I think one of the best books on the subject has been written by Rogozenko.

The Sveshnikov Reloaded explains the ideas very well with plenty of textual analysis and not only pages of long variations with only Informant type evaluation symbols. I have the book at home (even though I mainly play Najdorf and accelerated Dragon Sicilians), and I remember that one of things that pleases me most in this book is Rogozenko's clear explanations of the subtleties of move order tricks.

The first edition is a bit outdated and might run into refutations, especially in the tactical lines (such as the bishop sacrifice line). But if I am not mistaken there is a "recent" (2012?) second edition.

It is the Quality Chess edition. According to me, one of the best editing houses around.


Coordinate-style move output from chess engine, to control robot

I don't know how you would do that in gnuchess, but you could do little programming yourself in Python. This Python package would do that for you. It's main page has what you want:

>>> board.push_san("e4")
Move.from_uci('e2e4')
>>> board.push_san("e5")
Move.from_uci('e7e5')

You have the move string and chess board. It shouldn't be hard for you.


What is the optimal way to use Stockfish programmatically?

I think you're talking about how to fork a process for the engine and how to use it for the UCI protocol.

What you need to do is:

Fork a new child process for the Stockfish engine
Send and receive UCI commands to/from the engine
Parse the UCI commands yourself

Do you want to study existing source code? Look at:

http://talkchess.com/forum/viewtopic.php?t=57770

Download Chess Game Analyzer, it's a simple Python script for automatic annotation.

When you have the source code, look at the the following:

 p = subprocess.Popen(engineName, stdin=subprocess.PIPE,
                     stdout=subprocess.PIPE,
                     stderr=subprocess.STDOUT)

This line creates a new process for the engine, where engineName is the path of the engine executive.

p.stdin.write("uci\n")

This line sends the uci command to the engine.

for eline in iter(p.stdout.readline, '')

This line parses a UCI response.


White has to be precise, but I consider this position won.
The general plan Rd7 to prevent the bishop from reaching d4, bring the king to the center (net part of the plan, but this is always a good general plan and tends to restrict black's king), then find a path to get the knight to either b5 or b6.  Keeping in mind to not exchange too many pawns or to allow a perpetual, white should (IMO) easily win.


What is the farthest away a game can be from a guaranteed checkmate?

I doubt that anyone will be able to give you a definitive answer beyond this one, but the longest known win from the end of a game is a famous 549-move 7-piece tablebase win. Until we get to 8-piece tablebases, this is probably the longest anyone can prove.

You can see that position, and all 549 moves here.


I'm happy when I have a passed pawn, and my opponent has none. Yet, connected passed pawns are much better than isolated passed pawns.

Here are the raw advantages of a passed pawn:

A passed pawn can no more be exchanged against a pawn, so if it gets exchanged, it will be against something bigger.
If a passed pawn is defended by a non-passed pawn, and the opponent decides to exchange a minor piece against your passed pawn, the defending pawn becomes a passed pawn in turn, keeping your passed pawn advantage, in addition to gaining material. It makes it a little more difficult for the opponent to actually do this.

Still, there are caveats with regards to an isolated passed pawn:

Since your passed pawn can't be defended by another pawn, you'll have to mobilize something bigger to defend it. (leaving less material to act on the issues of the rest of the board)

But:

If you can have a rook defending your passed pawn from behind, you have one less rook on the rest of the board, but you can easily threaten to gain material by appropriately pushing your pawn.
If your opponent decides to block your pawn with a piece, to prevent you from pushing, well, that's one less opposite piece playing on the rest of the board.
If your opponent decides to exchange your pawn, you end up with a rook on an open file.

In the endgame, connected passed pawns beat the opposite king:

If they are side-by-side, they setup a wall of 4 controlled squares, so can't be threatened by the opposite king.

[fen "8/4k3/8/3PP3/8/8/8/8 w - - 0 1"]
If they are connected,  one row apart, the king has to capture the rear pawn first, effectively leaving the front pawn's promotion square.

All these are limited to what the specifics of every position allow.


What are key squares and critical squares?

The terms key squares and critical squares are sometimes used interchangeably in chess literature in king vs king and pawn endgames.

A square is called a key square when the occupation of it by the attacking king will secure a win regardless of which side is to move.

2nd through 4th Ranks
In this example, the key squares for the White pawn are e6, f6, and g6.
[FEN "8/8/8/8/5P2/8/8/8 w - - 0 1"]

A Pawn that Crosses the 5th Rank has More Key Squares
In this example, the pawn on f5 has two sets of key squares: e6, f6, and g6, as well as e7, f7, and g7. If White's king can occupy any of those 6 squares, they can secure the win.
[FEN "8/8/8/5P2/8/8/8/8 w - - 0 1"]

The Rooks Pawn are Exceptions
These positions show a draw regardless of which side has the move.
[FEN "5k1K/8/7P/8/8/8/8/8 w - - 0 1"]

[FEN "7k/8/7K/7P/8/8/8/8 w - - 0 1"]

In the first position, Black can simply shuffle his king between f7 and f8 and White makes no progress. In the second position, the move sequences 1. Kg6 Kg8 2. h6 K8 3. h7 stalemate. The sequence 1... Kg8 `. Kg6 Kh8 3. h6 Kg8 4. h7+ Kh8 with a stalemate, or loss of the pawn.
Related Topics
The Opposition
Rule of the Square
Resources
Wikipedia on key squares
Endgame Simulations (against a computer)
ChessDiary #2 - Monday Endgame Pawn Endgame - Key Squares


We have no way of knowing this, chess isn't remotely close to being solved. We only know that as opening theory digs deeper, it finds it harder and harder to find advantages for white, so the game is probably a draw. But that's no proof.

If the game is a draw, then any game that is won by either side must involve at least 1 wrong move. But we don't know which move was wrong. It is likely that most games involve quite a few bad moves. Mine do, anyway.

Using a computer doesn't help -- they're nowhere near strong enough. A match between the two strongest computers on really strong hardware gives many decisive results, so they're not playing perfectly, and they look much deeper than 10 ply. Their scores (+2, -2, etc) are merely estimates and not the final truth.

White does have a practical advantage, proven by the fact that white consistently scores a little bit better than black on all levels. Apparently, white gets positions that are easier to play right.


I think there can be no slower one than mate in 3. My standard checkmating attempt would be like the starting positions 1.e4 e6 2.Ke2 Qh4 3. pass Qxe4#. What can go wrong there? 1. Ke2 could be illegal in a position like Kb1 Qh8. With the king on b1 the a1 piece has to be a rook per rules of piece set up. In this case 1.a4 g5 2.Ka2 Qd4 3.Rb1 Qxa4#.
So finally we are left with a knight being a blocker. This can only be the case if there is a knight next to the king. In that case there is a knight on the opposite side that can go for a suffocated checkmate. So if we have e.g. Ke1 Nd1 then the Nd8-e6 can go to f4xg2 or d4xc2 for checkmate. If either is only defended once, white can put the defending piece on the respective square. So the only case left is the one where both these squares are defended twice. Furthermore there can't be a heavy piece on either side of the king as otherwise the original mate would work, with a pawn advance diagonal to the king, king advance and the heavy piece blocking the retreat path. The position that's left over is something like this
[FEN "brnknqrb/pppppppp/8/8/8/8/PPPPPPPP/BRNKNQRB w - - 0 1"]

In that case the defending queen can only be on one side of the board, the other side is defended by bishop, rook or knight in some combination. In that case if it is a rook that rook can move out of the way a la b3 Bb2 Ra1. A defending knight can move away to no longer defend, with two moves left over to fianchetto either rook or bishop.
This can only go wrong if the non queen side is defended by three pieces, however this does not work as the bishop not defending that pawn has no room. (both the defending knight and rook as well as the rook on the other side plus the king have to be on the same colour leaving no room for the bishop)
Sorry for the many edits, I hope I cleared up my not so clean initial explanation.


Black wins.

Black has a distant passed pawn and Blacks pawns are more advanced. White is bound to defend against g-pawn, while Black can do anything with a and b pawns. And White cannot win a pawn race, because Black is more advanced.

[Event "Original Position"]
[Site ""]
[Date ""]
[Round ""]
[White ""]
[Black ""]
[Result "0-1"]
[FEN "8/8/8/5kp1/p7/P4K2/1P6/8 b - - 1 2"]
[Setup "1"]

2... g4+ 3. Kg3 { Option 1, defending against g-pawn, fails.}  ( 3. Ke3 { Option
2, counter attack on the other side, which fails also, because Blacks pawns are
more advanced, Black wins the race.}  3... Ke5 4. Kd3 Kf4 5. b4 axb3 6. a4 g3
7. a5 g2 8. a6 g1=Q ) 3... Kg5 4. Kg2 Kf4 5. Kf2 g3+ 6. Kg1 Kf3 7. Kf1 g2+ 8.
Kg1 Kg3 9. b4 axb3

However, if Black wouldn't have a-pawn that advanced, White could catch Black and avoid promotion after dealing with g-pawn.

For example:

[Event "Queenside Pawns Shifted"]
[Site ""]
[Date ""]
[Round ""]
[White ""]
[Black ""]
[Result "1/2-1/2"]
[FEN "8/8/8/p4kp1/P7/1P3K2/8/8 b - - 1 3"]
[Setup "1"]

3... g4+ 4. Kg3 Kg5 ( 4... Ke5 5. Kxg4 Kd5 6. Kf4 Kc5 7. Ke5 ( 7. b4+ axb4 8.
Ke3 b3 9. Kd2 Kb4 10. Kc1 Kc4 11. Kb2 Kb4 12. a5 Kxa5 13. Kxb3 ) 7... Kb4 8.
Kd4 Kxb3 9. Kd3 Kxa4 10. Kc4 { Black king is trapped. Draw.}  ) 5. b4 ( 5. Kg2
$2 $19 Kf4 6. b4 axb4 7. a5 b3 8. a6 b2 9. a7 b1=Q 10. a8=Q Qc2+ 11. Kg1 Qd1+
12. Kg2 Qe2+ 13. Kg1 Qe1+ 14. Kg2 Qg3+ 15. Kf1 Qf3+ { And black takes
opposition, which is necessary to promote g-pawn.}  16. Qxf3+ Kxf3 17. Kg1 Kg3
18. Kh1 Kf2 19. Kh2 g3+ 20. Kh1 g2+ 21. Kh2 g1=Q+ ) 5... axb4 6. a5 b3 7. a6 b2
8. a7 b1=Q 9. a8=Q { This is a bit complicated, but according to tablebase,
this is draw.}


Why is b4 the only move suggested by every chess engine?

Black is down material but still has some strength. The most obvious one is that he has a pawn majority on the queenside, meaning potentially passed pawn if he manages to push his majority. So Black's plan will be to put both rooks behind the pawns and go for ...a5-a4, ...b5-b4 etc...

In a very simple way White can fight against Black play (it's prophylaxie) by pushing b4 preventing ...a5 and ...c5.
Moreover if we manage to push b4-b5, the pawn on a7 will now be a weakness so we can attack it (doubling rooks on a-file).


What is the name of this variation: 1. e4 b6 2. e5?

I don't think that this variation has a name. Variations that are infrequently played are less likely to be named. I don't have access to Megabase right now, but I can't even find a game starting with 1. e4 b6 2. e5 in online databases. You're already well away from main lines with 1... b6. 2. e5 seems weird (2. d4 would be my choice) and 2... Nc6 will impede the bishop on b7.


How can I deal with frustration in not being able to solve puzzles in time?

It happens every day to a lot of players! Some problems are very hard and can be very frustrating.
My advice would be to try hard during "your 10 minutes", and if the problem is challenging to move on without seeing the solution. Come back to the puzzle after you've had a break and cleared your head. At least, that works great for me!


Proof of irreversibility of 50 move rule

The two irreversible moves can be proved irreversible (it is impossible to replicate that board state later in the game) like so:

Assumptions:
 - Pawns can't move backward.
 - Every pawn move moves it forward.
 - Pieces can't be added to the board.
 - There is no way to create a pawn (unlike queens, bishops, knights, and rooks which can be created via pawn promotion).

Firstly, captures can be proved irreversible because they always remove a piece from the board. If a board state has N pieces and one is removed you now have N-1 pieces. There is no way to increase the number of pieces so you can never return to N pieces.

Secondly, since every pawn move moves it forward, a pawn can never return to its original position. The only way to have a pawn in that position later on is to have it be occupied by another pawn. But for another pawn to occupy the position that pawn has to move. There is only a finite number of pawns so after every pawn has moved to fill the position left by the previous pawn there are no pawns left to fill the position of the last pawn, preventing the board state from being reached again.


What is the reason (if any) for 1.e4 c5 2.Nf3 d6 3.Nc3?

It basically just stalls for a move before 100% committing to the open Sicilian. For example, suppose you were playing White and hated facing this Sicilian (1.e4 c5 2. Nf3 d6 3.d4 cd 4.Nxd4 Nc6). You could use the move order you described and after 3.Nc3, only play 4.d4 if your opponent doesn't play 3...Nc6. If they do play 3...Nc6, then go for some Closed Sicilian.

Also in online bullet some people have done the 3.Nc3 move order against me because it takes half a second to realize what's happening and then play 3...Nf6 instead of 3...cd.


Suggestions for Newb in search of improving mid and end game strategy

In order to improve you need to 1) study theory, 2) play games and 3) analyze those games. Repeat until you are world champion.

Specifically to these steps....

Study theory

As a beginner your biggest concern should be tactics. Start training yourself to always be aware of which pieces/squares are attacked, so that you don't blunder pieces in one move. You don't need to scan the whole board each and every time to check this. Use a gradual approach: since a move will only affect part of the board, update (in your memory) the information depending on which new squares/pieces are attacked (and which are not attacked anymore). For the long-range pieces (rook, bishop, queen), it might help if you imagine their range as some kind of "shooting range"/no-go zone,... whatever helps you to visualize it. For instance for a rook on h4 don't imagine that it attacks the squares g4, f4, e4, ..., a4, but imagine it as a piece which covers all of the 4th rank (giving it options to capture everywhere on this rank but also options to move everywhere on this rank). As you improve this will come naturally.

Also at this stage you want to learn and practice simple tactics, such as pawn and knight forks, pins, etc. There are many websites (lichess, chesstempo...) giving you tactics puzzles depending on your strength. For a beginner I recommend chesstempo, because each puzzle is tagged with the tactical motive(s). When solving puzzles (or fail to solve) make sure you recognize these motives in the respective puzzle.

Besides tactics, you need to learn some basic principles for the opening such as: develop pieces quickly, occupy the center, keep your king safe/castle, attack something.

Also learning some basic endgames such as mating with queen, rook, bishops, King+pawn vs king, ... will teach you a lot.

Don't bother learning any opening theory yet, because you are not in the position to understand the ideas behind the openings and will not be able to take advantage if your opponent plays a move you did not learn.

Play games

Avoid short time controls which don't give you enough time to think. I'd recommend at least 20 minutes or more.

Analyze

If you play online (e.g. on lichess) you have the option to automatically have the game analyzed by a computer engine. Do this and look for the main mistakes/blunders (where the evaluation jumped a lot). Understand why that was a bad move. Try to find a better move and compare with the computer suggested move. This will only teach you tactical mistakes.

Figuring out positional/strategic problems in your play is much more difficult and just about impossible if you are on your own. Ideally you'd have another, better player look over your games and point out some problems with your strategy.

For passive learning of strategy, reading/watching annotated games could be an option. Nowadays there are lots of streamers out there commenting while playing games online. Some of the chess24 streamers seem suitable for beginners.

Ideally you'd join a chess club where you can play, get tips from other players, etc.


Do different nationalities have "notably" different play styles?

Consider this quote from wikipedia regarding the Soviet Chess School:

  The main contribution of the Soviet School of Chess was not the style of players but their emphasis on rigorous training and study of the game, i.e. considering chess a sport rather than an art or science.

Emphasis is mine.

Given that chess is taught as a school subject in Russia, then this points to there not being trends in chess style by country.

Moreover there seems to be little evidence that openings named after regions are done so because of their popularity there. If this were the case, then Scandinavians would tend to play the scandinavian-defense, which has a different style to the italian-game. In fact, the Scandinavian is called such because it was first seriously analysed by Scandinavian masters.


Static Exchange Evaluation (SEE) without move undo

The pseudocode you copied from the wiki is just the easiest way to make you understand SEE. It is NOT used in a real chess engine, because building a swap list would be more efficient.

You should check Stockfish. I'll give you some hints here.

Goto position.cpp.
Find the function Value Position::see(Move m) const. This is where SEE is implemented
Check this loop:

do {
  assert(slIndex < 32);

  // Add the new entry to the swap list
  swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];

  // Locate and remove the next least valuable attacker
  captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
  stm = ~stm;
  stmAttackers = attackers & pieces(stm);
  ++slIndex;

} while (stmAttackers && (captured != KING || (--slIndex, false))); // Stop before a king capture

Stockfish doesn't do exactly what your pseudocode does. It loops for all for possible attackers from the least powerful (min_attacker). For each attacker, the engine checks it's value (PieceValues[MG]) and add it to the swap list. The swap list will then be looped over for nega-max:

  // Having built the swap list, we negamax through it to find the best
  // achievable score from the point of view of the side to move.
  while (--slIndex)
      swapList[slIndex - 1] = std::min(-swapList[slIndex], swapList[slIndex - 1]);

Don't be afraid of the while loop, all it does to check if an exchange is good or not. In fact, the wikipedia you stated has the reasoning:

This uses a trick, equivalent to negamax in tree search, where the loss for the current side is the gain for the opposite side. This can be seen in the expression piece_just_captured() - see(square); which is the value of the piece captured (piece_just_captured()) minus the gain that the opponent might make after the move by recapturing. If that term becomes negative, one would better choose standing pat rather than to capture, which can be done by a conditional assignment, or by a max function with zero as second argument.


What would chess openings be like without castling and/or the double pawn move?

Overall, the game would be slower and opening attacks would be more aggressive at times.
The purpose of implementing the double-step was to speed up the game. That way, those pesky pawns wouldn't have to waste so much time, i.e. moves, moving forward to mount an attack or to develop an area of advantage/control. But with the double-step gone, we would have to revert back to the slow way of the ancients.
The double-step is often done on the c and f files to let the knights out without blocking the pawns. Now it would take more time to flesh out that plan, as it would now take two turns to let the knight out onto its most advantageous opening square.
In some semi-closed positions, the double-step is used as an immediate can opener. However, having to move the can-opener pawn two times might give the opponent just enough time to react and defeat, or at least nullify, your attack. A few more draws might result because the position stays closed.
Additionally, in some games, the double-step is used to quickly advance a rook pawn, and break open the enemy's king's encampment. But with it gone, a single step must be done, thereby giving the opponent time to react. Have a look at the below position and deduce for yourself how this affects the game.
 [FEN "3r1r2/1bp3k1/1p1qp2p/p2p2n1/5NQ1/PBNP2P1/1PP4P/1K2R2R w KQkq - 0 1"]

As for no castling, it would also lead to a slower game, but at the same time lead to more aggressive opening attacks. The concept of castling, even if the move isn't allowed anymore, would still be a popular motif due to how it keeps the king safe.
Doing castling manually takes several moves, and with both players doing so, games would start to be several moves longer. Due to the slow process of doing so, an opponent may try to catch the king in the act and take him down. Kings would be in the center longer, also leading to a reason to favor, and as such an increase, in open positions. That allows for an attack to be done faster. Artificial kingside castling would increase in use due to the process taking much longer than on the queenside.
At the same time, however, with the hindrance of the double-step, such attacks may be also seen less often due to the need to spend time mobilizing pawns. The enemy might use your time to manually castle, ruining your plan.


Rook and knight used together within the same move - legal?

That's either a bug or some non standard chess variant


List of female chess players by peak FIDE rating

The raw data which could be used to extract this information is available on the FIDE website (from 2001) and the Olimpbase website (before 2001). What you will need to do is clean the data (the older the data the more "dirty" it is), construct a relational database and insert the data. Then you will be able to use SQL to search the database for the data you want.
Having done this, here is a list of the top female players of all time above 2500 appearing in the periodic FIDE rating lists (i.e. not the live list, because that data is not available to us)
FullName    Max Period

Polgar, Judit 2735 7/2005, 10/2005
Hou, Yifan 2686 3/2015, 5/2015
Koneru, Humpy 2623 7/2009
Muzychuk, Anna 2606 7/2012, 8/2012
Ju, Wenjun 2604 3/2017
Goryachkina, Aleksandra 2593 2/2021
Kosintseva, Tatiana 2581 11/2020
Zhao, Xue 2579 9/2013, 10/2013
Polgar, Zsuzsa 2577 1/2005 ->
Kosintseva, Nadezhda 2576 11/2010
Xie, Jun 2574 1/2008 ->
Dzagnidze, Nana 2573 6/2015 - 10/2015
Muzychuk, Mariya 2563 3/2016, 4-6/2019
Kosteniuk, Alexandra 2561 1/2018, 2/2018
Lahno, Kateryna 2560 12/2018 - 2/2019
Galliamova, Alisa 2560 7/1998
Stefanova, Antoaneta 2560 1/2003, 5-7/2010
Chiburdanidze, Maia 2560 1/1988
Cramling, Pia 2550 10/2008
Gunina, Valentina 2548 6-7/2015
Zhu, Chen 2548 1/2008
Lei, Tingjie 2545 3/2018
Harika, Dronavalli 2543 11-12/2016
Cmilyte, Viktorija 2542 6/2017
Sebag, Marie 2537 3/2013
Zatonskih, Anna 2537 5/2011
Khotenashvili, Bela 2531 6/2013
Tan, Zhongyi 2530 3-4/2016
Batsiashvili, Nino 2528 3/2018
Danielian, Elina 2521 7/2011
Ioseliani, Nana 2520 7/1977
Saduakassova, Dinara 2519 1/2020
Xu, Yuhua 2517 4/2006 - 7/2007
Paehtz, Elisabeth 2513 9-10/2018
Wang, Lei 2512 10/2001
Hoang, Thanh Trang 2511 11/2013 - 2/2014
Pogonina, Natalija 2508 7/2014
Kovalevskaya, Ekaterina 2507 7/2001
Zhu, Jiner 2507 10/2019
Arakhamia-Grant, Ketevan 2506 7/2009
Wang, Pin 2506 10/2000
Polgar, Sofia 2505 7/1998
Girya, Olga 2505 9/2017
Socko, Monika 2505 4/2008
Ruan, Lufei 2503 1/2014
Mkrtchian, Lilit 2503 1-3/2010
Matveeva, Svetlana 2502 1/2004
Krush, Irina 2502 10-11/2013
Ushenina, Anna 2502 7/2007
Qin, Kanying 2501 7/2000
Skripchenko, Almira 2501 1-4/2003


I guess you mean the game below and at the 7th-move: 7.Qa4+ doesn't win the bishop because black can reply with Nc6 blocking the check and defending the bishop.

 [title "Biel, Carlsen vs Navara 2018"]
 [fen ""]
 [startply "12"]

 1.d4 Nf6 2.Nf3 d5 3.c4 e6 4.Bg5 Bb4+ 5.Nc3 h6 6.Bxf6 Qxf6 7.e3 (7.Qa4+ Nc6) O-O 8.Rc1 dxc4 9.Bxc4 c5 10.dxc5 Nd7 11.O-O Nxc5 12.Nb5 a6 13.Nbd4 b5 14.Be2 e5 15.Nc2 Rd8 16.Nxb4 Rxd1 17.Rfxd1 a5 18.Nd5 Qd6 19.Nxe5 Bb7 20.Bf3 Rc8 21.Ng4 Qf8 22.h4 Nd7 23.Rxc8 Bxc8 24.a3 h5 25.Nh2 g6 26.Be2 Ne5 27.Bxb5 Bb7 28.Nc3 Qe7 29.Rd4 Qe6 30.Nf1 Qb3 31.Rd2 Nc4 32.Rd7 Nxb2 33.Rxb7 Qxc3 34.Be8 Kf8 35.Bxf7 Qc6 36.Rxb2 Kxf7 37.Rd2 Qa4 38.Rd3 Qxh4 39.Rd7+ Kg8 40.Rd4 Qe7 41.a4 Qa3 42.g3 Qa1 43.Kg2 g5 44.Nd2 g4 45.Ne4 Qc1 46.Nf6+ Kf7 47.Nxh5 Qc6+ 48.Kg1 Qc1+ 49.Kh2 Kg6 50.Nf4+ Kf6 51.Ng2 Kg5 52.Rf4 Qd1 53.Nh4 Qc2 54.Nf5 Qd3 55.e4 Qd7 56.e5 Qh7+ 57.Kg1 Qg6 58.Nd6 Qe6 59.Rf5+ Qxf5 60.Nxf5 Kxf5 61.f4 gxf3 62.Kf2 Kxe5 63.Kxf3 Kf5 64.Ke3 1-0

In case white tries to further pressurise the knight on c6 after 7.Qa4+ Nc6, with e.g. 8.Ne5 black always has the option of taking on c3 first with check and then reacting to Ne5 with Bd7.


Substituting one engine for another in a tournament

You can delete the old engine executable and copy a new one with the same filename to the same directory.


Can SCID be configured so that engines use Endgame Tablebases?

I just had the same question, and I thought I would post a belated answer for future persons.

I am using SCID vs. PC, but I think the solution may be the same or similar. First download the Gaviota tablebases here (http://www.olympuschess.com/egtb/gaviota/). Then go to SCID --> Tools --> Analysis Engines and select your engine (Critter is working best for me here. I have Houdini 1.5 and it is not working properly.) click Edit and then click the Configure button. You will see a GaviotaTbPath textbox; enter your directory, click save and everything should work.


6...b5 7.Bd5! Nxd5 8.exd5 leaves Black in trouble. The e-file has been opened and Black has to figure out how to castle before things get really heated. The c6-square is also a major weakness that White's d4-knight is ready to jump to at the right moment.


As you noted, w_i is not calculated by the search tree. It is simply the number of wins out of the total simulations performed at that node (if this is the method used to score the node). This scoring mechanism is also known as playout.


What's is the Least significant File and Least Significant Rank?

LSF and LSR are two ways to encode a chess board coordinate into a single integer number. LSF does that by { a1, b1, c1, ... } while LSR encodes by { a1, a2, a3 ... }.


And an interesting question you pose as to how good you could become playing 3|2.
The 3 min plus 2 second increment you play means roughly say a move rate overall of about say 6 seconds per move for an average game of 50 moves.
You try to always play slightly stronger players, excellent idea, so assuming you are not getting trounced ie at least breaking even I think you will progress perhaps to 1200 to 1300.
Games will be won or lost mostly by one or two move combinations  or simple oversights by you or your opponent.
Not an issue if you are playing mainly for the enjoyment of chess.
But if your real focus is to become a strong player this is a different matter.
To put your question into perspective consider other endeavours.
Would you expect a carpenter who only built small wooden boxes in five minutes to be able to build you a good house?
A computer programmer who only spent six seconds on each line of code to become an excellent programmer without further study or deeper reflection?
If your main goal is to improve you need to start playing longer games and to play through master games that are annotated.
You will notice a more rapid improvement in your games though it will require some dedicated work.
Don't go overboard on opening theory, just aim to get a playable position out of the opening.
But it is in the end-game that playing strength really shows so make some serious effort in this phase of the game and you will improve dramatically.
After studying endings you will find your middle game will start to improve as well because you now are aware of which endings to aim for and which to avoid.
Before the internet era I did not have much chance to play over-the-board so I played correspondence chess. This long style of chess forces you to carefully analyse your moves and to study openings and endgames otherwise you could be stuck with a bad position for a year or two!
When I did get to play OTB I did regularly get behind on the clock but managed to bowl over quite a few strong players including some with titles.


Can I host lichess server to my local machine to use the study offline?

Yes. I did it a little while ago. It's of course possible. You will need to be technical capable of doing it as it won't be like a one-click installer.


What are the main differences between the two?

  Extended Position Description is a standard for describing chess
  positions along with an extended set of structured attribute values
  using the ASCII (American Standard Code for Information Interchange)
  character set. It is intended for data and command interchange among
  chess playing programs. It is also intended for the representation of
  portable opening library repositories. The first four fields of the
  EPD specification are the same as the first four fields of the closely
  related FEN specification. Like FEN, EPD can also be used for general
  position description. However, unlike FEN, EPD is designed to be
  expandable by the addition of new operations that provide new
  functionality as needs arise. More information can be found at this site.

When should I use one over the other one?

  EPD is more expandable by the additon of new operations and is more
  versatile and is used primarily in chess programs.  See bullet point one.

Which one is more common to see?

  Overall, I would say FEN is more common, but this is relative to what you are trying to do.


What's the best alternative to the 'scoresheet' blunder checking strategy?

I don't know of any proven method but here's one idea: you could try to imagine writing the move. Translate your move into algebraic notation, imagine the text on your scoresheet, maybe even trace it with your finger. Hopefully that will be enough of a pause in your train of thought to enable you to see the move from a different perspective, which I think is the rationale behind the "write before you move" approach.


Could black have saved the rook-endgame?

Black's 34 ...cxd4 is probably a bad choice. Taking with the rook seems good if also they could have exchanged a pair of rooks, because the pawn is blocked by the white rook. Also Black's doubled pawns on the g-file from move 24 to 43 gives an advantage to white. So i think black couldn't have saved the game unless White blundered.


What is the correct definition of a bad bishop?

When evaluating a bishop, there are two totally separate things that must be considered.  The first is whether a bishop is "good" or "bad".  These are very much misnomers because they have nothing to do with the worth of the bishop.  The second consideration is whether the bishop is "active" or "inactive".  Finally, there may be mitigating factors as well (is the bishop doing something useful?).

Good vs Bad

A good bishop is on the opposite color as its pawns.  A bad bishop is on the same color as its pawns.  For example if the white pawn structure is c3, d4, e3, f4, then the light squared bishop is the good bishop and the dark squared bishop is the bad bishop.

Active vs Inactive

An active bishop is outside of the friendly pawn chain (in the above example, if the bishop is on e5, then it is clearly both active and bad).  An inactive bishop is trapped by pawn chains - either the player's color or the opponent's.

Mitigating Factors

There are two main mitigating factors.  The first can be remembered by a common phrase: "bad bishops defend good pawns".  This means that a bishop might be very bad (same color as all the friendly pawns) but if it is defending them from attack in the endgame, then it might be enough to hold a draw.  Usually it is much harder to win with the bad bishop though.
The other main mitigating factor is if the bishop is defending its own passed pawn or stopping an enemy passed pawn.


I would tend to think that you are the very first person to propose that, mostly because I really do not think it would work for this reason:

Even with the control you proposed, 90 minutes to 120, the guy with 90 minutes still has A LOT of time to think not only on his time, but also on the opponent's time. That makes draw odds a MUCH larger advantage at that control than in blitz.

I tried thinking about alternative controls that might even it up some, but they would have to be so unbalanced, that the players would be playing under radically different time controls like 15 or 30 minutes to two hours. Whatever the control, you would need to create a situation where white with the extra time has some reasonable chance to out-think black and win, and that is hard at that level to begin with, but it is all but impossible with that much extra time that black can think on while white is thinking.


How can I control my nerves during chess tournaments?

First of all, as @Jimmy360 stated, you should practice with tournament-like conditions. Apply the similar time controls, touch-move rule, threefold repetition, and all those 'boring' rules if you need to. This will surely make you nervous, however, it is a good practice, since tournaments will make you nervous anyway. When you get used to it, you will know how to relax, and furthermore, treat tournaments as friendlies!

Another suggestion I can give is that play in lots of tournaments. I know it isn't possible with limited time and money, however, chess.com and other chess websites have made things easier. Just play in lots of online tournaments, and you will feel that things will get easier, and you'll get used to playing under tournament atmosphere.

Finally, I suggest you to always think twice before making a move. This is what players of your level usually fail to do. Try inspecting your games; how often do you hang pieces, or fall to forks and pins? Well, the problem is, with the added stress due to it being a tournament, we tend to forget these 'little things' more easily. Therefore, every time you play in a tournament, try to sit back, relax, take a deep breath, double-check every move, and most importantly:

   Enjoy the game!


Is e5 fully playable in the following positions?

A quick analysis of the first position shows that 0...e5 was playable in that there was not a fundamentally better choice.  Stockfish would prefer 0...Nbd7 but the resulting score is only .2 points better than 0...e5.  Those fractions add up after a while, but if one is looking to uncramp one's game, it could be a bargain.  7 hours of grinding shows that neither side gets much of an advantage after 0...e5 1. O-O. The score settled on about .75 in White's favor.

Here's the continuation at 15 minutes per move. I think this shows that 1... e5 is playable and leads to a sharp game.  White retains a slight advantage the whole time.

[fen "rn1qkb1r/pp3pp1/2p2np1/4p3/3P4/6P1/PPP1NPBP/R1BQK2R w KQkq - 0 1"]

2.O-O Nbd7 3.b4 Be7 4.Rb1 O-O 5.c4 exd4 6.Nxd4 Nb6 7.b5 c5 8.Nb3 Qxd1 9.Rxd1 Nxc4 10.Bxb7 Rad8 11.Re1 Bd6 *

Here's the second position. I didn't see ALNS's message until this morning, so I thought I might as well post the results. There is a deviation in the moves, probably the result of me using the computer last evening while the program chugged in the background.

[fen "r2qkb1r/pp1n1pp1/2p2np1/4p3/3P4/6P1/PPP1NPBP/R1BQ1RK1 w KQkq - 0 1"]

1.b4 Be7 2.Rb1 O-O 3.c4 exd4 4.Nxd4 Nb6 5.c5 Nbd5 6.Qb3 a5 7.a3 Qd7 8.Bb2 Nc7 9.Rbd1 Nfd5 10.Nc2 Qg4 11.Bf3 Qf5 12.Rfe1 Rfe8 13.Be4 Qg4 14.Qc4 Qh5 *

The machine tallies this position as anywhere from .55 to .70 (through the next 16 moves!) depending on the exact variation being calculated. That is, there is no appreciable change in the score in the entire variation. It would seem 0... e5 is a viable move.


program to output features in a position

It's possible (statically) but you may need to do some works. Let's take a look at Stockfish.

In the terminal, start Stockfish and type eval.

Stockfish knows about your passed pawns, king safety, good knights etc. Your job is to pull it out from the source code.

Let's study Stockfish's evaluation. The source file is at: https://github.com/official-stockfish/Stockfish/blob/master/src/evaluate.cpp

Let's try two examples: bad knight and passed pawn.

Bad knight

The line:

pos.attacks_from<Pt>(s)

gives you the attack bitboard for your knight. The PST table for the knight is in psqt.cpp.

{ S(-144, -98), S(-96,-82), S(-80,-46), S(-73,-14) },
{ S( -83, -69), S(-43,-54), S(-21,-17), S(-10,  9) },
{ S( -71, -50), S(-22,-39), S(  0, -7), S(  9, 28) },
{ S( -25, -41), S( 18,-25), S( 43,  6), S( 47, 38) },
{ S( -26, -46), S( 16,-25), S( 38,  3), S( 50, 40) },
{ S( -11, -54), S( 37,-38), S( 56, -7), S( 65, 27) },
{ S( -62, -65), S(-17,-50), S(  5,-24), S( 14, 13) },
{ S(-194,-109), S(-66,-89), S(-42,-50), S(-29,-13) }

Do you see -29 for the h1 square?

Passed pawn

The line:

ei.pe->passed_pawns(Us)

gives you passed pawn information for a colour.


They appear to still be active.

https://www.serverchess.com/


Your friend is right. Think of it in terms of capturing the king: check means that your king could be captured on your opponent's next move. If you could move your king next to your opponent's king, your king could be captured on your opponent's next move; the fact that after that you could capture your opponent's king doesn't change that: your king has been captured, and you've lost the game.


Mate in 1, then No Mate in 1, then Mate in 1

The position is 16+15 (16 white units + 15 white units).
Part 1:

 Black has no legal retractions except -1...b7-b5, meaning en passant is legal and 1. axb5 ep mates.

Part 2:

 Removing anything that is not a king enables a different black retraction (there is one exception), meaning en passant is not legal, and there is no other mate in 1. Aside from obvious removals and retractions, notable cases are:

 Remove wPa5; the last move must still be ...b7-b5, but white can't take it en passant.

 Remove wPb4; the last move can be ...dxc6 (at some point white played bxc capturing a black pawn).

 Remove wPc4; the last move can be ...dxc6 (can be a pawn, for instance) or ...Kb7-a7 (white knight came from c4).

 Remove wPf2; the last move can be ...dxe6 (at some point white played fxe capturing a black pawn)

Part 3:

 Remove bBb8 and wBe8; 1. Rxc7# is mate.

 Removing any unit already invalidates en passant, and so does removing two (there are no interesting interactions here that would keep it legal). So we need to look for a regular mate. The only pieces that can deliver check are the wRc8 and wNd6. The knight can't deliver mate as it is the only thing that could guard b7. So the rook must deliver mate; not on a8 as we can't defend it there with just two removals, so on c7. So we need to remove bBb8 to unguard c7, and wBe8 to guard the b8 square again.


How much time it takes before searching for tactical themes becomes a subconscious process?

It is a bit like for example learning to play the piano.
At first as a beginner you look at the keys and where your fingers are going.
With increasing practice, and remember even a great piano virtuoso() will still practice every day, your thought patterns become better organised and you later play with your fingers seemingly doing the thinking for you.
() The great Artur Rubinstein practised several hours each day: he said that if he did not do this he would detect a decline in his performances.
For each player the speed that this happens will vary.
I find playing through lots of master games is most helpful.
I try to read any annotations and play through some of the variations given in the analysis.
At first I was slow and cumbersome but after a while this improved.
The secret is consistent practice.
Every day without fail set yourself the task of playing through 1 to 20 games. Little by little patterns of play will be absorbed and you will find yourself subconsciously playing better moves.
By the end of a month you will have played through 30 to 600 master games.
By the end of a year you will have played through 350 to 7000!
Create for yourself a concrete set of steps for each game.
I used to have them typed on a card and reviewed the steps before each tournament game.
After a while they become second nature.
Two phases: 1. It is your opponents move.
2. It is your move.
I can elaborate these steps if it is of interest.


Assuming you are Black, you have checked your opponent - your Queen on d1 is putting his King on g1 in check (and checkmate).
Edit: assuming Rewan Demontay's reading of your question is correct, then there's no stipulation that you have to check your opponent before checkmate. You can see this in well-known short checkmates, e.g. Scholar's mate. 1. e4 e5 2. Bc4 Bc5 3. Qh5 Nf6?? 4. Qx7# is checkmate without checking first.


What's the best move against this variation in the Philidor Defense?

As Ian Bush already mentioned in a comment, 5.Bb5+ is arguably the strongest reply. After 5....Nd7 6.Nf5 or 5....Bd7 6.Bxd7+ Qxd7 7.Nf5, black has some serious problems with the weak pawn on d6 and square d5.
Note that there are some similarities with a line in the Sicilian: 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 e5 5.Bb5+.

Other moves are less convincing. After 5.Nf5 Nf6 or 5.Nb5 a6 6.N5c3 Nf6, black is probably fine. 5.Nf3 is not a bad move, but it doesn't take advantage of black's weaknesses.

      [FEN ""]
      [StartPly "1"]

      1.e4 (1...c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 e5 5.Bb5+) e5 2.Nf3 d6 3.d4 exd4 4.Nxd4 c5 5.Bb5+ (5.Nf5 Nf6) (5.Nb5 a6 6.N5c3 Nf6) (5.Nf3) Bd7 (5...Nd7 6.Nf5) 6.Bxd7+ Qxd7 7.Nf5


How does the "French Defense, Winawer Variation, Fingerslip Variation" get its name?

According to "The Batsford Guide to Chess Openings" by Leonard Barden and Tim Harding:

"This move had its introduction into master play as the result of a fingerslip by Alekhine against Flohr, at Nottingham in 1936. He had intended 4 P-K5 P-QB4 5 B-Q2, but played the moves in the wrong order"

The game is at

http://www.chessgames.com/perl/chessgame?gid=1008345


Advances in the tactical acuity of the computer programs coupled with hardware improvements to CPU, memory, and disk storage,  plus the availability of robust opening book and endgame tables has made them all but unbeatable.

I don't know if computers have strategic "thinking", but their tactical prowess is such that it doesn't really matter.


Why do so many children stop playing chess?

In order to prevent my answer to be misunderstood/wrongly interpreted, let me state few thing now, at the beginning:

I LOVE to play chess.
I am inactive, and doubt I will ever play on tournaments again, but I still follow the game.

Now, let us proceed towards answering the OP's question:

...I know many people who stopped playing competitively after primary school but still follow the sport. Why is chess different: why do so many young people divorce themselves from chess completely when they feel they've reached their potential and can't advance any further?

In order for someone to continue sports/mountain climbing/collecting stamps/whatever they need to have a reason for doing it - and it must be a very good and strong one!
So let us start examining this from the athlete's point of view for a start, and then we shall compare our conclusions with those for a chess player.
ATHLETE'S POINT OF VIEW:
A child athlete could like sports because he can :

Play with people of similar interest and of the approximately same age and he can be a part of something;
He can improve his health or maintain its good shape, he can get popular which can give him many social benefits;
He needs little work to do in order to improve compared to a chess player, and if he continues to pursue sports there is a chance for him to have great future (fame, money and so on).

CHESS PLAYER'S POINT OF VIEW:

Young chess player is surrounded with his peers at the beginning but as soon as he progresses he meets usually older people to play against. Imagine a child on a decent tournament (this scenario is really plausible since 12 year old can reach FIDE master/near FIDE master strength) surrounded with older people - it makes him feel awkward, like he does not belong there. He can not socialize with them since they have no common conversational topics due to age difference - which will lead to loneliness, unlike the athlete who is usually surrounded with their peers and feels great for being a part of the team, for belonging to a group.

Chess improves mental abilities (some mathematical disciplines and  memory), but spending too much time on the board neglects a child's physical development. In that age physical development is far more important on the long run than to be a spelling champion. Furthermore, a successful athlete gets the social benefits, like popularity in school and many others, while being a chess player is not being fully approved today-nobody likes to lose from a girl and guys are labeled as boring geeks. Sorry to say it, but in the long run being the athlete really has its benefits even if you do it for fun but playing chess in your free time does not.

Regarding the improving method athlete again has it easier. Let us take basketball for an example: If a tall child and a short one start training and invest equal amount of work the taller one will still be a better player because of his innate height advantage. We see this in sports all the time-physical attributes play huge roll. In chess these two will be of equal strength if they invest equal amount of work. Why is this so important? In order to be the best in sports you need both physical attributes and skill yet in chess pure skill is the only thing that counts. Let us take Shaquille O'Neil as an example - his free throws are horrible, but he is still a top player because his physical attributes combined with other skills compensate. In chess, lack of skill can not be compensated - you must work hard to remove your shortcomings.

So what is the result for our 12 year old chess player? Work your butt off to be good chess player for what - to be socially labeled by a bad stereotype? So you can get kyphosis/scoliosis for sitting on the board for too long? We all know that only few chess players ended up millionaires compared to countless athletes out there. So what is the future for a child if decides to really pursue chess? He will most probably reach grandmaster strength with hard work only to realize that there are many others like him and that he will have to work even harder just to have a chance to become top level GM. Strong memory and good mathematical abilities do not count much - we have computers/smart phones and other stuff to do that for us, yet physical fitness is still of paramount importance for us.
Also, you can find sports report on any news station/newspaper/Internet page, yet chess resources are very skimpy - again this requires hard work or maybe devotion is the true word and not many 12 year old children possess it.
To conclude: After playing chess for sometime child will reach the peak at strengthening its memorization skills and after that it decides to pursue other interests and to explore new things. Devoting oneself to one thing at this early age is something that is not seen very often - children at that age learn about the world around them and it is normal for them to want to try everything. To devote oneself to chess - and you really need to devote yourself based on the reasons posted above - requires strong characters.
I will end this quoting Mikhail Botvinnik:

"Chess is for strong people, of strong character."

How many children do you know that possess these admirable traits?
Hopefully this answer will shed some light on the matter.
Again, I do not mean anything insulting, I just state my opinion which is backed up with arguments.
Feel free to comment, I will gladly reply.
Best regards.


While I'm not sure exactly how "fēənˈketō" would be pronounced (I'm not a native English speaker), that's more correct as to the pronunciation of the "ch" (following the Italian pronunciation).

The pronunciation written in English would be something like fee-ahn-keh-toh, with the accent on the third syllable (keh).

I just found this website in which there are actual recordings of italian (I hope) people pronouncing it. It sounds pretty good to me.


Is the Danish Gambit viable for Class D tournament play?

My old chess tutor answered a similar question of mine quite decisively: "Just don't worry about it: Below 2000 (FIDE) you can succeed with every opening."

Lower rated (or non-prepared) players do not know how to punish the weaknesses an opening like the Danish Gambit opens - and they make mistakes. Lots of them. Playing against as sharp of an opening as the DG requires your opponent to make really precise moves and prompts them to make even more mistakes on which you can capitalize on.

To conclude: I think you are perfectly fine playing the Danish Gambit in Class D tournament chess, as your opponents are not likely to know the theory and will probably blunder sooner or later, especially if the opening fits your style. Even in longer time controls. (Also playing sharp openings is just a lot of fun!)

Another opening that comes to mind is the Grob (1.g4). It is no less dubious at master-level, but if you put the effort into it and learn some theory behind it, you can absolutely obliterate a careless player.

Finally a word of warning: The higher you rise in the chess rankings (approaching 1800+), the harder it will get to win with "one-trick-pony" tactics. So put some time aside to improve your general Chess, not just one opening.


Why is it important to study classical games?

There are a variety of reasons:

Regardless of when they were played, there is always a lot to learn in analyzing better players's games.
Players from a century ago often used simpler strategical themes that are easier to understand and apply.
Opening theory was not that well developed back then, so the "actual game" starts earlier on. You also wouldn't find any "weird" moves that are justified by some obscure tactical sequence that only a computer can see.
Games between masters were, unlike today, rarely decided by at-home preparation.
Old masters had an awesome endgame technique.
The opposition was often weaker than today, so masters could execute their plan in a "pure" form. In more modern games, the main plan is most of the time hidden behind counterplay, counters to that counterplay, and so on...
A final point would be that these games have been reviewed multiple times by a lot of different people, each of them making their contribution


What should a player do when their opponent asks to see your notation sheet during a game?

Am I obligated to let an opponent see my game record so they can make corrections to theirs?

According to USCF rule 15D3, it's suggested that you do so, but it's not mandatory unless the tournament director tells you to:

The opponent is urged to comply with such a request, but this is not mandatory. If the opponent denies the request, the player may stop both clocks and see a director. A director who agrees that the request is appropriate shall instruct the opponent to lend the player the scoresheet. The opponent may not refuse as all scoresheets belong to the organizers.

The TD will probably allow it, unless there's some reason not to. Excessive requests may be denied and may even be penalized, according to rule 15D4.

Also, if I do show it to them, whose clock should be running as they make corrections?

According to USCF rule 15D2:

The clock of the player making such a request is running and shall continue to run until the scoresheet has been returned.

Under FIDE rules, the time control in question would be a Rapid game. According to FIDE rule A.3.2, which applies to rapid games:

The player may at any time, when it is his move, ask the arbiter or his assistant to show him the scoresheet. This may be requested a maximum of five times in a game. More requests shall be considered as a distraction of the opponent.


Why aren't 1.e4 g6 2.d4 Bh6, and 1.e4 b6 2.d4 Ba6 considered by theory?

White should trade bishops and use the unprotected knight to gain some extra tempo and gain a massive lead in development, e.g.

[FEN ""]

1. e4 g6 2. d4 Bh6 3. Bxh6 Nxh6 4. Qd2 Ng8 5. Nc3

4... Ng4 is best met by 5. h3 Nf6 (forced) 6. e5 Nd5 7. c4 Nb6 8. Qh6 and Black has problems completing his development, though there is no forced win at the moment.

I haven't analyzed the b6/Ba6 lines but I guess a similar concept holds.


How does a chess club become recognized by FIDE?

What would it take for the club to be recognized by FIDE?

FIDE does not recognize chess clubs (except perhaps maybe for club world cup competitions?). Depending on your country, your national chess federation (NCF) will likely need to recognize your club to allow you to participate in national team tournaments.

  I would like to give the members FIDE ratings

FIDE gives the ratings to players who have played in a tournament that has been registered as a FIDE-rated tournament. If you want to organize such a tournament, you should discuss with your NCF.

  and to participate in local and international events.

Your NCF may require each player to belong to a club recognized by the NCF before participating in tournaments rated by NCF. In international events, there is no requirement by FIDE to belong to a national club, but each player needs to register with FIDE via the NCF before entering the competition (since July 2014; before that registration was possible after the tournament).


The obvious issue with using an established engine to enumerate the moves is if there's a bug in the move generation function in the established engine.

Stockfish is always perfectly correct.

Goto https://github.com/official-stockfish/Stockfish/blob/master/src/search.cpp, add a std::cout in perft(). Recompile, and then run perft. Redirect your results to a text file.

Sort the results with: sort SFMoves.txt > SortedSFMoves.txt.

Similarly, repeat for your generator, sort it and then compare with Stockfish.

Common mistakes:

En-passpant
Underpromotion
Promote with a capture

Please check the special cases in your code.


Associating myself with my FIDE chess profile

Getting a login is easy, free and worthwhile if you want to see your or other players' histories (ratings, titles, performance, etc.) If you click on the link on your FIDE ratings page where it says "Get rating" next to "Online rating not rated" it will take you to the FIDE Online Arena page. Underneath the banner on that page is a menu item "Registration and fees" and in the drop down list when you hover over it is the item "Memberships"

That memberships page describes the different levels of membership available - "Guest Member", "FIDE Member", "Platinum Service". Guest membership is free and is what I have but it does not associate me with my FIDE profile. To do that I would have to join as a FIDE member and pay them 25 euros. On the form that comes up when I want to join as a FIDE member are entries for my name, date of birth, gender email address, FIDE number and the username and password I want to use. For the association to work the details I give would have to match those that FIDE have for me in their database.


Fischer objected to the proximity of the spectators, the intensity of the lighting, and the noise of the cameras. He did not request a separate venue. It was the organizers who suggested the ping-pong room as a compromise to address his objections.  They then set to work modifying the conditions in the main playing hall to meet his demands.

By the start of Game 3, they had been able to reduce the lighting, rearrange the seating of spectators, and relocate the cameras so their noise would not be heard by the players.


Why is Black supposed to attack on the kingside in the King's Indian?

There is a general principle that says that, in positions with a blocked center, every side must attack in the direction where his own pawn chain points to. For example, in the KID, sometimes White has pawns in e4 and d5 (White's pawn chain) and Black has pawns in d6 and e5 (Black's pawn chain). So we see that White's pawn chain points to the queenside, while Black's pawn chain points to the kingside.

The most efficient break move hits at the base of the opponent's pawn chain. So, for example, the base of White's pawn chain is the e4 pawn, so the most efficient break move for Black is f5 (and this is a kingside attack). The base of Black's pawn chain is the d6 pawn, so the most efficient break move for White is c5 (and this is a queenside attack).

If Black does not play e5, and he plays c5 instead, the argument above does not apply, and Black's strategy changes. Even if Black plays e5 and White decides to exchange with dxe5, opening up the center, then the situation is completely different. The KID is not a one-plan opening, it is very rich, I wish I could understand it better!

Another example of the aforementioned principle is given by the French Defense, where sometimes White has pawns in d4 and e5, and Black has pawns in d5 and e6. In this case White attacks on the kingside, and Black attacks on the queenside.


Undermining pawn chains at the "wrong" end

The first example that springs to mind are the Benoni structures:

[FEN ""]

1. d4 Nf6 2. c4 c5 3. d5 (3. dxc5? e6 {Black recovers the pawn favourably, so we see that 2...c5 induces the d-pawn forwards to be challenged later.}) e6 {Black challenges the head of the pawn chain, rather than the base.} (3... b5 {Attacking the base of the pawn chain with the Benko gambit is also a popular try.})


What happens if you move your king on stalemate?

Just like checkmate, stalemate immediately ends the game. From the FIDE Laws of Chess, 5.2a:

  The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in ‘stalemate’. This immediately ends the game,
  provided that the move producing the stalemate position was legal.

This is not overridden by any rules in Appendix B, covering Blitz, so the situation you describe is a draw.


What should be White’s move here in which each side has just a king and a knight?

Most people agree that this is a draw due to insufficient material, but FIDE and some chess websites say that a mate is possible.  Once you could also claim insufficient losing chances, but with increment clock, this rule has vanished.

To eliminate any possible mate, I would try to lose the knight.  The best move is Nd6 and chase the black knight until the draw is agreed upon.  An equally good move is Ne3 with the same objective.


Does playing correspondence chess improve your game?

Whether or not playing correspondence chess will help you to improve depends a lot on how you play.  If you move after a quick look at the position and use it more like a Blitz game with the possibility of pausing, then I do not think you will improve much.  If on the other hand, you use it to study the relevant openings, pawn structures, endgames, etc. then they can provide a real asset for improvement.  In particular if you combine them with some theoretical inputs from books etc. as you can then immediately try to turn the things you learn into praxis (which means you really learn them).

Another thing that may be worthwhile is to keep notes during the games of what moves you were considering and how you evaluated them.  In the post mortem you can then check your analysis and evaluation of the game and spot areas for further study and improvement (e.g., good moves you did not consider, or moves where your evaluation deviates strongly from that of, say, a chess engine or a coach).

Of course not everything improves by correspondence chess.  For example, if in OTB games you often hang your pieces or fall for simple tactics, then you really need to work on this separately.  The fact that you can try the moves in correspondence chess should help to eliminate these simple mistakes from your correspondence games but they will likely be back in OTB games.


How can I teach the endgame to someone who feels it is "boring"?

Many old endgame books are like encyclopedias, they have sections about one type of endgame and then a lot of analysis about all the various situations one might encounter in that endgame. I find those boring and very hard to remember. Let's forget about those.

I can think of three things to mention that might be helpful:

Jeremy Silman's endgame book is organized with chapters based on rating level. His point is that a 1600 player doesn't need to know all the intricacies of the endgame in the way a 2200+ player does. He also has a fun writing style. Maybe concentrating on the first chapters of that book helps.

Also, exercises. Both the Steps Method workbooks and Yusupov's series of books are full of exercises on chess in general, including chapters on various endgames. Challenging exercises are fun to solve and when you finally see how the solution works (usually there's only one way that works), that's memorable.

Thirdly, and probably the most work for the trainer, is to find a good, hard endgame study, and turn that into a whole lesson. I remember a training session I once had with GM Yge Visser (alas, I can't remember the position), where he showed a complicated endgame position. We, the students, could propose some lines but really had no clue.

He then wiped the board and started talking about various building blocks: the K+Q v K+pawn endgame (how it's usually a win, how the a and c pawns can draw, a few exceptions, then lines in which the white king is close enough that he can let black's pawn promote but threaten unpreventable mate on the next move, et cetera). He made this interesting by constantly asking the students, some of them knew some things already, nobody knew everything.

There were other building blocks like this, like the Reti study with the two passed pawns where it seems the black king has no chance to catch the white pawn or help his own promote, but then does it by cleverly keeping both options open.

After two hours or so of this sort of thing, he put the original position back -- and we recognized the main theme, and could suggest relevant moves. As we got a few moves in, it turned out that all those blocks were relevant, and eventually it was a mate in 8 or so, and we found it! "And if you manage to see all this during a game, then you're about GM level."

Although I can't remember the position anymore, I still learned everything I know about K+Q v K+pawn in that session, and it was great fun.

But to find such positions and to turn them into lessons that good takes quite a lot of experience as a trainer, I guess.

In short: don't teach him theory, challenge him with exercises and puzzles.


Could chess puzzles change with the introduction of stronger engines?

Our modern chess engines are already perfect for solving tactical puzzles. @Bad_Bishop's example is an easy problem for Stockfish.

If you're talking about artificial deep chess problems (not puzzles), even AlphaZero might have problems. Some chess engines (e.g. Houdini) has a "tactic" mode for those problems.

No. Nothing much will change with stronger engines.


Statistics on how a rating or winning percentage corresponds to the (opening, middle, end) game?

No.  There is a rating system based on wins, losses, and draws, not for proficiency in phases of the game.  How would you quantify that?  Knowing the main line on the MCO for your openings?  People are always finding improvements to main and obscure opening lines.  This is the TN (theoretical novelty) that people search feverishly for.  So what might be sound play in the opening in January may be unsound by August.

Further, I have seen flawless openings and middlegames come to grief because of a tiny blunder in the endgame.  As Tartakower once said, the winner is the player who makes the 2nd to last mistake.  So there is not really an accepted method of tying knowledge of component phases of the game to winning percentage, because there are too many other factors at hand.  If the game 's phases could be defined down to a formula of what is good play in the opening, middle game or ending, computers would always win.  We still have imperfections of shortsightedness and obliging opponents, and time controls, and other distractions.


In order to calculate effect on national rating, should it be enough
  to choose the relevant k koefficient (assuming this is what makes for
  the discrepancy between national rating and FIDE rating) and plug it
  in here: https://ratings.fide.com/calculator_rtd.phtml ?

No. For the simple reason that countries use different methods for their rating/grading system. Some use an elo system others don't. England, for instance, uses a completely different system.

If you go to the ECF grading website and click on help, on the left hand side of the page, then towards the bottom of the help there is a section describing how the ECF calculate their grades.

  HOW ECF GRADES ARE CALCULATED
  The basic method of calculation is as described in the next few paragraphs. For juniors, however,
  there are differences as described further down.

  Points are allocated in respect of each game. For a win you score the
  opponent's grade plus 50, for a draw the opponent's grade, and for a
  loss the opponent's grade minus 50. "Grade" means his grade current at
  the time of grading. There is a proviso that if your opponent's grade
  differs from yours by more than 40 points it is assumed to be exactly
  40 above (or below) yours. This applies whatever the result.

  If an opponent (or the player himself) is ungraded, a "starting grade"
  is estimated, using all available information. See Estimating a
  starting grade for an ungraded player below. Note that FIDE ratings
  are ignored. An opponent who has only a FIDE rating will be treated as
  ungraded.

  In the interval between the end of a grading period and publication of
  the new grades, the "current" grade for calculation purposes is the
  new, as yet unpublished, grade.

  The grade is calculated by dividing the total number of points scored
  by the number of games played. If there are 30 or more games in the
  most recent 12 months, then the grade is based on these games alone.
  If there are not, it is based on the most recent ** 30 games played;
  or on all the games played in the last 36 months if that is less. In
  no case does calculation go back more than 36 months. Where games are
  brought forward from a previous period, they are not recalculated. The
  number of points scored for a game always remains the same.

  ** "Most recent" has a special meaning here. In principle the program counts backwards till it reaches 30 games. But there are certain
  disadvantages (see Appendix) to applying this naïvely. Instead, if the
  30th game falls part way through a 6-month period, the program will
  take as many games from that period as it requires in order to make up
  the 30; but they will be notional games calculated at the average
  score for the whole 6-month period.

  How is "most recent 30" interpreted if a game has been reported late
  and graded in the "wrong" period? Answer: the game will be listed
  under the grading period in which it was reported and calculated, and
  it will go into that period's grade with a notional playing date of
  1st January (or 1st July as the case may be). This notional date will
  be used, where necessary, to determine the game's position in the
  backward count to 30.

  Rounding
  Grades are calculated to the nearest whole number (halves
  go up). Rounding is done once, at the end. A grade, once rounded and
  published as a whole number, is henceforth deemed to be that whole
  number.

You say -

  I'm located in Israel, so if anyone knows that specifically, even
  better

Really? Do you play chess in Israel? Do you have an Israeli rating? Can you read Hebrew?

I'm guessing some of the answers must be "No" since otherwise you would be better placed than 99.9% of forum members to find out the information for yourself and are only asking out of sheer laziness.

My ICF rating is in the 1800's and my k factor is 12.

Boris Gelfand's ICF k factor is 10 as you can see from the calculations for his Israeli rating from his games played abroad (i.e. converting his opponents' FIDE ratings to ICF and then using them to calculate changes to Gelfand's Israeli rating). This link takes you to Gelfand's ICF rating page and then you will have to click on  משחקים בחו"ל (middle / fourth of the box links underneath his main details).

Here is the same page for Liel Levitan, the European Schools girls U7 champion. Her Israeli rating is 1445 and her k factor is 14. Again, on the page click on משחקים בחו"ל to get to the calculation page.

Here is the Israeli rating list (but I don't understand why you couldn't get this for yourself if you are living and playing in Israel?) You can find players of different strengths and ages and check their k factors. I know the ICF website is hard to navigate. I found the old one from about 5 years ago much easier. It used to give the calculations, including k factor, for every game, not just the foreign ones, so including the Israeli ones.

As you can see from the FIDE Ratings Change Calculator you cannot type in any k factor. That means that in general you cannot use this for ICF ratings and for other federations only if they use the same k factors.


Does Stockfish(and other chess engines) learn after an analysis? (is there a machine learning algorithm implemented in it?)

No, there is no machine learning implemented
Due to hashing, next time when you run the same analysis you might not get the same results
Some other much weaker engines do have machine learning implemented, but not Stockfish
See My question is about inconsistencies in Stockfish 7 outputs


Why the ratings used for different time controls are different?

Different (though related) skills are involved in standard chess and blitz chess.

The standard rating is the one that really "counts" as far as people's lists of the best chess players goes. So you don't want to contaminate that rating, used for hours-long serious games, with results from 5-minute games. The blitz and rapid ratings were introduced recently so that players' games at those time controls can count for something without affecting their "real" standard rating.


If you do not play in tournaments, then you do not have a rating. You are unrated.

If you play online, then you will have a rating. However, this is unofficial and cannot be used anywhere else.


Parsing PGN files - when can a move be shortened?

From the PGN specification (http://www6.chessclub.com/help/PGN-spec):

  Neither the appearance nor the absence of either a check or
  checkmating indicator is used for disambiguation purposes.  This means
  that if two (or more) pieces of the same type can move to the same
  square the differences in checking status of the moves does not
  allieviate the need for the standard rank and file disabiguation
  described above.  (Note that a difference in checking status for the
  above may occur only in the case of a discovered check.)

This means you have to specify files respectively ranks in your two diagram examples.

My understanding is that you need to disambiguate in the last two situations you describe as well.


Is capturing a piece while castling legal?

No, such a move is illegal, because one requirement of castling is that there be no pieces (of either color) standing between the king and the rook. From the FIDE Rules of Chess, 3.8(b):

  Castling is prevented temporarily:

  a. if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or

  b. if there is any piece between the king and the rook with which castling is to be effected.


In what way is it allowed to alter tournament pairings in favor of a player?

It says the exact opposite.

  C.04.2 A It is not allowed to alter the correct pairings in favour of any player.

So no, you can't.

  Where it can be shown that modifications of the original pairings were made to help a player achieve a norm or a direct title, a report may be submitted to the QC to initiate disciplinary measures through the Ethics Commission.

FIDE could try to punish the player or you.


A list of chess variants and their popularity

To simply name a few of the variants here would need a huge amount of space, because there are many. However, you have a list of variations in the Wikipedia entry:

Chess variant.

This entry is not comprehensive, and a few variations that cannot be found there appear in the webpage:

Alphabetical Index of Chess variants.

These sites do not come with popularity rankings, and the same way chess itself probably does not have a "major" event (one could consider the World Chess Championship to be it, but as only two players play and the number of games and funds has been so drastically reduced, I'm not sure anymore), probably there is not a single "major" event for these variants too. However, to a certain extent, the length of the Wikipedia article on a certain variation can measure its popularity, so I suggest you take a look at the Wikipedia category:

Category: Chess variant


Why did Smirin resign against Anand in the Blitz semifinal 1994?

While in the final position, checkmate is still a move or 20 away, it's clear that White is lost. Black is a piece ahead with no compensation for White at all. People resign in such a position already on the higher level of club play. In a normal (i.e. non-blitz) game between grandmasters, White would probably already have resigned by move 30.

[FEN ""]
[White "A. Smirin"]
[Black "V. Anand"]
[Event "New York Intel Active (blitz)"]
[Result "0-1"]
[Date "1994"]
[StartPly "100"]

1. e4 e5 2. Nf3 Nf6 3. d4 Ne4 4. Ne5 d6 5. Nf3 d5 6. Bd3 Nc6 7. O-O Be7 8. c4 Nb4 9. Be2 Be6 10. Nc3 O-O 11. Be3 Bf5 12. Rc1 dxc4 13. Bc4 c6 14. Ne5 Nc3 15. bxc3 Nd5 16. Qb3 f6 17. Qb7 fxe5 18. Qc6 Be4 19. dxe5 Kh8 20. Bd4 Rc8 21. Qa6 Nf4 22. f3 Rc6 23. Qa4 Rc4 24. Qc4 Bd3 25. Qc6 Ne2 26. Kh1 Nd4 27. cxd4 Bf1 28. Rf1 Qd4 29. f4 Qe5 30. g3 Qc5 31. Qe4 Bf6 32. Kg2 Rc8 33. Rf2 Qc6 34. Qc6 Rc6 35. g4 h6 36. Kf3 Rc3 37. Ke4 Kh7 38. Re2 Rc4 39. Kf5 Rc5 40. Ke6 Rc4 41. Rf2 Kg6 42. h3 Rc3 43. Rh2 Rf3 44. f5 Kg5 45. a4 Kh4 46. Kd5 Ra3 47. Kc6 Ra4 48. Kb7 a5 49. Kb6 Ra3 50. Kb5 Rh3


Simple. Inter-thread communication. Specific implementations could be:

Internal UCI queues
Find the UCI loop function then hook it up (e.g. UCI::loop in Stockfish).
Redirect the standard input/output into pipes

Few points:

It's not a good idea to do your works with Swift, because Swift has poor support for C++. I prefer Objective-C as it works with C++ at the source level.
Redirecting is recommended if you're confident. All my iOS apps use that. You just need to send your UCI commands to a redirected pipe, while the engine receives them from the standard inputs (redirected). This is not a place for discussing unix programming, please ask Stackoverflow. It works.


I found one in 8 moves:

[Title "Shortest En Passant Helpmate?"]
[fen ""]

1. e4 f6 2. Bb5 Kf7 3. Qe2 Ke6 4. e5 Qe8 5. Qe4 Qf7 6. d4 a6 7. Bf4 d5 8.exd6#


What are good defenses of black King with Bishop on f8 or g7?

There are a lot of openings where Black fianchettos his king's bishop, and it ends up on g7. Versus 1. d4 you have the King's Indian Defense and the Grünfeld Defense; if White opens 1. e4 you can respond with the Pirc Defense. The Modern Defense is usable against both.

Without playing g6, Black has to move his rook on f8 (after castling short) and retreat the bishop to f8. That's far less common, though there are some (side)lines in the Sicilian and the Ruy Lopez where this happens.


Chess program that will play an opening against me?

Fritz published by ChessBase can do it for you.

Let's see this tutorial to force Fritz to play specific opening.


How to configure scidb to use ChessBase files like ChessBase?

Scidb does not support videos, and I don't think that videos will be supported before the second alpha version is released. Currently Scidb is still a beta (test) version. Whether it is really possible to read the ChessBase videos - this includes also the associated timing data - is still an open question.


When I said chess is a zero sum game in that answer, I wasn't referring to anything involving ratings. Obviously if we include ratings then chess isn't strictly a zero sum game, since the gains and losses aren't always balanced out. But different rating systems are arbitrary, and aren't part of the game of chess itself.

Your question should be "Is the FIDE rating system a zero sum game?"


Time Control for Bullet, Blitz and Standard

There is no such globally accepted formula. Time controls are defined only by their formal definitions (as unhelpful as that sounds). Any further descriptive language, like "blitz" or "lightning" or "bullet", while they carry certain conventional connotations, do not have objective criteria. However, certain organizations may define these terms concretely within their own domains.

USCF

The USCF defines three time-control zones: Regular, Quick, and Blitz. Different sets of time controls fall into one (or more--it is possible for a game to count as both Regular and Quick, in which case the player's ratings in both categories are affected) of these categories. Determining the category is simple: calculate the [estimated] total playing time (TPT_U) as:

TPT_U = Minutes + SecondsPerIncrement

The TPT_U is then slotted into a zone as follows:

TPT_U > 65: Regular
30 ≤ TPT_U ≤ 65: Regular AND Quick
10 < TPT_U < 30: Quick
5 ≤ TPT_U ≤ 10: Blitz

FIDE

FIDE defines (as far as I can tell) two time-control zones beyond the standard FIDE time control: Rapid and Blitz. To determine which of these zones a time control falls within, calculate the [estimated] total playing time (TPT_F) as:

TPT_F = Minutes + SecondsPerIncrement

The TPT_F is then slotted into a zone as follows:

10 < TPT_F < 60: Rapid
TPT_F ≤ 10: Blitz

CHESS.COM

Chess.com defines three time-control zones: Standard, Blitz, and Bullet. To determine which of these zones a time control falls within, calculate the [estimated] total playing time in minutes (TPT_C) as:

TPT_C = Minutes + 2/3*SecondsPerIncrement

This assumes a forty-move game and is derived from the following expression (multiply the increment in seconds by forty, then convert to minutes):

TPT_C = Minutes + (40 * SecondsPerIncrement / 60)

The TPT_C is then slotted into a zone as follows*:

15 ≤ TPT_C: Standard
3 ≤ TPT_C < 15: Blitz
TPT_C < 3: Bullet

*I've had to extrapolate here, as the definition actually appears to leave a gap between 14 and 15 minutes. I've filled this gap in the manner I considered most likely to be accurate.

Examples

Base | Incr | TPT_U | TPT_F | TPT_C | USCF  | FIDE  | CHESS.COM
-----|------|-------|-------|-------|-------|-------|----------
 2   | 1    | 3     | 3     | 2.667 | N/A   | Blitz | Bullet
 3   | 0    | 3     | 3     | 3     | N/A   | Blitz | Blitz
 3   | 2    | 5     | 5     | 4.333 | Blitz | Blitz | Blitz
 5   | 0    | 5     | 5     | 5     | Blitz | Blitz | Blitz
 10  | 0    | 10    | 10    | 10    | Blitz | Blitz | Blitz
 10  | 1    | 11    | 11    | 10.67 | Quick | Rapid | Blitz
 14  | 3    | 17    | 17    | 16    | Quick | Rapid | Standard


The sacrifice is quite dubious.  Besides the answers with 10.Nxe5, 10. Rxe5 is simply two knights for a rook and there is no attack for Black.


Easy to use, MS Word-like tool to record chess games

The closest thing I can think of to what you want, though it is still PGN file based, is ChessPad.  http://www.wmlsoftware.com/chesspad.html.  It's a very basic pgn file editor/viewer which maybe your friend could use standalone, or he could use it to create diagrams which he then pastes into MS Word.


Check the program pgn-extract (https://www.cs.kent.ac.uk/~djb/pgn-extract). It has what you probably need. Here I copy a fragment of its help:

Include a position evaluation after each move (--evaluation)
The --evaluation argument causes a comment to be appended to every move, which contains an evaluation of the position immediately following that move. The default evaluation is a simplified version of Shannon's board evaluation. In this case, the evaluation is the difference between the value of White's position and Black's, where the value of a position is a weighted sum of the pieces plus a multiplier (0.1) applied to the number of available moves for that player.
I see this primarily as being a hook for people who wish to embed their own evaluations in the output. See the evaluate function in apply.c if you wish to write your own.
However, an alternative approach to annotating games with engine analysis would be to consider using something like my UCI-analyser that can pass suitably formatted PGN files to a UCI-compatible engine. See, for instance, the section on obtaining annotated output in PGN format.

pgn-extract: A Portable Game Notation (PGN) Manipulator for Chess Games
Version 19-04 by David J. Barnes (@kentdjb)


Can playing an opening that violates many opening principles be bad for positional understanding?

Generally speaking, violating positional elements, at any time, is bad for positional understanding.  When you win a lot of games with bad positional play, this provides positive reinforcement for playing badly.
This opening, often called the Black Bear of the Philidor, isn't really breaking the opening principles.  Black has gained space on the kingside, has equal control of the center, is just as developed as white (especially considering that there's no good places to put the bishops), and the king is safe as long as the center remains mostly closed.
Great players know when to break the rules.  https://www.chessgames.com/perl/chessgame?gid=1282302


Python-chess : Are the move scores enough to rank moves from the most to least likely moves played by an engine?

The volatility of the score here is caused by the time limit you have set. With time=0.100 you're restricting the engine to 100 milliseconds. With such a small time limit, there are a lot of small factors that can dramatically change the results. You can try increasing the time limit, or instead of using a time limit you can try a depth limit instead. This will make the engine search to a specific depth, rather than searching for a set amount of time. A depth limit will probably make your results more robust.

An example of depth limit would be:

chess.engine.Limit(depth=20)


That specific opening is called the Anderssen Opening: Creepy Crawly Formation, Classical Defense
From about 1,000 test engine games it seems that its a remarkably even set up;
White : 45.5%
Black : 45.5%
Draw  : 9%
Based off that result I would say its very much playable. This is be cause you white usually plays the left side of the board slowly working towards the center;
One Notabale Game describing that concept Michael J Basman vs Yuri Yakovich - Hastings (1994)
 rnbqkbnr/pppppppp/8/8/8/7P/PPPPPPP1/RNBQKBNR w KQkq - 0 1

 1. h3 e5 2. a3 d5 3. c4 c6 4. e3 Nf6 5. b4 Bd6 6. Bb2 O-O 7. Nf3 Qe7 8. Qc2 Nbd7 9. cxd5 cxd5 10. Nc3 a6 11. Na4 d4 12. Rc1 b5 13. Nc5 Bxc5 14. bxc5 Bb7 15. c6 Rac8 16. c7 Nd5 17. Qf5 Rxc7 18. Rxc7 Nxc7 19. Be2 dxe3 20. dxe3 f6 21. O-O Nc5 22. Rd1 Rd8 23. Bc3 Rxd1+ 24. Bxd1 Qd7 25. Qb1 Be4 26. Qc1 N7e6 27. Nd2 Bg6 28. Bg4 h5 29. Be2 Qd5 30. Bb4 Kh7 31. Nf3 Nd3 32. Qc8 Nxb4 33. axb4 Qa2 34. Bf1 Bf7 35. Bd3+ g6 36. Qd7 Kg7 37. Be4 Nf8 38. Qb7 Qc4 39. Bc6 Kg8 40. Qxa6 e4 41. Nd4 Qxb4

Src: https://www.chess.com/games/view/657313


When is it appropriate to use a program during games with a longer timeframe, such as correspondence chess?

If you haven't agreed before the game then you should assume that it's not allowed. It will usually be regarded as cheating. If you wish to use a computer you should ask your opponent before you do so.

Playing with the assistance of a computer is sometimes called Advanced Chess. If you agree before hand that it's allowed, then there's no problem and both can use a computer freely. Some Advanced Chess tournaments are also played with standard time controls.

  Thinking about it, I'm not sure what the point of two players using engines would be.

The point of Advanced Chess is that a computer is strong at fast and accurate calculation but weak at strategy, while the human is stronger at strategy but more prone to errors in complex tactic situations. The human can use their strategic ability to guide the computer into strong strategical positions or won end game positions, while the computer can check that there are no blunders that the human may have missed. If played well, the playing strength of the human-computer team can be higher than each individual playing alone.


What's the winning box for the King in a Queen against 7th rank Bishop-pawn endgame?

There are actually two zones, depending on which side of the pawn the black king is. If it's already in the corner, the zone is small:

If the black king on the other side (towards the center), the zone is larger. The white queen can force the king to stand in front of the pawn, giving the white king an extra tempo to reach the 'small' zone above. (This also applies if the king is in front of the pawn already.)

(diagrams from Fundamental Chess Endings by Müller and Lamprecht)


Is there software or a device that allows bookmarking positions to allow variation analysis?

Chessbase is a commercial product that solves your problem.  Any position in Chessbase is in essence a bookmark.  You can just click on the move/position you want to go back to (all the moves are available visually beside the chess board).  I believe the same functionality is available for free with Scid.


I provided water bottle to my opponent, he drank it then lost on time due to the need of using bathroom. Is this unethical?

No, what you did is what is known as a gambit. You offered your opponent material (in this case a water bottle), which he accepted. This would be considered a blunder on his part, since although it gave him a temporary hydration advantage, it ended up costing him time due to the uncomfortable situation it caused for his bladder, which needed to be resolved. If he had instead declined the gambit, he may have won, but such is the way of the game.


Are there any websites that allow standard correspondence chess time controls?

http://ChessTempo.com offers a wide choice of correspondence time controls including a fixed number of days per game, or increment after a move. Just check it out.


The Art of the Checkmate, Quiz 24: Is there a win?

Yes, you're right, there is no forced win. With correct play, White avoids the mate, and Black can only win one of the two pawns he is currently behind. White will have a healthy pawn more with best play from both sides:

rn3rk1/pp3ppp/3b1n2/2pPq3/2B1P3/1NN2bP1/PPPQ1P1P/R1B2RK1 b - - 0 1

1... Qh5 2. Re1 Ng4 3. h4 Ne5 4. Bf1 Bxe4


Looking for resources on a sideline of the Caro Kann, 1. e4 c6 2. Nc3 d5 3. Qe2

I have several Caro-Kann books and none mention this line.
In general, http://www.kenilworthchessclub.org/, and https://www.chessgames.com/ are good opening resources.
When you're analyzing rarely played lines it's best to just use a database and an engine. That's all I really use anymore anyway. Occasionally, I'll look at book if I don't understand a particular move but mostly it's database and engine.
White is getting crushed in this line. After 4. Nd1, e5, black is at least equal. I don't know why you'd want to play it.  Something like the 2 knights or the KIA would lead to similar positions but are better openings.


About the 3D chess they play on Star Trek

Andrew Bartmess was the first Star Trek fan to reverse-engineer the game of tridimensional chess from the TV series (which never explained the rules). He sells his version of the rules for $9.95: Tri-D Chess Rules.

In the most popular version of Tri-D chess (which Andrew calls the “The Federation Standard 5.0” rules), the game is played on seven boards, three of which are the “main” boards and four of which are “repositionable attack boards”:

Players can reposition one of the four attack boards by repinning them to the static boards at different points, provided that one of their pieces occupies that board (and no other piece occupies it). This is instead of moving a piece in that turn. The boards are, in effect, treated as mobile “attack craft”.

The notation system uses a z-index from 1-7 to indicate which board the piece is moving to:

Unfortunately there’s no free version of Bartmess’ rules available online.

Jens Meder maintains an alternate but free online version of Tournament rules for Three-Dimensional Chess which are inspired by Star Trek and tied more closely to standard FIDE chess rules than Bartmess' version, albeit with the same wonderful board stand and complex notation:


Is any chess software specifically for forced mates?

Joseph Ellis on talkchess has a modified Stockfish for mate solving.

Updates:

1) Sync with latest SF.
2) Move to full hash key.
3) Increase max depth to 250.
4) Improve mate detection.

https://dl.dropboxusercontent.com/u/1145468/MateFinder.7z

The archive includes the source and two very basic windows compiles.

http://talkchess.com/forum/viewtopic.php?t=58597&highlight=mate+solver

The Github URL: https://github.com/jhellis3/Stockfish/tree/mate_finder

I never downloaded the archive and have no idea how good it is. I think it might worth a try as Joseph seemed to know what he was doing.


This position is not easy to assess.

Indeed, white has a rook, but black has a bishop and two pawns for it, which is roughly equal material-wise.

Also there are no open files, so white's rook do not have a straightforward way to enter black's position. The best white could currently do is to try to create counterplay against the pawn on e6 and create a blockade on the dark squares, preventing black from advancing the pawns. Since black does not have a dark squared bishop that should be reasonably easy to achieve.

As a long term plan, white can transfer his king to the queenside (e.g. to b2) and open some lines with g4, which does seem somewhat dangerous for black.

Still I think black is doing perfectly fine so far as the position is still closed, there are potential threats against g2 and the pawns are ready to run.

Overall I'd say the position is roughly equal (but interesting!).


Does any PGN actually use the '%' (escape) or ';' (rest of line comment) mechanisms?

You can use the percent sign to comment out a line of text in your PGN file (similar to Latex). For example, if you'd like to include personal comments that categorize the games within the database, such as % Games to study later. All such lines starting with % will not be interpreted by a PGN parser, so you can safely leave self-notes or other comments (that you might want to later parse in a script) in a PGN database.

An example of such a PGN file:

% Interesting games from Wijk aan zee

1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. d3 d6 5. c3 a6 6. Ba4 Be7 7. O-O O-O 8. Re1
Re8 9. Nbd2 Bf8 10. h3 b5 11. Bc2 Bb7 12. d4 g6 13. a3 Nb8 14. d5 c6 15. c4 Nbd7
16. a4 Qc7 17. b3 Rec8 18. Ra2 bxc4 19. bxc4 a5 20. Nf1 Ba6 21. Ne3 Nc5 22. Nd2
cxd5 23. cxd5 Rab8 24. Ba3 Qd8 25. Qf3 h5 26. Raa1 Bh6 27. Rab1 Rxb1 28. Rxb1
Kg7 29. Nef1 h4 30. Ne3 Bf4 31. Nef1 Qc7 32. g3 hxg3 33. fxg3 Bh6 34. h4 Qd7 35.
Kg2 Nxa4 36. Bxa4 Qxa4 37. Bxd6 Qd4 38. Qf2 Qxf2+ 39. Kxf2 Bxf1 0-1

% Caro-Kann games:

1. e4 c6 2. Nf3 d5 3. Nc3 Bg4 4. h3 Bxf3 5. Qxf3 Nf6 6. Be2 e6 7. O-O dxe4 8.
Nxe4 Nxe4 9. Qxe4 Nd7 10. d4 Nf6 11. Qd3 Qc7 12. Rd1 Be7 13. c4 O-O 14. Be3 Rfd8
15. Qb3 Rd7 16. Bf3 Rad8 17. a3 h6 18. g3 b6 19. Kg2 c5 20. Qc3 a5 21. Rac1 cxd4
22. Bxd4 Ne8 23. h4 Bf6 24. Bxf6 Nxf6 25. b4 axb4 26. axb4 Rxd1 27. Rxd1 Rxd1
28. Bxd1 Kf8 29. Bf3 Ke7 30. c5 bxc5 31. bxc5 Kf8 32. Qb4 Ne8 33. Qb6 Qe5 34.
Bc6 Ke7 35. Bxe8 Kxe8 36. c6 Qd6 37. Kg1 g5 38. h5 f5 39. Qb7 Qd1+ 40. Kg2 Qd5+
41. Kh2 Qd4 42. Kg1 Qd1+ 43. Kg2 Qd5+ 44. Kh2 Qd4 45. Kg1 1/2-1/2

You can experiment with this by loading the PGN file (like the above) on for example chesstempo in order to sanity check the parsing, and see that those lines are indeed correctly ignored.

As for annotations and the use of the semicolon see this answer by Andrew.

Briefly, the semicolon is another way of indicating move annotations but it's not efficient as it requires including redundant characters and line-skips per annotation, e.g.:

1. d4; closed system
1...d5 2. c4

instead of 1. d4 {closed system} d5 2. c4. And the semicolon notation is rarely supported by PGN parsers. So the use of curly brackets {} is always recommended, as it's well supported, simple and intuitive to use and less prone to mistakes in the notation.


Can I play on Lichess with my own "client"?

Lichess does not support the FICS-interface, therefore clients used for FICS do not support it. At the moment you can only play it via a web-client.

Maybe in the future the Lichess-API allows sending and receiving moves, etc. Apparently it is already possible as the API already allows it via HTTP, see Link.

EDIT:
As stated in this issue tracker thread pychess is interested in integrating Lichess support. An official desktop client will most likely not come in the near future as the web GUI is fantastic already and developers can use the time to further improve the current codebase.


Why is capturing the bishop in this position a blunder?

It is a blunder White can win a piece instead. Black's queen is trapped in a molasses of its own pieces, so to speak, and White has a very good chance of trapping it. Capturing the bishop loses this large possibility, and is thus a grave mistake.
Here is White's best line of play that quickly plants Black a firm loss.
[FEN "r2n1rk1/pp1bppbp/1n4p1/q1N5/3P3N/PB2B2P/1P3PP1/R2Q1RK1 w - - 0 1"]

1. a4 Qb4 2. a5

By playing a4, White threatens to play Bd2 on the next move, winning the Black queen. Moving the Black knight on b6 to clear room for the queen doesn't help. This is because moving it will lose the bishop on d7, which is attacked by the White knight on c5. As such, Black's best move is Qb4. Now White can play a5 and win a piece! Either the Black knight is taken by the pawn, or it moves, and the bishop is lost.
In other words, playing Nxd7 is a blunder because the chance to win a piece, and likely the game as a result, is lost. This teaches that it is very important to look out for any threats that you can make.


There is no "official" definition because there's no ISO standard for chess terminology, so the term means whatever the author wants it to mean, but I'd say the essence of it is that it is a "safe" and "advanced" square for a piece, where "advanced" typically means at least the 5th rank. As an analogy consider common non-chess definitions of outpost such as "an outlying or frontier settlement" or "a military base established in another country".

"A position on the chess board where a knight is defended by a pawn from its same side" is not only too restrictive by being limited to knights, but at the same time is too unrestricted because it would include something like a white knight on f3, which while protected, is hardly at an out-post; it's more of a "home base".

As for the "safe" part, it's a bit relative, but generally it means that it is not easy for the opponent to chase away or trade the piece. This may mean that the piece can't be chased away by pawns, because there are no pawns on the adjacent files or they are too far advanced, or because the pawn move to chase away the piece would come at a cost. Alternatively the opponent could trade it for a piece, but sometimes it's a bad tradeoff because the player who had the outpost might get some compensation such as a protected passed pawn. Or sometimes there is no way to trade it without sacrificing material, for example in a knight vs bishop scenario where the bishop is on the wrong color squares, so the only way to capture the knight is with a rook.

Finally, while not all outposts are for knights, perhaps most are; the reason for the emphasis on knights is due to knights being short-range pieces. Rooks and bishops can often be active from their home territory when on a good file or diagonal, but knights need to move closer to the action.


1700 rated games-On mistakes and how to correct them

Even at 1700, the vast majority of your mistakes are going to be tactical errors...especially at the faster controls. The only way around that is to start studying and practicing.

There may be some people, who can benefit from online tactics, but am of the belief that they lend themselves toward the trainee being shallow, and often the answers are the computer answer, not the human answer.

I am a firm believer in books, so get yourself some good tactic books that are well-categorized. It is better to study specific categories at one time, pins, skewers, etc. I still love the Fred Reinfeld 1001 books.

Try to do 50 per day, spending no more than two minutes per problem. Note in pencil on a scale from 1-5 how easy you found the problem because you will do them again in the future. The more time you spend on tactics, the less you will lose online.

One last thing, and that is I have found that even mid-level players think they are pretty good at tactics, but it is my experience that they are not. I am no longer above 2200 USCF, but even when I was, I always felt I could be stronger at that, and general calculating.