is one of the dangers of analyzing with a computer, and not having any understanding of the position. That line of analysis you give with 20...Nac7 and then shuffling around the pieces, frankly, did not make any sense at all plan-wise (and even my Stockfish 11 does not agree with your computer's line). I will discuss that in my notes to the game.

I opened my copy of that book, and what Reshevsky, correctly, said was that white has move space on the queenside, and that black needs to look for play on the kingside with f5. White's play, in theory, is generally  better, but what Reshevsky also said is that if white blindly pursues his own play on the queenside without any regards to his own king, he can easily lose to a direct attack. That is a common theme in the KID, especially the Classical variation. I have seen many games where white has a Na8, and is up a rook, but is helpless against the mating attack all the way on the other side of the board.

Here are Reshevsky's own words:

Reshevsky chose to play a line that he was well-prepared for f5, and then actually chipped away at f5, weakening e4, which led to the black king. In the vast majority of KID games, that is not the typical line of play, and white does not often get to be that active on the kingside. In most, white owns the queenside, and black owns the kingside, and each side tries to open their dominate side of the board. In most cases, going passive on your better side, and trying to just defend the other side where your opponent is better, is a recipe for a loss.

 [Event "Interzonal-07"]
 [Site "Sousse"]
 [Date "1967.11.02"]
 [Round "14"]
 [White "Reshevsky, Samuel Herman"]
 [Black "Mecking, Henrique"]
 [Result "1-0"]
 [ECO "E96"]
 [PlyCount "141"]
 [EventDate "1967.10.16"]
 [EventType "tourn"]
 [EventRounds "23"]
 [EventCountry "TUN"]
 [FEN ""]

 1. d4 Nf6 2. c4 d6 3. Nc3 g6 4. e4 Bg7 5. Be2 O-O 6. Nf3 e5 7. O-O Nbd7 8. Re1 a5 9. Bf1 c6 10. Rb1 Re8 11. d5 Nc5 12. b3 Na6 13. a3 c5 14. Bd2 Rf8 15. g3 Bg4 16. h3 Bd7 17. Bg5 h6 18. Be3 Ne8 19. Qd2 Kh7 20. Nh4 f5 (20... Nac7 {This gives up on slowing down white's play with b4, and from c7, the knight has no where to go. b5 might be an idea in some positions with the Ra8 on b8, but here b5 just loses a pawn.} 21. Na4 {The knight does nothing here, unless black cooperates and takes it. It also makes it harder to play b4, opening the queenside.} (21. b4 {This is not the best move per the computer, but it is the most natural, and leads to a solid static positional advantage immediately.} axb4 22. axb4 {+.75 depth 30, and the computer wants to pitch a pawn here with Na6.} Na6 23. bxc5 Nxc5 24. Bxc5 dxc5 25. Rxb7 Nd6 26. Rb3 $16) 21... Na6 {And it comes back.} (21... Bxa4 $2 22. bxa4 $16 {Doubled pawns, or not, white has huge pressure down the b-file.}) 22. Rec1 {Not an useless move, but how do you get in b4, opening the position?} Rb8 23. Nc3 Nf6 $2 {Blocking the move f5 cannot be right. Black will need that soon enough, but to be honest, I am not sure how to get it in anymore. If f5 is ruled out, then this knight probably belongs on c7, aiming for b5.} 24. Qb2 $2 {There is no point here since it cannot help with b4, or help stop b5 by black, and putting the queen on the same diagonal as the Bg7 unless there is a super reason, it probably also not a good idea.} Rg8 $2 {Again, no the right square to help any eventual f5 move. This is just a move that the computer things does not upset any balance, but it is not right.} 25. Qc2 {And back for no particular reason.} (25. Kh2 {This excellent waiting move could have been played at any number of moments.}) 25... Re8 {Still not the right square.} 26. Nb5 (26. Kh2 Nc7 27. Nf3 b5 $6 (27... b6) 28. b4 $1 $16) 26... Bf8 (26... Bxb5 $2 27. cxb5 Nc7 28. b4 axb4 29. axb4 $16) 27. Bd2 b6 {White does not want the queenside "fixed"...he wants it opened so the major (heavy) pieces can penetrate, and do damage.}) (20... Rb8 {If black is determined to be totally passive and only play on WHITE'S queenside (white is stronger there), this is the way preparing b5.} 21. Kh2 Nec7 {The Na6 stops b4, while the Rb8, Nc7, and Bd7 prepare b5, an action against b3 eventually. This is not destined to work, in my opinion.}) 21. exf5 gxf5 22. f4 e4 23. Bf2 Nf6 24. Nd1 Ng8 25. Ne3 Qf6 26. Bg2 Rae8 27. Qe2 Ne7 28. g4 Kg8 29. Bg3 fxg4 30. hxg4 Ng6 31. Nhf5 Bh8 32. Nxh6+ Kh7 33. Nhf5 Kg8 34. Nh6+ Kh7 35. Rf1 Qc3 36. Nef5 Bg7 37. Rbc1 Qxb3 38. Rb1 Qxa3 39. Rxb7 Nb8 40. Nxg7 Qxg3 41. Nxe8 Nxf4 42. Rxf4 Qxf4 43. Nxd6 Kxh6 44. Nxe4 Bxg4 45. Rb6+ Kh5 46. Qe1 Nd7 47. Ng3+ Kh4 48. Qe7+ Rf6 49. Qh7+ Kg5 50. Ne4+ Qxe4 51. Qxe4 Rxb6 52. Qe3+ Kg6 53. Bh3 Bxh3 54. Qxh3 Ne5 55. Qe3 Kf5 56. Qxc5 Rb1+ 57. Kg2 Rb2+ 58. Kf1 a4 59. d6 Rd2 60. Ke1 Rd4 61. Ke2 Ke4 62. Qa3 Rd3 63. Qb4 a3 64. c5+ Kf5 65. Qa4 Ke6 66. Qa8 Rb3 67. Qg8+ Nf7 68. Qg6+ Ke5 69. Qxf7 a2 70. Qa7 Rh3 71. d7 1-0


On Lichess, how do you promote to a rook with algebraic notation?

I figured out what is wrong. To promote a pawn to another piece, I need to first type the letter in which the pawn is, followed by the position I want the pawn to go, and lastly the equal sign with the piece I want to promote to.
Here is an example:
"Promote a pawn to a knight"
ee8=n "promote a pawn to a knight"

Here is how it works.
My pawn is at the letter e and I want the pawn to go to e8. So I typed:
ee8

The pawn should be a knight that is where =n came from.
Again here is the algebraic equation to use:
ee8=n


Why is there a draw in professional chess?

First of all let's put the numbers correct.

The 80% draw ratio is for correspondence chess, not something that the average person would associate with "chess".

In regular top level chess, the draw ratio is around 50%.

In either case, most games are not played out until a postions when it is impossible to checkmate, but rather most draws are agreed draws, i.e. draws in a position that could in principle be won by either player through checkmate.

If I understand your proposal correctly, you want to get rid of draws completely by evaluating dead positions (that cannot be won by either player, not even if cooperating) according to the piece value.

I see several difficulties/issues with this approach:

You'd have to decide what to do with perpetual check, stalemate and the 50 moves rule.
What do you do with positions that are equal/drawish with equal material but that are not dead draws (i.e.  either player can still checkmate)? Forcing players to continue until dead draws could lead to very long (and boring) games, similar to what we see with some games under Sofia rules.
Positions where it is impossible to checkmate are pretty rare. Basically only King vs King or King and one minor piece vs King (and a few exceptional/constructed cases). In the large majority of positions checkmate is possible if players cooperate. So the proposed change would not alter much.
If players in the dead draw position would have equal material it would still be a draw.


Polyglot Opening Books vs. Chess Opening Tree

Let's take a look what they are

Polyglot is an open source format. It is free to use, free to distribute, the file format is in public domain. You won't land yourself into any potential legal disputes with Polyglot, as long as you follow the GPL license for the source code.
CTG file format is owned by Chessbase. It's a closed format, and is not open for you to modify. The file format is proprietary. You might land yourself into possible legal disputes if you try to do something stupid. You --might-- need Chessbase's explicit permission if you want to embed it into your own application. Check with your lawyer.

People use Polyglot because:

It's free. The source code is there for everyone.
They don't know how to read the Chessbase opening file format
Open source chess engines don't use CTG. They generally use Polyglot or nothing. I believe it's illegal to embed a proprietary software (you need code to parse the CTG file) into an open source program.

People use CTG because:

It's a more powerful file format than Polyglot. The Polyglot format is really a binary compression of (position, moves, weights). For example, it doesn't have the number of games for each position.
Polyglot is designed for computer chess engines, it sits nicely with engine code, but lacks good support for chess GUI. CTG format is designed for both chess engines and chess GUI.
CTG is a more popular format than Polyglot. Most opening book makers use the Chessbase software.
Polyglot was developed on the UNIX operating system, the source code is much harder to compile on Windows. But most chess book makers use Windows!
There's an experimental CTG loader from scidb, and the related Java implementation somewhere else. However, the implementation in scidb is quite difficult to pull out (not abstracted in software engineering terminology). The Java implementation is useless if your application is not written in Java.

If both CTG and Polyglot were open source and free, there wouldn't be any reason for Polyglot to exist. CTG > Polyglot.


Why does the game end at checkmate and not upon taking the king?

Per wikipedia, citing Henry Davidson's A Short History of Chess (1949):

  In early Sanskrit chess (c. 500–700) the king could be captured and
  this ended the game. The Persians (c. 700–800) introduced the idea of
  warning that the king was under attack (announcing check in modern
  terminology). This was done to avoid the early and accidental end of a
  game. Later the Persians added the additional rule that a king could
  not be moved into check or left in check. As a result, the king could
  not be captured, and checkmate was the only decisive way of ending a
  game.


Even though the best answer is to use a pre-existing module instead of reinventing the wheel, just for illustrative purposes here's a version that works using only pure Python Popen(). The key is the use of "isready" and waiting for an answer:

import time
from subprocess import Popen, PIPE

def put(p, msg):
    p.stdin.write(msg+'\n')
    p.stdin.flush()

def get(p, verbose=False):
    put(p, 'isready')
    lines = []
    while True:
        s = p.stdout.readline().strip()
        if s == 'readyok':
            break
        if verbose:
            print(s)
        lines.append(s)
    return lines

def putget(p, msg, verbose=False):
    put(p, msg)
    get(p, verbose)

def go(p, depth=None, t=1.0, dt=0.05, verbose=False):
    depth = 'infinite' if depth is None else 'depth %d' % depth
    put(p, "go %s" % depth)
    t0 = time.time()
    stopped = False
    while True:
        time.sleep(dt)
        lines = get(p, verbose=verbose)
        for line in lines:
            if line.startswith('bestmove'):
                return line
        if not stopped and time.time() - t0 > t:
            put(p, "stop")
            stopped = True

p = Popen("stockfish-8-64", stdout=PIPE, stdin=PIPE, universal_newlines=True)
get(p, verbose=True)
putget(p, 'uci')
putget(p, 'position startpos')
bestmove = go(p, depth=20, t=3.0)
print(bestmove)


Chessbase is indeed just a database program, albeit a very powerful one. If Houdini doesn't already provide it then you will need some kind of front end to play games against it.

One of the best free ones is Scid vs PC. This is available for download on Sourceforge and if you need more help getting started with it then there is much useful information on the Watford Chess Club website. There it explains in great detail what you need to do to get Scid to use other engines like Houdini.


Chess Microbase is the only thing I found.

You can have 3 databases for free which is probably enough in most cases.
You can also share the link to the game.
Supports importing and exporting with PGN.
Has support for annotations.
I am using it for couple of years now (I think). It seems reliable and seem to get new features. Of course, take backups.


What does the sign of the score represent in chess engines?

Evaluation sign should be the colour. Your implementation looks correct to me. I compared yours with:

  https://chessprogramming.wikispaces.com/Minimax

What you did is conceptually identical to the pseudocode on the page.


What if Stockfish had infinite computing power?

No.

What do you mean by "perfect" chess moves after 10 moves? We don't know they are perfect until the game ends in checkmate! You'll need go mucher deeper than 10 moves. You can't even solve King's Gambit in just 10 moves.
The Stockfish algorithm heavily skips stupid moves off the search tree. It will not search everything no matter what CPU power you give it. You're actually talking about a brute-force engine (search all the possible moves). No, Stockfish is much smarter than that.
Nothing really happen. You could publish a new paper, but your results would not change the world. We don't need to know what happens after 10 moves, we want to know what happens after 100 moves.


Which openings lines are both sharp and drawish?

Typically by sharp you mean highly tactical lines, with few alternative moves, where any wrong move leads to immediate defeat.

A sharp and sound opening would be one that is so far analyzed that you can claim to lead to more or less equal position.

Many sharp openings tend to be drawish if players know what they are doing. Reasons for that:

because moves are basically forced, you have a small branching factor and it is possible to analyze such openings much further, sometimes all the way to a perpetual or very drawish endgame
sharp lines are usually found in open positions, which tend to favour exchanges. The fewer pieces on the board, the more drawish it often gets.

I have a limited repertoire, but I believe there are many lines in the Sicilian which are said to be drawish.

In any case for  many mortal chess players this is not an issue as it is unlikely that games are played perfectly through  to the draw. Also people at lower level tend to fight for a win playing black and white, so there is not so much of a risk running into a drawish line as white (unles you play a much lower rated player).


Any chess software with "force move" facility?

I know Chessmaster does this (see Ubisoft's list of controls for Chessmaster X), since I've used Chessmaster X.  In certain (i.e. non-competitive) game modes, Ctrl-F will force the computer to move during its turn.  It isn't a free program, but it has a lot of good resources for a beginner which IMO make it worth it.

Edit: It looks as if I have misread the question; I believe you actually meant the player can force the computer to make a certain move when it is the computer's turn.  As far as I know, you cannot do this without setting up the board to a certain position, then playing from that position.  E.g. you are White: 1. e4 e5 2. Nf3 ... and you want to make the computer play 2... f6 to practice your advantage against this opening.  In this case, you would set up the board manually (which Chessmaster as well as most other chess programs allow you to do) as FEN rnbqkbnr/pppp2pp/5p2/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R w KQkq - 1 2, and play as White from there  In most programs, including Chessmaster, you can manually move around/add/remove pieces to attain the desired position.


What is the process for becoming a FIDE rated chess player?

How can I can play in a FIDE tournament

In exactly the same way you would a non-FIDE rated tournament. First enter. Then play.

  How can I can become a FIDE-rated player?

To get a FIDE rating you need to score at least one draw against at least 5 FIDE rated opponents in FIDE rated tournaments with a performance rating of at least 1000 over a period of not more than 26 months.


I would recommmend The Retrograde Analysis Corner It is a top notch and well known site that explains castling and en passant conventions,  what exactly it is all about, and how to solve such problems among it's many, many helpful things.


Why is this move into a simple forced mate annotated dubious and not a blunder?

A blunder is a game-changing move. Nb8 does not change the result of the game which is utterly and completely lost regardless of black's move. Earlier in the game black did blunder when it gave away its queen.
The reason for the "!" part of the "?!" (dubious move) notation in this case is because moving the knight opens up the line of sight of the d7 bishop.


How many windmills types exist in chess?

Yet more possibilities . . .

: Two-way windmill, with either Rook or Bishop as the front piece;
e.g. with a Rook:

5n2/3bb2k/6pp/4B1pr/8/8/8/5RK1 w - - 0 0

1. Rf7+ Kg8
2. Rg7+ Kh8
3. Rxe7+ Kg8
4. Rg7+ Kh8
5. Rxd7+ Kg8
6. Rg7+ Kh8
7. Rxg6+ Kh7
8. Rg7+ Kh8
9. Rxg5+ Kh7
10. Rxh5

(it's important to capture g5 last, else Black has Rh5xe5)

: Windmill against a piece other than a King:

5kr1/6pp/8/4N1p1/6p1/6P1/6BP/6K1 w - - 0 0

1. Bd5! Rh8
2. Nf7! Rg8
3. Nxg5 Rh8
4. Nf7 Rg8
5. Ne5 Rh8
6. Nxg4

(with better winning chances than the immediate 1 Nxg4)

: That means that even the King can be the front piece of a
windmill of sorts against a Knight:

8/8/1n1p1p2/3K1k2/8/1P6/6B1/8 w - - 0 0

1. Kc6! Na8
2. Kxd6 Nb6
3. Kc7

(or first 3. Bb7 and then 4. Kc7(c6); if 1...Nc8 then 2 Bh3+ wins.)


Is this endgame a draw? 2 Bishops + 4 Pawns vs Queen + 1 Pawn

Black is winning handily from the diagram position, and has a fairly straightforward strategy going forward: force the b-pawn's advance to b2 with the support of the bishops (starting with 1...Be6 to gain control of the b3 square), and then slowly push for a new queen, making use of the facts that (1) White must always keep guard over b1, and (2) Black has plenty of material to shield from a potential perpetual.

The following is lightly annotated over the first few moves, and from move 5 on is just one line illustrating how Black can make steady progress with nothing to fear from the White queen.

[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "8/5pk1/6p1/2pQ1b2/1p1b1P2/5K2/8/8 b - - 0 1"]

1...Be6
    {Taking control of the b3 square with tempo, preparing to advance the
    b-pawn.}
2.Qb7 b3 3.f5
    {White needs to try this, as otherwise Black can simply follow with
    ...b2, ...Bf5 and queening. Playing this immediately forces Black to
    occupy f5 with the pawn, since ...Bxf5 drops the b3 pawn.}
    ( 3.Ke2 $2 b2 4.Kd2 Bf5 )
3...gxf5
    {Still, Black will be able to get in ...b2 from here, which will tie
    White to guarding against promotion on b1. The only hope for White
    would be a perpetual, but Black has plenty of material with which to
    shelter the king.}
4.Kf4 b2
    {What follows is just one illustrative line showing how Black can keep
    the king safe while pushing toward a new queen.}
5.Qg2+ Kf8 6.Qa8+ Ke7 7.Qb8 c4 8.Qc7+ Bd7 9.Qb7 f6 10.Qb4+ Ke8 11.Qb8+ Kf7
12.Qb7 Be5+ 13.Ke3 f4+ 14.Kd2 Kg6 15.Qg2+ Kh5 16.Qh1+ Kg5 17.Qg2+ Bg4 18.
Qb7 c3+ 19.Ke1 f3 20.Qg7+ Kf4 21.Qh6+ Kg3 22.Qg6 f2+ 23.Kf1 b1=Q+ 24.Qxb1
Bh3+ 25.Ke2 f1=Q+ 26.Qxf1 Bxf1+ 27.Kxf1 c2 *


First of all, I do not think Black's king would be safe at all on h5. After Kh5 simply Rd4 would threaten Bf3#. Many other concrete threats also come to mind with the king on h5, but the idea is the same: the king is one check away from checkmate, since no squares are available for him. Of course all of this is ignoring the fact that Black can force a draw.
I believe g4 is simply an overlook (yes, they happen in the elite too). Nepo was probably too enthusiastic about the threat of g5+ with all the subsequent mate threats after Kh5 that he overlooked the forced draw. So to answer your question: I think the idea behind g4 is simply to create a mating net against the enemy king. A strange overlook by such a strong player anyway.


In Queen's Indian - Classical Line, why is ... Bb4+, Bd2 Be7 preferred over Be7 directly

White's intended setup involves fianchettoing his dark-squared bishop on b2. The "free move" 6. Bd2 brings more harm than good:

Transferring the bishop onto the long diagonal, if white wishes to, will still take another move (i.e. Bd2-c3), but more importantly, if he does, the bishop on c3 takes away the square for the knight, which is preferred in many lines.
In many lines, white wants to play d5, aiming for a Benoni-like structure (which is bad for black in these cases); the bishop on d2 blocks the queen's defence of the d5 square, making this push harder to achieve.

For case 1: consider the "old" line, and compare this to a possible variation that arises after giving the check on move 5 instead:

[FEN ""]
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 (4... Ba6 5. b3 Bb4+ 6. Bd2 Be7 7. Bg2 Bb7 8. O-O O-O 9. Nc3) Bb7 5. Bg2 Be7 6. O-O O-O 7. Nc3 Ne4 8. Qc2 Nxc3 9. Qxc3 f5 10. b3 Bf6 11. Bb2

Clearly, in this case, having the bishop on d2 is worse than having it on c1!

Long story short: the check disrupts white's set-up.


Looking for a stable pawn structure after 1. Nf3

I would suggest something like a Sicilian Dragon / Sniper attack with moves like c5, g6, Bg7 etc. White will find it very difficult to stop you playing like this after opening with Nf3 and you don't have to worry about learning a boatload of white transpositional possibilities.


Does White have any feasible way to break through this position?

I don't see any way for White to make progress. There are a few ways but all don't lead to anything:

1) Maneuvering a knight to f6. This just gives Black an opportunity to exchange his bad h8-bishop. After ...Bxf6 gxf6, Black puts his knight on f8 and plays ...Ke8, defending the f7- and h7- pawns.

2) Playing the f5 pawn sac. The purpose of this would be to plant a knight on f4. But here Black just plays ...exf5 and again employs ...Nf8, defending the e6- and g6- squares.

3) Putting a knight on a5. This doesn't really due much and hardly warrants a response from Black.

I also let Stockfish think to depth 68. The evaluation it gave is 1.97, which sounds bad, except it gave this same evaluation before it reached depth 30. This suggests White has no way to make any progress, meaning most likely the result is a draw (though it doesn't prove it).

Btw, in a 1+0 game trying to flag your opponent in a dead drawn position is completely fine. Aiming to win on time in bullet is a huge part of that time control. I'd only considering playing on there an unfair practice maybe in longer time controls (say over 5+0).


As you mentioned, 4.g4 is interesting and not as stupid as it may look. If you don't like the positional maneuvering game, I think 4.f4 could be try for you.

There is one suicidal line that really isn't my taste, but for sure it is aggressive, at least till you get mated. It's

[FEN ""]
1.e4 d6 2.d4 Nf6 3.Nc3 e5 4.Nf3 Nbd7 5.Bc4 Be7 6.Ng5 O-O 7.Bxf7+ Rxf7 8.Ne6

even some correspondence player advocated it for white, but I'm not sure I would prefer white's position here. Anyway, good to know such a line exists and is probably not complete nonsense.


Initial FIDE rating below floor, what happens?

The rules FIDE use in calculating a player's first rating are outlined in the FIDE Rating Regulations effective from 1 July 2017.
The relevant sections are:

6.1 If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded. Otherwise if an unrated player has played rated games, then this result is included in computing his overall rating

and

7.14 A rating for a player new to the list shall be published only if it meets the following criteria:
7.14a If based on results obtained under 6.3, a minimum of 5 games.
7.14b If based on results obtained under 6.4, a minimum of 5 games played against rated opponents.
7.14c The condition of a minimum of 5 games need not be met in one tournament. Results from other tournaments played within consecutive rating periods of not more than 26 months are pooled to obtain the initial rating.
7.14d The rating is at least 1000.
7.14e The rating is calculated using all his results as if they were played in one tournament (it is not published until he has played at least 5 games) by using all the rating data available.

So, the answers to your questions are clear:

Are my first 6 results discarded and I have to play 5 new rated
opponents?

Since you scored more than zero in your first tournament then all the results will be used in calculating your rating provided they were played within a 26 month window. So, provided 26 months have not elapsed then the answer is "No".

If yes to (1), do I have to score at least half a point in a
tournament again before my results are considered for my initial
rating?

If your next tournament was more than 26 months after the first two (i.e. "yes to (1)) then that counts as your first tournament and the rule regarding scoring zero in your first tournament applies.

If no to (1), are all of my first 6 results kept, forcing me to keep
playing until I have pooled enough results to be above the floor of
1000 within 26 months?

According to 7.14e the answer is yes with the 26 month proviso. Every time an old tournament drops out of the 26 month window it is excluded from your results.


How bad is the English Opening Wing Gambit?

According to the Database of 365Chess, the English Wing Gambit has not been tried by a grandmaster in a rated game.

Although there might not be a clear refutation, the gambit seems to be somewhat dubious. Compared with most gambits, white does not obtain a quick development. Compared with the Sicilian Wing Gambit, white acquires less control in the center. Compared with the Benko Gambit, black's central pawns are still flexible (which was already pointed out by Brian Towers).

After 1.c4 c5 2.b4, the most principled reply is to accept the gambit by 2....cxb4. Now, white has two logical continuations: 3.a3 (Benko style) and 3.d4 (trying to occupy the center). Regardless of white's third move, black can play 3....e6 and 4....d5, after which white doesn't have enough compensation.

Instead of accepting the gambit, black is also more than fine after 2....Nf6, as he will regain the pawn after 3.bxc5 e5.

      [StartPly "3"]

      [FEN ""]
      1.c4 c5 2.b4 cxb4 (2...Nf6 3.bxc5 e5) 3.d4 (3.a3 e6) e6 4.e4 d5


What is the longest possible sequence of double checks?

I am pretty sure I could make this last longer, but here is already a sequence with 26 unforced consecutive double-checks without promoted pieces.

[FEN "8/8/8/Rp2p3/3Pk1N1/6pB/1Q2N2B/K3R3 w - - 0 1"]

1. Nc3+ Kxd4 2. Ne2+ Ke4 3. Nc3+ Kd4 4. Ne2+ Ke4 5. Nc3+ Kd4 6. Nxb5+ Kd5 7. Nc3+ Kd4 8. Nb5+ Kd5 9. Nc3+ Kd4 10. Ne2+ Ke4 11. Nxg3+ Kf4 12. Ne2+ Ke4 13. Nc3+ Kd4 14. Nb5+ Kd5 15. Nc3+ Kd4 16. Ne2+ Ke4 17. Ng3+ Kf4 18. Ne2+ Kf5 19. Nh6+ Ke4 20. Ng3+ Kf4 21. Ne2+ Ke4 22. Nc3+ Kd4 23. Nb5+ Kd5 24. Nc3+ Kd4 25. Nb5+ Kd5 26.Nc7+

12 forced double-checks, based on the scheme given by Hauke Reddmann in a comment:

[FEN "1RN5/5p2/7p/3P3p/2P3p1/QPk4N/1R1p1K2/BB6 w - - 0 1"]

1. Rc2 Kd3 2. Rc3 Kd4 3. Rd3 Ke4 4. Rd4 Ke5 5. Re4 Kf5 6. Re5 Kf6 7. Rf5 Kg6 8. Rf6 Kg7 9. Rg6 Kh7 10. Rg7 Kh8 11. Rh7 {11. Rg8} Kg8 12.Ne7


Advice for breaking Lichess's 2000 rating mark

"PhishMaster's Complete Guide To Improvement": What to study, and how.

Every player has times where they "plateau", and have trouble moving on, but they usually get past it eventually if they are continuing to study. Sometimes, it is a matter of patience.

Here is a set of comprehensive answers to questions I previously gave in various chunks, that are now combined, and will include how to break 2000.

First, this outline is more for the average player, who still may be very decent, but is not likely to be become a professional.

Beginners up to 1800, it is mostly about tactics: Tactics, tactics, and more tactics. I have found that even players, who are 2100, are not as strong at tactics as they think they are. I also found that having a very strong dose of endgames, even when I got my first rating of 1036 USCF back in 1980, has stuck with me all the way through being a Master. I still love Fine's "Basic Chess Endings" (any mistakes in it as far overshadowed by the principles that it puts forth).

For tactics, I actually recommend starting with Reinfeld's "1001 Brilliant Ways to Checkmate", and then "1001 Winning Chess Sacrifices and Combinations". I firmly believe in good groupings of themes in the beginning, rather than sites that totally randomize your study. I also firmly believe in immersion, in other words, doing a lot in a short period of time. It just sticks better as far as I am concerned.

I recommend doing 50 per day, spending no more than two minutes per move on each problem. In pencil, write down next to the problem how easy you found it on a scale of 1-5 because you will do these books multiple times. That immersion method has worked very well for me. I took a friend, who was about 38 at the time, from 1000 to 1850 on ICC in three months following this method.

Around 1800, people start getting more clued in on positional play, and start picking up more on that. I still love Ludek Pachman's trilogy: "Complete Chess Strategy". That was the first time I started to see real plans enter into my games, and I still credit that trilogy with making me a Master. For the first time, I started to really grasp pawn play.

Also, around 1800, I also think that players need to understand HOW to play opening pawn structures instead of focusing on memorizing openings that when their opponent deviates, they are lost and on their own. For this, books like Soltis' "Pawn Structure Chess" (a really bad book if you are looking at it with a computer, but the underlying principles are very strong), and Mauricio Flores Ríos' book "Chess Structures: A Grandmaster Guide" is a fantastic book that expounds upon what was in the Soltis book, and does it a lot better, but also at a higher level.

Starting at 2000, assuming you have a shot at 2200 and higher, you are going to start needing specific openings, and memorization as you face stronger competition. All along, you should have been still studying more and more endgame material as you will also need that when you face "monsters".

Over 2200, you are talking about in-depth refinement of what you have learned. A lot of people buy the Dvoretsky books before they are ready, and now is the time that you are just getting started to be ready for those. They will help with small details, and a lot of it above 2200 is analyzing better and better, so not only will his books refined and expand your knowledge, they are hand-picked difficult problems that need a lot of deep analysis.

Once at 2400, if you have not already had a professional coach, you probably will need one to really gain a lot more strength. In addition, if you have a kid, who is super talented, and clearly going places, it is also probably a good idea for them to have a professional coach at a lower rating, and younger age to get the most benefit.

Here is a list of areas of study, and what to read while doing them.

To help with basic visualization, read these books without a board, including sub-variations. If you are not sure how well you did, then put them on a board, and compare the board to your mind’s eye. In the beginning, I expect that you will have more on the board than not.
a.  “Combinations, the Heart of Chess” by Irving Chernev
b.  “1000 Best Short Games of Chess” by Irving Chernev (The games start short at only four moves, and gradually work up to 25 moves.)
c.  After these, you will still probably need work on visualization, so pick fun combination books to do in your head, concentrating on visualizing the final position rather than finding the solution. Solutions are in the next group.
To help with both basic visualization and tactical vision, do at least 25 problems per day, but preferably 50, spending no more than two minutes per move before looking at the answer. You will repeat these books at least twice over time. This alone, is why most players never get stronger…they drop pieces.
a.  “1001 Brilliant Ways to Checkmate”, 21st Century Edition by Fred Reinfeld
b.  “1001 Winning Chess Sacrifices and Combinations”, 21st Century Edition by Fred Reinfeld
c.  Continue with any of the multitude of tactics books or trainers out there doing as many as you can each day.
Endgame. Play all of these out on a board, not in your head.
a.  “100 Endgames You Must Know: Vital Lessons for Every Chess Player” by Jesus de la Villa (Try to memorize this book, especially rook endgames since they are the most common.)
b.  “The 100 Endgames You Must Know Workbook: Practical Endgame Exercises for Every Chess Player” by Jesus de la Villa
c.  “Basic Chess Endings” by Ruben Fine (Although there are mistakes that have been show by both humans and computers over the years, this book shows more about the plans and what you are striving for than most endgames books. Read all the sub-endgames since they reinforce the main endgames.
d.  “Dvoretsky’s Endgame Manual” (aka DEM. This is THE single greatest chess book ever written, in my opinion, and it is very advanced, but if you have reasonably mastered the above two books, this is the next step).
e.  “Tragicomedy in the Endgame: Instructive Mistakes of the Masters” by Mark Dvoretsky (This is, in essence, the workbook for DEM, giving practical positions of the material in DEM.)
Pawn Structures, and how to play chess, in general. A lot of chess is “what pawn break am I looking for, and how do I accomplish it?” These answer that in depth.
a.  “Complete Chess Strategy” volumes 1,2 and 3 by Ludek Pachman. (This teaches about many basic plans, and what you are striving for with your pieces and pawns, especially. THIS is what made me a master.)
b.  “Pawn Structure Chess” by Andy Soltis. (This extends the above to specific opening structures.)
c.  “Chess Structures: A Grandmaster Guide” by Mauricio Flores Rios (This is an extension of “Pawn Structure Chess”, and is deeper, and covers more structures. It is outstanding especially if you have already covered “Complete Chess Strategy”.)
Positional Chess. Play these out on a board and you will start to get a better feel for evaluating positions correctly.
a.  “Positional Chess Handbook” by Israel Gelfer (The quality of the printing in this book is not very good, but the content is excellent.)
b.  “Your Kingdom For My Horse” by Andy Soltis (This is all about exchanging, a little-covered, but incredibly important topic in chess. Frankly, Soltis is a LAZY writer, and when you read his books with a program running, you will find ALL KINDS of mistakes, but the prose, and general principles he is teaching are still valid, and in this case, hard to find in any other book. (There is a Russian-only book called "Encyclopedia of Exchanges" if you are capable of reading it.)

You will note that unlike the backpack of a typical 1200-player, there is not a single opening book listed here. That is because you are learning HOW to play chess, rather than memorizing lines that you get to the end of, and have no idea why you are there, or why it is good or bad. Most of your opponents, until you get to 2200, won’t know much about book, and you will both be on your own early on, so the one, who understands what you should be trying for, and who does not lose his pieces (tactics), will win the game most of the time.

In general, read the above list in order within any category, but you should have the visualization, tactics, endgame, and pawn structures categories all going at one time. As you start to really understand the structures more, then add in the last, “positional chess” category.


Trying to locate a historical game in which the win involves sacrificing two rooks

Could it be this game?

[FEN ""]
[Event "Living Chess Exhibition"]
[Site "Los Angeles, CA USA"]
[Date "1933"]
[Result "1-0"]
[White "Jose Raul Capablanca"]
[Black "Herman Steiner"]

1. e4 {From "Viaje al Reino del Ajedrez " de Y. Averbach et
al} e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 5. O-O O-O 6. d3 d6
7. Bg5 Bxc3 8. bxc3 Ne7 9. Nh4 c6 10. Bc4 Be6 11. Bxf6 gxf6
12. Bxe6 fxe6 13. Qg4+ Kf7 14. f4 Rg8 15. Qh5 Kg7 16. fxe5
dxe5 17. Rxf6 Kxf6 18. Rf1+ Nf5 19. Nxf5 exf5 20. Rxf5+ Ke7
21. Qf7+ Kd6 22. Rf6+ Kc5 23. Qb7 Qb6 24. Rxc6+ Qxc6 25. Qb4#
1-0

According to the comments on chessgames.com, this might have been a prearranged game.


Are there known opening gambit lines for black in the French defence?

There's the Poisoned Pawn variation of the Winawer:

[fen ""]

1. e4 e6
2. d4 d5
3. Nc3 Bb4
4. e5 c5
5. a3 Bxc3+
6. bxc3 Ne7
7. Qg4 Qc7
8. Qxg7 Rg8
9. Qxh7 cxd4

In general, though, it's hard to find a good pawn for Black to give away in the French.


What to do with no stronger players around?

If there are no stronger players convenient to you, and you don't want to use the technology available to play with stronger players further away, then you must go to where the stronger players are.

Organizations exist to do just this.  For instance the US Chess Federation has tournaments around the US throughout the year that allow players to meet and play together.

Check out the organizations that serve you and see what opportunities they offer.  Some will require extensive travel, but with time and patience you will find chess clubs and tournaments that are within driving distance.

Once you establish a relationship with such a club or organization, and specific players within it, you may find playing online more comfortable once you know the people you are playing against.  Sometimes the issue isn't the mechanism, but the distance and relative anonymity.


Positional motifs and training websites/softwares/apps?

I found a very useful guide to thinking about both positional and tactical situations in an online course offered by VisualWize, who make chess visualization training software.  You can find it here.

You might find the portion of the course on positional evaluation helpful.

There are both sections of content and exercises to practice what you've learned. I have not tried their other training courses, which go into this material in more depth, but this course struck me as comprehensive and effective.

I admit to using an amalgam of different methods that I've learned from
multiple sources, but this is the closest I can find to a comprehensive system.

You can also try a variety of chess training apps offered by ChessOK on the PC, and Chess King on Android (and probably Apple) - these are the same people, in two different markets.  On Android, their "Strategy" app offers a limited number of theoretical topics for free, plus a corresponding set of problems that cover Development, Space, Attack on the King, Attack on the Queenside, and Defense/Counterattack.  For a small charge (less than $10), you can buy the rest of the course, including 13 more topics in areas like: weak squares, positional sacrifices, hanging pawns, improving your pieces, pawn structure, open files and diagonals, etc.

Andrew Soltis wrote a good book on choosing a strategic move (well, any move) called How to Choose a Chess Move, in which he offered a short course in "priyomes", which are short plans to be used in certain types of positions to accomplish a short-term objective.  Unfortunately, there is no catalog of priyomes anywhere, since there 10's of thousands of them (apparently), but you get a good introduction to the concept.  Also, Mauricio Flores Rios' book, Chess Structures discusses quite a few openings, their tabiyas, and the types of plans each offers for both sides. That makes it a kind of catalog for priyomes for the openings.  These aren't software, but you can't always have everything...

Arthur Van De Oudeweetering has written an interesting book on 40 less well-known (but actually fairly frequently-occurring) priyomes that he has identified, which is called Improve Your Chess Pattern Recognition.  I'm working my way through that book, and adding the patterns to my pattern store, because they're surprisingly common (and effective).  He also does something I don't see often in chess training materials: he complements the normal "Do's" with some "Don'ts", pointing out some of the kinds of anomalies in the position that could render the pattern ineffective or even dangerous.

He has now published a sequel, called Train Your Chess Pattern Recognition.  I haven't seen this one, but I'd be surprised if it doesn't live up to the original. BTW: An Amazon reviewer has warned against buying the Kindle version of the 2nd book because the figurine characters don't render properly; the first book's Kindle edition is fine.


The 'From Position' variant seems to require that both sides have a king.  So, keep the kings on the board.  In particular, create a new game with a friend, select Variant: From Position, and paste '4k3/pppppppp/8/8/8/8/PPPPPPPP/4K3 w - - 0 1' into the field for the FEN text.

4k3/pppppppp/8/8/8/8/PPPPPPPP/4K3 w - - 0 1


Is a queen vs rook endgame always winning?

The best resource I know for endgame statistics remains the ICGA endgame stats. The spreadsheet posted there contains pretty much all endgames up to 6 men. So for example KQKR is found in row 27 (assuming White has KQ), with the following percentages:

       wtm    btm
W win 99.01 65.51
 draw  0.80  5.83
B win  0.19 28.65

So as long as White has the move, KQ is almost certain to win. Black victories with Black to move are likely due to be immediate capture or skewer. (Pin or fork of the queen leads at best to a draw, of course.)

Interesting to compare with KRBKR, row 107:

       wtm    btm
W win 41.25  5.09
 draw 58.70 94.06
B win  0.05  0.85

With White to move, Black does much better than in KQKR, which is curious since all that has happened is that the queen has been "unpacked" into its "constituent rook and bishop". With Black to move, the position is an almost certain draw: Black has lost the quick steals, but equally can protect himself from most of the situations where he might end up losing.

Note: (1) This is a tablebase based on computer analysis of all possible positions with up to 6 pieces. It does not refer to actual games played over the board. (2) The spreadsheet refers to "non-broken positions" which approximates to "legal positions".


What does double-check mean in four-player chess on chess.com?

Double Check in 4 man chess basically means  checking  two kings in one move.
Same goes for triple check.

PS. It's not worth the points so don't go for it unless you win because of it.


Why does Stockfish give "score mate -7" for this position?

Fist things first, I put the position into another chess program (Chessmaster, because I find it has the most reliable mate-search function) and told it to brute-force search for a mate. This is what it found:

So to answer one part of your question, no, there isn't a mate in 7 here.

That leaves the question of why you are getting the lines:

engine: info depth 32 seldepth 52 score mate -7 lowerbound nodes 3696286819 nps 6601691 time 559900 multipv 7 pv d8e7 a1c1 a8c8 c3e4 e6e5 d4d5 b7c5 d5d6 c5d3 d1d3 c8c1 e1d2 e7e6
engine: info depth 32 seldepth 52 score mate -7 nodes 3992249349 nps 6653549 time 600018 multipv 7 pv d8e7 a1c1 a8c8 c3e4 e6e5 d4d5 b7c5 d5d6 c5d3 d1d3 c8c1 e1d2 e7e6

I would suggest that the first of these is stating that as far as the engine has calculated, there is no mate in 7, hence the term lowerbound. The next line indicates that the engine is initiating a PV-search for a mate in 7.


The standard value for a piece that we learn early on (Queen=9 pawns, Rook=5 pawns, Bishop,Knight=3 pawns) is often a very good guidepost for people to make proper trades and find good tactical sequences. However, it should not be taken for granted that a rook will always be better than a bishop. Let's look at one extreme example:

       [fen "rn5k/3p4/p1pP4/PpP5/1P6/8/5B1P/7K w - - 0 1"]

       1.h4 {White wins by using the h-pawn as bait for the black king, and then infiltrate on black's queenside with the white king.} Kh7 2.Kg2 Kg6 3.Kf3 Kf5 4.Be3 Ra7 5.h5 Ra8 6.h6 Kg6 7.Ke4 Ra7 8.Ke5! {White places the king as close to the queenside as possible before sacrificing the h-pawn.} 8...Ra8 9.h7! {Luring the black king away from the defense of the f6 square.} 9...Kxh7 10.Kf6 Kg8 11.Ke7 Kg7 12.Kd8 Kf8 13.Kc8 Ke8 14.Kb7 Kd8 15.Kxa8 Kc8 16.Ka7 {Zugzwang! Black's king has to move, which means that the knight is lost.} Kd8 17.Kxb8 Ke8 18.Kb7 Kd8 19.Kxa6 Kc8 20.Ka7 Kd8 21.Kb8 {and white will win by promoting the a-pawn.}

Here white's bishop was stronger than black's rook and knight together, and it's not difficult to realize why; the knight was completely paralyzed, and the rook couldn't get out because of that. Black's pieces were nothing more than a couple of sitting ducks, so to speak.

In general, a piece is only good if it is performing some specific task on the chessboard, such as attacking weaknesses in the enemy camp or defending weak points in one's own camp. If the piece just sits on the edge of the board like a bystander (as in the example above) then it's totally worthless.

The rook is often a very good piece; since it's a long range piece, it can often attack and defend at the same time, and it can easily switch targets if there are many open ranks and files for the rook to move along. The same can be said about the bishop, using diagonals instead of rank and files, but the bishop has a clear disadvantage when compared with the rook: it can only influence squares of one color! Let's look at an example where the rook dominates the bishop, from Grischuk-Radjabov, Corus 2003:

    [fen "4k3/5R2/4K3/8/5p2/5P2/3b4/8 w - - 0 1"]

    1.Rc7! {White threatens checkmate in one move, which forces black's king to move.} 1...Kf8 (1...Kd8?? 2.Rd7+ {picks up the bishop for white.}) 2.Kf6 {Threatening mate in one move again. Note how white's rook covers c3 so that the bishop cannot check the white king.} 2...Ke8 (2...Kg8 3.Rg7+ Kf8 (3...Kh8? 4.Kg6 {and black is getting mated shortly.} 4...Bb4 5.Rc7 Kg8 6.Rc8+ Bf8 7.Ra8! {Zugzwang! Black's king has to move.} 7...Kh8 8.Rxf8#) 4.Rd7! {The white rook is hitting the black bishop, as well as it threatens mate in one yet again.} 4...Bc3+ 5.Kf5 {and white wins, since the black bishop is unable to defend the pawn on f4 due to the white rook covering the d2 square.}) 3.Re7+ Kd8 4.Re4! {White's rook cuts off the black king from the kingside, and therefore Radjabov decided it was time to resign in this position.} (4.Re4 Kd7 {For the sake of completeness, this is how white wins if black plays on:} 5.Kf5 Kd6 6.Rxf4! Bxf4 7.Kxf4 Ke6 8.Kg5! {and white has achieved a well known winning pawn ending.})1-0

In this example we saw that the rook can make multiple threats at the same time and take away squares from the bishop. This because the rook had many open ranks and files to work on, which made switching targets very easy to accomplish for the rook. If the rook is tied down and restricted, it becomes way less impressive, as can be clearly seen in the following example:

   [fen "1r6/2p1p1k1/p1B1P1p1/Pp3pPp/1P3P1P/2P5/5K2/8 w - - 0 1"]

   1.Ke3 Rd8 2.Bd7 {White doesn't let black get any activity whatsoever.} 2...Kf8 3.Kd4 Rb8 {There isn't much black can do.} (3...Rxd7+ 4.exd7 e5+ 5.fxe5 Ke7 6.e6 {is just a lost pawn ending.}) 4.Kc5 Ra8 5.Kd5! {Of course there are other ways to win, such as breaking with the c3 pawn to create a passer, but this nice use of zugzwang forces black to give up the c7 pawn without a fight.} 5...Ra7 6.Kc6 {and black's king has to move away from the e8 square due to zugzwang.} 6...Kg7 7.Bc8 Kf8 8.Bb7 Ke8 {Black's king can't get to d8 in time to defend c7.} 9.Kxc7 {and black will lose everything.}

Here black has an open file for the rook, but the rook is kind of dominated by the extremely influential bishop on c6, who can block the rook's path whenever black plays ...Rd8 by placing itself on d7, while at the same time keeping the black king imprisoned on the kingside. White wins by walking the king up the board to attack the weak pawn on c7, and there is little black can do about it besides watch in horror as the position starts to crumble.

Edit: I finally managed to think of an improved example of a bishop being stronger than a rook.


Are there any (free) games databases out there?

There is a pretty big one if you are willing to spend some 40 euro.

This (Million Base 2.2) is the biggest free database I know of.


please check Ekanayake E M Anindu Rehan Fide ID is 29909279

OK, so this is your playing record -

2017-10
1754    0
1155    0
1371    0

2017-11
1112    0

2018-04 (1018)
1286    0
1079    0
1018    1
1318    0
1067    1
1090    0

2018-05 (1018 - 25.2 -> 0)
1418    0
1332    0
1221    0
1292    0

2018-10
1352    0
1255    0
1174    0

2018-11
1288    0
1315    1
1153    0

2019-02
1227    0
1334    0.5

Let's go back and check the FIDE rating regulations.

  6.1 If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded.
  Otherwise if an unrated player has played rated games, then this
  result is included in computing his overall rating.

In your first two tournaments you scored zero points so these are not used in any rating calculations.

You got your first rating of 1018 in the April 2018 list after a tournament in the previous month. Let's see how the calculation works. First the relevant parts of rating regulations:

  8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
  8.21 If an unrated player scores zero in his first event his score is disregarded.    First determine the average rating of his competition
  'Rc'.
  (a) In a Swiss or Team tournament: this is simply the average
  rating of his opponents.    ...
  8.24 If he scores less than 50% in a Swiss or team tournament:  Ru = Ra + dp

2018-04 (1018)
1286    0
1079    0
1018    1
1318    0
1067    1
1090    0
Sum of opponents' ratings = 6858
Average of opponents' ratings = Rc = 6858 / 6 = 1143
You scored 2/6 which is 33%. Hence:
Fractional score = p = .33,
Then I look up in table 8.1a from the rating regulations to find 'dp'
dp = -125 so new rating = 1143 - 125 = 1018

Now if we repeat the calculation for what your current rating would be we again throw away the first two tournaments (2017-10 and 2017-11) and use all the tournaments since then.

We get:
Total sum of opponents' ratings = 6858 + 5263 + 3781 + 3756 + 2561 = 22219
Total games = 18
Rc = 22219 / 18 = 1234.39
p = 3.5/18 x 100 = 19.4%
dp = -251 (looking up in table 8.1a for p=0.19)
So new rating = 1234.39 - 251 = 983.39

This is less than 1000 so you are recorded as unrated.

If your fractional score had been 0.21 (i.e. you scored 4 / 18) then dp according to table 8.1a would be -230.4 and you would have had a rating of 1004.

So, basically you fell short by one draw. If you continue winning one game in three against similar opposition then you should make it.


Stalemate situation with all pieces on the board

Here is an example of a 12-move game after which White (to move) is stalemated. All 32 units (pieces and pawns) are still on the board. The original version of this concept game was created by Charles Henry Wheeler, and published in Sunny South in 1887, according to Edward Winter's C.N. 3679. Samuel Loyd is often, and wrongly, given credit.

[Title ""]
[StartFlipped "0"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.d4 e5 2.Qd2 e4 3.Qf4 f5 4.h3 Bb4+ 5.Nd2 d6 6.Qh2 Be6 7.a4 Qh4 8.Ra3 c5 9.Rg3 f4 10.f3 Bb3 11.d5 Ba5 12.c4 e3 1/2-1/2


It would help to see a specific example of your games.

Normally closed positions refers to positions with a closed center where the central (e and d pawns, sometimes also c and f pawns) pawns are blocking each other. It is unusual that all 8 pawns are blocked. In this case the normal plan is to attack the center by pawns from the side. For instance in the advance French black is attacking the center by a pawn from c5 and later also from the other side with f7-f6.

[FEN ""]
1. e4 e6 2. d4 d5 3. e5 c5

The technical term for this is pawn break and you can see other examples in the wikipedia article on pawn structure. (Search for "break").


What are some main lines of the Horwitz Defense (d4 e6) besides the French?

Basically, you have a lot of options left to transpose into other openings. I remember having read a book calling this opening the Franco-Indian for this very reason. I do not expect that many White players will actually play 2. e4; they played 1. d4 for a reason and are usually not experts in the French opening.

After 2. c4, you can:

transpose to the Orthodox Queen's Gambit with 2... d5
transpose to the Dutch opening with 2... f5 (but you lose the ability to play the Leningrad system)
transpose to the Nimzo-/Queen's Indian with 2... Nf6
transpose to the Benoni with 2... c5 (thanks @user1583209)
2... Bb4+ is about the only independent line.

2. Nf3 (and to a lesser extent, 2. g3) offer similar transpositional options.


What are techniques to improve the number of moves thought through in advance?

A very common approach is to work backwards. Instead of studying openings first, followed by the middlegame and the endgame, you study endgames first. Once you know some endgame positions, it may be sufficient to calculate only three moves deep in a late middlegame position, because you know that the resulting endgame is won for you.

Let's consider a position were you have a pawn, king and queen vs. your opponent's king and queen. You have the option to exchange queens and leave black's king too far away to stop your passed pawn. It takes you three more moves to promote that pawn and now you know that K + Q vs. K is easily winning, although it may take another 10 moves. Thus, you just saw 14 moves in advance by going from one position (K + Q + P vs. K + Q) to another (K + P vs. K) and then to a won K + Q vs. K endgame.

This is of course a very basic example, but the point is that grandmasters do not really calculate 30 moves ahead. They just know that the given position transforms into another, which leads to a won endgame. The more positions and the more patterns you know, the better you get at calculating. This might help you to improve that skill:

Learn the most basic endgames
Learn essential checkmate patterns
Learn tactical motifs and patterns
Play games and go over them afterwards

Those "shortcuts" should lead to fast improvement. After you did the above things (or while doing so) it might also be a good idea to practice your visualization. Try to say whether a given square is black or white, whether a given position is checkmate or whether a knight can reach some squares within one move. Furthermore, you should always imagine a combination in your head after a game. Try to move the pieces without touching them in reality and try to picture the position after some moves. A nice program to practice visualization is the freeware "Chess Training Tools". You might want to check that out. An interesting website to learn tactics is http://www.chesstactics.org/. It offers many examples and great explanations.


How to challenge a queen with a bishop pair in endgame?

This is one of the well known endgames and the side with the queen almost always (92% positions) wins, although some wins take more than 50 moves with perfect play.

See the solution for your position here by entering your position into the diagram.

I must point out that every move has been taken into account and every possible continuation has been explored.

I forgot to answer part of your question about challenging the queen:

with best play side with the bishop loses most of the time, as stated above;
side with the bishops can never win, due to reasons user ETD pointed out in his comment;
in order to defend vs queen, use bishops to create barrier for the enemy king; keep them close to your king in order to be safe from double attacks queen can make.

It is worth noting, that the position shifted down by one row is a fortress setup and black draws. The setup is known as the Lolli position.

8/6k1/5bb1/8/2Q5/8/3K4/8 w - - 0 1


Why is taking notes that encourage oneself illegal in chess?

I can't claim to know for sure what was going through the minds of the authors of the FIDE Laws of Chess, but I think the intent is to ensure that the players use only their unaided intellect to play the game.  Players aren't allowed to make/use written notes during the game.  At all.  About anything (chess-related or not).  If they're allowed to make notes about things other than chess, or the game in progress, you then put an arbiter in the position of having to determine if such notes are chess-related or not.  It would certainly be possible for a player determined to cheat to come up with a system in advance to disguise the nature of what they're writing.

It's worth pointing out that So wasn't forfeited for making the notes - he was forfeited because of rule 11.7 - "Persistent refusal by a player to comply with the Laws of Chess shall be penalised by loss of the game".  He had been warned twice before during the tournament that he wasn't permitted to make written notes, and the second time was warned that a third infraction would result in a forfeit.


Can K + N vs K force black into any corner?

I am not aware of being able to use an engine to calculate the possibility of such moves and no it is not possible to do this with one knight.

The easiest way to figure this out is by backtracking the position by one or two moves. No matter in which position the white king or knight were before this situation arose, black was not obligated to move to the corner of the board.

1k6/8/K2N4/8/8/8/8/8 w - - 0 0

black can move to C7

8/k7/2KN4/8/8/8/8/8 w - - 0 1

black can move to A6

8/k1K5/3N4/8/8/8/8/8 w - - 0 1

black can move to A6 here as well

2k5/8/1K6/1N6/8/8/8/8 w - - 0 1

And Regardless of the position of the Knight the black king has a square on D8 to go to.

The only way to actually get this done is if the king was in the corner to begin with:

k7/8/1K6/1N6/8/8/8/8 w - - 0 1


Any online site with limited number of games per day like chess.com or chess24

I have heard others make the same complaint and a friend decided to use the Makua software which will limit your computer time.  There is probably other software that does the same, mostly for parents to limit their kids but you can use it on yourself.


There is a comprehensive list on Tim Krabbé's page The Ultimate Blunder.


If elite players prefer to play short draws in knockout competitions, why not skip them and go straight to tiebreaks?

It is because there are tournament regulations, including the format, which are published before the tournament starts. You cannot really change that after a certain point, like players accepting invitations.. In addition, although certain players are amenable to draw because they believe they are better at faster time controls, by FIDE rules, they cannot technically agree to a draw before the game starts.

Also, they might sit down at the board, and play some moves to see if they actually like how the game has started, and actually press on if they like what the see.

I think that what you are asking, if they tried to do it, it might be more complex in practice, and might also have unforeseen consequences, since everyone should play be the same rules. You cannot really have some players playing it, and others opting out since everyone should play the same tournament. Nevertheless, they could change the pre-tournament regulations and try it to find out if it works.


It's a draw.  FIDE rule 6.9 states (emphasis mine):

  Except where one of Articles 5.1.1, 5.1.2, 5.2.1, 5.2.2, 5.2.3 applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

Since the player with the bare king cannot checkmate the opponent by any legal sequence of moves, the game is drawn if his opponent runs out of time.


Why doesn't my transposition table improve my move calculation time?

Let's give a try:

Are you sure your fen() is correct? Don't assume, check how many times your TB table is being used. If the fen() is bugged, your TB would never be used. A possibility is that you add halfmove clock and fullmove number into FEN (please check).
Please note the fen() function is very slow. Your line minimaxDict[game.fen() + ' [ ' + depth + ' maximizing ]'] is wrong, because you are asking the computer to compute the FEN position twice. It's important to note computing an FEN position can only be done by looping through the whole board (64 squares). Everytime when we read a square, we must append a character to the existing (possibly immutable) memory array. Appending a character to memory is a super slow operation, because the computer might need to allocate new memory. Please ask on Stackoverflow if you want clarification. This is a very serious issue. Your TB implementation is meaningless unless you're sure fen() is fast, and no reallocation complexity.
Please note a much better implementation is zobrist hashing. Why wouldn't you use it?
Please check, double-check and triple-check if your TB is being used. Are you sure if (minimaxDict[game.fen() + ' [ ' + depth + ' maximizing ]']) is true? Anything could happen in a program.
How many times your TB value was returned in the search? 1%? 2%? Do you have a number?
Your TB has the depth information and min/max. I've never done it myself like this. Are you sure it makes sense?


Since no one has managed to solve this problem entirely, here is the answer. Credit goes to @NoseKnowsAll and @Scrounged in the comments for identifying the mechanism White uses to force the reset. This answer merely shows how White can avoid a perpetual check by Black.
[Title "Geir Sune Tallaksen Østmoe, MatPlus.net Forum 8/14/2013, White To Move"]
[FEN "1K6/2p5/p5pr/q2k3n/P1pPp1rP/1pP1PpPR/1P3P1B/3N3N w - - 0 1"]

1. Kc8 Rh8+ 2. Kd7 Rh7+ 3. Ke8 Rh8+ 4. Kf7 Rh7+ 5. Kg8 Nf6+ 6. Kf8 Nd7+ 7. Ke8 Nf6+ 8. Kd8 Nh5 9. Bg1 Rh8+ 10. Kd7 Rh7+ 11. Ke8 Rh8+ 12. Kf7 Rh7+ 13. Kg8 Nf6+ 14. Kf8 Nd7+ 15. Ke8 Nf6+ 16. Kd8 Nh5 17. Rh2 Rh8+ 18. Kd7 Rh7+ 19. Ke8 Rh8+ 20. Kf7 Rh7+ 21. Kg8 Nf6+ 22. Kf8 Nd7+ 23. Ke8 Nf6+ 24. Kd8 Nh5 25. Rg2 Rh8+ 26. Kd7 Rh7+ 27. Ke8 Rh8+ 28. Kf7 Rh7+ 29. Kg8 Nf6+ 30. Kf8 Nd7+ 31. Ke8 Nf6+ 32. Kd8 Nh5 33. Bh2 Rh8+ 34. Kd7 Rh7+ 35. Ke8 Rh8+ 36. Kf7 Rh7+ 37. Kg8 Nf6+ 38. Kf8 Nd7+ 39. Ke8 Nf6+ 40. Kd8 Nh5 41. Rg1 Rh8+ 42. Kd7 Rh7+ 43. Ke8 Rh8+ 44. Kf7 Rh7+ 45. Kg8 Nf6+ 46. Kf8 Nd7+ 47. Ke8 Nf6+ 48. Kd8 Nh5 49. Re1 Rh8+ 50. Kd7 Rh7+ 51. Ke8 Rh8+ 52. Kf7 Rh7+ 53. Kg8 Nf6+ 54. Kf8 Nd7+ 55. Ke8 Nf6+ 56. Kd8 Nh5 57. Re2 Rh8+ 58. Kd7 Rh7+ 59. Ke8 Rh8+ 60. Kf7 Rh7+ 61. Kg8 Nf6+ 62. Kf8 Nd7+ 63. Ke8 Nf6+ 64. Kd8 Nh5 65. Rc2 Rh8+ 66. Kd7 Rh7+ 67. Ke8 Rh8+ 68. Kf7 Rh7+ 69. Kg8 Nf6+ 70. Kf8 Nd7+ 71. Ke8 Nf6+ 72. Kd8 Nh5 73. Rc1 Rh8+ 74. Kd7 Rh7+ 75. Ke8 Rh8+ 76. Kf7 Rh7+ 77. Kg8 Nf6+ 78. Kf8 Nd7+ 79. Ke8 Nf6+ 80. Kd8 Nh5 81. Ra1 Rh8+ 82. Kd7 Rh7+ 83. Ke8 Rh8+ 84. Kf7 Rh7+ 85. Kg8 Nf6+ 86. Kf8 Nd7+ 87. Ke8 Nf6+ 88. Kd8 Nh5 89. Ra3 Rh8+ 90. Kd7 Rh7+ 91. Ke8 Rh8+ 92. Kf7 Rh7+ 93. Kg8 Nf6+ 94. Kf8 Nd7+ 95. Ke8 Nf6+ 96. Kd8 Rh8+ 97. Ke7 Ng8+ 98. Kf7 Nh6+ 99. Kg7 Rg8+ 100. Kxh6


White have an advantage with the first move

It really depends on what level of chess you're looking at. At the amateur level (<2200), I would hypothesize that white's supposed "first-move advantage" is relatively insignificant. However, it's quite evident at the higher levels that white has an advantage when playing mainstream openings - please reference the Shredder Opening Database for the details of individual moves. For example, out of the 242,221 Grandmaster games where White has played 1. e4, he has scored 54.5%.

Chess players and theorists generally agree that White has a certain first-move advantage. The page on Wikipedia is certainly a fascinating read.


There were a select of games published played between AlphaZero and Stockfish 8, see e.g. here on chess24. Some of them were played without book and some with the TCEC opening book, which I reckon led to a bigger likelihood for the QGD to occur.

Considering that QGD itself is an opening for black, how frequently they occurred in AlphaZero's games playing the white side is mostly dependent on how compliant Stockfish was to playing such systems. As it happened and whether it was directly or by transposition, QGD structures did occur a few times, at least among the ones I can recall/find at the moment, which I will share below along with some other closely related lines that can potentially be of interest to you. Otherwise, and in particular when without a book, Stockfish seemed to favour lines more along Nimzo-Indian and Queen's Indian defense.

Since the games tended to be quite long, I will only include a portion of the starting moves of the games and provide a direct link to each game so you can study the games in their entirety on your own.

With TCEC openings:

Game 82 QGD Vienna variation, from move 7 off-book:

 [title "TCEC openings, game 82, AlphaZero vs Stockfish 8 (draw)"]
 [fen ""]

 1.d4 e6 2.c4 d5 3.Nc3 Nf6 4.Nf3 dxc4 5.e4 Bb4 6.Bg5 b5 7.a4 c5 8.axb5 cxd4 9.Bxf6 Qxf6 10.Qxd4 Qxd4 11.Nxd4 Bc5 12.Nf3

Game 85 QGD Harrwitz Attack, from move 11 off-book:

 [title "TCEC openings, game 85, AlphaZero vs Stockfish 8 (draw)"]
 [fen ""]

 1.d4 e6 2.c4 d5 3.Nc3 Nf6 4.Nf3 Be7 5.Bf4 O-O 6.e3 c5 7.dxc5 Bxc5 8.a3 Nc6 9.Qc2 Qa5 10.O-O-O Be7 11.h4 a6 12.Kb1 Rd8 13.g4 dxc4 14.Rxd8+ Bxd8 15.Bxc4 Nxg4 16.Rg1 Nf6 17.Ng5 g6 18.Bd3 e5 19.h5 exf4 20.Qb3 Qc7 21.hxg6 hxg6 22.Bxg6 Kf8 23.Bxf7 Bf5 24.Ka2

Game 1, Semi-Slav (nearly QGD) mainline, Semi-Slav lines are always closely related to both Slav and QGD due to the rich transpositional lines that exist between them. From move ...12 off-book:

 [title "TCEC openings, game 1, AlphaZero vs Stockfish 8 (1-0)"]
 [fen ""]

 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.e3 Nbd7 6.Qc2 Bd6 7.g4 Bb4 8.Bd2 Qe7 9.Rg1 Bxc3 10.Bxc3 Ne4 11.O-O-O O-O 12.Be1 b6 13.h4 Bb7 14.Ng5 Nxg5 15.hxg5 Qxg5 16.f4 Qe7 17.Kb1 c5 18.Bd3 g6 19.cxd5 cxd4 20.e4 Rac8 21.Qh2 f6 22.f5 exd5 23.fxg6 hxg6 24.Rh1 Qg7 25.Bc2 Ne5 26.Bb3

Without book:

Game 15, Semi-Slav (nearly QGD):

 [title "Without opening books: game 15, AlphaZero vs Stockfish 8 (1-0)"]
 [fen ""]

 1.Nf3 Nf6 2.d4 d5 3.c4 e6 4.Nc3 c6 5.Bg5 h6 6.Bh4 dxc4 7.e4 g5 8.Bg3 b5 9.h4 g4 10.Ne5 Nbd7 11.Be2 Nxe5 12.Bxe5 Rg8 13.O-O Bb7 14.Re1 a6 15.g3 h5 16.Qc2

The list is by no means exhaustive, you might find more examples by browsing through all the available games.


Your summary of the rules left out an important one, namely, how else can you win a game besides being stalemated. The answer is that the player who runs out of men wins. (I suppose you could consider having no men to move a kind of stalemate.) And "antichess" is a new name for the chess variant traditionally known as Losing Chess or Giveaway Chess.

The answer to your question is that, when a pawn reaches the 8th rank, the owner of the pawn decides what to promote it to. I have looked at several books on chess variants, and haven't found a clear statement on that point. Apparently, it never occurred to the writers that anyone would think that the opponent gets to choose the promotion rank.

The rules for Losing Chess at The Chess Variant Pages (surely a more authoritative source than Wikipedia) do not say anything about the opponent choosing the promotion rank of a promoted pawn. Some of the endgame studies in John Beasley's article involve pawn promotion, and it's clear that the owner of the pawn is doing the choosing. Here's one from Hans Klüver (Chess Amateur 1923):

[FEN "8/P6/8/k7/P7/8/8/8 - - - 0 0 "]

Losing Chess. White to play and "win".

The solution:

  1.a8N! Kxa4 2.Nb6 any 3.Na4 Kxa4

Of course if Black controlled the promotion he would choose a queen or rook.


Plans for black in Pirc when white responds to e5 with d5

Engines don't like philosophy behind KID and if they are forced to play KID, they play c6 there all day long too. Here it's quite similar. You can play for both plans but I see nothing wrong with the f5 ideas. It seems to be much better version of main line KID.


I think the term 'intersect' is not really intuitive here.
From c2, the white king can go to d2 and c3 in one move.
That means the black king must find a square from which it can reach f3 and e3 in one move. That square is f4; this would be true for e2 and f2 as well, but then the black king is outside the pawn's square and it can run to promotion.
It doesn't matter that it's not the same geometrical shape on the chessboard. (Actually, it is the same geometrical shape if you switch to the Chebyshev distance metric, but I digress.)


How do I keep my bishop pair in this Ruy Lopez line?

In that position, you can't keep your bishop pair if Black wishes to take your Bishop. Acording to Modern Chess Openings, with this variant Black throws away the White Bishop by ceding the initiative in the center. In the recomended continuations, White has an advantage (+/=) and White must proceed to an inmediate attack:

[Event "Analysis"]
[Site "Ruy Lopez"]
[Date "2020.04.11"]
[Round "?"]
[White "Player"]
[Black "Oponent"]
[Result "*"]
[FEN ""]
[StartPly "10"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5 5.Bb3 Na5 6.O-O d6 7.d4 Nxb3
    ( 7...exd4 8.Nxd4 Bb7 9.Bd2 Nxb3 10.Nxb3 Nf6 11.Re1 Be7 12.Na5 Rb8 $14
    {Smagin - Kupreichik, Minsk 1985.} )
8.axb3 f6 9.Nh4 Ne7 10.f4 exd4 $5
    {It is a possible improvement.}
    ( 10...Bb7 11.d5 c6 12.c4 exf4 $14 {Arnason - Agdestein, Gausdal 1987.
    } )
11.Qxd4 Bb7 12.Nc3 $10
    {1/2-1/2(64) Alves, Lair Valio - Petters Merino, Oscar Augusto / CLEA4
    B07 email, CADAP Email 2000.}
*


Making an inferior move to get out of threefold repetition?

Could this theoretically go on forever in a game with time increment?

No, because the arbiter would step in and declare the game drawn after the fifth repetition of the position.

According to the FIDE Laws of Chess -

  9.6 If one or both of the following occur(s) then the game is drawn:
  9.6.1 the same position has appeared, as in 9.2.2 at least five times.

and -

  9.2.1 The game is drawn, upon a correct claim by a player having the move, when the same position for at least the third time (not
  necessarily by a repetition of moves):
  9.2.1.1 is about to appear, if he first writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his
  intention to make this move, or
  9.2.1.2 has just appeared, and the player claiming the draw has the move.


What are the benefits of becoming a chess (player, team or tournament) sponsor?

How about this benefit?

  It is probably well known that Magnus Carlsen is sponsored by Arctic
  Securities.

Being well known is the benefit. One minute ago I had not even heard about arctic securities. And now I know, as well as may be thousand of other people watching/reading about the game. Why Vodaphone or whatever is sponsoring football? Do they care, do they have any connection to football? - No.

The idea behind sponsorship is always the same - let people know about you or see your sign.

Answer to Rauan's comment:

I do not want to disappoint you, but there is nothing unique about sponsorship in chess. In business all that matters is money / revenue / stock prices / public awareness.

Why did IBM gave half a million in 1996 to Kasparov for a match with a machine? They did not care about chess, they cared about advertising and stock market price. That's why they cared so much about the rematch in 1997 giving $1.1M for it and offering $0.7M to a winner. Not a lot of chess players who know about the matches, know how this ended up for IBM

  IBM estimated it received $500 million of free publicity from the
  match, and IBM stock prices went up over $10 to reach a new high for
  the company.

I think this is one of the best money investments.


My own experience (from high school, decades ago), is that balanced teams do better. That's because most opposing teams are unbalanced.

I was first board on my team, and "league average" against other first boards.

But my lower boards were barely worse than me. They "cleaned up" against their counterparts, few of whom were "barely" weaker than me.

Hopefully your first board will get you a "random" result, and the lower boards will prevail against their opponents.


How would top grandmasters fare against engines in correspondence chess?

short answer: the computer would still win

long answer: a human player has much more time to think, well. but a chess-computerprogram would also have much more time to calculate much more variants. (and every good "classical" chess-computerprogram would use this time to evaluate as many variants as deep as possible). so the skill-difference would become linear bigger whilst you give them more time to think (assuming the players can use this time really prolific productively). the limits will be reached for a human when he wants to think deeper about more variants. for computers the limits a much broader because a computer would never be confused when it analyzes millions of positions.


Planning in the endgame (this is what I seek on endgames)

Here is a breakdown of the different imbalances and what you should aim for:

Material (owning pieces of greater value than the opponent's);
Space (the annexation of territory on a chess board);
Superior Minor Piece (the interplay between Bishops and Knights);
Pawn Structure (a broad subject that encompasses doubled pawns,
isolated pawns, etc.);
Control of a key file or square (files and diagonals act as pathways
for your pieces, while squares act as outposts);
Lead in development (more force in a specific area of the board);
Initiative (dictating the tempo of a game).

If we are to use these things properly we must be able to break down our thinking in a way that allows us to dissect any particular position.

Here are the stages of my thinking technique that enables us to accomplish this:

Figure out the positive and negative imbalances for both sides;
Figure out the side of the board you wish to play on. You can only
play where a favorable imbalance or the possibility of creating a
favorable imbalance exists;
Don't calculate! Instead, dream up various fantasy positions, i.e.,
the positions you would most like to achieve;
Once you find a fantasy position that makes you happy, you must
figure out if you can reach it. If you find that your choice was not
possible to achieve, you must create another dream position easier
to achieve;
Only now you will look at the moves you wish to calculate (called
candidate moves). The candidate moves are all the moves that lead to
our dream position.


Against the Slow Slav, after 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. e3, is the 4... a6 Chebanenko still good for Black?

I am by no means an openings expert, but I have played the Slow Slav as White for a long time so I will just make some comments.

In general, lines with an early b7-b5 in Chebanenko positions tend to work better with a Nc3 than a Nd2.  As you have already noted, a Nd2 makes it much more likely that White will be able to find some way to exploit the holes on Black's queenside (particularly c5, a5, and c6, often exploited by a well-timed a2-a4) created by an early b7-b5.  Positions with b7-b5 and Nb1-d2 are not necessarily very good for White, but they do seem to give a better chance of White gaining a small advantage than the main lines, and a small advantage is usually the best that White can hope for against the Chebanenko these days.  Positions with a Nc3 make it much more difficult for White to exploit the holes Black makes on the queenside with b7-b5, and give Black more dynamic compensation for such holes due to the possibility in many lines of a well-timed b5-b4, forcing the Nc3 to an awkward square.

Since an eventual b7-b5 is the general idea behind a7-a6, I always respond to 4...a6 by playing Nb1-d2 (either right away, or more commonly a little later after Bf1-d3). This is probably White's best try for an advantage in these lines. If Black goes ahead and plays b7-b5 anyways, I generally get the kind of position I want, which I would describe as lightly +=.

However, if Black refrains from playing a quick b7-b5 and plays something like an immediate Bc8-g4 (say, after 4...a6 5.Bd3), he still has a very solid Slav position in which the "wasted" move a7-a6 is compensated for by the fact that d2 is not an ideal square for the White N in lines where Black does not play b7-b5 (that is, because it removes some of the pressure from d5 and because in some variations the Nd2 can also get in the way of the Nf3).  Typically, in positions with a strong center like this (pawns at c4/d4/e3), White would prefer his Ns on the most active squares, c3 and f3, where they simultaneously pressure Black's center and support possible pawn advances by White.  So the move Nbd2 after a7-a6 may also be viewed as a kind concession.

I like to look at the exchange as a kind of exercise in prophylaxis: Black plays a7-a6 as prophylaxis against White's ideal set-up in the center with Nc3; White then plays Nb1-d2 (or just refrains for committing the N to c3 for a while) as prophylaxis against Black's idea of b7-b5.  Black, having now discouraged White from playing his ideal set-up with the N on c3 (I use the word "discouraged" very loosely here because positions with Nc3 and b7-b5 are fully playable for White), then plays Bc8-g4 with the idea that this set-up is even better after the exchange of a7-a6 and Nb1-d2, because a7-a6 does not hurt Black and the Nd2 is slightly misplaced.  White is not entirely convinced of this last point, because Nd2 is at least a developing move, while a7-a6 is not.  And so the discussion continues, with White trying to find lines in which his Nbd2 is actually useful.

As far as I know, there is no clear way to an advantage for White in lines with the Nbd2/Bd3 set-up against a7-a6, but the play is different and less forcing that the positions with a Nc3.  Having played many games with this set-up and a number of games with the main line Slow Slav positions (that is, with an immediate Bc8-f5 or Bc8-g4 instead of a7-a6), I would evaluate both set-ups as roughly the same: +=/=.  They are very slightly easier to play for White, but White has no significant advantage if Black knows what he/she is doing.

The upshot of all this is that 4...a7-a6 appears to be fine against the Slow Slav set-up as long as Black refrains from an early b7-b5 before White commits his N to c3.  In such positions, the move a7-a6 once again proves to be a high-class waiting move, with a dollop of added prophylaxis.


What's the benefit of using books during correspondence games?

What you get from the books/databases during your correspondece games is the same as what you get when you read them generally. You can make use of

Opening lines, which become more important as the games get slower and slower
Tactics, which you may encounter during your games
Positional concepts and maneuvers, which play the most important part of a correspondence game
Endgames, though usually tablebases (7-man) are allowed in correspondence games.

All of these (not including tablebases) are allowed because they are simply undiscoverable in a cheating investigation (for example, you can expect perfect opening play from any player), as well as to help you, as you stated.