Puzzle training: rotating tactical themes or exhausting each one? I agree that many people like it more when chess puzzles do not give a clue on the tactical theme. That is not my question, and I would like to focus on how to study a collection of chess puzzles classified by themes. I have one of those books, with one chapter devoted to each theme. In each chapter the difficulty is supposed to increase.

When I was preparing for undergraduate math exams, I used to rotate the exercises: one exercise per chapter, instead of devoting myself to one chapter exhaustively until jumping to the next one. That way, I was reviewing all the material in each session and was exposed to a bit of everything all the time. This approach has always served me well.

So I am doing the 1st chess puzzle in each chapter and, after reaching the end of the book, I go back to the beginning and solve the 2nd problem of each chapter and so on.

However, authors do not seem to have designed chess puzzle books for this approach. Sometimes they may even give detailed instructions like "look at each puzzle for 5 minutes and then look at the solution", "try to be exposed to 20 puzzles per day in order to develop a sense of pattern recognition" but there is no mention to this rotation approach I think I should use.

Is it better to focus on one tactical motive for a while instead?

Whatever works best for you.

I guess for a beginner it does make sense to see / study different variations of the same theme first. If you feel that it is too easy studying one chapter at a time, i.e. if you can spot the solution within a few seconds, it would make sense to mix it up a bit. You can do this by randomly picking problems from your book or online at sites like chesstempo or lichess or many others that have chess puzzles and that automatically adapt to your strength.

Once you get to more advanced puzzles you will see that the solution usually consists of several motives, e.g. a "clearance" followed by a "fork". At that stage you will not run into the problem of being stuck with one motif.


Why is a6 strong in this position? I was spectating an online simul given by a GM (this game in particular) and as the game was played I was very surprised to see GM Chessweeb play 24... a6.
Here is the position.
[Title "Black to move"]
[StartFlipped "1"]
[fen "7Q/ppk1qp2/4p3/3pPp1P/5P2/2P5/PP4r1/1K1R4 b - - 0 24"]

I was expecting a continuation like
24... Qh4
25. h6 Qxf4
Stockfish confirms that a6 is indeed the best move but I'm having trouble understanding why that is. The only thing I can think of is perhaps a6 gives the king a hideout to prevent future perpetual check?

You're correct. The idea of 24...a6 is to allow the king to avoid a perpetual. This could be of relevance if Black's queen moves away to go after White's king (e.g., ...Qc5). It could also be useful for the king to hide on a7 if things go haywire and a dangerous attack happens, such as the h-pawn promoting or White's rook getting involved. Although, in the position before 24...a6, Stockfish gives an evaluation of 0.00 no matter whose move it is. So purely in an objective sense, ...a6 isn't a necessary move -- but practically it's quite nice. Your anticipated move of 24...Qh4 is also evaluated at 0.00 by Stockfish, so it's just as good.
One interesting line goes 24...a6 25.h6 (White has other moves that are fine too) 25...Qc5. Now White's going to get mated from ...Qf2 if he's not careful. For example, 26.Qe8 Qf2 27.Qe7+ Kb8 28.Qf8+ Ka7. Now White can't stop the dual threats of ...Qxb2# and ...Qc2+ (picking up the d1-rook with mate). Another faulty try is 26.Qg7. The idea is that 26...Rxg7 27.hxg7 sees White about to promote, leaving him up a rook. However, Black has 26...Qf2, and 27.Qxf7+ Kb6 28.Qxe6+ Ka7 sees Black's king being safe, again thanks to the a6-pawn. Therefore, White's only 26th move which maintains equality is 26.Ka1!, preparing to defend with Rb1 if needed.


What system do DGT boards use? DGT boards allow it to be connected with a computer, and thus sending it the moves. WHat algorithm does it use to verify the moves pieces?

This page contains a lot of information about DGT boards, including the patent, detailed description of technologies and algorithms used. Many additional references are provided, too. It is definitely an interesting read!


What is a move that "is recorded in such a way that its true significance is impossible to establish"? According to FIDE rule E.8 on temporary adjournment (my emphasis),

  Except in the cases mentioned in Articles 5, 6.9, 9.6 and 9.7, the game is lost by a player whose recording of his sealed move:

  a. is ambiguous, or

  b. is recorded in such a way that its true significance is impossible to establish, or

  c. is illegal.

The items a. and c. above are pretty clear. An illegal move is, well, illegal (e.g. moving a pawn backwards, moving one's king into check), and an ambiguous move is one that does not fully indicate the piece to be moved and its destination, such as "I move my bishop back", "castling", or "I'm gonna queen a pawn".

What is the meaning of clause b. above? My instinct says that it refers to a move that is unambiguous on its face, but that is not sufficiently identified as the player's sealed move, but it is unclear how that would also not qualify under E.8.a as an ambiguous move, and I found an older version of the rules which states the following (emphasis mine):

  10.16

  At the resumption, the game is lost by a player whose recording of his sealed move:

  (a) is ambiguous; or

  (b) would result in a false move the true significance of which is impossible to establish; or

  (c) would result in an illegal move.

This version seems to emphasize that this rule is intended to prevent "false" moves as opposed to ones that are merely ambiguous or illegal. E.g. the player's sealed move might be perfectly unambiguous and 100% legal, but it might still be unacceptable because it is somehow "false". It also implies that a move that is "false", but not ambiguous or illegal, may be permitted if its "true significance" can be established, but that seems impossibly unclear.

What kind of specific misconduct or poor play does this rule forbid?

an ambiguous move is one that does not fully indicate the piece to be
  moved and its destination, such as "I move my bishop back",
  "castling", or "I'm gonna queen a pawn".

No. You obviously haven't reached "Recording of the Moves" and clarifications given in the glossary. A move, to be a move, has to be written in algebraic notation. None of the expressions you have written qualify as moves let alone ambiguous moves.

If the player had rooks on a7 and c7 and he wrote Rb7 then that would be ambiguous.

  What is the meaning of clause b. above?

If the person trying to read the move can't work out what the move is because part or all of it is illegible then that would qualify. In general this a catch-all clause that basically says you can't work out what the move is for some reason other than ambiguity. Complete absence would also do. i.e. the player seals a blank sheet of paper.


Threefold repetition: Am I getting it right? I was wondering if this is the right way of how the threefold repetition works. Thanks. (The image is in gif format, it should play automatically.)

The confusion regarding the right to claim a draw when the position occurs 3 times results from the common misnomer for the situation: "Three-Fold Repetition".  A correct term could be Three-Fold Occurrence.

As a result, in your diagram, after there have been 2 repetitions (which shows in the animation as "Repitition (sic) 2", there have been 3 occurrences of the position, and a draw may be claimed.  The game is not actually "drawn" until a claim is made and the Arbiter or Tournament Director approves the claim. This also has the result that if the player creating the 3rd occurrence of the position neglects to make the claim and proceeds to make a move, the right to claim a draw for this situation expires instantly, with his move.

Note that the protocol for making such a claim must be (to avoid causing his right to claim to expire) the following: The player announces his intention to make the move and cause the 3-fold occurrence, makes the claim to the TD before moving, and the claim is adjudicated. The rules do not describe whether the TD will require the player to make the move, but it would seem that he must, for the claim to be completed, or he will not have fulfilled his claim by causing the position to appear.  If it is determined (after the move has been made, presumably) that the position is not in fact a third occurrence, presumably his move must stand, and a penalty for incorrect claim would be levied.

Note that all of the legal moves in all of the 3 occurrences must be identical, including rights to castle as well as any possibility of en passant capture.  It is not sufficient that the same pieces merely appear on the same squares.


How is this a winning position for white? [FEN "r4r1k/pbq2p1p/1p1ppPp1/8/2P3P1/PP6/R2Q2P1/1B3R1K w KQkq - 0 1"]

1. Qh6 Rg8 2. Rf4 e5 3. Rf3 Bxf3 4. gxf3

This is what I got from "ChessCademy -> Attack and Defence -> Attacking Castled King -> Combining Focal points" lesson.
After this small play, I got :

  Excellent! After attacking the g7 square, black is forced to close off
  g8 as an escape square for his king. From there, you opened up the
  h-file, resulting in a decisive attack.

I don't understand how White got an advantage and there why Black did the moves he did.  Sadly, I didn't find a way to get the more in depth analysis on the website, or have variations of games that I could play.
It would be wonderful if someone could explain to me, or show, why White is winning and was this the best course of action?
Is there anything else Black could have done to better himself?

Qh6 threatens Qg7 mate, so Rg8 was the only way to defend.

Now if white finds a way for a rook to get to the h-line, Qxh7 Kxh7 Rh+ would be mate.

One idea would be 2.Rf3 Bxf3 3.gxf3 and then execute this idea with 4.Qxh7 and Ra2-h2. Unfortunately in this line 3…d5 attacks the h2 square and 4.Qxh7 Kxh7 5.Rh2 is foiled by 5…Qxh2.

So white plays 2.Rf4 first, this threatens g5 and then the execution. Therefore black forces the rook away with 2…e5. But now the Rf3-idea works because d5 no longer allows the queen to attack h2. No more way to prevent Qh7 and mate.

[FEN "r4r1k/pbq2p1p/1p1ppPp1/8/2P3P1/PP6/R2Q2P1/1B3R1K w KQkq - 0 1"]

1. Qh6 Rg8 2. Rf4 e5 3. Rf3 Bxf3 4. gxf3 d5 5.Qxh7 Kxh7 6.Rh2


How do you write "castles" in algebraic? Sorry if this question is a duplicate one, but I can't find the algebraic notation for castling. What is it?

In either algebraic or descriptive notation, castling is notated 0-0 or O-O on the Kingside (when the King goes to g1 or g8) and 0-0-0 or O-O-O on the Queenside (when the King goes to c1 to c8).  See for example https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Castling


Database without rapid and blitz games Last years Mega Database is full of rapid and blitz games taken from live broadcast boards.

Is it possible to filter them out?

Are there other bases that have games only from long time controls?

I'd prefer to review long games only, so interesting novelty from your favorite player won't turn to be a game played in blitz game...

Here's a sample PGN header (player names are skipped to protect the innocent):

[WhiteElo "2027"]
[BlackElo "2370"]
[BlackIsComp "Yes"]
[TimeControl "180+0"]
[Date "1999.12.31"]
[Time "23:02:00"]
[WhiteClock "0:03:00.000"]
[BlackClock "0:03:00.000"]
[ECO "D00"]
[PlyCount "100"]
[Result "0-1"]

There's no consensus, which fields are supposed to be included, but as a safe bet, I'd recommend to look for "WhiteClock/BlackClock" as well as for "TimeControl" -- at least one of them is usually present, if not both at the same time.

"TimeControl" is basically easier to parse, but since it might be not included, you might want to process White/BlackClock as well, just to be safe.


What are good chess tournaments that are FIDE rated in China for foreigners? What are good FIDE rated tournaments in China? I'm currently a FIDE class B and would like to play up. What would be some tournament recommendations and how would I register?

FIDE's worldwide calendar of tournament events normally lists tournaments around the world, but for some reason no tournaments located in China appear. The Chinese Chess Federation has this website, which carries notices of future tournaments.


Benko's three-mover that stumped Fischer In Christian Hesse's book The Joy of Chess one reads about a mate-in-3 problem composed by Pál Benkö that stumped Bobby Fischer.  Hesse gives the following diagram:

[FEN "8/8/8/4k3/8/8/8/2BQKB2 w - - 0 1"]

On the other hand, on ChessBase a slightly different diagram is given:

[FEN "8/8/8/8/4k3/8/8/2BQKB2 w - - 0 1"]

Curiously, both of these positions are valid three-movers with the same key move!  But which one is Benkö's actual composition?

You can find this chess problem

[FEN "8/8/8/8/4k3/8/8/2BQKB2 w - - 0 1"]

on page 582 of Pal Benko's book "My Life, Games and Compositions" 2003 ISBN:1-890085-08-1 which also states it was first published in "Chess life" in 1968, so ChessBase is correct.


Which is the oldest chess game? Chess has more than 1000 years of existence and the pieces got their modern day movements in 15th century Spain. But which is the oldest chess game of which we know the moves?

The oldest recorded game with the modern rules for moves is this game played in 1475. Although it's not clear if castling and en passant were in force.

[FEN ""]
[Event "Valencia "]
[Date "1475"]
[White "Francesco di Castellvi"]
[Black "Narciso Vinyoles"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd8 4.Bc4 Nf6 5.Nf3 Bg4 6.h3 Bxf3 7.Qxf3 e6 8.Qxb7 Nbd7 9.Nb5 Rc8 10.Nxa7 Nb6 11.Nxc8 Nxc8 12.d4 Nd6 13.Bb5+ Nxb5 14.Qxb5+ Nd7 15.d5 exd5 16.Be3 Bd6 17.Rd1 Qf6 18.Rxd5 Qg6 19.Bf4 Bxf4 20.Qxd7+ Kf8 21.Qd8#

There is also this - http://www.chess2u.com/t8826-oldest-recorded-chess-game - game which is supposed to have been played some time in the 10th century with old move rules. So, no double first move for pawns, bishops moving like a knight (2 squares diagonally but jumping over the intervening square) and possibly other rules for queens for example.


Atomic Chess - Pawns I have been playing atomic chess on lichess for some time but I still can't definitively state what pawns captures will look like. I think they have a kill radius of 1 but it doesn't effect other pawns? If anyone has a clear and decisive answer, I would love to hear it!

The captures in atomic chess work as follows:

The captured and capturing piece always die.
Then, anything around the capture square that's not a pawn dies.

For en passant, the capture square is the "bypassed" square of the double pawn move.
See https://lichess.org/variant/atomic or https://illion-atomic.netlify.app/atomic-rules/


Why would one promote a pawn to a knight? I know that it is makes no sense to promote a pawn to a bishop or a rook as the queen can compensate for both but a knight is something different. However, the queen is still much more powerful. So what situations would provoke you into promoting your hard-labored pawn to just a knight rather than a queen?

White to move:

[FEN "8/q1P1k3/8/8/8/8/6PP/7K w - - 0 1"]

Since my example is rather contrived and artificial, I'll also say that the so-called Lasker trap in the Albin Countergambit gives a more realistic setting, and one where a knight promotion is the best option as early as move 7:

[FEN ""]

1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3 $2 Bb4+ 5.Bd2 dxe3! 6.Bxb4 $4 exf2+ 7.Ke2
fxg1=N+ $1 8.Ke1 Qh4+ 9.Kd2 (9.g3 Qe4+) Nc6 $19

Oddly enough, I happened across that line for the first time just earlier today.

Oh, and there are situations where underpromotion to a bishop or rook is necessary in order to avoid a stalemate that a queen might create. For instance, in the sequence of moves coming from the Saavedra position, if white were to create a queen with 6. c8=Q, this would allow black to draw by stalemate, and so white must instead play 6. c8=R in order to win:

[FEN "8/8/1KP5/3r4/8/8/8/k7 w - - 0 1"]

1.c7 Rd6+ 2.Kb5 Rd5+ 3.Kb4 Rd4+ 4.Kb3 Rd3+ 5.Kc2 $1 Rd4 $1
6.c8=R $1 (6.c8=Q $2 Rc4+ $1 7.Qxc4 $10) 6...Ra4 7.Kb3 $18


Experience of big difference between Elo and national rating? I was just wondering if others have experienced big differences between players Elo and their national rating?

Currently I am playing a tournament outside of my own country. The tournament is Elo rated and expected scores etc are of course then based on Elo. My own Elo is very close my my national rating, around 2050 both of them.

However, in this tournament, a big swiss, I mostly face players around 1600-1700 Elo and they play incredible strong for such a rating.

After the games I ask what their national rating is, and for all of them it's around 2000-2100, which makes more sense. But then the expected scores that are calculated using Elo is hugely in favour of them. It seems the Elo system, is not really accurate in this situation.

Have other people experienced such a huge difference between national and Elo rating?
For one opponent the difference was even around 600!

I guess this situation occurs because very few tournaments in this country are Elo rated leading to the two ratings to be wildly out of sync.

Unfortunately, for me this has the effect of pretty much being mathematical doomed to lose a lot of rating in such a tournament.

As you suspect this can easily happen, if only very few tournaments are Elo rated, and the players are still developing in strength. The problem is often exacerbated by the lower k-factor in Elo, which means that Elo changes more slowly.

Despite not really being an up and coming player anymore, my Elo is still catching up to where it should be according to my national rating and, alas, I expect that to continue for quite some time.


Term for checkmate where every participating piece attacks exactly one square around king I am looking for the term for a checkmate position which is an aesthetic feature for a chess composition. It is closely related to pure mate. I shall say that a piece (incl. pawn) participates in the mate if the piece attacks the king or a square around it.
Pure mate:
The  checkmating position in which the square occupied by the mated king and all vacant squares around it are attacked exactly once, and squares around the king occupied by friendly pieces are not attacked by any opponent piece.
What I am looking for:
The  checkmating position in which the square occupied by the mated king and all vacant squares around it are attacked exactly once, and every piece (or pawn) participating in  the mate attack exactly one of these squares.
 [Title "The Evergreen Game, Anderssen- Dufresne (1852)"]
[FEN "1r3kr1/pbpBBp1p/1b3P2/8/8/2P2q2/P4PPP/3R2K1 w - - 0 1"]

This is a pure mate, but not the type of mate I am looking for because the f6 pawn attacks both g7 and e7.
[FEN "3B1nqr/6kp/3N1P1p/8/8/3B4/2K5/8 w - - 0 1"]

This is the type of mate I am looking for, but not a pure mate because the h7 pawn is attacked by the bishop on d3.

As a problemist, I can assure you that the term as such does not exist in problem language. Bohemian school did only know three concepts: pure mate, economic mate (all pieces - but not necessarily king or pawns - participate) and both at the same time.
Yet, not all hope is lost. At least one Bohemian troll had the following idea: What is the most uneconomic economic mate? Well, obviously one where each white piece idles as much as possible, i.e. guards only one flight, i.e. exactly which you describe. I don't remember the position offhand, but I'm fairly sure "the swarm" could dig it up if I take your request to a specialist forum. I edit it in if I can come up with it and you are interested, but don't expect that its historical solution comments contain the "Oh, look, an XYZ mate!" notion you seek.


What is the maximum number of checked squares on a board that delivers checkmate without a draw? I’ve long dreamt of delivering a “super checkmate”.
Imagine that as his dying wish, when in checkmate, the king can magically transport himself to any open square on the board.
What is the board configuration which minimizes the number of squares he can safely teleport to? Is it possible for there to be no safe squares, so the king’s wish can’t save him?
Of course, we can imagine somehow the opponent promoted all his pawns to queens along the back rank, so every square is covered, but this configuration is not achievable without having drawn along the way (I believe; but prove me wrong!).
So I’m looking for a practical configuration that can be achieved naturally where the last move is checkmate.
Bonus points for each square that is under attack more than once.

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

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

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

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


Why is castling seen as making the king so safe? I'm an amateur chess player.

I was reading an article about how f7 is such a vulnerable square and how castling makes the king safe and attacks on F7 no longer worrisome.  But looking at it, I am wondering, is this really that much better for the king?

Sure, originally F7 is only protected by the King himself.  But after castling (king side) it has only one additional protector, the rook (compare that with the four protectors the E2 pawn has at the beginning of the game).  Secondly, that rook is unlikely to stay there anyways and protect the F7 pawn, as it's likely to move to an open file early in the game.  It would be a waste a five point piece to keep there just to protect the pawn.  Lastly, we now also have the additional concern of backrank mate in this position.

Can someone explain to me why castling is so important for king safety?

The f7 pawn is really only a concern for beginners. It is not easy to attack for white with many pieces and is easily defended.

Generally (in the opening/middlegame) you want to surround your king with pieces or pawns for protection. Usually you don't want to bind your pieces to the protection of the king as they have other (attacking) duties. This leaves you with hiding the king behind pawns.

You want those protective pawns to be difficult to attack and difficult to exchange for other pawns as this would open files and diagonals, leaving your king without protection. A typical motive in chess (particularly with opposite side castling) is a pawn storm where the attacking side pushes its pawns forward in order to open lines around the enemy king. Obviously this is most difficult to achieve if the pawns are far away, i.e. close to their original position.

Another way to attack the protective pawns would be with pieces. This is often easier to do in the middle than towards the border where there are fewer squares available for the attacking pieces.

Now in the opening both sides fight for control of the center; basically in order to gain space to operate the pieces and because pieces can easily move to either side of the board from the center. In order to achieve this central control the players typically move one or two central pawns and concentrate piece activity around the center. This means that often the situation in the center is very dynamic and lines can be opened, pieces exchanged... (another typical motive: ''open lines in the center against an uncastled king''). You don't want to find your king among all this action in the middle of the board.

Taking all of this together in many cases hiding the king behind pawn chains on the side of the board after castling is usually a good idea for king safety. Another added advantage is that castling joins the rooks, i.e. the castled rook can easily get to the central files (c-d-e-f) where  there are often open or half open files to occupy.

There are also cases where players don't chose to castle (e.g. in some Sicilian and French opening lines), usually in positions with static, blocked centers and easily to attack king-/queen-sides.


What are examples of grandmaster games where both Black and White castle opposite sides and the queenside players loses? I want to become better at attacking my opponent king when they castle queenside. What are Grandmaster games where the players who castles queensides gets mated or loses due to a powerful attack on the queenside?

That's a pretty typical scenario, you'll find a lot of examples if you search for games in the sicilian opening.

[Event "Sarajevo"]
[Site "Sarajevo BIH"]
[Date "2000.05.29"]
[EventDate "2000.05.17"]
[Round "11"]
[Result "0-1"]
[White "Sergei Movsesian"]
[Black "Garry Kasparov"]
[ECO "B90"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "64"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e6 7.f3
b5 8.Qd2 Nbd7 9.O-O-O Bb7 10.g4 Nb6 11.Qf2 Nfd7 12.Kb1 Rc8
13.Bd3 Rxc3 14.bxc3 Qc7 15.Ne2 Be7 16.g5 O-O 17.h4 Na4 18.Bc1
Ne5 19.h5 d5 20.Qh2 Bd6 21.Qh3 Nxd3 22.cxd3 b4 23.cxb4 Rc8
24.Ka1 dxe4 25.fxe4 Bxe4 26.g6 Bxh1 27.Qxh1 Bxb4 28.gxf7+ Kf8
29.Qg2 Rb8 30.Bb2 Nxb2 31.Nd4 Nxd1 32.Nxe6+ Kxf7 0-1


Why can I only move my Queen vertically? I'm playing a game on chess.com and I want to move my Queen to h7. The website won't let me move it there. I tried moving it to other places but the only way I will let me move it is vertically. Is there a rule or something I'm missing, or is this a bug in the game?

The Rook on e8 is pinning your Queen against the King. You cannot expose your King to check.


Disallow opponent from offering draw on lichess How can I turn off the ability of the opponent to offer a draw? It has happened a couple of times now. I thought opponent was asking for takeback, in a hugely losing position. But it was actually a draw offer, so I ending up drawing a game that should have been easily won.

You can't. You can disable takebacks though. If you don't play games long enough with enough time to read what is being asked, perhaps you should accept mouseslips as part of the game.


Reference for good French Defense games? I want to learn this opening right now, and I was wondering what are some good games that have been played in these two openings. I prefer games in between modern players so I can relate to the game. I also need some kind of commentary on what the problems and advantages with the opening are.

For example, Harikrishnan vs Giri was a good example of French Defense in which black won.

What is the best way to study it ?

First, you need to narrow down your scope a bit. The French Defense has a massive amount of theory and you only need to learn a small portion of that to play it competitively.

You'll most commonly face 1. e4 e6 2. d4 d5 3. Nc3. Here, there are two main choices: 3... Nf6 and 3... Bb4. From an openings database or explorer (here, for example), you can pick the one you prefer. Notice the "Notable Games" section of the interface. These games are usually thematic and will teach you a lot about a variation with careful study. The black players are also more often than not "heroes" of the given opening, and you can look through more of their games.

Starting out, I would avoid only looking at the games of modern players. This tweet by Garry Kasparov illustrates the problem with that nicely, in my opinion. You don't need cutting-edge theory to play the opening well, you need the core ideas. These were fleshed out in the games of classical masters.

There are other lines that you need to learn as well. I commonly face the Exchange French, the Advance French, and the Tarrasch French in tournaments, and sometimes other variations. You need to know a little bit about each of these. The same process should suffice.

Apart from looking at games, I learned a great deal by reading The Flexible French by Viktor Moskalenko. The expanded version is available here.


Wording of Troitsky line rule The current Wikipedia article on the two knights endgame states:

  For the position with White to move, Troitsky established that if a black pawn is securely blockaded (by one of the white knights) on a square no further forward than the line a4–b6–c5–d4–e4–f5–g6–h4, then White can win the resulting endgame (and similarly in reverse for Black), no matter where the other pieces are placed.

I think the wording needs to be changed because various positions seem to me to be exceptions to the rule as stated. I'm having difficulty persuading the author of this, so perhaps it's me misunderstanding it.

I thought, out of interest, that I might take a straw poll of how many people think that the draws below are adequately covered by the wording as it is and how many people think they area valid exceptions.

Please leave a comment saying "covered" or "exception" if you read this. (If you think "covered" it would be helpful to me if you could say why, but you don't need to add any explanation if you don't want to.)

I should mention here that, since this is a poll and I'm hoping for as many responses as possible, I won't actually accept any answers even if they are perfect.

(I removed my first diagram because it was "cooked" as pointed out by GloriaVictis. The diagram was as shown in his answer.)

2.

[fen "N6k/2p5/2N2K2/8/8/8/8/8 w - - 0 1"]
[White "Either"]
[Black "to Move"]

3.

[fen "2N5/4p3/4N3/1k2K3/8/8/8/8 b - - 0 1"]
[White "Black"]
[Black "to Move"]

4.

[fen "7N/2p5/2N5/3K2k1/8/8/8/8 b - - 0 1"]
[White "Black"]
[Black "to Move"]

The key word in the rule is "securely".

Meaning, that there is nothing the opponent can do to lift the blockade.

In the posted position, white has to play 1. Ng6  - otherwise black will play 1. .. g5 and be beyond the Troitzky line - achieving draw immediately.

Subsequently, the black king will march toward the pawn, starting with 1. .. Kc5 and force the g6 knight away, as white is not in time to defend it, neither with the king nor the other knight. Then, g5 will and draw will follow.

Thus, the position appears to be covered by the rule in its current wording, as the pawn is not securely blockaded.

EDIT - answering to the comment.

4N3/6p1/8/8/1k5N/8/8/7K w - - 0 1

1. Ng6 Kc5 2. Kg2 (2. Nc7 Kd6 3. Nb5+ (3. Ne8+ {pointless}) Ke6 {white is one move short of getting the other knight to e5} 4. Nd4+ Kf6 {white must move the knight away and g5 follows}) Kd5 Kg3 Ke6 4. Kg4 (4. Nf4+ Ke7 {white has to move the knight away and g5 follows}) (4. Nc7+ Kf7 {white is not in time to defend the knight, g5 will inevitably follow after a couple checks}) Kf7 {white cannot defend both knights}

EDIT 2

As for the later added positions, I believe they are all covered by ETD's answer.


Has anyone ever played and recorded a full game of Taikyoku Shogi? I have googled for a little while and found pages and pages of rules and explanations but no documentation. Are there any documented games where the moves have been recorded? It's so ridiculous, I don't believe that anyone has ever been able to finish a game, let alone remember all of the piece movements.

The answer is yes.
According to jawp article, a game of Taikyoku Shogi was played for Japanese TV show "Tribia-no-Izumi" (=Fountain of trivia), broadcast on 19th May 2004.  The game continued 32 hours 41 minutes and 3805 moves before the first player won.  This seems to be the first full-recorded game of the variant.
Also, there is a webpage
dedicated to Taikyoku Shogi with a playing webservice（大局FLASH, requiring Flash Player）.


Reading PGN files using thr Stockfish engine Is there a way to read a PGN file using the Stockfish engine? If so, please give a sample command.

Stockfish is an engine that's called by apps that read PGN files, it doesn't read the PGN data itself.

There are many very good free apps that can read PGN files and analyse the games they contain using Stockfish (which is also free) and/or similar engines (mostly not free)

A lot of good free PGN reader apps that are able to call Stockfish can be downloaded and installed from SourceForge, such as

ChessX An old app but a good one

Scid The most popular app on SourceForge at the time of writing

PGN ChessBook Which comes with the requested Stockfish engine built in

If you search for "pgn" on SourceForge you should find more apps, but in my opinion these are the best ones currently available.


Database of correspondence games? Where can I find databases of correspondence games? I prefer freely available ones, but commercial products can also be suggested.

Maxwell,

Congrats on your request for finding correspondence games.  These are pure gems as today you can expect these games to be examples of almost perfect chess (yes, all correspondence players let the computer do 99% of the work).  You can also get databases of computer games at longer time controls to get the same 'perfect games'.

The go to database for correspondence is probably the disk that ChessBase sells and they just updated it.  http://shop.chessbase.com/en/products/corr_2015?Ref=RF70-5OH0EFN840

A while ago, Tim Harding put out a disk as well, and it may not have current games, but you never know until you check.  UltraCorr CD-ROM (Chess Mail Ltd., 2006). Followed by Ultracorr2 (2008), UltraCorr3 (2009), and UltraCorr3a (2010). No longer available.   I am not sure about the no longer available part, but google Tim Harding and ask him!

You can also download games from the ICCF (the granddaddy of all "correspondence chess") which as you may know runs the REAL World Championship. ( www dot iccf dot com) and have a look around.

Sorry I am only able to post 2 links per answer at this time.

Lastly there are probably tens of thousands of places to download games if you google it.  Here is a really good one!  http://chessgameslinks.lars-balzer.info/#correspondence-chess_worldwide    Now if you drop off the part after .info i.e. chessgameslinks dot lars-balzer dot info/  you will have enough to keep you busy even in the afterlife!


How does one become a theoretician? What does it mean to be an opening theoretician, and how does one achieve this status? Does it imply that one should not be an active tournament player? Apart from opening theoreticians are there middlegame and endgame theoreticians, too? Why are most theoreticians from eastern europe?

A theoretician is someone who has created a new opening, middlegame and / or endgame variation. You don't have to be a grandmaster to become one, and not all grandmasters are ones.

It may not apply if your variation is not tactical or is useless.

I don't think it matters where a theoretician comes from, as everyone has different chess experience, and whether you are an active tournament player or not.

People who have written about chess theory in general are chess theoreticians.


Can a knight move through all squares from its original position? I'm so confused about this. I googled it and read about knight's tours, however they all start from illegitimate positions. I want to know if a knight can move through all squares from its original position (e.g. b8, g8, b1, and g1).

Yes, it can

This particular knight's tour is closed, meaning that it starts and finishes in the same square. Therefore, the knight can start at any square on the board and finish on the same square, since it just starts at a different point along the cycle.


Going from Expert to Master What is the difference in mindset or technique that really makes the difference between an expert and a master?  I am trying to decide whether or not to start playing again and try to make that leap.

To become a master from expert, I think having a mentor is the most important factor. I know personaly a chess player who got elo rating from 2000 to 2300 with a well-known mentor from Switzerland.

Moreover, I think knowing theory and playing against very good players (2400+) can really help.


White gives checkmate in two moves [FEN "5rk1/2Q2ppp/p7/2P5/1p6/1B5P/Pq2nPP1/3R1K2 w - - 0 1"]

White, to move, gives checkmate in two moves. Can anyone find the solution?

The solution is

 1.Qxf7+.  If Kh8, then Qxf8#.  And if Rxf7, then Rd8# - the rook cannot block because it is pinned by the bishop.


A variant in the French defence advance variation Consider the following beginning, quite typical of the advance variation of the French defense:

[fen ""]

1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.a3

On what I have seen on the web, the recommended black's next moves are
6. ... Nh6, or 6. ... Bd7. But what about 6. ... f6 ? Lately this has been played
regularly against me with the white pieces, and I don't know what to do. Any idea?

Thanks,

Joël

Actually, the GM who taught me (Vladimir Kosyrev) plays c4! closing the structure then Na5 then Bd7 then Nb3, after Nxb3, you pin the N on b3 with Ba4! and you can leave the pin until the queen moves, of course castle long and f5 to break through on the king side

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 e6 2. d4 d5 3. e5 c5 4. c3 Nc6 5. Nf3 Qb6 6. a3 c4 7. Nbd2 Na5! 8. g3 Bd7 9. Bg2 Nb3 10. Nxb3 Ba4!

Feel free to look up Vladimir Kosyrevs french games in this position after 6... c4!


How do I go about learning the Najdorf Sicilian? I want to play and learn the Najdorf Sicilian.  I know that white has three main options:

6.Bg5
6.Be3
6.Bc4

But I don't know much more than that.  Furthermore, I want to play the Open Sicilian as white and against the Najdorf play 6.Bg5, so I think for me it's worth learning these variations.

Should I get Starting Out: Najdorf Sicilian?

Probably(I haven't read it) , other options are a video series eg

https://chess24.com/en/learn/advanced/video/a-complete-najdorf-repertoire/najdorf-introduction

or a more detailed book eg

http://www.qualitychess.co.uk/products/1/49/grandmaster_repertoire_6_-_the_sicilian_defence_by_lubomir_ftacnik/

or

https://www.newinchess.com/The_Sharpest_Sicilian_2012-p-1523.html.

In general I would recommend the Starting Out repertoires for anyone under 2000 FIDE.


I know my mistakes but how would I learn from them? Learning from your mistakes is the whole point of analyzing your own games is it not? By learning from your mistakes you are able to improve but my question is once I know I played a inaccurate or bad move what can I do about it? Maybe give examples to help me understand?

Identify an error - you've done that.
Identify a better move - have you done that?
Find a memorable difference between 1 & 2.

Step 3 most often involves finding some sort of principle that the better move adheres to. "Exchange when ahead in material" for example. But this is an over simplification. There are different types of errors and they require different responses.

Some errors occur because we are tired or didn't have a good breakfast before the game. Others because we didn't see some tactic and only practicing tactics or chess problems will make significant inroads there.

Sometimes you make an error in the opening. When that happens; find example games where the correct move occurred. Play few a couple of them, find one you like, then memorise it. The whole thing. It's easier than you think and it really helps with opening study.

Strategic errors do seem to require reducing to principles. "I thought exchanging bishop for knight was ok but later I wasn't able to fight my opponents control on the light squares." This situation is difficult. Was the error the exchange or was it the way you played afterwards? Only studying strategy will allow you to judge. Once you make a judgement, trust in it, come up with a way to express why the move is better, some sort of principle that it exemplifies "bishops are stronger than knights if the center is open." And then see how you do.


How to use nodestime option in Stockfish 10? By looking at the uci option file of Stockfish 10 I found this line:

o["nodestime"]             << Option(0, 0, 10000);

How exactly does one use nodestime?

https://github.com/official-stockfish/Stockfish/commit/926f215061311392bc26c7bc4bde5b719dbab4e5

has everything you need. Essentially, it's an option for chess engine testing, not for production use. The option ensures the engine plays perfectly equally during development.

As a user, you shouldn't bother with this option because number of nodes per ms is not something easy to give a value.


Is there any analysis of the Carlsen-Caruana World Championsip match by AlphaZero? How cool would it be to have the world's most powerful computer analyzing games played in a match between the world's two strongest human players? Has it happened yet and is the analysis available?

Yes, there is: AlphaZero on Carlsen-Caruana Games 1-8 and AlphaZero on Carlsen-Caruana Games 9-12. We don't have seen the PGNs with their concrete lines so far.

I'm not sure how helpful that is. Just one minute thinking time … seems to be a bit short. Some deeper calculation might be more valuable.


Best chess player with Down Syndrome Who is the best chess player with Down Syndrome? Wiki says that the mental ability of a person with Down Syndrome equals to this of a healthy person 8 or 9 years old. So, are there some players with this syndrome, as there are many admirable healthy players at the age of 8-9?

What is the elo ceiling in that case? Is it possible a "Magnus Carlsen with Down Syndrome" to get in 2000 or 2200 elo?

What about other types of intellectual disabilities?

There are a lot of titled players with high functioning autism.

One known is GM David Navara, but there are others. It is discussed if Bobby Fischer was Asperger too. There was a buzzing Magnus Carlsen was autistic too, but looks false according to Quora. Another example of GM that looks to be autistic is GM Julio Granda from Peru.

As for Down Syndrome, they have not the abilities an Asperger has, but they can learn how to play chess competitively.

Subramaniam Karaan, from India, has Down Syndrome, and he is rated 1806 when I write on FIDE list. He is also rated 1832 in blitz, and was close to reach 2000 in 2015.


Not Developing a Piece in the First Five Moves Here are the first few moves:

1.c4 e5 2.Nc3 Bb4 3.Nd5 Bc5 4.Nf3 e4 5.d4 Bf8

After the fifth move, black has essentially only pushed one pawn, while while has developed two knights and his c-pawn and d-pawn. However, the current position does not seem bad for black at all. 365chess.com gives winnings percentage White / Draw / Black as 25% /50% /25%.

[fen ""]
1.c4 e5 2.Nc3 Bb4 3.Nd5 Bc5 4.Nf3 e4 5.d4 Bf8

My question is, in the first few moves, has black violated any opening principles? Why this position is not too bad for black while he has only pushed one pawn while white has developed two nights (and it is white's turn now)?

Obviously black has violated principles such as:

don't move a piece twice
develop pieces

However opening principles are just general guidelines and in very concrete positions like the one at hand they are of little use. There are many established openings where opening principles are broken, so nothing wrong with that.

In the final position it is white's move, however the knight on f3 is attacked and has to move. After the knight has moved, black will most certainly kick away the other knight by playing c6 and then create a strong pawn center with d5 or f5.

White has currently a lead in development but black has more space and will have an easier development for its minor pieces than white. If there is nothing immediately threatening from white, I don't see why black should have a bad position.

Note that my engine still prefers white's position by about +0.5.


Does the FIDE 75-move rule apply after checkmate or resignation? 75 move rule says

  9.6 If one or both of the following occur(s) then the game is drawn: (...) any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture.

This rule can be read to mean that the game ends after 75 moves without capture or pawn move and anything that occurs after that doesn't matter. Let's say I defend a pawnless endgame and over 75 moves pass without capture. I don't realize it and a few moves later I'm about to be checkmated and resign. The scoresheet is signed as a loss. Then I count the moves and see that 75 moves were exceeded. Am I right that I can claim that the game had ended in a draw before I resigned and my resignation has no effect? I think FIDE rules could be clearer on this point, but is this interpretation valid?

Bonus question: if the game is in rapid with no scoresheets, but with video recording, such as at top level tournments, could a player who resigned make the same kind of claim and request counting moves from DGT or video to ascertain that 75 moves have passed?

The FIDE Laws of Chess (I'm giving a link to the version in the Arbiter's Handbook because FIDE have Munged their own site) do give a definitive answer but it takes some searching to find. The key appears in the section on the Chess clock!

  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),

We turn to 9.6.1 and 9.6.2 -

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

  9.6.2 any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture. If the last
  move resulted in checkmate, that shall take precedence.

Checkmate or resignation occurred after the 75 moves hence the game had already ended and provided the rules of the competition allow for appeals / claims then your claim of a draw is valid. Note that if you wait too long the decision is not going to be reversed. For instance if the results have already been sent to FIDE for rating then it is way too late. If you notice 10 minutes after the game then you should still be able to appeal and claim the draw.

Note that had you been paying attention then you would have claimed the draw after 50 moves. After 75 moves it is the arbiter who is supposed to be paying attention and you should not have to take any action. It is his responsibility to pay attention and step in to declare the game drawn. The only reason you have to take action and appeal in this case is to correct the mistake of the arbiter.


Moving pawns which are defending the king Is f4 a good move here?

 [Title ""]
 [SetUp "1"]
 [FEN "r2qk1nr/pbp3pp/1p2p/4b/4P/2N/PPP2PPP/R1BQ1RK1 w - - 0 1"]

 1. f4

On the one hand, many times you would move like this way to attack some pieces - sometimes to f3 or to f4. On the other hand, I feel that I leave open my king.

What are the disadvantages/advantages of this move?

There are no advantages.

The really big disadvantage is that after:
1. f4 BxN
2. bxB QxQ
3. RxQ Bxe4
you are completely lost, a clear piece down with no compensation whereas after
1. Qh5+ Kf8
2. QxB
you would have been a pawn up with a much better position.


What level of player is Kasparov's MasterClass suited for? I am about 1400. I was wondering if I should pay for Kasparov's MasterClass, but I am not sure if it is worth the money.

Has anyone bought this?

I have seen the materials in the program, and they are for players well below your level of play. I am not sure that they are even for a 1000 player since they are very basic. While he uses positions, they are more about teaching basic terminology and showing various themes, but on a very basic level.

For example, here is one position that you are to find 5 different skewers (Bf3, Bb3, Qg2, Qh1, and Rh5).

 [FEN "6n1/1r6/8/q2k4/8/7R/7Q/3B1K2 w - - 0 1"]

The most “difficult” problems are really no more than two- or three-move tactics like this one.

 [FEN "5rk1/p3P2p/1p4pb/q7/3N4/1P4Pb/PB3Q1P/6KR b - - 0 1"]

 1... Qe1+ 2. Qxe1 Be3+ 3. Qxe3 Rf1#

The vast majority of these problems are very famous, and can be found in other books. He does give book recommendations, but they are ones that have been recommended here many times already, including by myself. He has some practical advice about how to study, but again, it is mostly common sense that may have seen recommended already right here on SEC.

Of course, Kasparov is great, and if you were much weaker, I would have a different opinion, but my verdict is that you probably would be wasting your money.


Help me with this puzzle Look at this puzzle:

[FEN "r3q3/1pb1rbk1/2pn1p1p/p1Qp1Bp1/3P4/4P1NP/PP3PPB/3RR1K1 b - - 0 1"]

The aim of the puzzle is: Black to play and attain a good position. But I can't find a good position here. Then I looked at the solution, which was 1... Nc4!! . But I can't understand what happens after this move. I think both sides are equal. Can anyone help me?

Black will trap the queen on the next move, either with Bd6 or b6. For example:

[FEN "r3q3/1pb1rbk1/2pn1p1p/p1Qp1Bp1/3P4/4P1NP/PP3PPB/3RR1K1 b - - 0 1"]

1... Nc4 2. b3 Bd6 3. bxc4 Bxc5 4. dxc5 dxc4

and with a queen and a (passed) pawn for two minor pieces, Black will have no problems to win this game.


Is the Evans Gambit declined good for black? According to this answer, Evans gambit is not popular anymore. I looked at it and I don't see anything wrong with it. I can't go over all the variations here, but you could look for an article or a Youtube video, I chose this one.

I can only see black losing, so what's wrong with Evans Gambit declined? Am I missing a variation?

Evans gambit is not popular anymore.

The problem with the Evans gambit comes when Black accepts the gambit since he can return the gambit pawn in proper moment to defuse White's attack.

This is the crucial line:

[fen ""]

 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 d6 7.Qb3 Qd7 8.dxe5 Bb6!=

Until this day nobody was able to find edge for White-that is why nobody plays it anymore.

  I looked at it and I don't see anything wrong with it. I can't go over all the variations here, but you could look for an article or a Youtube video

Forget the YouTube and find opinions of the strongest Grandmasters.

Quality of those videos is usually low, as they intend to get subscribers by showing them attractive variations instead objectively the best lines.

Not a single theoretical main line was examined properly-only sidelines that give Black poor play.

  I can only see black losing, so what's wrong with Evans Gambit declined?

Declining the gambit is not the best option for Black. White has no problems since he gets the initiative because his opening idea was fulfilled. He will use his free tempo to further hinder coordination of the Black pieces.

Still, Black has good play in all lines, but must defend first for a long time, and attack later.

  Am I missing a variation?

If all your sources provide as "quality" coverage as the video you linked to-then yes, you do miss a lot.

I will quote the Chess Informant ECO 2006 for the lines in Evans gambit declined:

LEGEND OF SYMBOLS:

+/=    Minimal advantage for White

=/+    Minimal advantage for Black

+/-    White is better

-/+    Black is better

=/∞    Compensation for material

∞      Unclear

+-     White wins

-+     Black wins

->     Attack

↑      Initiative

[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bb6 (4...d5 5.exd5 Nb4 6.O-O Nf6 7.Nxe5 Nbxd5 8.d4 Bd6 9.Bg5 c6 10.Nd2 O-O 11.Qf3 h6 12.Bh4 Be6 13.Rab1+/=) 5.a4 ( 5.Bb2 d6 6.a4 a6 7.b5 axb5 8.axb5 Rxa1 9.Bxa1 Nd4 10.Nxd4 exd4 11.c3 Nf6 12.O-O O-O 13.d3 d5= ) ( 5.b5 Na5 6.Nxe5 Nh6 ( 6...Bd4 7.Nxf7 Qf6 8.Qe2 Nxc4 9.Nxh8 Ne5 10.Nc3 Ne7 11.Bb2+/= ) 7.d4 d6 8.Bxh6 dxe5! 9.Bxg7 Rg8 10.Bxf7+ Kxf7 11.Bxe5 Qg5 12.Nd2 ( 12.Nc3? Nc4-/+ ) 12...Be6 13.Qf3 Ke7 14.O-O-O! Raf8 15.Qa3+ Kd8 16.f4 Qe7!? 17.Qxe7+ Kxe7 18.g3 Bxa2∞ ) 5...a6 ( 5...a5 6.b5 Nd4 7.Nxd4 ( 7.Nxe5 Qg5 8.O-O ( 8.Bxf7+ Kf8 9.Ng4=/∞ ) 8...Qxe5 9.c3 Ne6 10.Re1 Nf6 ( 10...Bxf2 11.Kxf2 Qc5+ 12.d4 Qxc4 13.Re3 Nf8 14.d5 Qc5 15.Ba3 Qb6 16.d6=/∞↑)  11.d4 Nxd4 12.cxd4 Qxd4 (12...Bxd4 13.Ra2=/∞ ) 13.Qe2!? (13.Qxd4!? Bxd4 14.Ra2=/∞ ) 13...Qxa1 14.e5=/∞↑ ) 7...Bxd4 8.c3 Bb6 9.d4 Qe7 (9...exd4 10.O-O! Ne7 11.Bg5 h6 12.Bxe7 Qxe7 13.cxd4 Qb4 14.Na3 O-O 15.Qd3 d5! 16.exd5 Bd7 17.Nc2 Qd6 18.Ne3+/= ) 10.O-O ( 10.Qg4 Nf6 11.Qxg7 Rg8 12.Qh6 Rg6∞ ) 10...d6 11.f4 ( 11.Be3!? ) 11...Be6 12.Na3 exd4 13.cxd4 O-O-O 14.Be2 Nf6 15.Bf3 d5 16.e5 Ne4 17.Nc2 h5!= ) 6.Nc3 Nf6 7.Nd5 ( 7.d4 Bxd4!? ( 7...exd4 8.Nd5 Nxd5 9.exd5 Qe7 10.Kf1! Ne5 11.d6 cxd6 12.Bd5=/∞ ) 8.Nxd4 Nxd4 9.f4 ( 9.O-O d6 10.f4 Be6! 11.Bxe6 fxe6 12.Be3 Nc6 13.b5 axb5 14.axb5 Rxa1 15.Qxa1 Ng4!? 16.bxc6 Nxe3 17.Qa2 Nxf1 18.Qxe6 Qe7 19.Qc8+ Qd8 20.cxb7 O-O 21.Nd5! Kf7 22.Qf5+ Kg8 23.Qc8= ) 9...d6 10.O-O O-O 11.fxe5 dxe5 12.Nd5 Be6 13.Nxf6+ gxf6 14.Bd3 Qe7 ( 14...Nb3? 15.cxb3 Qd4+ 16.Kh1 Qxa1 17.Qf3!+-->) 15.Bh6 Rfd8∞) 7...Nxd5 ( 7...Nxe4 8.O-O d6 9.d3 Nf6 10.Bg5+/= ) 8.exd5 Nd4 ( 8...e4?+/- ) 9.a5 Ba7 10.d6 ( 10.O-O?!=/+ ) 10...cxd6 11.O-O O-O 12.Nxd4 Bxd4 13.c3 Ba7 14.Qf3=/∞

  How could black win against Evans Gambit declined?

How could he not win?

In all the variations above Black has sufficient counter-play and equal chances to win.

He will first try to parry White's initiative, and then he will have won endgame due to his healthier pawn structure and White being overextended-this is a standard plan for Black in most openings.

Summary:

Evans gambit is not popular anymore because White does not get the attack he hoped for, and after Black properly returns the pawn he has better or at least equal chances in the endgame. Why would anyone play with White just to fight an uphill battle to draw?

As for the declined variation, White will get lasting initiative but Black still holds. In all lines quoted above Black has sufficient counter-play and both players need to play accurate in order not to lose.

For a detailed coverage of the Evans gambit find repertoire books like The Great Evans Gambit Debate series or Play the Evans gambit-Tim Harding.

Hopefully this answer sheds some light. If you have further questions leave a comment and I will try to respond as soon as possible.

Best regards.


Software for opening repertoire practice I am developing an opening repertoire for white based on d4 and c4. I think this is going all right, but what I am looking for is a chess program that can exercise my repertoire knowledge.

Essentially, I want to be able to enter variations, and let the program test me on responses from black (to put it more clearly, I want the program to "play" black according to the variations that have been entered). When I make a mistake, it must notify me of that fact and show me what the "correct" move at the time was.

Importantly, this program should be accessible on Android or IOS, as I often have this need when commuting. Obviously it would be great if it was free, but I'm willing to pay for it as well.

Do anyone know of a chess program that will allow me to do this? Just to be clear, I'm not looking for chess playing software (I already use Shredder and DroidFish and they are great), but a tool for exercising pre-recorded opening variations. I did have a look around, but except for a promising looking Windows-based commercial tool, I can't find any apps that explicitly do this (it may be possible that some existing chess apps include this functionality but does not advertise it very well).

Chess Position Trainer is really great! I use it very day and love it a lot.

Still, there is no IOS version yet.


Examples of forced stalemate The usual case one often sees specially in blitz play is when one side (usually the winning) mis-plays and then stalemate occurs with the losing side dodging a loss. But are there positions where stalemate is a forced (maybe planned) outcome no matter what the opponent does?

Oh sure, here are two examples (annotated):

This is a neat puzzle from the chess.com tactics, with white to play!

 [title "White to play!"]
 [fen "1q6/2b2ppb/4p1k1/7p/2Np1p1P/3P1Q2/6PK/8 w - - 0 1"]

 1.Ne5+ Bxe5 {black has to take else white either checkmates or wins the queen.} 2.Qg3+ fxg3+ {Pawn takes queen is forced else white checkmates} 3.Kh3 {and black has no way to avoid the imminent stalemate, any move draws!}

Sometimes stalemates are exploited strategically or tactically to force
a draw, e.g. in the game below between So and Karjakin, where black may
have had the stalemate setup in mind already when the white pawns got
to
g6 and h7.

 [title "W. So vs S. Karjakin 2017, black to move"]
 [fen "4r2k/4P1pP/2pB2P1/2P2K2/8/8/R7/4r3 b - - 0 1"]

 1.R8xe7 {black switches to antichess style of play to force the draw.} Bxe7 2.Re5+ {and white has no way to avoid the stalemate, the rook will keep checking the king where ever it goes.} Kxe5


Development problems for black after f4 in French Defence I am a French player as black. I am having problems in lines where white advances their e pawn and plays f4 to defend e5. I feel like the break on f6 is useless. I am afraid to castle short. My bad bishop gets trapped and in general I get a misdevelopment of my pieces while I cannot stop white's space opening in queenside.
Here is a game I played today against a FIDE Master (FM).
[FEN ""]
[White "Fide Master Urriza (2289)"]
[Black "Manuel Ignacio Muro Sabater (1637)"]
[startply "9"]

1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. e5 Nfd7 5. f4 c5 6. c3 Nc6 7.Ndf3 cxd4 8. cxd4 Qb6 9. g3  Bb4+ 10. Kf2 f6 (10...g5 {very strong move suggested in answers that opens the position with good perspectives for black})  11. Kg2 Kf7 12. Bd3 Nf8 13. Ne2 Ng6 14. h4 h5 15. a3 Be7 16. b4 Bd7 17. Nc3 Rac8 18. Bb2 a6 19. Na4 Qa7 20. Rf1 f5 21. Nc5 Bxc5 22. dxc5 Nce7 (22...Nge7 23. Ng5+ Ke8 24. Be2 g6) 23. Ng5+ Kf8 Be2 1-0

If I had moved the other knight in words of the FIDE Master "White has still some work", but my position was suffocating, an engine gives an advantage for white practically all the game.
How could I develop better my pieces in lines with f4 in the French?

You're playing a very sharp opening line that only works thanks to the option of playing 10...g5!. You should only enter this type of position if you're aware of what you're doing. Otherwise you'd be better sticking to quieter, easier positions. If you choose to play a theory-heavy line, then you should definitely know the theory first!


How long can a player hold off a draw by the 50-move rule? Going by rules strictly about the board state, how long can a player theoretically hold off a draw by the 50-move rule? White will play as long as possible, and not want to lose. Black will claim a draw as soon as possible, if not win, so threefold repetition and dead position apply.
Here is my starting offer of 703 moves
[FEN "5bkq/p1p1p1pR/P1P1P1P1/8/4K3/8/P1P1P2P/7n w - - 0 1"]

1. Rxh8+ Kxh8 2. Kf3 Nf2 3. Kxf2

After taking 1 move to capture the queen and 2 for the Black knight,
White starts the 50-move reset counter. White shuffles around their
king to avoid repetition while Black's king is entombed. Every 50 moves thereafter, White plays a pawn move, with 12 total (playing h6 loses). After the 12th one, it will be another 50 moves until Black may rest: 1+2+50+(12*50)+50=704. (White's h-pawn position prevents dead position.)

The answer is trivially the starting position -
[fen ""]

This exact question hasn't been asked before (I think) but it has been answered here. Here is the relevant part of that answer -

The maximum number of moves in a chess game is not infinite, it's
11797 plies = 5898 moves and a half. This is due to the fifty-move
rule.

As an interim possibility here is an obvious extension of the OP's original position (before he made dozens of edits):
[FEN "5b1k/p1p1p1p1/P1P1P1P1/8/8/8/P1P1P2P/RNBQKBNR w - - 0 1"]

White makes the same starting pawn and king moves as in the OP's post minus allowing any captures and then brings a piece out to capture the a pawn, taking 49 moves to do that, then queens one of the a pawns taking 49 moves per pawn move, then takes 49 moves to sacrifice that queen next to the king, then same again with white's other a pawn, ditto taking the c pawn, etc., etc.


How do I learn to understand the middlegame? I am trying to train tactics as well as my general understanding of the beginning/middlegame. I spent a good bit of time understanding endgames, per chessmaster recommendations and those I can understand.

As far as tactics, I have been able to "train" them through chesstempo.com and "see" lots of variations through chesstactics.org.

But how do I learn to understand what I am training? I feel like I can execute tactics now without thinking, but I am not really sure what I just did. It just "feels right" because I trained it.

So what I am really asking:

  Is there a good place to get a real understanding of the middle game, or is it just raw calculation? Maybe I am missing a positional understanding?

I am thinking about getting a chess.com membership and going through the chess mentor courses.

I feel like by just doing raw training I am missing out on the real soul of the game.

In principle, the middlegame is indeed just raw calculation. In principle, the entire game of chess boils down to only that. But since the space of possible move sequences is so vast, chess is of course too complex from the standpoint of pure calculation for that to be all that we do when we play. And after all, even our computational superiors (chess engines) need to be guided with built-in positional understanding in order to play a good game of chess.

So yes, if you're feeling fairly comfortable with your grasp of calculation and the execution of tactical operations, but often find yourself "not really sure what [you] just did," then it does sound like positional understanding is what you need to accrue. A good way to look at things is this: tactics are a means to an end - and at bottom they are the means to all ends in chess - but it's not terribly useful to see tactics as the ends themselves, and that is where heuristic positional knowledge is most useful, as a guide telling you what purposes various tactics should be put toward.

For instance, former champion Vladimir Kramnik described the play of two of his predecessors thus:

  To a certain extent, Smyslov was the pioneer of this style, which was later brilliantly developed by Karpov, i.e. the gradual mounting of positional pressure based on the most accurate calculation of short lines.

Now, regardless of whether you want to play like a Smyslov or Karpov, or more like an Alekhine or Tal, I point to Kramnik's words here just because they bring out this idea of letting positional considerations guide your hand, while your tactical acumen gives you the wherewithal to achieve your aims. OK, so how to acquire positional understanding?

Here there are many many options. You mention chess.com's chess mentor course; I have no knowledge of that, and so have no opinion. I can point you to a couple of books that are designed to begin to steer amateurs toward an expert/master understanding of positional play:

How to Reassess Your Chess by Jeremy Silman. This is perhaps the most widely-known book on the subject these days, and with good reason I think. Silman does a fine job of getting the reader to (1) look at positions through the lens of various types of imbalances - e.g. who has more space, is one side's bishop better than the other's, is one king safer than the other's, etc. - and (2) begin to use those imbalances as guiding factors in determining what your plan/goals should be - e.g. I have two bishops against two knights, so I'd like to open up the position to make use of the bishops' long-range power.
The Giants of Strategy by Neil McDonald. This book is less systematically instructional than Silman's, but it is still instructive. McDonald looks at examples of play from Kramnik, Karpov, Petrosian, Capablanca and Nimzowitsch in chapters grouped around positional themes (e.g. the seventh rank, outposts, pawn breaks, planning). This isn't an overly advanced book, and is probably well-suited to the same audience as Silman's. I wouldn't recommend this book alone for gaining positional understanding, but I think it can act very nicely as a supplement to Silman, say.


Must chess pieces be within a square? In lightning chess. must pieces be moved so they are completely within a square? If not then how much overlap is allowed? If my opponent breaks this rule do I stop the clock and call the DOP?

Yes, pieces need to be properly placed. You can either tap the clock back and ask him/her to adjust his/her piece (which is what happens in many local level tournaments). It is generally better to check with the arbiter before the start of the game on what is the rule for handling such a scenario in their tournament since calling the arbiter mid-game can get you penalised.

The official FIDE site says that pieces can be adjusted only in each player's time.

I would suggest use your judgement and good sportsmanship sense and not call for the adjust for a small overlap but that is my opinion.


Rook and bishop vs. opposite color bishop I drew a game with rook and bishop vs an opposite color bishop due to the 50-move rule.
[FEN "4b3/k1B5/8/2K5/8/8/R7/8 w - - 0 1"]

Is this a theoretical draw? If not, what is the technique to win?

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

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

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


Why is the King's Gambit not played often? I have observed that the King's Gambit is usually not played at international level.  Is there any specific reason for this?

One of the more common lines for the King's Gambit is accepting, followed by 3. Nf3.  That is, 1. e4 e5  2. f4 exf4 3. Nf3.  After this, black can follow with 3... d6,
the so called Fischer defense.  Fischer was extremely confident that this was a bad position for white.  He wrote an entire article about this line, and famously said, "In my opinion the King's Gambit is busted. It loses by force."  On top of this he added, "Of course White can always play differently, in which case he merely loses differently."

I am not sure about other lines, but likely top grandmasters have analyzed them, and come to similar conclusions that white's position is not a good one.

Remark: Interestingly Fischer himself played the gambit a few times with great success, but he opened 3. Bc4.


What is the strongest chess engine for blitz time controls? There are all kinds of lists of the strongest chess engines at standard time controls. Here's one I picked more or less at random. But does anyone track which engines are strongest at faster time controls, say, game in 5 minutes?

As @FranS points out, the CCRL 40/4 list I linked to fits the bill pretty well. I was digging around on a lot of sites and must have thought that this one was showing results for 40 moves in 4 hours. I'm leaving the question up rather than deleting it in case someone comes along with the same question later.

Also, by following some links on the question that @Salvador Dali linked to I learned that there was an event called The World Computer Speed Chess Championship that seems to have died after 2011.


Good and in-depth books on Queen's Gambit and French Defense? After following the studying advises of a Chess Stack Exchange fellow (PhishMaster, if you read this, thank you!) I'm about to break 2200 Lichess elo finally. I think it is time to truly and deeply study the openings and defenses I enjoy playing. That is why I'm looking for in-depth books on the QG (or specifically QGD) and French Defense.

I'm not looking for introductory books, or key-ideas-presentations sort of literature; I'm aiming at studying and memorizing lines and variations in depth, for I feel I have come to the point this is necessary to improve my game.

An excellent example of the type of book I want is Pachamn's Queen's Gambit Declined, but the problem is the book is clearly outdated and I know many of the lines it presents as solid have been refuted both by the human mind or by the engines (still excellent book, don't get me wrong).

What books of this sort can you recommend me on this openings?

I am 2300 USCF and I recommend Boris Avrukh's books. His main focus has been the Catalan for some years now but the QGD is well covered.


What is the highest known lower bound for mate in N from starting position? Edit: It seems my question was not clear enough. Let me rephrase: What is the largest N for which we can knowingly say "chess, from the starting position, is not a forced mate in N moves"?

Chess is not solved, i.e. it is not known what the outcome from starting position is given perfect play.

However, if the starting position is win for either player, it is a mate in N for some N. Also by example, if we know for certain that the starting position is not winnable in 5 moves (for either player), 5 is a lower bound for N.

Roughly how deep is it feasible to search exhaustively from the starting position in practice? How high a lower bound for N is known?

This is essentially the question of what is the game complexity of chess. Note that by finiteness, we know that chess is determined, but we do not know if the starting position is a win for white, a win for black, or a draw.  The game complexity of chess is roughly the minimum number of positions we need to check in the game tree to determine the state of the initial position.  This is known as the Shannon number.  In the influential paper Programming a Computer for Playing Chess, Shannon estimated that the Shannon number is at least 10^{120).  Note that the number of particles in the Universe is estimated to be 10^(80).  To answer the question, we actually want to know the height of the game tree  when the initial position becomes determined.  We should also divide this height by 2, since a move in chess is typically considered a white and black move.   The branching factor of the tree is estimated to be about 30.  Thus, we can take the largest N such that 30^(2N) < 10^(120).

Answer. By the back of the envelope, N=40 works.  Coincidentally, this happens to be the length of an average game between grandmasters (although they often resign and do not actually play the game to conclusion).

Edit. The moral of the story is that I was trying to estimate an upper bound for your lower bound.  The first part of Shannon's reasoning is not circular; he says that there are about 30 legal moves from each position, and this number is reasonably constant for the first portion of a game.

Thus, we can estimate the current known value of N (which is really what you are asking, let's call this N') to be at most log_30 (C) where C is equal to the amount of computing power that has existed in the history of mankind.  Even with conservative estimates for C, we get something like  N' at most 20.  In practice, I don't think anyone has carried out this computation very far up the tree, since a priori we know that the computation becomes infeasible after a very short height and it is not necessary to exhaustively search the tree to write good chess programs.

Note however, that you are asking a slightly weaker question, since it is possible that the initial state of the game is a draw with optimal play.  So, one could get bounds for N by writing a program whose goal was to not lose for as long as possible.  We could then play this program against the best programs or human players in the world and see what the length of a shortest game is.  Again, this does not properly answer the question, since we cannot assume that our opponents are playing optimally.  True optimal play requires full knowledge of the game tree, but we have seen that this is computationally infeasible.  Thus, the best we can currently do is approximate an optimally playing opponent with a Kasparov or a very good chess program.


Intuitive play vs learning strategies When I first 'learned' chess, it was just the moves of each piece and then I started playing. I had no plan at all other than just moving pieces and trying to take from my opponent and protecting myself from losing pieces so in a way it was the shortest of short sighted play.
I never thought about the centre of the board or piece development or openings but now, I've seen videos and books etc that talk about these things extensively.
My question: Is it dishonest to start out playing serious chess by learning from books and such instead of coming up with a lot of this stuff independently at first?
To clarify:
I'm concerned that I should have independently realized that the centre of the board is the most important and that certain moves are good because they open the way for other pieces and some moves are bad because they block other pieces etc.
I'm also wondering if I should have independently been able to come up with things like Queen's gambit accepted/declined or the Sicilian defense etc.
I suppose I don't want to cheat myself and I also don't want to  'beat' others by regurgitation.
It's for this same reason I never looked at Rubik's cube algorithms online because I know for a fact that many of these super solvers of the cube just do it by playing around. I won't let myself solve a cube by a recipe.

If you compare games of past masters with modern master games you will find that the modern masters are playing at a significantly higher level. This is because modern chess masters are able to draw inspiration from and refine the ideas of the older masters. If they weren't doing this, chess theory would become stagnant and new ideas would be few and far inbetween.
Chess is a very difficult game, and nobody will fault you for trying to improve by reading general chess theory. In fact, most people (myself included) would commend you for studying chess to become a stronger player. If you want to become great at chess you have to become a great student of the craft, as with any artform. Indeed, you will struggle to find a single great artist in the history of mankind who didn't study the work of people that came before them. It's simply a very important aspect of how human beings learn things, and it is what drives society forward.
Don't romanticize/fetischize the idea of reinventing the wheel, it's a fool's errand. If you want to improve, it is not wrong to ask for guidance from people who are better than you (with the caveat that not every good chess player is also a good chess teacher). With knowledge comes confidence, and with confidence comes independence and creativity. This doesn't really depend on whether you discovered the knowledge or if someone gave it to you.
As a final note, positional concepts like central control and piece activity and coordination are far more difficult to come up with than they are to understand (at least superficially) once explained. Just because a concept is easy to understand doesn't mean that it's easy to come up with, so don't feel bad for not coming up with these things on your own. Believe me, while most players know about these concepts only very few players have actually managed to master these concepts completely. And with regards to specific openings: you have absolutely no chance of coming up with these concrete openings on your own! The modern theory of Queen's gambit/Sicilian is the result of centuries of intensive development by the greatest players of their time trying to outfox their competitors by coming up with one creative new idea at the time. Some of these ideas became part of established theory and others fell into obscurity, but every single one of these innovations required a great deal of effort. There is no way a single human being could ever dream of coming up with all these ideas on their own.


Best way to use UCI engine to play against itself So far I used UCI only to make analysis of particular positions, sending FEN, showing multipv, analysing fixed depth/time, clearing hash for every next position.

Now I would like to make the same engine play against itself a blitz game and I guess this approach might waste a lot of CPU resources. Any information on this topic, ideally with example of UCI communication included, will be appreciated. Especially I want to ask:

How should I setup hash and when should I clear it? After each move, after reaching certain amount of nodes searched from last clearing to defend against hash colisions?

Is there a better way than sending FEN after each move to UCI?

Should I setup multipv to 1 and always wait for "bestmove"?

I'm not very concerned by slowdowns caused by fen parsing etc, but I would like not to make some huge mistake like clearing knowledge made on previous moves. Of course I want engine being able to reuse as much calculations as possible for both sides from last moves.

I don't think it's a good idea to write a new framework. You should use Cutechess. CuteChess is free, stable, fast and reliable.

I'll answer your questions anyway:

You should not clear the hash, it's the engine job to fill it and replace it
You don't have to send FEN, you can also give a move list
By default, multipv is 1 so you don't need to do anything


Determine ELO strength without playing in FIDE tournaments I don't play club chess or tournaments, how can I determine my ELO strength?
I often play on chess.com how well does it compare to the FIDE system? (I am aware that one cannot account for people cheating online)

This is going to sound tautological, but Elo is inherently a measure of how you do in tournaments. Your question is sort of like asking "I don't run, how can I determine how fast I can run a mile?" We could guess from how generally fit you look, but in reality you just have to go run a mile to find out.

There are correlations between various online ratings and a FIDE rating, but they're just correlations; the context of how you play online is very different from playing live (for one thing, online games are usually much faster).

I can tell you that the first time you play in a live tournament you will likely perform 100-200 points worse than you might expect from such a correlation, just because you're not used to the environment of a face-to-face tournament (moving real pieces, using a clock, writing down your moves, having your opponent right there in front of you, being distracted by other games). Luckily it does not take long to settle in.


What openings provide "mini-objectives" in the early game? As a beginner I've found that it is psychologically really nice playing QGA as white simply because I have a clear task at hand in the early game - namely recapture that pawn.  Similarly, hedgehog for black is satisfying because you are aiming for a layout rather than a sequence.

I often find it quite hard to stumble through the early game when there is no clear objective - many openings the objective is simply to "develop pieces onto good squares".  I'm not yet good enough to visualise that task so play pretty aimlessly.

What other openings should I look at that have clear, understandable, short term objectives to get you to the mid-game?

I think this question divides into two parts:

Openings with "mini objectives" early in the game.
Openings that go for a layout instead of a sequence.

The second part is easier to tackle: There are a lot of openings, usually called "systems", that go for a certain structure without bothering too much with what the opponent is doing. Some examples:

The London System
The Colle-Zukertort
The Stonewall-Dutch
The Stonewall with white

Also in many sicilian lines (most notably the dragon) white just castles long and starts to march his kingside pawns --> sac,sac,mate as Bobby Fischer famously said. But these are much more dependent on move order issues and concrete tactics.
You could interpret "long castles" as a mini-objective for white in the English attack, which is almost always achieved by playing f3, Be3, Qd2.

Mini-objective vary from variation to variation, but I think there is one mini-objective that is almost always relevant, especially when playing black: pawn levers.

For example if you play the black side of a QGA, you might go for the pawn lever c5. In a King's Indian black prepares the pawn lever f5, and sometimes c6 (whereas white goes for c5). In a Benoni he goes for b5 and sometimes f5. In a Meran you will always play c5 or e5 at some point, while white usually plays e4, in a Italian or Spanish game white prepares e4, in a French black goes c5 and white hopes for f5 … they are all over the place!

So my advice would be to look out for pawn levers in the openings you play. They should very often provide the mini-objective that gets you from the opening into the middlegame.


Why is, according to Stockfish (depth = 28), a4 the best move here for White? This is a position from a game between Fischer and Ibrahimglu, 1970.

Black's last move was 11. ... Qc7 from d8. According to Stockfish (depth = 28), 12. a4 is the best move for White. The other recommended moves are Nb3 and Rd1. But a4 seems to be better than Nb3 by more than 0.1 point.

It seems to be a very logical move as Fischer played it too. Only the logic behind it is out of my (an intermediate player) reach. :)

The game continued with 12. ... Rad8 13. Nb3 b6 14. Be3 c5... Fischer went on winning this game.

1. a4 allows White to place his knight on the c4-square without having to worry about ...b5 kicking it away because that would be too weakening for Black, because it would make the a-pawn backwards on an open file.

1. a4 also gains space and opens the possibility of a5-a6 to soften the Black queenside for the g2-bishop. If black stops this with ...a6 or ...a5, then Black will have a hole on b6.

A knight on c4 would allow white to move his bishop to f4 to attack the black queen. If Black responds ...e5, this creates a permanent weakness on d6, and White can put his knight there. ...e5 also blocks Black's bishop. The knight on c4 also takes away many squares from the black queen, so if Black does not want to weaken with ...e5, the black queen will have to go to an inactive square.


Assessment of O'Kelly Sicilian side line I have an opponent who is going into this as Black:

[FEN ""]
1.e4 c5 2.Nf3 a6 3.Nc3 d6 4.d4 cxd4 5.Nxd4 e5 6.Nf5

He usually follows with 6...Bxf5 and after 7.exf5 Nf6 I play 8.g4 with a sharp game.  I like the positions I get and score well; I am seeking objective assessments of this variation as I may be biased towards White.

Black's move 5...e5 seems questionable to me. The move 6. Nf5!? is a little unusual but definitely playable. The only well-known player ever to have tried it was Jacek Bednarski, who used to obtain a draw in one of his games in the Polish national championship back in the 1960s. Bednarski is best known for losing game #55 in Bobby Fischer's "My 60 Memorable Games."

The move is a good line in a club setting because it is provocative and will take your opponent out of the book. It has good surprise value, and the resulting positions are not standard patterns which a player will be familar with, therefore, White will definitely have the edge in preparation.

In my opinion, Black is better off playing in a non-committal fashion with 6...Nf6 and aiming for g6 later.

After:

[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 a6 5. Nc3 e5 6. Nf5 Bxf5 7. exf5 Nf6 8.Bg5 Be7 9. Bxf6 Bxf6 10. Qd5 Qd7 11. g4

White has a small but definite advantage.


Why is the rook worth 5 points while the bishop is only worth 3? Why is the rook worth 5 points while the bishop is only worth 3? Rooks only move straight, but bishops only move diagonally. Is there something that makes moving straight more to moving diagonally?

You need to understand that the point system is only a rough guideline meant to assist you in evaluating positions or in deciding on potential exchanges. Many factors, particularly the pawn structure, influences how valuable pieces are. Rooks tend to be better in open positions with fewer pieces/pawns on the board, bishops can get hindered in closed positions by pawns of the same color ("bad bishop"), etc.

Despite of all this, the 5/3 values for rook/bishop (or the piece valuation system in general) is surprisingly reliable.

A rook is generally more valuable than a bishop because:

it can reach all squares of the board, while a bishop can stay only on squares of the same color
it can mate in KR vs K, while you cannot win KB vs K.
it covers more squares (can always move to 14 squares on an empty board independent on where it is placed, while with a bishop it can vary between 7 (corner) and 13 (center) squares)

The exact values "5" and "3" are basically found from experience and since there is a bit of a drawing margin in chess, the exact values don't really matter.

One notable and very common exception to the rule is found in many (beginner's) opening play where a bishop and knight can be exchanged for a rook + pawn on f2 or f7. In these cases almost always having two light pieces is better even though you exchange 6 pawn units for 6 pawn units.


Multiple opening books in Arena? In Arena, you can select an "Arena main book" which will be the chess opening book that will be displayed in the Book/TB tab.  However, is there any way to merge multiple opening books into that tab?  It would be useful to combine a couple of good normal books with, perhaps, a special gambit book.

PGN files are simple flat text files.  Using a program such as Notepad++ you can simply merge the PGN files containing the openings you wish, into a single PGN file.  It's pretty simple.

That said, if the two books you're merging contain the same openings you will have duplicates.  Accordingly another strategy is to find the largest PGN book of openings you can, and simply add the missing openings you seek.

You can also convert PGN books to other formats such as the native *.abk format favoured by Arena.

Using one book at a time seems to be a natural constraint of Arena. So you will have much more success working within that constraint and adopting the idea of merging multiple books into a single one and using it.


How should I deal with two siblings in the same section? How can I deal with two family members who are playing in the same section?  For example, my brother and I both played in the same local tournament (one section) fairly frequently.  Usually, we could avoid being paired (there were enough people, and the other players were willing to cut us some slack).

Occasionally, we would be leading the tournament and there was no way around pairing us.  The most drastic case was when we both had perfect scores and were playing for first place (and potentially third for the loser).  As a good big brother, I soundly trounced my younger brother.

Now it's not far-fetched to imagine a case where the game between family members impacted prizes/tournament standings at the end of a cash tournament.  Is there a fair way to deal with the situation?  Obviously any kind of collusion would be grounds for a double forfeit, but it would also be very hard to prove that it was a pre-arranged result.

An interesting side note - I seem to remember seeing that former World Champion Kosteniuk used to play in tournaments with her sister, and she said that they would be paired in round one to avoid any conflicts later.  Is this a reasonable solution or is there a more equitable way to deal with things?

The situation is not very different to two training partners or two friends being paired. The dilemma between sportsmanship and friendship is the same. Are you allowed to "misuse" personal information about weaknesses of your opponent? Should you pre-arrange a result to fit the needs of each other?

The keyword is sportsmanship here. You are playing in a chess tournament because you like the thrill of a tournament, the competition and over everything else: the game. You both share this love. Why should you sacrifice the idea of the sport at all? Trying to win against an opponent is not a personal affair, but a trial of strength between the two players. That is why you joined the tournament in the first place! If someone beats me, he might still be my best friend (at least, after my embarrassment of having lost is gone). If you pre-arrange a game, you harm the idea of the tournament and you harm yourself, because you get less excitement and benefits from playing there.

There are several cases of successful siblings competing in the same sport at the highest level. In Formula 1, the Schumacher siblings Ralf and Michael were competing for several years at the same races. In woman chess, the Kosintseva siblings Tatiana and Nadezhda are both ranked among the 20 strongest women. I think they attend the same tournament together very often. I doubt any of them would sacrifice the sport, nor did I ever hear someone voicing that opinion.

Hence I would suggest, the more professional the level of play is, the less you have to worry about siblings being paired against each other. As a tournament director my fear about cheating players would not increase only because there are siblings playing.


Meaning of move stats in opening databases I naively thought that if I picked the biggest winning move (for example using white) in the database and kept picking moves that white would always win,
 but at some point the advantage for white suddenly will often turn negative or even to 100% losing.

It seems that the move before that must have some bad data if it had a winning edge but one move later loses.

If the tree bears down to a total loss then how could the move before have had a winning edge?

Is this whole concept of winning % by move erroneous?

Am I missing something?

What other explanation can you provide?

You have to keep in mind that a tree of variations isn't actually a tree. You can reach the same position in many different ways, i.e. the branches can grow back together. So when you go through a variations the number of games doesn't necessarily dwindle until there is just one game left, occasionally games from another move order will join the fray and possibly change the statistics a lot.

So if you are following ten games with 90% for white, but reach a position that was also reached by a different move order, suddenly you might be looking at 50 games. And if for some reason white did much worse in the additional 40 games, the statistics will flip.

This is not as unlikely as it seems, because employing a different move order can indicate different overall knowledge of an opening. For example the 40-games move order may have been all the rage in a time when a very good later continuation for white wasn't known.


"Pawn Power in Chess" by Hans Kmoch vs "Pawn Structure Chess" by Andrew Soltis I have Pawn Power in Chess by Hans Kmoch, but I can hardly understand what he is trying to convey in the book.  Maybe this has to do with my level of play or maybe it has to do with the way Kmoch writes.  I do not have Soltis' book, so I was curious to know if anyone has read it and if it is similar to Kmoch's book?

I haven't read either but here's an excerpt from Dan Heisman's Novice Nook #17

  A "break" move is a pawn move that “breaks up” an opponent's (fixed)
  pawn chain by attacking the opponent's pawns with that pawn. In his
  classic work Pawn Power in Chess, Hans Kmoch calls this move a
  liberation lever. Don’t be put off by Kmoch’s arcane nomenclature –
  Pawn Power is a great book for players in the 1300-1900 rating range.

[edit] Current world champion Viswanathan Anand also mentioned the book in this interview.

Hope this helps for something... I'm also thinking of buying one of these two books.