Variation in Max Lange Attack In the position at 15:29 of this video, what are some possible variations the line starting with the move 12...Qe5 that lead to an advantage for white?

 [FEN ""]

 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d4 exd4 5. O-O Nf6 6. e5 d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5 11. Nce4 O-O-O 12. g4 Qe5

In that position, 12...Qe5 is the main line since the other lines all lead to clear advantages for white. 12...Qd5 and 12...Qg6 are forced losses in short order, while 12...Qg4, even though not best, it leads to crazy lines, which I also added to the analysis. Even then, there are a thousand more lines, but I added in only some of the most reasonable alternatives. If you wonder about about a line that was not included in a tactical sequence of captures, there is probably some obvious win that you should be able to find with a little thought.

After 12...Qe5, there are only two decent moves for white, which both lead to roughly equal games, but it is still incredibly complicated: 13.Nxe6, which is the main move, and even 13.fxg7 is not bad.

I used both my database, and what it shows has been played before, and a fairly strong computer running Stockfish 11 to come up with these lines. There is A LOT of stuff here, and I do not recommend trying to memorize all of it if that is your goal, but you can play through it and just enjoy some of the tactics.

In super tactical lines like this, especially as you get stronger, many players memorize a few of the main branches of such lines, but they know that if the opponent varies from them, that there is something there, and spend more time to try to find it over-the-board. In other words, the opponent not playing the memorized line is like a big flag waving that there is something hidden there, and you have to find it.

 [FEN ""]

 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d4 exd4 5. O-O Nf6 6. e5 d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5 11. Nce4 O-O-O 12. g4 Qe5 {This is the main move because the other two are bad to just losing in a few moves.} (12... Qd5 $4 13. fxg7 Rhg8 14. Nf6 Qd6 15. Nge4 Qe5 16. f4 d3+ 17. Kg2 Qd4 18. c3 $18 {And the queen is trapped. This has been played three times in my database.}) (12... Qxg4+ $2 13. Qxg4 Bxg4 14. Nxf7 gxf6 $1 (14... Bd6 15. Nxd8 Rxd8 16. Nxd6+ cxd6 (16... Rxd6 $4 17. Re8+ Kd7 18. fxg7 $18) 17. fxg7 $16) 15. Nxh8 Bb4 (15... Rxh8 16. Nxc5 Nb4 17. f3 Bf5 18. c3 Nc2 19. Bf4 Nxa1 20. Rxa1 dxc3 21. bxc3 $18) (15... Bh3 16. Nf7 Rg8+ 17. Ng3 Bb4 18. Re4 Bf5 19. Re2 d3 20. Re3 Bg6 (20... d2 21. Bxd2 Bxd2 22. Nh6 $18) 21. c3 Bc5 22. Nh6 Rd8 23. Nf1 Bxe3 24. Bxe3 $16) 16. c3 dxc3 17. bxc3 Nd4 (17... Ne5 18. Bf4 Nf3+ 19. Kg2 Nxe1+ 20. Rxe1 Be7 21. Ng3 Ba3 22. f3 Bd7 23. Nf7 Re8 24. Rd1 $16) 18. Bf4 f5 (18...Nf3+ 19. Kg2 Nxe1+ 20. Rxe1 Be7 21. Ng3 Ba3 {As above.}) 19. cxb4 Nf3+ 20. Kf1 Nxe1 (20... fxe4 21. Rxe4 Bf5 (21... Rxh8 22. Rxc4 c6 $18) 22. Nf7 Bxe4 (22...Rg8 23. Nd6+ $3 {Only move.} cxd6 (23... Kd7 $4 24. Nxf5 Rg1+ 25. Ke2 Rxa1 26. Kxf3 $18) 24. Rxc4+ Kd7 25. Rd1 $18) 23. Nxd8 Kxd8 24. Ke2 $16) 21. Nf7 Nd3 (21... Nc2 22. Rc1 Rf8 $4 23. Ned6+ cxd6 24. Nxd6+ Kd7 25. Rxc2) 22. Nxd8 Nxf4 (22... fxe4 23. Bg5 h6 24. Bf6 c3 25. Bxc3 Kxd8 26. Kg2 $18) 23. Nxb7 Kxb7 24. Nc3 $16) (12... Qg6 $4 13. Nxe6 fxe6 14. fxg7 $18 {As both Bc5 and Rh8 hang.}) 13. Nxe6 fxe6 (13... Qxe6 $4 14. Nxc5 $16) 14. fxg7 Rhg8 15. Bh6 {It is important to prevent that rook from becoming active against your king.} d3 (15... Be7 {Keeping an extra piece on g5, which may be relevant later. It also stops Nxc5.} 16. Qf3 Qd5 (16... d3 17. c3) 17. Qf7 $1 $16 {Stopping Ne5 with Rad1 next.}) 16. c3 d2 {This is the main line, but there may be room for improvement here.} 17. Re2 Rd3 18. Qf1 Qd5 19. Nxd2 {This natural computer move is new, and should leave black looking for improvements on move 16.} (19. Rd1 {This is the line that was played previously.} Ne5 20. Nf6 Qf3 21. Nxg8 Qxg4+ 22. Kh1 Qf3+ 23. Kg1 {Withe perpetual check.}) 19... e5 (19... Ne5 $2 20. Rxe5 Qxe5 21. Nxc4 Qe4 22. Ne5 $1 $18) 20. Ne4 Qe6 21. g5 $16 Qg4+ 22. Ng3 $18


At what playing strength level should one be able to mate with King Bishop and Knight vs King? As in title above, at what playing strength level should one be able to mate with King, Bishop and Knight vs King without much effort (with reasonable time left for the game)?

A member of my club, rated about 1900 FIDE, had this in a championship blitz game about 2 years ago with 30 seconds left on the clock. He delivered mate with time to spare. IMs  have failed. Go figure. If you study and learn then you should be able to deliver mate. If you don't study then you won't. Playing strength doesn't have that much to do with it.


What are the main differences between 2...d5 and 2...e5 in the anti-Caro-Kann? In the anti-Caro-Kann (also known as the Pseudo Panov-Botvinnik or Panov's little Brother), reached by 1. e4 c6 2. c4, what are the main differences between 2...d5 and 2...e5?

[FEN ""]
[StartPly "4"]

1. e4 c6 2. c4 d5 (2...e5)

The reason why I ask this question is because I play the Black side of this opening, using 2...d5, as suggested in The Caro-Kann: Move-by-Move. I also own The Panov-Botvinnik: Move-by-Move, which covers 2...e5 but from White's point of view, so Black ends up making a mistake, or the author annotates the White moves more heavily.

I don't play this from either side, but apparently 2... d5 leads to positions known as isolated queen pawn (isolani) which can also result from many other openings. Look it up, there is lots of information out there about this. There is a fairly standard plan in these positions. White wants to avoid getting into an endgame where the pawn would be a weakness. Typically black would try to control the square in front of the isolani (i.e. d5 in this case) preventing white from exchanging the pawn playing d5 himself. White usually has a bit more active play in the middle-game.

I don't like 2...e5. If white attacks the e5 pawn, e.g. with 3. Nf3, black is almost forced to play 3...d6 and the set-up with pawns on e5,d6 and c6 is gernerally not good. White can later play d4 and open the d-file after which the pawn on d6 might get weak.


What does the FIDE president do? What is the role of the president of the International Chess Federation? What does he or she do, and what is he or she supposed to do?

I have looked at sources such as Wikepedia

The FIDE President's role is defined in one of the FIDE Handbooks on the FIDE website. The relevant part is Chapter 09 - The President and Deputy President in the FIDE Statutes.

There it says -

  9.1.  The President represents FIDE officially and can solely sign for FIDE.  All contracts signed by the President shall be subject to prior
  approval or subsequent ratification by the Presidential Board. Any
  contract that commits FIDE to an obligation or exposes FIDE to a
  potential liability of more than €100,000 must be submitted for
  ratification by the Executive Board or General Assembly.
  9.2.  The President presides over the meetings of the General Assembly, the Executive Board and the Presidential Board.
  9.3.  The President presents an annual report to the General Assembly.
  9.4.  The President’s decisions may be appealed to the General Assembly, Executive Board or Presidential Board.
  9.5.  If the President is unable to act or if he duly authorises, then he can be represented by the Deputy President who shall exercise the
  powers of the President. The Deputy President can thus represent FIDE
  officially and can solely sign for FIDE.
  9.6.  In certain cases the FIDE President can also delegate specific tasks to other persons; this includes authorising in writing other
  FIDE officials to sign contracts on his behalf.

Details of the General Assembly, the Executive Board and the Presidential Board are given in the FIDE Statutes.


Caro-Kann c5-c4 push I am having trouble understanding why the push c4 here is incorrect for Black.

After 9. Qc2 b5 10. a4 a6 11. axb5 axb5 12. Rxa8 can be recaptured with the Queen and the pawn chain is stable.

What is wrong then with this push?

c4 is the usual beginner's mistake of releasing the tension unnecessarily. With the pawn on c5 you exert some pressure on d4 which can be increased with moves like Ne7-c6. When the pawn moves to c4 that pressure disappears.

If you played Ne7 instead then taking the c5 pawn is bad for white. You are not going to retake immediately but instead play Nc6. This gives white the choice between allowing you to recapture on c5 with the bishop with gain of tempo or allowing you to take the more important e5 pawn. Instead of taking on c5 white will want to develop his queenside pieces but this is awkward in the current position. His dark squared bishop is problematic.

  After 9. Qc2 b5 10. a4 a6 11. axb5 axb5 12. Rxa8

This is "hope" chess. You "hope" your opponent is going to make some bad moves and then your bad move magically becomes a good move. If you want to improve then you have to stop doing this.

Your opponent is not going to play Qc2 because if the c file opens then he wants a rook on that file not the queen. Qe2 is better. He is also not going to play 10. a4. He is going to play 10. b3, immediately attacking the front of your pawn chain.

Furthermore you are a long way behind in development with your king still stuck in the middle. You should not be wasting time on further pawn moves, particularly ones which threaten to open the position leaving your king exposed to attack. Ne7 is more to the point, developing a piece and getting you one move closer to being able to castle.


Why is Qf5-c2+ a blunder? Wikipedia defines a blunder as follows:

In chess, a blunder is a very bad move. It is usually caused by some tactical oversight, whether from time trouble, overconfidence or carelessness.

Here when I use the engine from chess.com to analyse a game, the engine considers black's move Qf5-c2+ as a blunder and Qf5-h3 is considered as the best move. I failed to see why Qc2+ is a blunder; can anyone help me to explain?

By the way, is this game a draw before Qf5-c2+ (assuming both sides make best moves)?

Edit: I am still curious about this position; anyone can help me with a deep engine analysis and see if it is a draw?

The engine considers Qc2+ a blunder because it's a draw by repetition. (I think the position is probably a draw anyway, but Black could at least try for a win.) The problem is that you have already reached this position twice before. If this was the first time you had reached this position, there would be no problem: Qc2+ is actually a good move in itself. But since you have kept repeating the position instead of making progress, you now need to play something different, such as Qh3.


How to limit the depth of analysis in Arena? I am using Arena with Stockfish-222-64-ja-intel. It thinks about 50 moves deep and heats up my laptop processor. All I was interested in, was a depth of about 12-13 moves and for the best line to be shown on the top. I am not able to find the options to configure the gui is such a manner. Let me know if you have an answer.

Update: I know how to limit the level for computer strength. That's plain - it's Levels>>Adjust>>Fixed Search Depth>>8 half moves. The problem still persists though. When I click the Analyze button, the computer starts thinking really deep (and yes, the heating problem is a bit irritating and drains the battery).

What you want to do is limit the number of cores Stockfish has access to. I'm sure your computer/laptop has more than one core, but if improperly set, a UCI engine can eat up all of your processing power and leave your computer sluggish. There are two ways to fix this.

Arena should have a "Lower than normal process priority" in Engine Management Options. You should check this off.

Also, I know Chessbase lets you allocate a certain amount of cores (or threads) for the engine, and I'm sure Arena does as well. However, I'm not entirely sure how to do it with the specified software.


Where can I download (or buy) a database of Chess960 games? Where can I download (or buy) a database of Chess960 games? Or at least find games from the major Chess960 tournaments?

edit:
If some is interested here are games I managed to find in internet.

Interesting question, and the answer is little bit funny.

Guess where I found these games, would you?

On chessgames.com! But it's not called Chess960, nor Fischer's chess, nor random chess, it's called: Chess variants (000)

If you go to to ChessBase Database and you enter in the search form chess960 you will find many games.

EDIT

I emailed 365Chess.com and Chesstempo.com and they said they don't have Chess960 games, I emailed Chessgames.com and they replied.

  There are a couple of them.  There’s no easy way to pull them up, but
  here is a collection with 3.

  There might be one or two more.

I guess I did a better job than Chessgames team at finding chess960 games in their own database :)

I emailed Chess.com, they said

  Thanks for your email. Unfortunately we don't have a database of
  Chess960 games available for download. Premium members of Chess.com
  have access to all the Chess960 games played on Chess.com.


FIDE rules when opponent accidentally promotes to your Queen This happened to someone else recently in a time scramble during an OTB game. His opponent promoted a pawn and placed a Queen of the wrong color on the board. He was corrected by the player and the game continued for a bit.

I was wondering what the rules say about this situation.

So if your opponent promotes a pawn to a Queen and accidentally places your Queen on the board instead of his own, can you claim a win because of an illegal move? And if you don't claim, but continue to play on without correcting the situation, is that Queen officially yours?

So if your opponent promotes a pawn to a Queen and accidentally places
  your Queen on the board instead of his own, can you claim a win
  because of an illegal move?

No, you can't. There is no illegal move until the player either presses the clock or makes another move (after the opponent has moved).

Here is what the FIDE Laws of Chess have to say:

  3.7.5.1   When a player, having the move, plays a pawn to the rank furthest from its starting position, he must exchange that pawn as
  part of the same move for a new queen, rook, bishop or knight of the
  same colour on the intended square of arrival.

  3.10.2    A move is illegal when it fails to meet the relevant requirements of Articles 3.1 – 3.9

  6.2.1 During the game each player, having made his move on the chessboard, shall stop his own clock and start his opponent’s clock
  (that is to say, he shall press his clock). This “completes” the
  move. A move is also completed if:

  6.2.1.1   the move ends the game (see Articles 5.1.1, 5.2.1, 5.2.2, 9.6.1 and 9.6.2), or

  6.2.1.2 the player has made his next move, when his previous move was not completed.

  7.5.1 An illegal move is completed once the player has pressed his clock. If during a game it is found that an illegal move has been
  completed, the position immediately before the irregularity shall be
  reinstated. If the position immediately before the irregularity cannot
  be determined, the game shall continue from the last identifiable
  position prior to the irregularity. Articles 4.3 and 4.7 apply to the
  move replacing the illegal move. The game shall then continue from
  this reinstated position.

  7.5.5 After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; for the
  second completed illegal move by the same player the arbiter shall
  declare the game lost by this player. However, the game is drawn if
  the position is such that the opponent cannot checkmate the player’s
  king by any possible series of legal moves.

So, first of all, yes, promoting to the wrong piece is an illegal move (3.7.5.1 and 3.10.2)

Secondly, just making an illegal move does not attract any penalty (other than having to make a legal move with the piece touched or captured). The move only attracts punishment when it is completed (7.5.1 and 7.5.5) by pressing the clock or making a subsequent move.

Thirdly, you cannot claim a win for the first completed illegal move, only for the second (7.5.5). This rule now also applies to rapid and blitz.

  And if you don't claim, but continue to play on without correcting the
  situation, is that Queen officially yours?

At standard time controls, no. According to 7.5.1 the position before the illegal move must be reinstated and a legal move made.

However, rapid and blitz are different.

  Appendix A. Rapid chess

  ...

  A.4.2 If the arbiter observes an action taken under Article 7.5.1,
  7.5.2, 7.5.3 or 7.5.4, he shall act according to Article 7.5.5, provided the opponent has not made his next move. If the arbiter does
  not intervene, the opponent is entitled to claim, provided the
  opponent has not made his next move. If the opponent does not claim
  and the arbiter does not intervene, the illegal move shall stand and
  the game shall continue. Once the opponent has made his next move,
  an illegal move cannot be corrected unless this is agreed by the
  players without intervention of the arbiter.

  Appendix B. Blitz

  ...

  B.4 Otherwise, play shall be governed by the Rapid chess Laws as in
  Article A.2 and A.4.

In rapid and blitz the standard rules for punishment only apply if there are conditions which will only occur in very high level tournaments, if then. These are that the moves are recorded independently and there are enough arbiters (one per 3 games at rapid and one per game at blitz) to properly see what is going on. Otherwise article A.4 applies and you can keep your extra queen.


Why does the engine tell me to sacrifice a queen for bishop after a failed Scholar's mate? I am a beginner. Recently I have looked at the computer-generated analysis of one of my games and I found a surprising recommendation. Why is it best to sacrifice my Queen in this situation, as the screenshot shows?
[FEN ""]
[StartPly "10"]

1. e4 e5 2. Qf3 c6 3. Bxc4 Nf6 4. d3 d6 5. Bg5 Bg4

It's basically a trade. After you take the bishop, if the opponent takes your queen with the knight, then your bishop is no longer blocked by the knight and you can take their queen too. The advantage here is that after the trade, the opponent's king will have to take your bishop, and thus can no longer castle.


What is the number of "CPU" next to each engine's name in engines rating list? And is my computer 1CPU, 2CPU or 4CPU? Look at this engine rating list which compares all the versions of Stockfish.

After the name of each engine we can see one of these three things:

4CPU
2CPU
Nothing, which probably means: 1CPU

And it seems that the same engine is stronger by roughly 80 Elo when run on 4CPU instead of 1CPU.

I'm not exactly sure what the number of "CPU" is... Is it related to the number of cores?

I would like to know if my computer is 1CPU, 2CPU or 4CPU.

Here is the specifications of my computer (which I found in Control Panel\System and Security\System):

Alienware M18x
Windows 8.1
Processor: Intel(R) Core(TM) i7-3740QM CPU @ 2.70 GHz 2.70 GHz
Installed memory (RAM): 16.0 GB
System type: 64-bit operating system, x64-based processor

So is my computer 1CPU, 2CPU or 4CPU ?

Before multicore processors, if you saw something like 4 CPUs they would be referring to a chess engine running on a computer that had a motherboard that actually had 4 separate processors on it. Now, they they could be referring to multicore processors. For example, your i7 is a quad-core processor with 4 processor cores. It's like 4 processors in 1 package.

It's hard to say for sure which one it is, because even after reading their testing information in the about page, etc. They do not make clarifications about the actual hardware it is running on.

This is all I could find:

  Should be set to the same value of either 128 or 256 MB for all engines in a match or tourney. There are two exeptions: 1) Engines using 2 CPUs should have double hash size, compared to single-CPU engines in the same tourney. 4-CPU engines should have 4 times amount of hash. 2) Smaller hash size can be used if an engine has problems with particular hash size, or if it does not allow to configure hash size.


How to develop tactical and combinational awareness? Most of my learning comes from trial-and-error sort of self-teaching. I cannot say I am completely blind to tactics and combinations, but, while solving puzzles (approx. ~1600+) I tend to miss something critical within the time allotted. Though a longer stare would get me solve it eventually.

My goal is to play comfortably at blitz (3m+2s) for 1800-2000 elo bracket without making tactical blunders and without missing not so difficult t&cs.

In this regard I want to delve deeper into tactical and combinational aspect of chess. What resources (books, videos, online material, etc) will you recommend?

The recommended way to improve tactics is to practice looking for them.  ChessTempo is the best site to practice tactics.  chess24 also has tactics training and has good videos.  Lichess has tactics and one of the best playing sites.  Youtube.com has too many chess videos to list them all.
There are some clues to look for to find tactics.  An unprotected back rank, pieces which are on the same line, pieces which are a Knight fork away, and pieces which are unprotected.  More advanced themes are overloaded piece, trapped pieces, and zwischenzug et al.
Alburt's 300 most important positions and Reinfeld's 1001 best checkmates are PGNs which you can download.  Chess Hero is a program which will test you with these files (includes Reinfeld's pgn.)
Along with tactics, you will find attacking becomes easier.
spy-faith(2113) jonesmh(2052) lichess.org 3 0
Exploiting an overloaded Knight on c3.

   [FEN ""]
1. e4 c5 2. d4 cxd4 3. c3 d3 4. c4 g6 5. Nc3 Bg7 6. Qxd3 Nc6 7. Bf4 d6 8. O-O-O Nf6 9. Bg3 O-O 10. f4 Qa5 11. Kb1 Nb4 12. Qd2 Nxe4 0-1

jonesmh(2000) mitchell(2000)
Unusual attack on the king.

[fen "r3rbk1/ppq2pp1/2n2n1p/2pp1P2/5P2/2PBB2P/PPQN2P1/R3R1K1 b - - 0 0"]

1...c4 2.Bf1 Rxe3 3. Rxe3 Bc5

With every piece protected, the attack broke through.  A hard example of a weak square complex.
jonesmh(2080) kavookavala(2133) lichess.org 3 2
Exploiting uncoordinated pieces

[fen ""]
1. f4 d5 2. e4 dxe4 3. Nc3 Bf5 4. Qe2 Nf6 5. Qb5+ Bd7 6. Qxb7 Bc6 7. Bb5 Bxb5 8. Nxb5 Qd5 9. Qc8+ 1-0

jonesmh(2079) nfc3000(2061) lichess.org 3 2
Overlooked Knight fork by both player.

[fen ""]
1. e4 c5 2. Nf3 d6 3. d3 Nf6 4. g3 g6 5. Bg2 Bg7 6. O-O O-O 7. Nbd2 Nc6 8. a4 Bd7 9. Re1 a6 10. Nc4 Rb8 11. a5 Be6 12. e5 Bxc4 13. exf6 Bxf6 14. dxc4 Nxa5 15. Qd3 Qc7 16. Bd2 Nc6 17. c3 Ra8 18. Bh6 Rfb8 19. Qe2 Na5 20. Bg5 Bxg5 21. Nxg5 Re8 22. Rad1 Rab8 23. Qd3 b5 24. cxb5 axb5 25. b4 Nc4 26. Bd5 Ne5 27. Rxe5 dxe5 28. Bxf7+ Kg7 29. Bxe8 Rxe8 30. Ne6+ 1-0

These examples show that 2000 rated players miss simple tactics in blitz.  The longer you play and/or solve tactical puzzles, the easier you will find the combinations..
(As I kept going back and forth to input the examples, I lost track of what I was saying many times.  Hopefully I did not stray off topic too much and did provide helpful information.)


Chess tactics #5: Yugra Governor's cup I took this position from a game that has been played today at the Yugra Governor's Cup between GM Aleksej Aleksandrov from Belarus and GM Ivan Bukavshin from Russia. White (Aleksandrov) has just played 27. Rc2 and that's a huge blunder. How did Bukavshin win the game?

[fen "1r6/5kpp/3qpb2/1Bpb4/8/5N1P/1PR1QPP1/6K1 w - - 0 1"]

@Bad_Bishop is almost correct, and this illustrates a general pattern in chess tactics: if a sequence of moves almost works, try changing the move order:

   1 ... Bxf3! 2. gxf3 Rxb5 3. Qxb5 Qd1+ winning the rook, or 2. Qxf3 Rxb5 winning a piece.


What is the status of correspondence chess? Considering the rise of the Internet for playing games online and the increasing strength of computers / engines for evaluation of positions and finding best moves, what is the status of traditional correspondence chess?

Correspondence chess is still alive and well. Just as in the pre-engine days it is the branch of chess which comes closest to chess "truth".

Before the internet and strong chess engines correspondence players had days rather than minutes and seconds to consider their moves. They could use books with openings and analysis by the best players in the world. This extra help allowed the best correspondence players to play chess at a higher level than even the top over the board players who had to play all their moves in 5 or 6 hours.

Nowadays strong engines substitute for the earlier forms of help but the result is pretty much the same. The best correspondence players play the best chess, better even than the engines unaided.

Note that top chess players, like Boris Gelfand for instance, are quite scathing about the capabilities of engines in many positions.

This is also something I've seen at first hand in some of my games. A couple of times recently I've reached an endgame I thought was going to be winning only to find that there was no way to do it. Later, looking at the game with an engine it gave me +1 or +2 but couldn't give me a winning line.

Engines are useful for avoiding blunders and checking lines but when an engine gives a position a good plus score you should always check it with "the human eye" before you use it in your preparation.

Of course now with email it is possible to play correspondence chess much cheaper and easier than in the old days. There is also much less chance of moves getting lost in the post.


Multi (N>3) dimensional chess designs I was wondering whether anyone has ever designed chess rules for more than 3 dimensions. At that point you wouldn't be able to visualize the play using one board. And you'd instead need to to use 8 3-D boards (in the case of 4-D). When searching for multidimensional chess, the only thing I can find is 3-D chess. So has anyone ever designed a multidimensional chess game where (N > 3)?

If you think this question should be posted elsewhere, please inform me.

Yes, there are a few four-dimensional chess variants:
https://www.chessvariants.com/index/mainquery.php?type=Any&category=4d&usethisheading=Four+(or+more)+Dimensions

Sphinx Chess, by V.R. Parton, is probably the first, c.1970.  Timeline is also described there (it's actually a full 4 spatial dimensions, being 4x4x4x4, plus the "timelines"), as well as my own variant TessChess.

Most 3D chess (at least online) is played by splaying the levels out next to each other, since seeing and reaching between levels may be difficult.  Once you get used to that, it's not so unnatural to put the levels in a grid, and you've got four dimensions.

Also, most 3D chess is on a smaller board than 8x8x8 (8x8x3 or 5x5x5 are common), and higher dimensions similarly shrink the edge length.  This, together with appropriately extending piece movements, get around NoseKnowsAll's density argument.  But, of course they are also right that the game becomes rather different from chess.

V.R. Parton also created a 6-dimensional game, Ecila.  I and others have toyed around with even more dimensions, but it obviously becomes more difficult for the "array of array of arrays" board simulation to work out.


Three Pieces in the Attack As a kid, my coach, an International Master, was repeating "if you have three pieces or more in the attack you can sacrifice without thinking!"

However, don't take this rule too literally!

Chess is a concrete game and we should not follow a rule "without thinking". However, I believe that chess is guided by some rules and general principles.
We can redefine the rule of "Three Pieces in the Attack" as "Play more aggressively in the attack" in a context where the number of pieces attacking exceeds the number of pieces defending.

My question is: by searching on the Internet, I could see this rule from time to time but I could not find its origin. Who devised this rule? How old is it?

I found a cute example here to illustrate this rule. White plays and checkmates a strong GM!

[title "Juarez Flores, C - Lputian, S, Manilla 1990"]
[fen "r6r/p4ppp/2p1b3/4R3/1kpR1N2/6P1/P1P2P1P/2K5 w - - 0 1"]

1.

I cover the solution for those who want to search:

    1. a3! Kxa3 (1...Kc3 2. Ne2#) (1...Ka4 2.Nxe6 fxe6 3.Rxc4+ Kxa3 4.Ra5#) 2.Nxe6 Kb4 (2...fxe6 3.Rxc4 c5 4.Re3 Ka2 5. Ra4#) 3.Rc5 fxe6 4.Rdxc4 Ka3 5.Ra5#

The Greek Gift is another illustration of this rule because the Bd3, the Nf3 and the Qd1 coordinate to attack (the Bc1 and the Rh1 can also join the party)

[title "Greco 1792"]
[fen "r1bq1rk1/ppppbppp/2n1p3/3nP3/3P3P/3B1N2/PPP2PP1/RNBQK2R w KQ - 1 1"]

1. Bxh7!  Kxh7 2.Ng5 Kg8 3.Qh5 Bxg5 4.hxg5 f5 5.g6+-

Francesco di Castellvi vs Narciso Vinyoles

[Event "?"]
[Site "?"]
[Date "1475"]
[Round "?"]
[White "Don Francí de Castellví(mars aka love)"]
[Black "Narcís Vinyoles(venus aka glory)"]
[Result "white"]
[FEN "?"]
[Time "?"]
[TimeControl "?"]

1. e4 d5 2. exd5 Qd5 3. Nc3 Qd8 4. Bc4 Nf6 5. Nf3 Bg4 6. h3 Bf3 7. Qf3 e6 8. Qb7 Nbd7 9. Nb5 Rc8 10. Na7 Nb6 11. Nc8 Nc8 12. d4 Nd6 13. Bb5 Nb5 14. Qb5 Nd7 15. d5 exd5 16. Be3 Bd6 17. Rd1 Qf6 18. Rd5 Qg6 19. Bf4 Bf4 20. Qd7 Kf8 21. Qd8#

This is derived from the poem which you can read here. I found this while watching this youtube channel.

At move 19 here I can see the three piece attack you were talking about. Here the bishop gets sacrificed for getting a checkmate. This the oldest usage of it that you'll find where the rules followed are the same as today.

Closest thing i could find was this sentence:

   "3 Piece Rule Compiled by notyetagm  --*-- You need three pieces to
  checkmate the enemy king, one to sacrifice and two to deliver mate. Of
  course more is better. :-)"

Rule: one of a set of explicit or understood regulations or principles governing conduct or procedure within a particular area of activity. It should be absolute(a value or principle which is regarded as universally valid or which may be viewed without relation to other things)

But we know that it is possible to Checkmate your opponent using less than 3 pieces.
Example: For checkmate using single piece => Back rank checkmate or a smothered checkmate
For checkmate with 2 piece there is => classic queen rook checkmate or Diagonal checkmate,etc

Hence, it is not applicable everywhere and thus it isn't a rule (you shouldn't considered it either).
"if you have three pieces or more in the attack you can sacrifice without thinking!" But this is a line that works a lot of time. So the question arises what is this? It's just a strategy or if you wanna be specific its a attack strategy or even a checkmate strategy in cases.

You can even generalize this as "trade off when you have more number of attacking pieces that defending pieces". It actually establishes the basics of our chess today, that might not be fruitful in all the cases. As there is one and only one goal in chess , that is to defeat your opponent and obtain a victory.
So, Apply it all you want but make sure to win. Or at least its application should be fruitful to you and not your opponent.

As to my final answer to you, it isn't a rule it's a strategy and like other strategy's there is a very strong likely hood that someone played it before it got recognized by some name. As to oldest usage its  Mars vs Venus,1475 if you'll consider this. So, regarding who and when, it's something i feel that has evolved with time along with the modern chess.

Thank you!


Does my online chess rating reflect my ELO rating? I play a fair amount of chess online, on a chess site that updates my chess rating based on my performance using, I believe, the ELO system.

I do not play in rated, "real" tournaments that often, and so I do not have an official ELO rating.

Is my online chess rating a good estimate of my "real" rating? I've heard that one's online rating is systematically biased upwards compared with one's "real" rating, is there any truth to this?

That depends a lot on the platform.

My different online ratings differ by more than 500 points. And there is the additional factor that online chess is not tournament chess. The time control is either faster or looser and you don't have to play at set times. Also your opponents tend to be less serious about it.

Chess24 has high ratings, ICC has low ratings, your Elo is probably somewhere in between, but to speak of a good estimate would be an exaggeration.


Why does the black king evade to f8, and not to h7? I'm trying to practice with the app https://f-droid.org/en/packages/jwtc.android.chess

Why does the black king go to f8, and not Kh7 instead?

 [FEN "r2rb3/1p2RBk1/2pP1ppR/p7/P7/7P/1q3PP1/3Q2K1 w - - 0 1"]

 1. Rxg6+ Kf8 (1...Kh7) 2. Rg8#

Kh7 would also result in mate due to Qh5. So both moves are equally "good" Kf8 Rg8 maybe was seen as less obvious than Qh5.


Is it bad etiquette to try to make an opponent lose on time when a position is clearly drawn? The other day I was playing a rapid game (30 minutes each side) online. I got into time trouble but I managed to convert the position into a drawn endgame. (Not just a theoretical draw—a clear draw for both sides.) In the final moments of the game, I had less than 20 seconds on my clock, and my opponent started checking me repeatedly in an attempt to make me lose on time. While I know this is standard in blitz or bullet games, I considered it to be bad form given that we were playing a slower time control. Am I right in believing this is a breach of etiquette, even if it is strictly legal?

Edit #1: Here is the final position. (I slightly misremembered what my opponent did—they weren't repeatedly checking me. Instead, they were moving their bishop around aimlessly. However, I don't think this has a huge impact on the debate. I was playing White.)

2b5/1kP1K3/8/8/8/8/8/8 w - - 16 86

Edit #2: It has been mentioned that there is another similar question that has already been asked before on the chess stack exchange. While I appreciate the similarity between these two questions, I would argue that the fact that I was playing a rapid game could have an impact on the answer. Not everyone agrees, but some people do hold this belief. Therefore, I'd like to keep this question open.

Etiquette doesn't really come into it unless your name is Gata Kamsky (strong language warning for the link). The rule is very simple. If you want flagging to be a part of the game then play with no increment, otherwise always play with an increment.


How do you calculate elo? I am starting a chess club at my school, and I want to create a Python program to calculate and store Elo ratings for each player. I am confident I can program it, but I just need to know:

How do you calculate Elo?

What i am looking for:

Equations to calculate expected outcome for each player.
Equations to calculate elo change using this.
How to deal with a draw.
How the value of K can be calculated, or suggestions for a static value of K which would work for students.

So far the best explanation I have found is the League of Legends rating system explained in this video (which happens to be the same system used in chess).

Here you have some more information about Elo system that maybe it's useful for you.

Arpad Elo designed his system assuming a normal distribution in the results achieved by the players with a standard deviation of 200 rating points. So he used a logistic function to calculate the expected results by a player. The actual function (actually a table is used with minimal differences with this function) is:

WEa = 1 / (1 + 10^((Rb-Ra)/400)), rounded to two decimal digits

WEa is the expected result for player a, while Rb and Ra are the ratings of both players. As you can see in a game between two players having 400 points of difference in rating the chances of winning the game are 10:1.

After the game(s) expected and actual results of a player are compared, so players performing better than their expected results increase their ratings, and players performing worse decrease them. To do that the difference between expected and actual results is multiplied by a constant factor K. This constant value has to be small enough to make the system stable and avoid reflecting the very last results only, but large enough to be able to track players evolution. I guess a good value would be between 20 and 30, Jeff Sonas for example suggest 24 as the optimum value, while FIDE handbook points that rating stabilizes after 70 games (K10), 35 games (K20) and 18 games (K40), maybe these numbers can be useful for you to set your own K value.

Using a greater K value the very first few games can help your students to reach an approximate rating quickly and then you can change to a smaller K value.


Looking for an aggressive opening for black vs 1. d4 I like the King's Gambit a lot, and even the Latvian Gambit as black (with dubious results), so my style is very aggressive openings with potentially sharp lines and hack n' slash type of tactical sacrifice lines. However as black when facing the 1.d4 opening from white I'm unsure what to do, and just try to play some kind of King's Indian Defence, which seems solid, but I almost never get my pieces lined up as nicely as Kingscrusher does.

So what are some good offensive lines to play against 1. d4?

You seem to enjoy tactical play, so there are a few options for you against 1. d4. As it appears you prefer gambits over other openings, consider looking at the relatively offbeat Budapest Gambit which is characterized by the opening moves 1. d4 Nf6 2. c4 e5 where after 3. dxe5 black can reply with either 3...Ne4 or 3...Ng4 with the latter being more popular. That being said, the Budapest is rooted in strategic themes, and the King's Indian Defense is certainly regarded as the one of the most aggressive replies to 1. d4.

For a more mainstream approach, I would recommend the Grunfeld as a great hypermodern choice. It's highly regarded from the amateur to world class levels. The general idea is to allow white to build up a center and then target it as a weakness, and the positional themes that arise in the middlegame focus primarily on undermining the pawns on e4 and d4.

For a more comprehensive response, please reference this excellent answer to a generalization of your question.


What's the verdict with Qa5 in the Accelerated Dragon? After

[FEN ""]
1.e4 c5 2.Nf3 g6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Bg7 6.Be3 Nf6 7.Bc4 Qa5

Does White have to castle here? If so, what is wrong with 8...Qb4?

In master level games (2400+ for both) 8. 0-0 is the only move.

White scores rather too well (34% wins) after 0-0, with black having 15% wins.

Including lower rated players white scores 38% wins vs 28% wins for black after 8.0-0. Thus this is very playable at lower levels.

Now about 8. ... Qb4 it appears dubious at higher levels but worth the shot in a regular game.

The sole high level game Solak (2566) vs. Djukic (2402) Serbian Ch 2007 proceeded as follows:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[White "Solak, Dragan"]
[Black "Djukic, Zeljko"]
[Date "2007.08.29"]
[WhiteElo "2566"]
[BlackElo "2402"]

1. e4 c5 2. Nc3 g6 3. Nf3 Bg7 4. d4 cxd4 5. Nxd4 Nc6 6. Be3 Nf6 7. Bc4 Qa5 8.  O-O Qb4 9. Qe2 Ng4 10. Nd5 Qd6 11. Qxg4 Bxd4 12. Bxd4 Nxd4 13. Rad1 Qc5 14. e5  Ne6 15. b4 Qc6 16. Bb3 h5 17. Qh4 g5 18. Qe4 a5 19. a3 axb4 20. axb4 b5? 21.  Nf6!+ exf6 22. Bd5  1-0

and white converted his exchange, overall very uncomfortable game for black even without blunder.

Also 9. Bb3 seems good for white too as 9. ... Nxe4 appears bad:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[White "Hofmann, Brigitte"]
[Black "Kratochvilova, Magdalena"]
[Date "1973.06.??"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 6. Be3 Nf6 7. Bc4 Qa5 8.  O-O Qb4 9. Bb3 Nxe4 10. Nxc6 dxc6 11. a3 Nxc3 12. Qf3! Ne2+ 13. Kh1! Qh4 14.  Qxf7+ Kd8 15. Qxg7 Bh3 16. Qxh8+ Kc7 17. Qe5+ 1-0

Similar play proceeds after 10. .... bxc6

So if 9. .... Nxe4 is not playable then 8. ... Qb4 is questionable


Is the exchange of a rook for two minor pieces really worth it? I recently played a game with my friend I wish I had memorized the entire game, but, unfortunately, my memory isn’t too good.

In summary, I was in a really tight position, and playing as black. I had a very active rook on the open f-file However my opponent was attacking my king. and it looked really bad. As a result, I sacrificed my very active rook for a bishop and a knight. I still lost the game, however.

Is that kind of exchange worth it? Once I lost my rook, my opponent was able to monopolize on the f-file by making a triple battery, and consequently I lost.

Also, when is it a good idea to make sacrifices concerning Rooks and minor pieces?

You say your opponent had a strong attack against your king and you had to "sacrifice" your rook for two minor pieces and went on to lose. I think you have it the wrong way round. It sounds like your opponent had a strong attack against your king and sacrificed two minor pieces for your rook, your one active piece by the sound of it.

In general a rook and a pawn are roughly equivalent to two minor pieces. However in the middlegame this is usually not a good trade for the player losing the two minor pieces because two minor pieces are two pieces which can attack/defend whereas one rook is only one piece which can attack/defend and the number of pieces participating in the attack or defence is generally more significant than their precise power.


How to play for a win with White without fighting for an opening advantage I know that there are practical methods of playing for a win with White without bothering with an opening advantage. In Kasparov's multivolume work on his predecessors Bent Larsen is described as someone who excelled at building complex playable positions without attention to opening advantage. It was enough for him that the position held enough complexity to make for a hard battle.

Presumably, this kind of playing is easier than fighting for an advantage. My question is about the reason why opening books focus only on finding an advantage for white rather than make life simipler for the reader and show how to obtain a good promising position with equal chances using the White pieces as a means of forcing one's will.

In my earlier question in this vein there was a lot of controversy over the value of winning versus drawing, which I find amazing because people don't seem to value draw as an outcome of a game of chess. So here I ask a similar question that is focused on winning rather than drawing but without fighting for the so called opening advantage. Compare
Advice on how to draw with White

One way to play for a win without seeking an opening advantage is to play a system opening. In this answer, I recommended the English Botvinnik System to a player struggling against the Sicilian.

A system opening is where one player develops their pieces to the same squares and has similar plans available no matter what their opponent does.

System openings have the advantage of saving you clock time and giving you a position that you are familiar with, hence allowing you to play for a win.

The problem with system openings is that they ignore the opponent's play and you tend to play with a mind that is half closed. That is, you may miss interesting moves that take advantage of an opponent's mistakes. This is why system openings are not objectively 'the best', i.e. they don't give a theoretical opening advantage.


What type of tournament is needed to get a true chess rating? I'm at the point I'd like to throw my hat in the ring and see what happens. What is the most basic and affordable tournament I should be looking at that still counts for a rating? Would that be FIDE? USCF? Something else? Do I have to do one of those very expensive multiple day competitions or are there cheaper one day events that still come with official ratings?

A "real" rating is gained by joining the USCF and playing rated tournaments.  You can get a rating from any USCF sanctioned tournament.  They don't have to be all-weekend tournamants; I've played in several G30 tournaments that had 3 rounds in one evening.  In addition, you and an opponent can play a rated match if a USCF tournament director approves it.

You can also get a (non-USCF) rating by playing on one of any number of internet sites.

EDIT - here are some clubs in Orlando.  I recommend you join one and mingle.  The first one here has USCF tournaments...

ORLANDO FL 32810 FL. CENTRAL FLORIDA CHESS CLUB (USCF ID A6007091). Affiliate Type: Club. Call for information. Call for information, ORLANDO FL 32810. Contact: HARVEY LERMAN. Contact Phone: 407-644-3542. Club Phone: 407-629-6946. Address: C/O HARVEY LERMAN, 921 N THISTLE LANE, MAITLAND, FL, 32751-3736. email: harveylerman@embarqmail.com. Web Site: www.centralflchess.org, Club Membership Not Required, Casual Play, USCF Rated Events, Blitz Events, Club Championships, Private Lessons Offered, Under Age 18 Welcome, Prison chess support. (Crosstables from past rated tourneys for this affiliate)

ORLANDO FL. ORLANDO CHESS & GAMES CENTER (USCF ID A6018039). Affiliate Type: Club. 10AM-10PM MON-SUN. 8853 COMMIDITY CIRCLE, ORLANDO FL 32819, ORLANDO. Contact: ALEX ZELNER. Contact Phone: 407-248-0818. email: alex@orlandochess.com. (Crosstables from past rated tourneys for this affiliate)

from this page.


Is there a name for a chess variant where you are allowed to capture your own pieces? I occasionally think it might be fun to play a chess variant that is exactly the same as regular chess, except that it is permitted to capture your own pieces as well as your opponent's pieces - so, for example, if your king was alone on the back rank with some pawns in front of it, and your opponent moved a rook or queen to the back rank and that attacking piece could not be legally captured (which would be checkmate in normal chess), it might be possible in such a variant to escape checkmate if the king could "capture" one of it's own pawns in front of it.  In the way I imagine this variant, "friendly" pieces captured in this way would be removed from play permanently, just as an opponent's piece would be - so (in this example), you've jettisoned some of your own material (which is now gone for good), but at least you were able to save yourself from checkmate...

I can imagine other scenarios where it might also be useful to give up some of your own material by "capturing" it like this, in support of the greater good....

Is this a known chess variant, does it have a name that people might recognize?  I've tried searching around and haven't been able to locate any discussions of a variant like this - but I can't be the first person to think about this.

Just as full disclosure, the only variant I really know anything about is bughouse, I'm not familiar with other variants, so I'm not sure I'm even Google searching for the right words...

In German, we would call this "Schlagschach". The German Wikipedia translates this to "Capturechess".

However, I could not find an English resource that describes this variant.
But there is a thread on chess.com where someone asked about the exact same thing.

Edit: Thanks to @bitchaser who dug that thread more thoroughly and found a link to another page that calls this variant "Self-Eliminator", which states:

  John Gallicano and Steve Mann invented this variant in 1997.

There is also a Java applet on that page, which is not easy to use nowadays, since for security reasons, modern browsers just don't support Java applets anymore.

I hope, this is not too off-topic for Chess.SE, but for those of you, who are interested, here follows a short instruction on how to run the game, nonetheless:

first, make sure you have the tool appletviewer on your PC. If not, you have to install the Java 8 JDK or earlier, since the tool is deprecated since Java 9. Make sure, it's the JDK, not JRE.
second, download the following files of the applet and put them all in the same folder:

https://www.chessvariants.com/play/erf/SelfElim.html (the html code is enough, no pictures, CSS or scripts are required)
https://www.chessvariants.com/play/erf/SelfElim.class
https://www.chessvariants.com/play/erf/EasyChss.class
https://www.chessvariants.com/play/erf/Chsq.class
https://www.chessvariants.com/play/erf/Chmo.class
https://www.chessvariants.com/play/erf/CB10_10.class

last, navigate to that folder and run the following command in a terminal: appletviewer file:SelfElim.html

The applet should pop up and show you the game screen:


Why did Gelfand resign against Anand in the shortest match in WCC? I saw the notations of the match in chessbase, and I couldn't understand why Boris resigned. Anand was no where close to checkmate. I don't see why he didn't just trade his queen for a bishop and continue and maybe force a draw.

More importantly, resigning gives away the advantage he got by winning the previous match. Can someone explain what Anand should have done to checkmate Gelfand from the final position ? I can't see it.

http://www.chessgames.com/perl/chessgame?gid=1666558 the shortest game is World Championship history.  It's not so much the material difference, after Bd3 Qxb1+ two Rooks is not enough for the Queen and the Bishop, but the weakness around the Black King will cause Gelfand to lose anyway.  After h6 and Ne4, d6 will fall and mate is always possible on g7.  A thorough annotation is at http://www.ajschess.com/lifemasteraj/FIDE_World-Champ-2012_game-eight.html

[fen ""]

1.d4 Nf6 2.c4 g6 3.f3 c5 4.d5 d6 5.e4 Bg7 6.Ne2 O-O 7.Nec3 Nh5
8.Bg5 Bf6 9.Bxf6 exf6 10.Qd2 f5 11.exf5 Bxf5 12.g4 Re8+ 13.Kd1
Bxb1 14.Rxb1 Qf6 15.gxh5 Qxf3+ 16.Kc2 Qxh1 17.Qf2


What activities should we set up in a chess club? I am planning to begin a chess club in the engineering college I study.
I am an average player myself, but enthusiastic.

My question is how should we go about it, once its up and running?

One thing I get in mind is to organize games between members.

There's also watching lectures, but who decides what lectures will we watch?

I don't know if there are any existing chess clubs in my city, though it is unlikely.
There are some government bodies which hold yearly competitions, and there are some institutes that offer tution, in neighboring cities.
Thanks

I run a chess club at my college. We have two meetings a week, 2 hours each, one run by myself and one run by someone else. We have a locker for our chess boards, mats and clocks and a meeting place in a lounge area that's not super busy but with decent foot traffic. We update our meeting times every academic quarter/semester to work around our classes and send out a survey to our email list to see when our members are available.

At our regular meetings, we just play chess, it's very casual. Usually blitz 5+0 or 10+0. We switch players every few games. Sometimes we play bughouse if there are enough willing participants. Sometimes we'll look at a position from a game, an opening, or a puzzle/tactic if people want to or have something interesting to talk about. If someone doesn't know how to play we teach them, we're not popular enough to be exclusive.

We have enough funding from the school to go to USCF tournaments in and around our city. Usually they're within walking distance, otherwise we carpool. We also sometimes host tournaments with $1 buy in.

People often say they would be interested in "workshops" to learn chess, but I don't want to host them.


Mate in 1, then No Mate in 1, then Mate in 1 Anand and Bobby both are members of their school's chess club. And while cleaning up the games room at the end of the day, they saw a board with the following position:
[FEN "rbR1B1Q1/k1n1nN1p/p1pNpBb1/PpKPRqpP/1PP1PrP1/5p2/5P2/8 w - b6 0 1"]

Then the following conversation happened:

Anand claimed that if it were white to move, white has a mate in 1
Bobby then pointed out that if any non-king piece is removed from the board, there is no longer mate in 1
Anand agreed, and further pointed out that in fact there is exactly one combination of two non-king pieces that he can remove from the original position that would still result in a mate in 1

Can you prove each of the statements above?
Source: myself, inspired by my answer to a puzzling question (spoilers in there for the first two questions)

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.


Could I have improved my position in this pawn up exchange Slav? This game was my first correspondence game on chess.com.

I played as black. I felt my position was quite good. Then I grabbed a pawn and the game ended in a draw by threefold repetition.

My questions are:

How could black improve their game instead of playing 25...Rxe3?
Can you provide any other feedback to my game?

[FEN ""]
[White "mario401"]
[Black "Bad_Bishop"]
[StartPly "50"]

1. c4 c6 2. d4 d5 3. cxd5 cxd5 4. Nc3 Nf6 5. Bf4 Nc6 6. Nf3 a6 7. e3 Bg4 8. Be2 e6 9. h3 Bxf3 10. Bxf3 Bd6 11. Bxd6 Qxd6 12. O-O O-O 13. a3 Rac8 14. Be2 Na5 15. b4 Nc4? (15...Rxc3 {I played an 'auto-pilot' move and saw this tactic immediately afterwards,} 16. bxa5 Rxa3) 16. Bxc4 Rxc4 17. Na4 b6 18. Nb2 Rc3 19. Qd2 Ne4 20. Qe1 Rfc8 21. f3 Ng3 22. Rf2 h5 23. f4 h4 24. Na4 Rb3 {this was a crude attempt to trap the knight. Maybe I should have considered 24...R3c6 to maintain control of the c-file} 25. Qd1 Rxe3? {Only now do I realise that the rook can't go to e4 if attacked with 26. Qd2} 26. Qd2 Rb3 (26...Re4? 27. Nc3 f5 28. Nxe4 fxe4 {Black might look OK, having a protected passed pawn, but it is easily blockaded}) 27. Qd1 Re3 28. Qd2 Rb3 29. Qd1 Re3  1/2-1/2

Your play was good, and you managed to slowly gain the upper hand from the more or less dead equal opening.  At the end Rxe3 is forced, but after Qd2 I would have definitely considered Re4.  You actually don't lose the exchange:

25... Rxe3 26. Qd2 Re4 27. Nc3 Rc4!

Now at this point you're threatening to take on d4, so 28. Nxe4.  But then you take back on e4 with your g3 Knight and you have White's Queen and Rook in a fork.  You are winning back the exchange and are a pawn ahead.

Overall you played a good game.


What are the mistakes committed by players who take many years to become an expert? I am a beginner and am targeting to become an expert. I see many people who barely takes 4 years to become an expert and many people who take 10 years to become an expert. I don't want to repeat the mistakes committed by players who had slow progress. What are the mistakes committed by players with slow progress? Some of them that I could think of are 1) lack of reading books  2) lack of proper coaching  3) merely playing thousands of games without strategic development. What do you think? Can you please provide suggestions on how to be efficient in my preparation? What is the best way to train?

I can think of three mistakes that a lot of class players who think they're working on their chess make:

They read chess books.

In particular they buy lots of them and then skim them, or study / try to memorize them as if they were textbooks.

Most low level players don't take the time to really get to the bottom of the positions in the books, they don't work with them, only passive consumption.

They memorize openings.

Opening books sell far better than all other types of chess book combined, even though the best they have to offer a class player is a slightly better position against someone who else who had memorized the opening but not quite as far. It's fun to feel like you're playing as a grandmaster, and sure it will lead to some short term improvement, but in the long term this is mostly wasted time.

They don't analyze.

What class player is actually able to take any position and start analyzing it to figure out what's going on? Not many, even though that's what the actual game is about. The best way to improve is just analyze a lot of positions, especially together with a mate (so you can argue and learn from each other), especially your own games. But few put in the work.

I know this because I'm very guilty of all three.


A certain game with a knight promotion checkmate I once remember (this happened 2-3 years ago) one of my friends showing me a game that was about 20 moves long. It was maybe a little longer, but it definitely ended in the middle game. It ended with a knight underpromotion checkmate, where the promoted knight both attacked the opposing king, and the knight also defended a rook that blocked off most of the king’s escape squares.
I am not 100% sure, but I think the winning player was down a whole lot of material before the knight promotion. I don’t remember whether the winning player was black or white.
I am sorry if this isn’t enough information to answer the question.

Due to prior knowledge, I scoured these three chessgames.com collections that I knew of. I found two games that match.
They do fit the bill of having the promoted knight protecting a rook. However, they're quite longer than 20 moves, are in the endgame, and have different material balances from what you think. It does help that they are recent games, relatively speaking, I'd say. So while they are similar, they may not be what you are looking for.
[Title "Gawain Jones-Danny Raznikov, Isle of Man Masters, Douglas Isle of Man, 10/12/2014"]
[FEN ""]
[startply "136"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 Ng4 7. Bg5 h6 8. Bh4 g5 9. Bg3 Bg7 10. Be2 h5 11. h4 gxh4 12. Bxh4 Nc6 13. Nb3 Be6 14. Qd2 Qb6 15. Nd5 Bxd5 16. exd5 Nce5 17. c3 Ng6 18. Bf3 Rc8 19. Bg5 N6e5 20. Bxg4 hxg4 21. Rxh8+ Bxh8 22. O-O-O Kd7 23. Qc2 Rg8 24. Qf5+ Kd8 25. Be3 Qb5 26. Bd4 Qd7 27. Qh7 Rf8 28. f4 gxf3 29. gxf3 Bf6 30. Qe4 Rh8 31. f4 Qg4 32. Nc5 dxc5 33. Bxe5 Bxe5 34. Qxe5 Rh4 35. Rf1 f6 36. Qe4 Qd7 37. Qg2 Kc7 38. Qf2 Qb5 39. Re1 Rh7 40. Qg3 Kb6 41. b3 Ka7 42. Qf2 Ka8 43. Qc2 Rg7 44. Kb2 Qd7 45. Qe4 Qg4 46. Ka3 Qd7 47. Rh1 Ka7 48. Rh2 Qd6 49. Re2 Rg4 50. Qxe7 Qxe7 51. Rxe7 Rxf4 52. Rc7 Kb6 53. Rc8 Rf3 54. Kb2 Rd3 55. c4 f5 56. Kc2 Rh3 57. b4 cxb4 58. d6 Rh7 59. Kb3 Ka5 60. Rc7 Rh3+ 61. Kc2 Rh2+ 62. Kd3 Kb6 63. c5+ Kb5 64. d7 Rh1 65. Ke2 Rh2+ 66. Ke3 Rh3+ 67. Kd4 Rh1 68. Rxb7+ Kc6 69. d8=N#

[Title "Martyn Kravtsiv-Ding Liren, World Cup, Tbilisi Georgia, 9/8/2018"]
[FEN ""]
[startply "219"]

1. c4 Nf6 2. Nc3 e6 3. d4 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 dxc4 7. Bxc4 c5 8. O-O cxd4 9. exd4 b6 10. Qe2 Bb7 11. Rd1 Bxc3 12. bxc3 Qc7 13. Ne5 Nbd7 14. Nxd7 Qxd7 15. Bd2 Ne4 16. f3 Nxd2 17. Qxd2 Rac8 18. Bb3 Bd5 19. Qd3 Qc6 20. Rac1 Bc4 21. Bxc4 Qxc4 22. Rc2 Rfd8 23. Kf2 h5 24. Qxc4 Rxc4 25. Ke2 b5 26. f4 f6 27. Kd3 e5 28. fxe5 fxe5 29. Rb1 a6 30. Rbb2 exd4 31. cxd4 Rdxd4+ 32. Ke3 Re4+ 33. Kf3 Rf4+ 34. Ke3 Kh7 35. g3 Rfe4+ 36. Kf3 Rxc2 37. Rxc2 Ra4 38. h4 Kg6 39. Rc6+ Kf7 40. Rc7+ Kf6 41. Rc6+ Ke5 42. Rc5+ Kf6 43. Rc6+ Kf7 44. Rc7+ Kg6 45. Rc6+ Kh7 46. Rc2 g6 47. Ke3 Kg7 48. Rc7+ Kf6 49. Rc6+ Kf5 50. Rc5+ Ke6 51. Rc6+ Ke5 52. Rxg6 Ra3+ 53. Kd2 Rxa2+ 54. Kc3 Ke4 55. Rg5 Kf3 56. Rxh5 Kxg3 57. Rh8 Ra4 58. h5 Kg4 59. Kb3 Kg5 60. Kb2 Rh4 61. Ra8 Rb4+ 62. Kc3 Rc4+ 63. Kb3 Rc6 64. Rh8 Rh6 65. Rd8 Kxh5 66. Rd5+ Kg4 67. Kb4 Kf4 68. Rd1 Ke3 69. Kc5 Ke2 70. Rd4 Rh1 71. Rd6 Ra1 72. Rh6 Kd3 73. Kb4 Rb1+ 74. Ka5 Ra1+ 75. Kb4 Kd4 76. Rh4+ Ke5 77. Rh5+ Kf6 78. Rh6+ Kg5 79. Rd6 Ra4+ 80. Kb3 Kf5 81. Rh6 Ke5 82. Rg6 Kd5 83. Rf6 Kc5 84. Rh6 Ra1 85. Kb2 Ra4 86. Kb3 Rb4+ 87. Ka3 a5 88. Rh5+ Kd6 89. Rh6+ Ke5 90. Rh5+ Kf6 91. Rh6+ Kg5 92. Ra6 Ra4+ 93. Kb3 Kf5 94. Rh6 Rg4 95. Rb6 a4+ 96. Ka2 Rb4 97. Rh6 Rb3 98. Rh4 Ke5 99. Rg4 Kd5 100. Rh4 Kc5 101. Rh5+ Kb4 102. Rh4+ Ka5 103. Rh5 Rf3 104. Rg5 a3 105. Rg4 b4 106. Rh4 Rf2+ 107. Kb3 Rb2+ 108. Kc4 a2 109. Rh8 Rc2+ 110. Kb3 a1=N#


How do I change Stockfish's Engine Parameters? I have no clue how to do this, I want to change its Contempt to -100.

As shown in the screenshot below. Goto Tools -> Analysis Engines -> Edit. You'll see a UCI configure dialog. In this example, I had another engine but the idea remains the same.


Why not 4.Bd2 in the Nimzo-Indian? After the initial moves of the Nimzo-Indian 4.Bd2 is rarely played and it gets poor results according to databases.

[FEN ""]
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bd2

It looks like the most natural move to me, because:

After Bxc3 Bxc3 White keeps the bishop pair and preserves the pawn structure.
It breaks the pin, so the knight can influence the center again.
It doesn't block any piece and it develops a piece.

And Bd2 is played against Bb4 in other openings.

So, why the move is weak?

There are really two questions here.

Why is 4.Bd2 rarely played?

In a nutshell, 4.Bd2 is playable, but there are better alternatives.

  After Bxc3 Bxc3 White keeps the bishop pair and preserves the pawn structure.

Even if Black decides to reply with 4...Bxc3, White won't keep his bishop pair after 5...Ne4.

[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 Bd2 Bxc3 Bxc3 Ne4 Qc2 Nxc3 Qxc3
(6. Bb4 c5 dxc5 Qf6 Nf3 Qxb2 Rb1 Qxa2)

  It breaks the pin, so the knight can influence the center again.

Black pins the knight to prevent White from playing e4. Even after 4.Bd2, White cannot do this.

[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 Bd2 O-O e4? Bxc3 Bxc3 Nxe4

  It doesn't block any piece and it develops a piece.

But it leaves the pawn on d4 undefended and prevents the queen from defending the bishop if it develops to d3.

Let's look at the alternatives:

[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 e3
(4. Qc2)

4.e3 (Rubinstein System) ignores the pin, prepares to develop the bishop to d3, protects the pawn on d4 and takes White one step closer to castling.

4.Qc2 (Classical Variation) is a better alternative to 4.Bd2 if you want to avoid doubled pawns at all costs.

Why does 4.Bd2 get poor results according to databases?

As I said before, 4.Bd2 is playable. In fact, it's what Stockfish suggests after 3...Bb4. However, engines are particularly bad at openings and, as we have seen before, there are better alternatives.

Therefore, 4.Bd2 is mostly played by amateurs, which face the Nimzo-Indian and do not know the corresponding theory.

This makes the winning percentages in databases entirely useless. For example, according to 365Chess.com, White's first move with the highest winning percentage is 1.Na3.


How do I become better at counter play when I'm down in material? How do I practice counter play when I'm down material?

Counter play, especially when down material, is often about creating dynamic chances. So you should probably work in that area:

Study the games of some attacking geniuses like Tal, Shirov, Morphy, Anderssen.
Work through some good books on attacking chess.
Play some gambits in training games.
Train tactics, but thats a given anyway.


What are good chess books of 2016? I'm rated around 1582 blitz on lichess. My rating is much higher in classical ( around 1900). I have a USCF rating but it is still provisional and I don't think it really reflects my skill (also I'm aware lichess ratings are not extremely accurate).

What current chess books would you think would be good to review. I have read through My System and played through some of the games in Fischer's "My 50 Memorable Games". Now I'm looking for modern books that deal directly with variations, not general material.

Of course I could just google "good chess books on" + opening but this leads to a lot of different options and I was hoping someone here might have more insight.

One of the very best opening book series is Grandmaster Repertoire of Quality Chess. Also Chess Stars Publishing is known for publishing high-level opening books.

There is a new chess publisher that looks promising: Thinkers Publishing. Currently, they have an opening book on the Richter-Rauzer and this year they'll publish books discussing the Grünfeld, Taimanov and King's Indian.

You can also take a look at the ChessPub Forum. They have topics on practically every opening line.


Does knowing your opponent's personality have any influence on the game-plan From Reputation and badges should be kept hidden until the question is answered, the below assertion is presented:

It is often asked in chess, that does the personality of the opponent player has any influence on their game plan, the answer is almost yes for all grandmasters. Most also feel uncomfortable playing against Computer as a competitor in chess even if it's radically low-rated running at 1/10th of its strength. Why, because people lose, not because that they are weak players but because of the inherent psychology involved that "computers make no mistakes". On the other hand, low-rated players often lose quickly when they know before-hand that the opponent player is a grandmaster. However, if the opponent rating is unknown, he tends to a better play, and even a long shot at winning it.

Do you agree with the above assertion or did you had any contrary experiences in chess. How do grandmasters employ assessing the personality as a tool to develop their game plan?

You can only adjust your plan to your opponent when you have multiple moves that are equally or almost equally good objectively, since sometimes one of these moves might seem better than the others against a particular opponent. But making an objectively poor move in the hopes that your opponent will not find the refutation is asking for punishment.

By far the primary means of adjusting one's style to one's opponent is selecting the opening. For example, the Sicilian Defense and the French Defense are both good choices objectively, but you might have reason to believe your opponent will perform worse against the Sicilian than the French. But if you know the French better than the Sicilian, you should probably choose the French, or else your choice of opening might hurt you more than your opponent.

This isn't the sort of thing most players really need to worry about until they become quite strong (master level). Usually in a tournament game you should just make the moves you're most comfortable with and play the moves that seem objectively best.


Why did non-Russian masters allow Capablanca to play "standard" openings against them? Former world champion JR Capablanca was not a particularly good opening player. Yet he was the "champ" because once he survived the opening, he played better middle and endgames than others. And this occurred because he was able to play a handful of openings time and time again.

Late in his career, he had particular difficulties against Russian masters. Not only the stars like Alekhine, Botvinnik, and Keres, but even second-rank Russian players. A major reason was that they played varied and complicated openings, and got the "jump" on Capablanca in this part of the game.

Why didn't non-Russian players do more to take Capablanca out of his familiar opening lines?

Capablanca's non-Russian rivals did not press him hard in the opening because they didn't know how:

  Capa continued to dominate until the unthinkable happened: He lost his world title to Alekhine. A grossly overconfident Capa entered the match unprepared psychologically for the new and improved Alekhine. In the end Capa lost the match because he had never previously been tested to the degree with which Alekhine pressed him.

Source: Capablanca: Move by Move by Cyrus Lakdawala. Emphasis is mine


Why is e5 the strongest move here for white? [FEN "rnb1kb1r/pp1pp2p/2p2ppn/q7/2BPP3/5N1P/PPPN1PP1/R1BQ1RK1 w kq - 3 8"]

I'm a noob at chess, as I just started playing a week back. I played
as White here, and Stockfish recommended e5 as the next move. I understand the correct move for Black would be f5 after I play e5, but just in case black plays fxe5, I'd have to take that pawn with dxe5. So Black lost a side pawn in exchange for my center pawn and my pawn on d4 got stuck alone on e5 and will be easier to kill rather than a pawn chain. What am I missing here in this move being the strongest move at this position? It cannot be queened since d6/d7 is coming. What does this do apart from just threatening the Black pawn, from going d6/d7, and breaking black into 2 pawn islands?

You've given some good, very long-term reasons not to play e5. But in this position, dynamic considerations outweigh these long-term reasons.
Look again at the position: you have developed (if you have not encountered this term before, it means moving your pieces from their starting squares so they can participate in the game) two knights, a bishop, and castled. Your opponent has developed a queen and a knight, and hasn't castled. In other words, you are well ahead in development. It's for this reason Stockfish already says your position is very strong - SF 11 is giving +3 eval at depth 22.
A lead in development is usually a signal to attack - you have more pieces that can attack than your opponent can defend. Therefore you want to attack in this position. You want open lines so your major pieces can infiltrate, and you definitely want to do this before your opponent completes their development and castles. e5 does that. Follow what Stockfish gives as the principal variation after e5.
[fen "rnb1kb1r/pp1pp2p/2p2ppn/q7/2BPP3/5N1P/PPPN1PP1/R1BQ1RK1 w kq - 3 8"]

1. e5 f5 {You also mention 1...fxe5, but this move would be even worse since after 2.dxe5 White can now play Ne4-d6+. If Black plays ...exd6 then the King would be on an open file and perish quickly, but if Black plays ...Kd8, Bxh6 followed by Nf7+ still wins material. Stockfish even wants to play 2.b4 Qxb4 3. Rb1, sacrificing a pawn to develop even faster, illustrating how much attacking potential White has.} 2. Bb3 {Threatening Nc4-d6 with the same plan as the analysis in the previous move. Note White can also play on the kingside with Ng5 or in the center with Re1 intending e6.} Nf7 3. Nc4 Qd8 {"Undeveloping" the Queen. Black could play ...Qc7 but at this point Black needs first and foremost to guard against White's attack. Still, having to undevelop the Queen shows just how awful Black's position is.} 4. Ng5 {Knight's defended by the c1-Bishop.} e6 {Or what? White threatens Nc4-d6+. If Black plays ...Nxd6, then exd6 would threaten both Bf7# and Nf7 winning material. 4...Nxg5? Bxg5 simply threatens Nd6+ winning the Queen, and 5...Bg7 6. Nd6+ Kf8 7. Nf7 still wins material. Black has to block the a2-g8 diagonal.} 5. Nxf7 Kxf7

Black's kingside looks like Swiss cheese and White has many promising ideas such as Nd6+ (effectively forces Bxd6) followed by Bh6, Qf3 intending g4 to pry open Black's pawn shield, etc. Either way, White is attacking, and the position is one where long-term pawn structure is not important.


Productive tactical puzzles: random or themed? Simply, which of the following two approaches will typically improve tactical ability the fastest:

Doing puzzles around a known theme or tactical motif - i.e. do 100 puzzles that involve a discovered attack, or a skewer, or mate in 3, mate in 2 etc. etc.
Doing random puzzles where you don't know the theme or motif behind the puzzle. You may even throw in a number of puzzles without a tactical solution to simply force you think about the next best move.

I always assumed number 2 would be better, but is there any research/authoritative anecdotes/good reasoning that show it is better to do 1?

In my experience if you are starting out it is better to solve same thematic tactical problems in a series and slowly moving onto other themes. After you get accustomed with the themes random problems or problems which doesn't tell you what to do helps.


Chess variant where king is captured While trying to teach my 4 year oldson the rules of chess, I found it difficult to explain the rules of check, checkmate and stalemate. Having already explained the moves of each piece and how capturing works, I found it much easier to say simply that one wins by capturing the other king.

Was this variant ever considered and would strategy be significantly different from normal chess? What are the essential differences between normal chess and this (arguably simpler to explain) variant?

What I can think of are the following:

there's more chance of losing due to a "silly mistake", by "stepping into check" or failing to move out of it.
a particular kind of stalemate is now impossible. If one is not currently checked but can only move into a check, then one loses, whereas in normal chess this is a stalemate.

These don't seem like crucial problems. Am I overlooking something else? How to "motivate" the normal rules when teaching chess to a child?

Other than making stalemate impossible as you already mentioned, it doesn't seem to me like this would make a meaningful difference (or any difference) to the strategy of the game. If you allow your King to be captured, that's presumably the worst move you could possibly make, so with best play the King wouldn't be captured until after it has been checkmated conventionally anyway.

Especially when teaching the rules to a four-year-old, I'd say this house rule is totally benign, as long as it's eventually explained that it's nonstandard, once he's got a better grasp on the game.


How to continue in this game? I saw the following position and was wondering how white should continue:

Should white exchange bishops?
Should white play a4 to protect the bishop?
Should white play c4 to protect the bishop and undefended pawn on d5?
Should white do something else

Which of the options above, would be the best way to continue and what should be the thought process behind each suggestion.

As white is a pawn down without compensation, piece exchanges should be avoided. White's only practical chance is a king side attack.  Maybe Bc4, with the plan of Bc4-a2, c2-c4, Ba2-b1. Along with Qh5 and/or Qc2 plus g2-g4. Its slow and black can defend, but what else can white try?


Did black have a chance to save the rook endgame? [Event "FIDE Women's World Chess Championship"]
[Site "Sochi RUS"]
[Date "2015.03.24"]
[Round "3.2"]
[White "Natalia Pogonina"]
[Black "Marie Sebag"]
[Result "1-0"]
[ECO "D46"]
[PlyCount "134"]
[EventDate "2015.03.17"]
[FEN ""]

1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 e6 5. e3 Nbd7 6. Qc2 Bd6 7. Bd3 O-O 8. O-O
e5 9. cxd5 cxd5 10. e4 exd4 11. Nxd5 Nxd5 12. exd5 h6 13. Rd1 Nf6 14. h3 Nxd5
15. Bh7+ Kh8 16. Rxd4 Nf6 17. Bf4 Nxh7 18. Bxd6 Re8 19. Qb3 Kg8 20. Ne5 Qf6 21.
Rad1 Ng5 22. h4 Ne6 23. Re4 Nf4 24. Qa4 b5 25. Qxb5 Be6 26. Qa4 Ng6 27. Nxg6
Qxg6 28. Rde1 Red8 29. Be5 Rac8 30. a3 Kh7 31. Bc3 Bd7 32. Qxa7 Bc6 33. h5 Qg5
34. Qxf7 Bxe4 35. Rxe4 Rd1+ 36. Kh2 Rc5 37. Qg6+ Qxg6 38. hxg6+ Kxg6 39. Re7
Rh5+ 40. Kg3 Rg5+ 41. Kf3 Rd3+ 42. Ke2 Rxc3 43. bxc3 Rxg2 44. Re3 Rh2 45. c4
Rh4 46. Kd3 Rf4 47. c5 Kf7 48. Re2 Ra4 49. c6 Rxa3+ 50. Kd4 Ra1 51. Rc2 Rd1+
52. Ke5 Re1+ 53. Kd6 Rd1+ 54. Kc7 Re1 55. Kc8 h5 56. c7 Re7 57. Kd8 Rxc7 58.
Kxc7 Kf6 59. Kd6 Kf5 60. Rc5+ Kg4 61. f3+ Kxf3 62. Rxh5 Kf4 63. Rh4+ Kf5 64.
Kd5 g5 65. Rh8 Kf4 66. Kd4 g4 67. Rf8+ Kg3 1-0

The position after 58.Kc7 is won for white and white did not allow a draw
position afterwards. Could Black have saved the rook ending somewhere ?

Yes, Black had a chance to save the game on moves 45, 46,  and 48. Her entire plan from 45 to 49 is wrong. She needed to bring her king and leave the rook uncommitted (in various positions) for as long as possible. See the analysis below (thanks to Stockfish 6 x64 in Deep Fritz GUI).

[Event "FIDE Women's World Chess Championship"]
[Site "Sochi RUS"]
[Date "2015.03.24"]
[Round "3.2"]
[White "Natalia Pogonina"]
[Black "Marie Sebag"]
[Result "1-0"]
[ECO "D46"]
[PlyCount "134"]
[EventDate "2015.03.17"]
[FEN ""]

1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 e6 5. e3 Nbd7 6. Qc2 Bd6 7. Bd3 O-O
8. O-O e5 9. cxd5 cxd5 10. e4 exd4 11. Nxd5 Nxd5 12. exd5 h6 13. Rd1 Nf6
14. h3 Nxd5 15. Bh7+ Kh8 16. Rxd4 Nf6 17. Bf4 Nxh7 18. Bxd6 Re8 19. Qb3
Kg8 20. Ne5 Qf6 21. Rad1 Ng5 22. h4 Ne6 23. Re4 Nf4 24. Qa4 b5 25. Qxb5
Be6 26. Qa4 Ng6 27. Nxg6 Qxg6 28. Rde1 Red8 29. Be5 Rac8 30. a3 Kh7 31.
Bc3 Bd7 32. Qxa7 Bc6 33. h5 Qg5 34. Qxf7 Bxe4 35. Rxe4 Rd1+ 36. Kh2 Rc5
37. Qg6+ Qxg6 38. hxg6+ Kxg6 39. Re7 Rh5+ 40. Kg3 Rg5+ 41. Kf3 Rd3+ 42.
Ke2 Rxc3 43. bxc3 Rxg2 44. Re3 Rh2 45. c4 Rh4 (45... Kf7 46. Rf3+ (46.
c5 Rh4 (46... Rh5) 47. Kd3 (47. Kd2 Ra4 48. c6 ( 48. Kc2 Ra5 49. c6 Ra8
50. Kb3 Rc8 51. a4 Rxc6 52. a5 Rf6 53. Re4 Rxf2 54. a6 Rd2 55. a7 Rd8
56. Rg4 Ra8 57. Ra4 Ke6 {0.00/19}) 48... Ra8 49. Rd3 Ke6 50. Rd7 g5
51. Rh7 Kd6 52. Rxh6+ Kc7 53. Rh3 Kxc6 54. Rd3 Ra4 55. Ke3 Kc5 56. Ke2
Re4+ 57. Kf1 Ra4 {0.60/19}) (47. Rc3 Ke7 48. c6 (48. Rg3 g5 49. Rd3
Ra4 50. Rd6 Rxa3 51. Rxh6 g4 52. f3 Rxf3 53. Rg6 Rc3 54. Rxg4 Rxc5 55.
Rg6 Rc3 56. Rb6 Ra3 57. Rc6 Rg3 {0.00/0}) 48... Kd8 49. Rd3+ Kc8 50.
Rd6 Rg4 51. Rd7 g5 52. Rh7 Re4+ 53. Kd1 Re6 54. f3 Rxc6 55. a4 Rf6 56.
a5 Rxf3 57. Rxh6 Ra3 {0.00/ 19}) 47... Rf4 (47... Ra4 48. Kc2 (48.
Re5 Rxa3+ 49. Kc4 Kf6 50. Re8 Kf7 51. Re2 h5 52. c6 Ra1 53. Kc5 h4 54.
f3 h3 55. f4 Rc1+ 56. Kd5 Kf6 57. Rh2 Rc3 {0. 00/19}) 48... h5 49. Kb3
Ra6 50. Kb4 Re6 51. Rh3 g6 52. a4 Ke7 53. Kb5 Kd7 54. Rd3+ Kc8 55. a5
Re2 56. Rd6 g5 57. f3 Kc7 {1.56/19}) 48. Re2 (48. Re1 Rf3+ 49. Kc4 Rxf2
50. a4 h5 51. Kb3 Rf5 52. Kb4 Rf2 53. a5 Rb2+ 54. Kc4 Rc2+ 55. Kb5 Rb2+
56. Kc6 Ra2 57. Kb6 Rb2+ {0.67/19}) (48. a4 Rxa4 49. Re2 h5 50. f3
h4 51. c6 h3 52. f4 Ra6 53. Rc2 Ra8 54. f5 Kf6 55. c7 Rc8 56. Ke4 h2 57.
Rxh2 Rxc7 {0.00/19}) 48... h5 49. c6 Ra4 50. c7 Ra8 51. Rc2 Rc8 52.
Ke4 Ke6 53. Kf4 g6 54. Kg5 Kd7 55. Kxg6 h4 56. Kg5 h3 57. Rc3 Rh8
{1.37/19}) (46. a4 Rh5 47. Ra3 (47. Kd2 Rf5 48. Kc3 (48. Ra3 Ke7 49. f3
Kd6 50. a5 Rf7 51. Rd3+ Kc5 52. Kc3 Rf5 53. a6 Rf7 54. f4 Rxf4 55. a7
Rf8 56. Rd1 Ra8 57. Rd7 g6 {0.00/ 19}) 48... Rxf2 49. c5 g5 50. Kb3
Rf6 51. Kc4 g4 52. a5 h5 53. Kb5 h4 54. c6 Rh6 55. c7 Rh8 56. Rd3 Rc8
57. Rd4 Rxc7 {0.00/19}) (47. Rf3+ Ke6 48. Rg3 ( 48. Rb3 Ra5 49. Rb6+
Kf7 50. Rb4 h5 51. Kd3 h4 52. Ke4 g5 53. Rb7+ Ke6 54. Rb6+ Ke7 55. Rb7+
Ke6 56. Rb6+ Ke7 57. Rh6 Rxa4 {0.00/19}) 48... Kf6 49. Ra3 Ra5 50.
Kd3 Ke7 51. Kc3 Rf5 52. Ra2 Kd6 53. Kb4 Rf7 54. Rd2+ Kc6 55. a5 Rb7+ 56.
Kc3 Ra7 57. Ra2 Kc5 {0.34/19}) 47... Ra5 48. Kd2 (48. Kd3 Ke7 49. Kc3
Rf5 50. Ra2 Kd6 51. Kb4 Rf7 52. a5 Rb7+ 53. Kc3 Kc5 54. a6 Ra7 55. f4
Kb6 56. Kd4 Rxa6 57. Rg2 Ra7 {0.29/19}) 48... Ke6 {0.50/29} 49.
Kc3 Kd6 50. Kb4 Ra8 51. c5+ Kc6 52. Re3 h5 53. Re6+ Kd5 54. Rd6+ Ke5 55.
Rd1 h4 56. c6 h3 57. Kb5 Rb8+ {2.55/19}) (46. Rb3 Rh4 47. Rb4 (47.
Rc3 Rh1 48. Ke3 (48. Kd3 g5 49. Ke4 Ke6 50. a4 Kd6 51. a5 Kc5 52. Rf3
Ra1 53. Rf6 Ra2 54. f3 Kxc4 55. Rxh6 Rxa5 56. f4 gxf4 57. Kxf4 Ra8
{0.00/0}) 48... Ke7 49. Kd4 Kd6 50. Rf3 Rd1+ 51. Rd3 Ra1 52. Rg3 Rd1+
53. Kc3 Rc1+ 54. Kd3 Rd1+ 55. Kc2 Rd4 56. Kc3 Kc5 57. Rxg7 Rxc4+
{0.24/19}) (47. Rf3+) 47... Rh3 48. f3 (48. Rb7+ Kf6 49. f3 Rh1 50. Ke3
Ra1 51. Ra7 h5 52. Ra6+ Ke7 53. Kf4 Rc1 54. Rc6 Kd7 55. Rc5 Kd6 56. Rxh5
Rxc4+ 57. Ke3 Rc3+ {0.00/19}) 48... h5 49. a4 Rh2+ 50. Kd3 Ra2 51.
c5 Ke6 52. Kc4 g5 53. Kb5 h4 54. c6 Rc2 55. Rb1 Kd6 56. Rd1+ Kc7 57.
Rd7+ Kc8 {0. 93/19}) (46. Re5 Rh3 47. f3 (47. a4 Rc3 48. Rc5 (48. c5
Ra3 49. f3 Rxa4 50. Kd3 Ra1 51. Kc4 Kf6 52. Re8 Rc1+ 53. Kd4 h5
{0.00/19} 54. Rf8+ Ke6 55. Re8+ Kf6 56. Rf8+ Ke6 57. Re8+ Kf6 {0.00/19})
48... Ke6 49. a5 Kd6 50. Kd2 Rf3 51. Rd5+ Ke6 52. Rd8 Rf5 53. a6 Rxf2+
54. Kc3 Ra2 55. Ra8 Kd6 56. Kd3 Kc6 57. a7 h5 {0. 00/19}) (47. Ra5
Rc3 48. Ra7+ (48. a4 Rxc4 49. Ra7+ Kf6 50. a5 Ra4 51. a6 Ke5 52. Ra8 Kd5
53. a7 Kc6 54. Rc8+ Kb7 55. Rg8 Kxa7 56. Rxg7+ Kb6 57. f3 Kc6 {
0.00/19}) 48... Kf6 49. a4 Rxc4 50. a5 Ra4 51. a6 Ke5 52. Ra8 Kd5 53. a7
Kc6 54. Rc8+ Kb7 55. Rg8 Kxa7 56. Rxg7+ Kb6 57. f3 Kc6 {0.00/19})
47... Kf6 48. Re3 (48. Re8 Rh1 49. a4 Ra1 50. Ra8 h5 51. f4 Ra3 52. c5
Ke6 53. Re8+ Kd5 54. Re5+ Kc6 55. Rxh5 Rxa4 56. Kf3 Rc4 57. Kg4 Rxc5
{0.04/19}) 48... h5 49. c5 Rh2+ 50. Kd1 Rb2 51. c6 Rb8 52. a4 Rc8 53.
Rc3 Ke6 54. Rc5 g6 55. a5 Kd6 56. Rg5 Rg8 57. Ke2 Re8+ {0.18/19})
(46. Rc3 Rh1 47. c5 (47. Ke3 g5 48. Kd4 ( 48. c5) 48... h5 49. Ke5 g4
50. c5 Ke7 51. Kf4 Kd7 52. f3 Rh3 53. a4 Kc6 54. a5 Rxf3+ 55. Rxf3 gxf3
56. Kxf3 Kb5 57. a6 Kxa6 {0.00/1}) (47. f4 Ke6 48. Re3+ (48. Kf2 Kd6
49. a4 Ra1 50. Rg3 g5 51. fxg5 hxg5 52. Rxg5 Rxa4 53. c5+ Kc6 54. Ke3
Rc4 55. Rg1 Kxc5 56. Ra1 Kd6 57. Kd3 Rg4 {0.00/0}) 48... Kf5 49. Rc3
Ke6 50. Kf2 Kd6 51. Rg3 g5 52. Rd3+ Ke6 53. a4 Ra1 54. fxg5 hxg5 55. c5
Rxa4 56. Rg3 g4 57. Re3+ Kd5 {0.00/19}) 47... Ke7 48. Rg3 (48. Rb3)
48... g5 49. a4 Ra1 50. Rh3 Rxa4 51. Rxh6 g4 52. Kf1 Rc4 53. Rh7+ Kd8
54. f3 gxf3 55. Rh2 Rxc5 56. Rh7 Rd5 57. Kf2 Rf5 {0.00/0}) 46... Ke6
47. Rg3 (47. a4 Rh5 48. Re3+ (48. Rg3 Ra5 49. Rxg7 Rxa4 50. Rg4 Kf5 51.
Rh4 Kg5 52. Re4 h5 53. Kf3 Kf5 54. Rd4 Ra3+ 55. Ke2 Rc3 56. f3 Kg5 57.
Kd2 Rxf3 {0.00/19}) 48... Kd6 49. Rg3 Ra5 50. Rxg7 Rxa4 51. Kd3 Ra3+
52. Ke4 Rc3 53. Rg6+ Kd7 54. Kd5 Rf3 55. Rg7+ Kc8 56. Rg2 Kd7 57. Ke4
Rc3 {0.06/19}) (47. Rf8 Rh3 48. f3 (48. a4 Ra3 49. Ra8 Kd6 50. a5
Kc5 51. a6 Kb6 52. Rb8+ Kc5 53. Rc8+ Kb6 54. Rg8 Rxa6 55. Rxg7 Kc5 56.
f4 Kxc4 57. f5 Kd5 {0.00/19}) 48... Rh2+ 49. Ke3 Ra2 50. Ra8 h5 51.
a4 Ra3+ 52. Kf2 Ke5 53. a5 Kf4 54. c5 Ra2+ 55. Ke1 h4 56. c6 h3 57. c7
h2 {0.00/19}) 47... Kf6 48. Ke3 (48. a4 Rh5 49. Ra3 Ra5 50. Kd3 Ke7 51.
Ra1 Kd6 52. Kd4 Rf5 53. Rd1 Kc7 54. Rd2 h5 55. Re2 h4 56. Ke4 Rc5 57.
Rc2 Kc6 {0.10/19} ) 48... Rh1 49. Ke4 h5 50. c5 Rc1 51. Kd5 h4 52. Rf3+
Ke7 53. Rh3 g5 54. f4 Kf6 55. c6 gxf4 56. Rxh4 Kg5 57. Rh2 f3 {2.56/19})
(45... Kf6 46. a4 (46. c5 Rh4 47. Kd3 Ra4 48. Re8 Rxa3+) 46... Rh5 47.
Ra3 Ra5 48. Kd3 Ke6 {0.63/29}) (45... Rh1 46. Kd2 Rb1 (46... Kf6 47. c5
Rb1 (47... Rh5 48. c6 Ra5 {2.01/29}) 48. Kc3 h5 {1.07/29}) (46... Kf7
47. c5 Rb1 (47... Rh5 48. c6 Ra5 {1.75/29}) 48. a4 h5 {1.40/29}) 47. c5
Kf7 (47... Kf6 48. Kc3 h5 {1.11/29}) 48. Kc3 g5 {0.60/29}) 46. Kd3 Rf4
({Stockfish 6 64:} 46... Kf7 47. Kc3 (47. Rf3+ Ke7 (47... Ke6 48. a4
(48. Kc3 Rh1 49. a4 g5 50. a5 h5 51. Kb4 g4 52. Ra3 Kd6 53. a6 Rb1+ 54.
Kc3 Rb8 55. Ra5 h4 56. Rg5 h3 57. Rxg4 Rh8 58. Rg1 h2 59. Rh1 Kc6 60.
Kd4 Kb6 61. f4 Kxa6 62. f5 Kb7 63. f6 Kc6 64. Ke4 Kc5 65. f7 Kxc4
{0.57/37}) 48... Rh1 {0. 68/29}) 48. a4 Rh1 {0.56/29}) (47. c5 Rf4 48.
a4) 47... Rf4 (47... Rh2 48. Rf3+ Ke6 {1.17/29}) 48. c5 g5 {0.69/29})
(46... Kf6 47. a4 Rf4 (47... h5 48. Kc3 Rh1 {2.19/29}) 48. Kc3 Rxf2
{1.61/29}) (46... h5 47. c5 Kf7 (47... Ra4 48. c6 Kf7 { 1.26/29}) 48. c6
Ra4 {1.25/29}) 47. c5 Kf7 (47... h5 48. c6 Rf8 {7.31/29}) 48. Re2 Ra4
(48... Rf6 {2.98/29}) 49. c6 Rxa3+ (49... Ra6 50. Rc2 Ra8 $18) 50. Kd4
Ra1 51. Rc2 {0} Rd1+ 52. Ke5 Re1+ 53. Kd6 Rd1+ 54. Kc7 Re1 (54... Rb1
55. Kd7 Rd1+ 56. Kc8 Rb1 57. c7 Ke7 58. Ra2 g5 59. Ra7 Kf6 60. Rb7 Rc1
61. Kb8 Kf5 62. c8=Q+ Rxc8+ 63. Kxc8 h5 64. Rb5+ Kf4 65. Kd7 h4 66. Ke6
g4 67. Rh5 h3 68. Rf5+ Ke4 69. Rf6 Kd3 70. Kf5 h2) (54... h5 55. Rb2
(55. Kc8 h4 56. c7 h3 57. f4 (57. f3 g6 58. Kb7 h2 59. Rxh2 Rb1+ 60. Kc6
Rc1+ 61. Kd7 Rd1+ 62. Kc8 Rb1 63. f4 Rb4 64. Rd2 Ke7 65. Rd7+ Ke8 66.
Rd6 {123.44/19}) 57... g6 (57... Kf6 58. Kb8 Rb1+ 59. Ka8 (59. Ka7 Ra1+
(59... h2 60. Rc6+ Kf7 61. c8=Q Ra1+ 62. Kb6 Rb1+ 63. Ka5 Ra1+ 64. Kb4
Rb1+ 65. Ka3 Ra1+ 66. Kb2 {123.47/19}) 60. Kb7 Rb1+ (60... h2 61. Rxh2
Rb1+ 62. Kc8 g6 63. Rc2 Ke7 64. Re2+ Kf6 65. Re5 Kg7 66. Kd7
{123.44/19}) 61. Kc6 h2 62. Rxh2 Rc1+ 63. Kb7 Rb1+ 64. Kc8 Ke7 (64...
Kf5 65. Rg2 Rd1 66. Rxg7 {123.45/19}) 65. Rg2 (65. Re2+ Kf7 66. Re5
{123.44/19}) 65... Kf7 66. Rg5 {123.44/19} (66. Rd2 Ke8 67. Rd8+ Kf7 68.
Rd7+ Ke8 69. Rxg7 Rd1 70. Rg6 Rb1 71. Re6+ Kf7 72. Re5 Kg7 73. Kd7 Rd1+
74. Kc6 Rc1+ 75. Rc5 Rh1 76. c8=Q Rh6+ 77. Kb7 Rf6 78. Rc7+ Rf7 79.
Rxf7+)) 59... Ra1+ 60. Kb7 h2 61. Rxh2 Rb1+ 62. Kc8 Rc1 63. Rh5 g6 64.
Re5 Rc4 65. Kb7 Rb4+ 66. Kc6 {123.48/19}) 58. Kb7 Rb1+ 59. Kc6 h2 60.
Rxh2 Rc1+ 61. Kd7 Rd1+ 62. Kc8 Rb1 63. Rc2 Ke7 64. Rc5 Ke8 65. Re5+ Kf8
66. Kd7 {123.45/19 White checkmates Black in nine moves}) 55... h4 56.
Kb8 (56. Kb7 h3 57. f3 Rc1 58. c7 Kf6 59. Rh2 Rb1+ 60. Kc8 g6 61. Rxh3
Kg7 62. Rh4 Kf6 63. Rd4 Ke7 64. Rd7+ Ke8 65. Rd6 Ke7 66. Rxg6 {123.44/19
White checkmates Black in fifteen moves}) 56... h3 57. Rb7+ Kf6 58. c7
Rc1 59. c8=Q Rxc8+ 60. Kxc8 g5 61. Rb3 g4 62. Rb5 Kg6 63. Kd7 Kh6 64.
Kd6 Kg6 65. Ke6 Kh6 66. Kf6 { 123.50/19 White checkmates Black in eleven
moves}) 55. Kc8 h5 56. c7 Re7 57. Kd8 Rxc7 58. Kxc7 Kf6 59. Kd6 Kf5 60.
Rc5+ Kg4 61. f3+ {deflection} Kxf3 62. Rxh5 Kf4 63. Rh4+ Kf5 64. Kd5
g5 65. Rh8 Kf4 66. Kd4 g4 67. Rf8+ Kg3 1-0

Probably GM Sebag calculated that she could win the outside a-pawn, but did not consider that this plan would lead to a lost rook and pawn endgame. Or, she got to that point, saw that 49...Rxa3+ was losing either way, so she opted to go for tactical chances.


Layering multiple chess games Does anyone know if an application exists where you can import multiple PGN files and layer them on top of one another?

It would be interesting to upload say 1,000 games and somehow visualise the most common moves for winning.

I was wondering if something like this exists?

If I understood well what you are asking, you are looking for a chess database application. Yes, they exist, and there many examples. Among non-commercial ones you can find Scid and among commercial ones you have for example ChessBase.


Does three-player chess have any special tactics I should know about? In chess, attacking the centre and using major pieces to support minor pieces to support pawns are common tactics. In three-player chess the game is more complex.
Should I be taking the centre, knowing I will be attacked from both sides, or should I try to flank opponents? If two players team up against one for a couple turns, how can I prevent my teammate from launching a surprise attack against me? There is little research into the mechanics of three-player chess and I find it very interesting.

Well, since an exchange between A and B is in the sole benefit of player C, your primary objective should be: avoid exchanges. How do you avoid exchanges in a normal chess game? Play an opening with a closed center (e.g. King's Indian, Ruy Lopez), or choose a modest setup (like the Hedgehog system). The less you're exposed, the better.


Which top engine is strong on what? We select an engine to use, and stick with it. But I heard that all engines have different characteristics, and can be better or worse comparing to each other, in different positions. For example: The champion engine can be beaten by another engine in some specific position.

So my question is, which engine to use in which positions?

Thanks in advance.

According to Hartmann's findings in an article in ChessBase:

  Houdini is a tactical juggernaut. It tends to do best on the various
  tactical test sets that some engine experts have put together, and it
  is fairly quick to see those tactics, making it useful for a quick
  analysis of most positions. Its numerical evaluations also differ from
  other engines in that they are calibrated to specific predicted
  outcomes:

  A +1.00 pawn advantage gives a 80% chance of winning the game against
  an equal opponent at blitz time control. At +2.00 the engine will win
  95% of the time, and at +3.00 about 99% of the time. If the advantage
  is +0.50, expect to win nearly 50% of the time. (from the Houdini
  website)

Larry Kaufman, who works on Komodo, said in an interview on the Quality Chess blog that:

  Komodo is best at evaluating middlegame positions accurately once the
  tactics are resolved. Stockfish seems to be best in the endgame and in
  seeing very deep tactics. Houdini is the best at blitz and at seeing
  tactics quickly. Rybka is just obsolete; I like to think of Komodo as
  its spiritual desceendant, since I worked on the evaluation for both,
  although the rest of the engines are not similar. Komodo’s assessment
  of positions is its strong point relative to the other top two, which
  overvalue the queen. Komodo has the best sense for relative piece
  values I think. Komodo is also best at playing the opening when out of
  book very early.

In the article, they conduct some tests using very complex positions, to see if engines can find the solution.


The New Art of Defense in Chess vs The Art Defense in Chess Is The New Art of Defense in Chess or The Art Defense in Chess better? I am 1900 on an upward trend.

Yes, the new book is quite different to the old one:

  On the whole, however, The New Art of Defense in Chess should be seen as a fundamentally new book. This is because Soltis recognizes the way in which dynamism and activity have become fundamental to modern defensive techniques.

Source: ChessBookReviews, emphasis is mine.

Synthesising the review, the reasons why the book is different is because:

Computer analysis has helped players find flaws in the attack in postmortems, which they use to improve their defensive technique
Players are more open to playing 'ugly', counter intuitive moves that are based on concrete analysis
After Tal's reign as world champion, players realised that active defensive is usually better than passive defence


In online chess with long time controls, does having a title encourage opponents to cheat against you? I was looking through the top classical players list on LiChess, and I'm gradually improving.  I noticed I'm catching up with IM Eric Rosen, which I found surprising (I'm nowhere near that strong).

So I went through his rated losses: his opponent cheated (1, 2 (probably), 3, 4) in all but one game (which seems to involve a mouse slip).  They don't just win---they crush him without problems.

I speculate that he encounters more cheating than I do because he has his title on display---his opponents want an IM scalp, and cheat to obtain it.  However, maybe this is not accurate.

Question: In online chess with long time controls, does having a title encourage opponents to cheat against you?

I'm hoping a titled player will describe their experiences with and without their titled displayed online.

I've displayed an FM title and never noticed a problem with cheating once. Your question is the first time I've ever thought about the concept of someone wanting to cheat more against a titled player.

If anything, most players would want the opportunity to get to play a titled player, and wouldn't waste it by cheating with an engine. How do you know that his opponents were cheating in most of his losses?


Are there any known examples of spurious strong chess openings, which have been determined to be dubious with the introduction of the first engines? I'm curious about the history of chess openings. Nowadays there is a lot of theory about what opening moves are considered mainstream and (near) optimal, such that either side can keep up with their opponent and maintain equality (or an advantage if anyone errs).

This sometimes goes for up to 25-30 moves without either player thinking much at all, simply because they know the best moves and have studies it extensively, and undoubtedly validated it with chess engines.

Now I'm wondering about before engines were a thing. Are there any known examples of openings, previously considered to be strong or played regularly by strong players, but later -- with the help of engines --  determined to be dubious/easily counterable?

Pretty much any opening that is no longer played was "refuted" by an engine. You can check for example the 9. 0-0-0 Nxd4 line in the Sicilian Dragon.

Computer analysis has also found interesting ways for White to keep the advantage in the From's gambit, although this opening was never that popular (because of 1.f4 being a rarity)

About 25 years ago, Kasparov reintroduced the Evans gambit into elite chess. Despite initial success computer-assisted analysis forced it to step away again.

The list goes on and on, but sometimes it's just about a variation in a particular line being changed by another, rather than something like the Sicilian or the French being abandonned altogether


Improving the endgame: Principles I find I am weakest in the endgame, which is arguably the most important part of chess.  Usually when I reach the endgame I have an advantage, often a pawn or a "winning" pawn formation, but I am not sure how to capitalize and convert this into the win.

I was wondering, what are the key ideas to keep in mind when playing the endgame, and what can I do to improve my endgame play?

I hope this isn't too general, but I believe it is an extremely common problem.

Here are a very few principles which are key:

Centralize/activate/use your king. In the endgame he is one of your strongest pieces, and needs to be utilized.
When you have the advantage, exchange pieces, and don't exchange pawns. Every exchange of pawns means one less potential promotion for the side with the advantage.
Passed pawns must be pushed, and outside passers are the best. An outside passed pawn can be the most distracting to an opponent's king or other pieces, keeping them out of other action.
Principle of 2 Weaknesses. One of the best way to convert an advantage into a win is to use it to induce another problem in the opponent's position, when he or she will then be forced to fight a war on two fronts. (For instance, this can be why an outside passer is so strong: while the opponent deals with it, a second weakness can be created and exploited on the other side of the board.)
Do not hurry! Here are some words from Shereshevsky, coming from his chapter with this title in his classic Endgame Strategy:

  How many endings have not been won, merely because the stronger side tried to win as quickly as possible, and neglected to make simple strengthening moves before embarking on positive action. Following the principle of "do not hurry", it is possible to battle for a win in positions with a slight but persistent advantage. ... The logic behind the "do not hurry" principle is mainly psychological. It can be especially recommended to act according to this principle when the opponent is deprived of active counterplay.

  Plenty more such principles can be formulated of course. These are just a few very general ones that can apply in most any endgame.

One book along the lines of your question that I cannot recommend highly enough is Rate Your Endgame by Edmar Mednis and Colin Crouch (based on Mednis' earlier Practical Endgame Lessons). It's now out of print, but if you can find a used copy, grab it. It offers its own explanation of endgame principles, and illustrates them with many examples, which are presented in a "test your play" format, where you are prompted to play one side of an ending from actual play. I got this book early on when I started "really" playing chess, and remember loving it, and learning a good deal. It is very much a general manual on how to approach the endgame, rather than being a discussion of various theoretical positions/endings. I've never read a poor opinion of this book, and when someone like Mark Dvoretsky gives something praise, it's not to be ignored.


Pawn structure search in Scid on the Go In scid on the go on android, latest version, I would like to search for a given pawn structure in the current database.

In "search" then "search current board" the closest to "search a pawn structure" would be "same material, all pawns on same squares", but it will obviously not provide what I am looking for. Plus, the "search current board" would concern ... the current board, while I would rather prefer to search directly the database. For this we have the "search" then "search header" menu, but it doesn't contain searching for a given pawn structure.

Am I missing something or is this not possible in Scid on the go on android ?

(I am not putting the scid tag as this is not a question related to scid (where searching for a pawn structure is by the way possible) but to the android app scid on the go.)

I am a not missing anything and it is indeed not possible, confirmed by the app programmer, which pointed to me the repository of its app :

https://github.com/gkalab/scidonthego

and saying that he won't provide any support/modifications except bug correction for scid on the go in the future. He is by the way happy to receive pull requests from other contributors, I will give it a try if I can spare time.


Retrograde problem websites I am looking for a good chess website about retrograde analysis problems, but after a few searches, I haven't found anything. Are there any websites that you can recommend?

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