I developed all the pieces I could. Now what? I was playing chess against an AI, and found myself in this position (Black/me to move):
r1b2rk1/4n3/p1p1p1p1/1p1pPp1p/1PnN1P2/2NB4/2PP2PP/1RB2RK1 b - - 0 1

The only moves I could think of were either obviously bad (e.g. trying to move the knight on c4), obviously pointless (e.g. shuffling the king around), or would mess up my pawn structure.
I tried plugging this into an analysis engine, and it suggested 1. ... a5 (which, now that I look at it properly, makes a great deal of sense to me). It also said that I'm down about four pawns in evaluation, which is unsurprising as I'm down a bishop, the other bishop is bad, and neither of my knights has much freedom of movement. Meanwhile, White's bishop and knights are active and greatly limiting my options. So, on the whole, this game does not seem to be going well for me.
But my broader question is not "what specific move should I be making?" Instead, what should I be trying to accomplish, in general terms? Because on this board, in this position, I really have no idea what my next goal should be. I feel like most of my pieces are either already developed, or impractical to (further) develop; I cannot see any reasonable lines of attack that might actually yield an advantage; and it's also rather difficult for me to infer what White should be doing, so I can't even effectively defend myself.
The AI doesn't allow draw offers. Should I just shuffle the king around and count to 50, or do I actually have a chance of pulling this one back?
(Lest anyone accuse me of cheating against an AI, the game is already over, but I still find this position utterly baffling.)

Let's look at the position and try to evaluate the situation on the board. This is always a good idea, especially if you're struggling to come up with a concrete plan.
r1b2rk1/4n3/p1p1p1p1/1p1pPp1p/1PnN1P2/2NB4/2PP2PP/1RB2RK1 b - - 0 1

HOW TO EVALUATE THIS POSITION?
In this position black is a piece down for a pawn, so this in and of itself should be cause for concern. But this is actually not the only issue with black's position, although the material situation is of course the easiest thing to consider in a position since it doesn't require anything besides basic arithmetics to calculate.
Factors that are just as important, but often much harder to appreciate for beginners, include king safety, piece activity and coordination, pawn structure, space, etc. Let's begin by looking at black's pawn structure, as it will make clear just how problematic black's position really is.
The "sawtooth" kind of structure that black has set up is something I often see beginners play for, as they feel like it's easy to make sure that everything's protected. But the structure has some serious flaws. First off, the pawns in the back of the structure (g6, e6, c6, a6) are at serious risk of becoming weak since there is no way to defend them with other pawns and it's very hard to advance them without losing them; for instance, moving the g- or c-pawn forward here just lets white capture the pawns for free. But this is not where the problems end. The pawns that are further advanced (h5, f5, d5, b5) are also virtually immobilized; if they were to move forward they would immediately lose support and be vulnerable to attack (imagine if black were to play ...h4, then white would win that pawn if they just manage to threaten it somehow). So in the end, black's pawn structure is rigid and inflexible, and much weaker than it seems at first glance. Another problem with this structure is that it leaves your dark squares very weak. If you want to defend a dark square it has to be done with a piece, and since you're lacking a dark-squared bishop it will be difficult to do this efficiently.
The inflexible pawn structure causes a lot of other headaches for black as well. For instance, black already controls less space than white (in this case it can be clearly seen by the fact that black is relegated to play on the 6th to 8th rank with almost all of their pieces, while white's pieces have a lot more opportunity for movement). This means that black will have less space available to move around their pieces. This, in turn, makes it harder for black's pieces to coordinate without stepping on each others' toes which makes it harder for black to react to white's threats in the long term.
So, to summarize, black is material down and has a weak and inflexible pawn structure which makes their position cramped and gives their pieces a harder time to move effectively (the bishop on c8 is especially terrible here). The only "good" thing about black's position is that their king is pretty safe at the moment. Therefore your aim in this position as black is to draw, since winning is out of the question as long as white doesn't blunder something serious.
HOW DOES WHITE WIN?
Depending on the opposition a draw for black can be easy or difficult or impossible to achieve. A grandmaster would easily win this position as white no matter what black does, the average player could potentially struggle against optimal play and a beginner is probably not going to win this as long as black hunkers down and plays passive defense. Let's discuss a bit how white actually wins this position so that we know what we must try to prevent.
At the moment, the position is pretty locked, so white should ultimately aim to open it up somehow. An open file is enough here to work with, so a pawn breakthrough with h3-g4 is going to be enough to open the position eventually. But the fact of the matter is that with a locked central structure there is no real need to play this immediately, and white can instead focus on improving their position by developing the dark-squared bishop on c1; if this bishop were to awaken it could easily become very strong, since black's dark squares are desperately weak as I described earlier. In fact, a pawn break with h3-g4 may not even be necessary to win here if the c1 bishop manages to worm its way into black's position.
In general, white should try to use their extra space to their advantage in order to "optimize" the position of their pieces and threaten as many of black's weak points as possible at once while at the same time take away squares for black's pieces to occupy safely. Therefore, the following would be an excellent sequence of moves for white to be able to play: Nb3 (this opens the potential scope of the bishop on c1 later on, and it blocks black from making any pawn breaks; also, this knight could be very annoying for black if it were to reach c5, as this would practically immobilize the bishop on c8 completely), Be2 (opens up the d-pawn, and it also starts to prepare for a future g4 pawn break), d3 (pushes black's knight away from its active post on c4), Be3 (this bishop may go c5-d6 or f2-h4, depending on what black decides to defend against). If white so pleases, they could begin the entire operation by playing Be2, d3, Be3 first.
SO WHAT SHOULD BLACK DO HERE?
This is by far the hardest question to answer. Black is objectively lost here, and to be honest, I'm struggling to see a decent way for black to play this in order to make life hard for white. If I were playing a weaker opponent I would probably just hunker down here and play passively, hoping that white doesn't find a winning plan (which they probably wouldn't find, at least immediately).
However, the problem with this is that white just wins then by playing along the plan I outlined above, and this is something I kind of expect the average player (~1600 Elo) to find eventually. So I guess that ...a5 is really the best move to try here in practical terms. This move is good to try because it eliminates the pawn on b4, which gives black some chances to take back some terrain on the queenside by means of just rolling their pawns forward if white is careless enough. This would solve the space issue nicely, and give black's pieces a fighting chance to activate themselves. Note, however, that black is dead lost with decent play from white here and even if ...a5 is relatively best it's still far from nearly enough to ensure a draw. For instance, the line 1...a5 2.bxa5 Rxa5 (if 2...Nxa5 white just plays Ba3, activating their dark-squared bishop immediately and threatening the knight on e7) 3.Nb3, and white dominates completely. But since the pawn on b4 has been removed this means that the pawns on the queenside are a bit more mobile, which means that white has to be a bit more tactically alert.


How do you get to this trap position? [FEN "rn1qkbnr/ppp1pppp/8/8/2B3b1/2N2N2/PPPP1PPP/R1BQK2R b KQkq - 0 1"]

1...Nf6 2.Bxf7+ Kxf7 3.Ne5+ Kg8 4.Nxg4

It's black to move. There is a trap: 1...Nf6 2.Bxf7+ Kxf7 3.Ne5+ Kg8 4.Nxg4 and white wins a pawn (from Capablanca's Chess Fundamentals). I wonder how do you get to the initial position. The only way I've thought of involves black playing a bad opening, moving a piece twice. For instance:

[FEN " w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd8 4.Nf3 Bg4 5.Bc4

Is there a more natural way to get to the position?

Your proposal is a plausible way to get to that position. I wouldn't call the Scandinavian "bad" just because it moves a piece twice. It's perfectly playable.

When the trap was played in the following game, it was the knight rather than the queen which moved twice.

[Site "Sao Paulo (Brazil)"]
[Date "1973.??.??"]
[White "Nobrega Adaucto Da "]
[Black "Barata Hemar"]
[Result "1-0"]
[FEN ""]

1. e4 d5 2. exd5 Nf6 3. Nc3 Nxd5 4. Bc4 Nf6 5. Nf3 Bg4 6. Bxf7+ Kxf7 7. Ne5+ Kg8
8. Nxg4

And by the way, you have to be a little careful when playing this. Someone once tried this on me, but the position was slightly different:

[FEN ""]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 c6 5.Nf3 Nf6 6.Bc4 Bg4 D 7.Bxf7+?

And now after Kxf7 8.Ne5+, Black has Qxe5+ 9.dxe5 Bxd1 and will end up with an extra minor piece.


Most pins in a chess game I've looked at a few chess games on ChessBase that have a lot of pins, and I am wondering, what is the most number of pins that has occurred in a game, and what is the game?

The most pins in a real game position that I know is 3 from an extremely famous game nicknamed "On Pins And Needles" by chessgames.com. Agadmator covered in a YouTube video a few years ago.
[Title "Geoff Chandler-Richard Kynoch, Edinburgh Club Championship, Scotland, 1981"]
[FEN ""]
[startply "53"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4 Bg6 6. Nge2 c5 7. Be3 Nc6 8. dxc5 Nxe5 9. Nd4 Rc8 10. Bb5+ Nc6 11. Qe2 Nf612. O-O-O Be7 13. h4 h5 14. f3 Nd7 15. gxh5 Rxh5 16. Rhg1 Nxd4 17. Bxd4 Qc7 18. Rxg6 fxg6 19. Qxe6 Rf5 20. Nxd5 Qd8 21. Qxg6+ Rf7 22. Re1 Kf8 23. Qh7 Ke8 24. Qg8+ Rf8 25. Qxg7 Rf7 26. Qg8+ Rf8 27. Nf6#


Indian game pawn push variation A recent game of mine went like this (I was Black):

[FEN ""]
1.d4 Nf6 2.d5

Looking at the lichess database (amateur games book) I see that the more common responses are:

2..d6
2..c6
2..e6

… in that order.

In the master games book there are only two games in this variation where the responses were 2..d6 and 2..c6.

I played 2..e5 which seems to be a rather infrequent response. The continuation in my game was:

[FEN ""]
1.d4 Nf6 2.d5 e5 3.dxe6 fxe6 4.Bg5 b6 5.e3 Bb7 6.Nc3 Nc6

I then proceeded to castle Queen-side and took advantage of the open f column. The game went well but apparently my response to the "pawn push variation" was suboptimal.

Can someone explain the ideas behind the more common responses and why 2..e5 is bad?

As you noticed there are very few games in the database with this line. That's why it does not make much sense to speak of "more common"/"infrequent" response here.

The move 2. d5 is not good, but not so bad that you can expect to get a huge advantage as black soon. Basically it gives away the first move advantage and gives black an equal position for free. Generally, if your opponent plays an unusual move like this to which you don't see an immediate refutation, stay calm and make normal moves.

Problems with 2. d5 are:

it neglects development (don't move a piece twice if you don't have to)
it weakens the dark squares in the centre
it does not do much; Typically a pawn push like this is meant to limit the opponents options. Here it prevents the knight going to c6, however the knight rarely wants to go to c6 in these kind of openings. Also black has not fixed the position of its central pawns so is free to attack the pawn at wish with c6, e6 ...

Your opening repertoire or your preference for closed vs open positions might influence your decision on how to respond to it.

If you are a King's Indian or Benoni player you could for instance transfer this to a main line King's Indian or Benoni. Or just go for a fianchetto on g7 first, trying to take advantage of the weakened dark squares and don't fix your central pawns yet.

If you don't mind unknown territory, 2 .. c6 seems like a good choice questioning the pawn immediately  and giving you tactics with Qa5+ (and attack on d5) in some lines.

But any other continuation such as 2 ... e6, d6, e5, g6,.... can't be wrong either. I don't understand why you think that e5 was bad. The position you achieved seems quite normal to me.


How do chess engines manage time when they play real games? I was just watching a video on YouTube that analysed a game in between two chess engines. So, chess engines do find good moves but how do they manage their time when they're playing a game ? Is there any algorithm that tells them how much longer they must continue thinking till they make a move, keeping the amount of time left for them in the game in mind ?

Possibilities:

Number of nodes
Fixed depth
Fixed time
Divide a fixed percentage of remaining time
By the complexity of the position

Let's take a quick look at Stockfish. Briefly, the file timemann.cpp calculates the minimum time allowed for a move. The default minimum time allowed is about 20 seconds.

Later, during the search it does:

 // Stop the search if only one legal move is available, or if all
 // of the available time has been used, or if we matched an easyMove
 // from the previous search and just did a fast verification.

 ...

 if (   rootMoves.size() == 1
              || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 628
              || (mainThread->easyMovePlayed = doEasyMove, doEasyMove))

If the position requires longer thinking (unstable position -
 unstablePvFactor), the engine would extend the search. How long it extend depend on calibrated parameters.

If there is an obvious move (doEasyMove), Stockfish plays it immediately.


Doubt about defending piece I just played a chess ga,e whose link is:
https://lichess.org/mn8mcGT7/white#15
And I reached this position after the seventh move of Black.

I want to know why it is wrong to defend the piece with the bishop and is the right thing to do that with the white queen.

You should always be skeptical about the "inaccuracy" annotations you get from Lichess (or similar sites) because it runs an extremely quick analysis; the small differences in evaluation that get called inaccuracies may go away when you let the engine run deeper. (Blunder annotations, on the other hand, are much more likely to be meaningful.)

While the engine initially liked Qc2 best, after letting the analysis of your position run to "completion" (depth 25) with 5 lines, the situation changes. Your results may vary because it's not even completely deterministic, but here's what I got:

As you can see, the "best" move now is to castle! But the first four moves are practically tied, between +0.7 and +0.6, and the two moves you mentioned, Qc2 vs Bd2 are now both at +0.6. At some points while the analysis was running, Bd2 was actually ahead. And I'm sure if you let it run longer (there's the "infinite analysis" option for that), they may trade places yet again.

In practice, they are both good moves as far as the engine can tell you, so you have to decide based on human factors or personal preference. For example, castling looks like it might lead to losing a pawn. Stockfish doesn't mind it, maybe because it can "see" the compensation (or how to recover it several moves later), but you might not be comfortable risking it.


Which side should I castle if I have opportunity to castle on both sides? It's a little bit confusing for me to make good decisions when I have opportunity to castle on both sides.

Can somebody explain what are the factors should be considered if we have opportunity to castle on both sides?

can somebody explain what are the factors should be considered if we have opportunity to castle on both sides?

1. The most important factor is king safety;

Long castle is less safe than short one, because king is closer to the center, thus can be attacked faster. You will lose a tempo to properly secure the king with Kb1/Kb8 ( thus protecting the loose a-pawn as well ). In many openings c-file is open/semi open which heightens the danger for the king.

Short castling moves the king far away and there are no loose pawns to protect. Furthermore, opponent must invest considerable amount of time to organize the attack by moving his forces to the kingside. This means that he must abandon some squares/pawn protection which enables you to organize strong counterplay.

2. King's activity in an endgame;

Long castle is preferred as your king will be close to the center. This fact can constitute a big advantage in endgame as king now becomes very powerful.

3. How fast do you need to develop pieces/launch an attack?

You need 2 moves to castle short ( you must move f1 bishop and g1 knight and you are done ), while you need 3 for long castle ( you need to move the queen, c1 bishop and b1 knight ). In opening speed is very important, therefore super GMs prefer short castle.

On the other hand, when castling long, rook lands immediately to d1 which is the best square for him, while with short castle you need to spend extra tempo to centralize rook with Re1.

When choosing where to castle, you should also ask yourself where do you lead the attack. If you play in the center and you plan a fast attack, prefer long castle. If you do not know what will you do at the moment than short castle is more flexible.

PRACTICAL GUIDELINES FOR APPLYING THE ABOVE:

First you need to form a general plan based on the factors listed above and personal preferences:

Will you attack or play positionally?
Are you willing to play the endgame or you are going for mate?
On which side of the board are you stronger, regarding your piece placement?
How well are you placed to attack on kingside/queenside?
Is your pawn structure healthy, on the side where you want to castle?
What is the state of center of the board -> is it closed/open/semi-open?

If you have opportunity to castle both sides than first look at your pawn structure. Is it healthy ( pawns are at starting positions ) or you have doubled pawns/pawn islands/"holes"? You should prefer the side that has healthy pawn structure.

Once you answer this question ask yourself the following: How well are my pieces placed to defend my king from opposing forces? If you have enough defenders, then go for that side.

This was the easy case, you have healthy pawn structure and solid defense on one side of the board, but what if you are good on both sides? What if your pawn structure and piece placement is good on both wings?

Then you must take endgame into consideration! If you can force a lot of exchanges go for the long castle ( even better if opponent went short castle! ). If the game will last long, and will be sharp or simply there are no signs for lots of exchanges, then you need to take attacking potential into consideration. Maybe you could go for "opposite side castling" because you will get promising pawn storm, or you could go for quiet game by castling to the same side as the opponent since you plan to attack in the center? This is really position-dependent part.

PRACTICAL EXAMPLES THAT ILLUSTRATE THE ABOVE:

Let us take a look at the following position and apply the above principles:

[Title "Where to castle?"]
[fen "r1bqr1k1/pp1nbppp/2p2n2/3p2B1/3P4/2NBPN2/PPQ2PPP/R3K2R w KQ - 0 1"]

First factor, king safety: we see that White is safer on kingside, and if he castles there he has good prospects for minority attack on the queenside, and for "f4 push" on the kingside ( please see my answer to this question for detailed coverage of these plans if you need further explanations ). The later option is beneficial for positional players.

Second factor, the activity of the king in the endgame, is bad for White since his king is further from the center then it would be after long castle. But if he wishes to play for minority attack he need both rooks on quenside, and in those positions the endgame will not appear for a long time.

Third factor, speed, is in favor of short castling, since White can generate minority attack or "f4 push" faster than the kingside pawn storm ( again see my answer to the question I linked above, if you need concrete explanations/examples ).

Since a positional player will always keep his options open and his king safe, castling short would be a good option, and is played most of the time at top level.

OK, this all sounds great but what about long castle? What about players who like sharp play?

White has healthy pawn structure at queenside, queen + bishop battery is directed on kingside, and Bg5 + Nf3 are aggressively positioned. White also has space advantage and better development, but Black can open c-file with ...c5 at some point. Therefore, based on the first factor, this should scare White a little.

But notice that I stated that we must take opponents attacking chances as well. Black will lose a lot of time to prepare an attack, and even then White can just play Kb1 and simply use rook on d1 to pressure the d5 pawn after the dxc5 exchange. The point is that long castle speeds up White's development thus strengthening his development advantage and central pressure according to the third factor.

This is the reason some GMs took the risk to castle queenside, claiming that Black is misplaced for queenside counter-attack so they counted that they will be faster on the kingside ( again, third factor is more important here then king safety ) which proved to be true. Therefore Black had to enter an endgame to keep equal chances ( again, see my answer I linked before ), but the second factor I mentioned helped White to still keep small pressure ( king is closer to the center and rook controls d-file, these are all important things in an endgame ).

I could give you another example in Caro-Kann, but I have "ran out of steam" :(

The point is to do the same as I did in the above practical example:

Evaluate kings safety ( your pawn structure, piece placement, opponents attacking chances on that side of the board... );
See how castling long/short fits into your overall plan ( is there a high probability for an endgame to arise or do you need sharp position and so on... );
How fast do you really need to mobilize your forces ( do you need fast action in the center or can this wait; can you afford slightly exposed king to get sharp position with "opposite side castling" and so on.. );

If you need further help leave a comment. Best regards.


Understanding vs. Memorization Is memorization necessary in modern chess? Whenever I play chess, I always run out of time because I move slowly in the opening; unlike others who move fast in the opening because they have memorized it, and slowly in the middle game to execute their plans.

Should I should memorize opening theory to save time in the middle game?

Who better to answer this question than the legendary former World Champion and master of opening preparation Garry Kasparov himself? I quote

  In June 2005 in New York I gave a special training session to a group
  of the leading young players in the United States. I had asked them
  each to bring two of their games for us to review, one win and one
  loss. A talented twelve-year-old raced through the opening moves of
  his loss, eager to get to the point where he thought he'd gone wrong.
  I stopped him and asked why he had played a certain pawn push in the
  sharp opening variation. His answer didn't surprise me: "That's what
  Vallejo played!" Of course I also knew that the Spanish Grandmaster
  had employed this move in a recent game, but I also knew that if this
  youngster didn't understand the motive behind the move, he was already
  headed for trouble.

  This boy's response took me back to my own sessions with Botvinnik
  thirty years earlier. On more than one occasion he chided me for
  committing this same sin of blind emulation. The great teacher
  insisted that his students recognize the rationale behind every move.
  As a result, all of us learned to become great skeptics, even of the
  moves of the best players. We would discover a powerful idea behind
  each Grandmaster move, but we also found improvements. We studied, we
  questioned, we grappled with the idea behind a series of moves, and
  eventually we could build our understanding and create more and better
  strategies.

  For players who depend on memorization, the opening ends when their
  memory runs out of moves and they have to start thinking for
  themselves. A rote opening might carry you to move five, or even move
  thirty, but this practice always inhibits your development as a
  player. It is one thing for a world-class player to rely on
  memorization; he already knows all of the whys behind the moves. For
  your own development it's far more important to think for yourself
  from the very start.

  --- Garry Kasparov, How Life Imitates Chess (emphasis mine)

Following Garry Kasparov's advice, I myself do not recommend memorization of opening moves. If you really want to improve your game, you must understand (rather than memorize) why a certain move is played and only then play it.

  Should I do memorizing to saved time in middle game?

No! Instead, you should study the openings more and understand why certain moves are played. When you understand these moves, the result is that you often automatically remember them because you have found the rationale behind them. The focus should be on understanding and not on memorization.

Great players have fallen prey to blind memorization, including legends like Viswanathan Anand himself. Consider the game where he lost in just 6 moves (!!!) because he blindly memorized a line played earlier by a grandmaster.

     [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
     [Event "Blind memorization makes Anand lose in 6 moves"]
     [White "Zapata"]
     [Black "Anand"]

     1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Nc3 Bf5?? 6. Qe2! 1-0

Or consider his loss in the first game in his World Championship match with Topalov where he "forgot" his preparation and blundered and lost the game.

     [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
     [Event "Anand forgets his preparation and blunders"]
     [White "Topalov"]
     [Black "Anand"]
     [Result "1-0"]

     1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Bc4 c5 8.
     Ne2 Nc6 9. Be3 O-O 10. O-O Na5 11. Bd3 b6 12. Qd2 e5 13. Bh6 cxd4 14. Bxg7 Kxg7
     15. cxd4 exd4 16. Rac1 Qd6 17. f4 f6 18. f5 Qe5 19. Nf4 g5 20. Nh5+ Kg8 21. h4
     h6 22. hxg5 hxg5 23. Rf3 Kf7?? ({not thinking objectively and trying to repeat moves from memory}) 24. Nxf6 Kxf6 25. Rh3 Rg8 26. Rh6+ Kf7 27. Rh7+
     Ke8 28. Rcc7 Kd8 29. Bb5 Qxe4 30. Rxc8+ 1-0

Now to redeem Anand a bit, I must mention his smashing win against Bologan, where Bologan blindly copied a line that had been played by other grandmasters before and got smashed by Anand's stunning novelty.

    [FEN ""]
    [Event "Bologan merely copies known opening moves and Anand punishes him"]
    [White "Anand"]
    [Black "Bologan"]
    [Result "1-0"]

    1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Nd7 5. Ng5 Ngf6 6. Bd3 e6 7. N1f3 Bd6 8.
    Qe2 h6 9. Ne4 Nxe4 10. Qxe4 Qc7 11. O-O b6 12. Qg4 g5 13. Qh3 Rg8 14. Re1!! Bf8
    15. Qf5 Bg7 16. h4 Kf8 17. Qh3 Rh8 18. hxg5 hxg5 19. Qg4 c5 20. Bxg5 cxd4 21.
    Rad1 Bb7 22. Rxe6 fxe6 23. Be7+ Kxe7 24. Qxg7+ Kd6 25. Nxd4 Qc5 26. Bf5 Qe5 27.
    Nf3+ Qd5 28. Qg3+ Ke7 29. Rxd5 Bxd5 30. Qg5+ Kd6 31. Qf4+ Ke7 32. Be4 Rh5 33.
    Nh4 Rg8 34. Ng6+ Kd8 35. Qf7 Re8 36. Bd3 1-0

Even after this game, I checked a database and found that many strong players unaware of this novelty also lost their games in this variation in the same manner.

Moral of the story - do not merely copy the moves of grandmasters or just memorize them. Analyze them and understand them and see if they can be improved.


What should I do about the dilemma of castling early? OK, it has been said that one of the opening fundamentals is to castle early, but I have a dilemma with this and it may very well be a natural dilemma that has to be dealt with or there many be signs that one could look for. Here is the dilemma:

If I castle early, I feel my opponent has a slight advantage especially because now they know where to direct their pieces, but if I delay castling and my opponent moves their pieces to the one side of the board and I castle on the opposite, I feel I have gained some time because they have to work their way back to my castled side, however, I do know that if I do not castle early, I risk leaving my king wide open.  Further light on this would be helpful.

I think you outline the balance well, that is what it is. You are talking about attempting to misdirect an opponent. In any game, misdirection is a dangerous tactic that takes skill to know when to make your move.

If you can get to know your opponent you can try to judge how they will move on you. If you are dead set on castling to a particular side, and your opponent knows that, then delaying doesn't help you at all.

The best solution is to remain flexible and let your opponents over or under steps dictate which tactic to use. This is as true for when to castle as anything other tactic.


What rearrangent of the starting position's pieces, in any manner, has the fastest stalemate? It is well known that the fastest stalemate is in 19 ply. But what is the fastest possible if all pieces, not pawns, may be shuffled at will on their first ranks? This will be difficult since there is much to consider, but 19 ply is certainly beatable.

I don't know if this is the fastest, but I managed to shave one ply off of the standard chess example by moving the queen to a better starting square. This allows the side giving stalemate to start capturing one move sooner, resulting in stalemate in 18 ply instead of 19.

[Result "1/2-1/2"]
[FEN "rnbnqbkr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

1. a4 d6 2. Ra3 Qxa4 3. h4 h5 4. Rah3 Qxc2 5. f3 Qxd2+ 6. Kf2 Qxb2 7. Qxd6 Qxb1 8. Qh2 Qxc1 9. Kg3 Qe3 1/2-1/2


Earliest text which mentions the pawn promotion rule My question is about the history of the pawn promotion rule (promotion to a queen).

  What is the earliest existing text (authentic written document in any language) which mentions the pawn promotion rule?

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

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


Are banter blitz players who draw arrows on the board during the game breaking the FIDE Laws of Chess? According to the FIDE Laws of Chess:

  11.3.1 During play the players are forbidden to use any notes, sources of information or advice, or analyse any game on another chessboard.

Streamers and banter blitz players often draw lines and arrows on the board while discussing what moves they are thinking about. Here is Eric Rosen doing exactly that.

Surely this is every bit against the rules as using an engine?

If Wesley So can be defaulted for basically writing notes saying things like "Must try harder" why is this allowed?

I agree that it would break the FIDE rules against note taking, but this is not a FIDE tournament; it is online blitz on Lichess, so FIDE rules need not apply. You'd have to look at the Lichess terms of service instead. They say

  Cheating. We define this as using any external assistance to strengthen your knowledge and, or, calculation ability to gain an unfair advantage over your opponent. Some examples would include computer engine assistance, opening books (except for correspondence games), endgame tablebases, and asking another player for help, although these aren’t the only things we would consider cheating.

The definition is open-ended so it's really up to the Lichess administrators to interpret. Does drawing an arrow on the board during a blitz game "strengthen your calculation ability?". Perhaps, but one could also argue that it makes you waste precious time, so it is probably more of a handicap than anything else. More importantly, just the fact that the Lichess user interface supports drawing arrows during a game (something which I had never noticed, despite being a frequent user!) may reasonably be interpreted as implying that the administrators approve of that use.

I don't think the "banterers" who stream their games draw arrows as a calculation aid, but rather to communicate their ideas to their audience. I'd love to hear from anyone who uses this feature and finds it helpful while playing blitz for non-streaming purposes. (Arrows might be more useful for correspondence chess, but there you are definitely allowed to use analysis boards, opening books, notes, etc., so arrows shouldn't be a problem.)


Chess variants where black is considered equal? In normal chess, black isn't that bad, but not that good either. White has the initiative and opening theory dictates how to win these positions. Variants like Chess960 have made it possible to play with common sense rather than grandmaster sense. But still correct play leads to the same result in variants that do not offer a pawn for either side right in the opening. While there are many books that try to convince me that black is OK, still the statistics show other things for normal chess at least. So that leads me to my question.
Are there any chess variants where black is considered equal? Not better, just equal.

In Synchronistic Chess, both players make their moves simultaneously. Black must be quite equal in this variant!

Additionally, a bunch of the variants listed on the Wikipedia page could likely be considered "equal" for Black, as they may involve elements of chance that would be far more significant than the first-move advantage normally conferred on White. Some variants have arbitrary rules that change from game to game, though these may be getting so far removed from actual Chess that their inclusion is a bit questionable. ;-)


Where can I find a big chess database? I am searching for a big chess games database, in PGN or CBH or SCID format.
ICOfY Base is no longer available, I think. I found nothing in torrent sites (I am searching for something that is legal).

I use the games published by The Week In Chess, which are published in a weekly basis. These games make a superb database, although maybe you'll miss some historical games. It takes some effort to build the database with all games published to the date, but from then on it's easy to keep it up to date.

It is also possible to download the Million Database and then to keep it up to date with TWIC games.


free alternatives to SwissSys? I was going to do a tournament recently, and then, I found out just how much $$ SwissSys Tournament software costs...

My question is:

  What good alternatives to this expensive mainstream software are there, if any?

The one I like is Vega - http://www.vegachess.com/tl/index.php. This is free on Linux. The guy who wrote it is an open source supporter who welcomes feedback and is willing to make changes. He is also an active FIDE arbiter. It is also free on Windows for up to 30 players and 50 euros for unlimited use.

There is a review by an English arbiter here - http://chessarbitersassociation.co.uk/Vega.pdf.


What is the state of the Panno variation of the King's Indian Defense Saemisch? In the Saemisch King's Indian

[FEN ""]
[StartPly "10"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O

It seems current (2017) literature and practice promotes Black's play 6...c5.  What I am wondering is there something wrong with the Panno (6...Nc6 with a6, Rb8, b5) that got players to move to 6...c5 or is it just the current trend?

The Panno is a sharp line that has received a lot of attention lately, particularly the variation below where White opens the centre favourably. The variation isn't refuted by any means, but Black players have found this variation to be uncomfortable.

[FEN ""]
[StartPly "12"]

1. d4 Nf6
2. c4 g6
3. Nc3 Bg7
4. e4 d6
5. f3 O-O
6. Be3 Nc6
7. Nge2 a6
8. Qd2 Rb8
9. h4 h5
10. O-O-O b5
11. Bh6 Bh6
12. Qxh6 e5
13. dxe5


Understanding the Tarrasch defence to the Queen's gambit I do not understand the diagrammed position. Do you?

[fen ""]
[title "A. Grischuk vs. V. Kramnik, FIDE Candidates 2018"]
[startply "8"]

1. c4 e6 2. Nc3 d5 3. d4 Nf6 4. Nf3 c5 5. e3 dxc4 6. Bxc4 a6 7. Bb3 b5 8. e4 cxd4 9. Nxd4 Bb7 10. e5 Ne4 11. O-O Nxc3 12. bxc3 Nc6 13. a4 Bc5 14. axb5 axb5 15. Rxa8 Bxa8 16. Nxb5 O-O 17. Qxd8 Rxd8 18. Bf4 h6 19. h4 Ne7 20. Rd1 Rb8 21. Bc4 Bc6 22. Nd4 Be4 23. h5 Nd5 24. Bxd5 Bxd5 25. Be3 Rc8 26. Re1 Bc4 27. Nf3 Ba3 28. Bd4 Bd3 29. Nd2 Bb2 30. Nf1 Rc4 31. Re3 Bf5 32. Ng3 Bh7 33. Kh2 Bc1 34. Re2 Bf4 35. Kh3 Ra4 36. Kg4 Bc1 37. Kf3 Bd3 38. Re1 Bb2 39. Ke3 Bc2 40. Kd2 Bb3 41. Rb1 Ra2 42. Kd3 Ba4 43. Ne4 Ba3 44. Ke3 Bc2 45. Re1 Bb3 46. g4 Bd5 47. Kd3 Be7 48. Rb1 Ra8 49. f4 Bh4 50. Rh1 Bd8 51. Rb1 Bc7 52. Ke3 Kh7 53. Nd6 Kg8 54. Rb5 Bc6 55. Rb4 Bd8 56. Bb6 Bh4 57. Bd4 Bg2 58. Rb2 Bc6 59. Rb6 Bg2 60. Rb2 Bc6 61. Rb3 Bg3 62. c4 Bh2 63. f5 exf5 64. Nxf5 Kh7 65. Bb2 Re8 66. Nd6 Re7 67. Rb8 f6 68. Rc8 Bh1 69. Nf5 Rb7 70. exf6 Rb3+ 71. Bc3 gxf6 72. Kd2 Bf4+ 73. Kc2 Rb8 74. Rxb8 Bxb8 75. Ne7 Be4+ 76. Kd2 Bf4+ 77. Ke2 Kg7 78. Nf5+ Kf7 79. Bd2 Be5 80. Bxh6 Ke6 81. Be3 Bxf5 82. gxf5+ Kxf5 83. h6 Kg6 84. c5 f5 85. Kf3 Kf7 86. Bf4 Bd4 87. c6 Ke7 88. c7 Kd7 89. h7 Kc8 90. Ke2 Kd7 91. Kd3 1-0

What is the idea behind 4... c5? Why form a hostile bloc of two black against two white pawns on the c and d files? Once the bloc is formed, how does one decide whether

to capture toward the c file (as Black soon does),
to capture toward the d file (which, inscrutably, neither player wishes to do), or
not to capture at all?

This kind of position is opaque to me. I do not understand it. I am aware of no principles by which one can treat it. I perceive no relevant pattern in a bloc of four pawns. Please advise.

I would gladly read an answer at any level but would find most useful an answer pitched at about Elo 1350 or USCF class C.

(Source for the game: Chess.com.)

What is the idea behind 4... c5?

Basically the same ideas as behind playing c4 in the Queen's gambit:

challenging the center,
potentially exchanging the c-pawn for a valuable central pawn,
opening the c file for a rook,
giving the knight a square on c6 (which is often a better square for the knight if the pawn has moved to c5 already)
potentially threatening to leave white with an isolated queen pawn (see below)

  Why form a hostile bloc of two black against two white pawns on the c and d files?

Why not? "Hostility" is not something you should be afraid of when playing chess.

  Once the bloc is formed, how does one decide whether ...

There is no strict rule here and various captures and no-captures have been tried and tested by good players. A typical motive you need to be aware of in these positions is the isolated queen pawn (IQP), i.e. a player might be left with a pawn on the d-file and without any pawns on the c and e files which could support it.

An IQP leads to somewhat asymmetric play, with one player trying to block and put pressure on this potentially weak pawn, while the other player (the one with the IQP) is trying to take advantage of his better piece play that is a result of the pawn structure and also has ideas related to advancing the IQP.

If there is no IQP on either side, the positions resulting from this opening are often very symmetric, potentially boring, and it is difficult to find a good plan in them.

So I'd say the decision on how to capture is basically determined by what kind of game you want:

with an IQP; asymmetric, unbalanced game with clear plans for both sides
without an IQP; symmetric, equal position, with unclear plans


Is it possible to be in check by three pieces? Is it possible to be in check with three pieces?  My thoughts so far:

A normal move can't, due to the fact that you may only unblock one piece to make a discovered check, and then that piece may also threaten.
Castling also can't, due to the fact that when you castle you can't result in check (or even move through check).
Possibly en passant can, because you move one piece, and doing so may create a discovered check. Removing the pawn also creates a discovered check.

En passant also doesn't work. You can, potentially, discover two checks, one because the capturing pawn moves off a file and one because the removed pawn unblocks a diagonal. However, you can't simultaneously discover a check via the removed pawn and give check with the capturing pawn, because the only two squares threatened by the capturing pawn are a knight's move away from the removed pawn. So if the opponent's king is on one of these squares, it is not in line with the removed pawn. Consequently at most two checks can occur (either both discovered or one discovered and one normal).


How to write the first move of a PGN that starts with blacks? Some programs/websites use 1. ... e5 2.f3 (e.g Arena or LT-PGN-Viewer) while others use 1...e5 2.f3 (e.g chess.com). To achieve this, I loaded a FEN that is black-to-move, then made a move.

Which one is best to use? What does the specs say about this?

Just to make this clear, my question is not about using 3 dots after a white move comment, for this one I got to the conclusion that it is best to use 1.e4 { comment } 1...e5 2.Nf3 over 1.e4 { comment } e5 2.Nf3, but it is somewhat optional.

1...e5 is best. I quote from Section 8.2.2.2 of the PGN specification, with the relevant phrases in bold:

  There are two export format move number indication formats, one for use appearing immediately before a white move element and one for use
  appearing immediately before a black move element.  A white move
  number indication is formed from the integer giving the fullmove
  number with a single period character appended.  A black move number
  indication is formed from the integer giving the fullmove number with
  three period characters appended.

  All white move elements have a preceding move number indication.  A
  black move element has a preceding move number indication only in two
  cases: first, if there is intervening annotation or commentary between
  the black move and the previous white move; and second, if there is no
  previous white move in the special case where a game starts from a
  position where Black is the active player.


Why don't we see more Kings Indian Defenses in top level chess? One of the most interesting openings, in my opinion, is the Kings Indian Defense (KID). 2-4 decades ago it used to be very popular at the top level with Bobby Fischer and Garry Kasparov using it regularly. Even a few years ago it used to be quite popular with Radjabov and Nakamura having it in their repertoires.

Why has it started to go out of fashion at the elite level, and especially with the Neural Network engines on the rise? Leela has been able to use it quite effectively. Nakamura said in an interview that the Kings Indian is lost for black. What are the drawbacks of the openings that prevent it from being seen at the top level?

The Interview is from 2015 Sinquefield cup after Hikaru obliterated Wesley So with the Kings Indian

It is simply not as solid as other openings, mostly because it cedes too much space, and especially with the advent of computers: White has simply found more ways to press black.

In a 2017 interview, Magnus Carlsen did not think too highly of it.
"If he had wanted a worse position, he would have played the King’s Indian," Carlsen said.

Nevertheless, it still gets played at the highest level from time to time, probably mostly as a surprise weapon. Here is a recent search of Mega 2020 (I previously searched incorrectly, and have edited this). This is from 2015-2020, sorted by rating first, and then date. You can see that despite the quote above, even Carlsen has played it.


Magnus vs Tomashevsky Blitz 2012 - why doesn't he take the knight on e7 I'm not sure if anyone is familiar with this game, I watched it a while ago and had just rewatched it now and cannot understand why Magnus didn't take the knight on e7.

Here's the screenshot before this went down:

The moves are in this order: Green, Blue, Red. So the board looks like this:

He doesn't take the knight, why? Instead he plays Bxb2.

I'm sorry if this is obvious to more experienced players, I'm not expert by any means just trying to get someones opinion. Thanks.

Magnus doesn't take the knight because it simply results in a loss of material:

[FEN "r1bqk3/p2pNpbn/1p4p1/8/2P5/1N4P1/PP2PP2/R2QK2B b Qq - 0 1"]

1... Qxe7 2. Bxa8 Bxb2 3. Rb1 Bc3+ 4. Kf1

By taking on b2, Black threatens to take his opponent's rook, while at the same time frees the c3 square for a check, which gains a tempo. White will then either exchange rooks or move their rook away from danger, also giving Black a chance to flee with their rook.

Taking on b2 is not the best according to engines, but at least it avoids the material loss. The position is significantly better for white.


For long OTB games, what is the percentage of players who have a rating which is below X FIDE Elo? I am looking for statistics on the FIDE Elo of chess players.

I would like to know what is the percentage of players who have a rating which is:

Below 1000 Elo
Below 800 Elo
Below 600 Elo
Below 400 Elo
Below 200 Elo
Higher than 2000 Elo
Higher than 2200 Elo
Higher than 2500 Elo

I'm making it clear that I am only interested in statistics for the FIDE Elo, not the USCF Elo. And I am only looking for statistics for OTB games (not correspondence) of long time control (not rapid, nor blitz).

You can get the FIDE rating list here. I used R statistical software to analyse the data for the latest OTB rating list (of 15th Sep. 2014). At the moment there are 383543 active FIDE players. Among them, slightly less than one third (107320 players) are rated.

As noted by others, the FIDE rating floor is 1000:

  "Players whose ratings drop below 1000 are listed on the next list as ‘delisted’. Thereafter, they are treated in the same manner as any other unrated player." (FIDE Rating Regulations effective from 1 July 2014, article 7.21).

From that I understand that players going below 1000 Elo are unrated at all effects. However, the list shows 14 people with a rating of 0 (I do not know what this means, though).

For rated players, please see the figure below. It shows the number of FIDE active rated players for different Elo intervals: 1000-1100, 1100-1200, etc. So, to answer your last three bullets, as of 15th Sep. 2014:

there are 31603 players with Elo higher than 2000, or 8.2% of the
total
there are 10220 players with Elo higher than 2200, or 2.7% of
the total
there are 768 players with Elo higher than 2500, or 0.2% of
the total


The end of anti-computer chess In the old days it was possible to beat computers basically by playing slow, closed positions with weaknesses that can be exploited in the long term, beyond the calculation depth of the engine.

As far as algorithms are concerned, what has been done to improve on this weakness of computers? Or is it just the increased calculating power/depth that makes beating computers so much harder nowadays?

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

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


What was Nakamura thinking with 62...g5 against Carlsen in Senquefield Cup 2018 rd. 9? I (a 2300 player) would never consider 62...g5 in this position giving White a protected passed pawn.  Nakamura either thought it was a drawing method, or the toughest defense, but Carlsen showed there is a clear winning plan for White. 62...g5 strikes me as a clear mistake but are other moves easier for White to win against?

I am trying to understand this decision by a 2800 player, thanks.

Let's say that Naka doesn't push g5 and instead waits (with for instance Rb7). Then it is white who can play g5+, taking advantage of the pin on the 6th rank. If black plays Kg6, then Kg4 and h5+ is unstoppable. It is clear that white is making progress. If black instead plays Kh5, then gxf6 hxf6, Rxf6 and black has lost a pawn and his king is completely stuck in a box. Rf5+ might be a possibility (taking on e5), black still cannot move the a pawn (due to an immediate Ra6 getting behind it), and again white has clearly made progress.

I believe Naka was sure that these lines were easy wins for white. Better to make the committal, but potentially holdable, g5 move, and try and hold the position with a static pawn structure, than sit and wait only to lose in a few moves.


What is the best way to sell old chess books? I listed some books on eBay but had little interest (few pageviews/few bids etc.) meaning that I would make an untenable loss on them (I'm not selling them for profit, but I want a reasonable price for them).

I've sold other products on eBay before, so I'm not after advise on how to sell more effectively there. My question is, what are the 'best' (i.e. most profitable) ways to sell chess books online?

If you live in the UK I would suggest the English Chess Forum. They have a "For Sale" thread. That way you are advertising to a dedicated audience. If you live in another country I would suggest you look for an equivalent forum in your country.

I would add that opening books devalue very quickly. A 10 year old opening book probably has value as a doorstop or paperweight only, unless it is a rare ancient first edition.


Good UCI to WinBoard adapter I found one before on the internet but it keeps the CPU at 100%, hangs a lot, and doesn't exit when the program (ChessMaster in this case) closes.

UCI2WB which you can find it in Winboard packages.

PolyGlot is another option.

Many modern chess GUIs doesn't need external converter such as ChessX, Fritz, ...


Scandinavian Defense with 3.c4 I've recently played some games as Black that opened like this:

[White "Opponent"]
[Black "Me"]
[Result "*"]
[ECO "B01"]
[FEN ""]
[CurrentPosition "rnb1kbnr/ppp1pppp/8/3q4/2P5/8/PP1P1PPP/RNBQKBNR b KQkq c3 0 3"]

1.e4 d5 2.exd5 Qxd5 3.c4  *

c4 seems to be a very uncommon move as opposed to Nc3.  But it doesn't seem bad at first glance - it allows the knight to go behind the pawn when Nc3 is later played, and grabs some central/queenside space.  It also forces the queen to move (although 3.Nc3 would also have done that.)

How do I refute this variation?  Or is it perfectly playable?

My opponent and I both have USCF ratings in the 1500s, if that matters.

This is what I try to accomplish as white, but I play Nf3 first.
Although your can't take advantage this early, there are good moves depending on your temperament.

Qe4+ forces Qe2, else a pawn hangs, and the trade of queens.

Qa5 pins the d-pawn which gives you the opportunity to get in c5 (e5 is more drawish) and get a central majority.

With a normal game continuation, that is Qa5 => Nf6..., the d-pawn is slightly weaker as white can't play c3 to support it.

Just the opinion of a 2000 player.


Intention of two moves of Topalov vs Anand What was the intention for the moves  23. ... Bb6 and 24. ... Bd7 ?

[FEN ""]
[White "Anand"]
[Black "Topalov"]
[StartPly "45"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 dxc4 5. Bg2 a6 6. Ne5 c5 7. Na3 cxd4 8. Naxc4 Bc5 9. O-O O-O 10. Bg5 h6 11. Bxf6 Qxf6 12. Nd3 Ba7 13. Qa4 Nc6 14. Rac1 e5 15. Bxc6 b5 16. Qc2 Qxc6 17. Ncxe5 Qe4 18. Qc6 Bb7 19. Qxe4 Bxe4 20. Rc2 Rfe8 21. Rfc1 f6 22. Nd7 Bf5 23. N7c5 Bb6 24. Nb7 Bd7 25. Nf4 Rab8 26. Nd6 Re5 27. Nc8 Ba5 28. Nd3 Re8 29. Na7 Bb6 30. Nc6 Rb7 31. Ncb4 a5 32. Nd5 a4 33. Nxb6 Rxb6 34. Nc5 Bf5 35. Rd2 Rc6 36. b4 axb3 37. axb3 b4 38. Rxd4 Rxe2 39. Rxb4 Bh3 40. Rbc4 Rd6 41. Re4 Rb2 42. Ree1 Rdd2 43. Ne4 Rd4 44. Nc5 Rdd2 45. Ne4 Rd3 46. Rb1 Rdxb3 47. Nd2 Rb4 48. f3 g5 49. Rxb2 Rxb2 50. Rd1 Kf7 51. Kf2 h5 52. Ke3 Rc2 53. Ra1 Kg6 54. Ra6 Bf5 55. Rd6 Rc3+ 56. Kf2 Rc2 57. Ke3 Rc3+ 58. Kf2 Rc2  1/2-1/2

Alongside @IanBush's answer, the bishops prevent white's doubled rooks from penetrating black's camp:

[FEN ""]
[White "Anand"]
[Black "Topalov"]
[StartPly "48"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 dxc4 5. Bg2 a6 6. Ne5 c5 7. Na3 cxd4 8. Naxc4 Bc5 9. O-O O-O 10. Bg5 h6 11. Bxf6 Qxf6 12. Nd3 Ba7 13. Qa4 Nc6 14. Rac1 e5 15. Bxc6 b5 16. Qc2 Qxc6 17. Ncxe5 Qe4 18. Qc6 Bb7 19. Qxe4 Bxe4 20. Rc2 Rfe8 21. Rfc1 f6 22. Nd7 Bf5 23. N7c5 Bb6 24. Nb7 Bd7 {[%draw full,c4,red][%draw full,c5,red][%draw full,c6,red][%draw full,c7,red][%draw full,c8,red][%draw arrow,b5,c4,green][%draw arrow,b6,c5,green][%draw arrow,b6,c7,green][%draw arrow,d7,c6,green][%draw arrow,d7,c8,green]} 25. Nf4 Rab8 26. Nd6 Re5 27. Nc8 Ba5 28. Nd3 Re8 29. Na7 Bb6 30. Nc6 Rb7 31. Ncb4 a5 32. Nd5 a4 33. Nxb6 Rxb6 34. Nc5 Bf5 35. Rd2 Rc6 36. b4 axb3 37. axb3 b4 38. Rxd4 Rxe2 39. Rxb4 Bh3 40. Rbc4 Rd6 41. Re4 Rb2 42. Ree1 Rdd2 43. Ne4 Rd4 44. Nc5 Rdd2 45. Ne4 Rd3 46. Rb1 Rdxb3 47. Nd2 Rb4 48. f3 g5 49. Rxb2 Rxb2 50. Rd1 Kf7 51. Kf2 h5 52. Ke3 Rc2 53. Ra1 Kg6 54. Ra6 Bf5 55. Rd6 Rc3+ 56. Kf2 Rc2 57. Ke3 Rc3+ 58. Kf2 Rc2  1/2-1/2


What term is used to describe the following situation? A situation where the movement of the opponent's pieces gets more and more restricted as the attack develops. The opponent can't make moves easily without losing something.

As @Ywapom notes, Zugzwang is often used to the describe the end of this situation, like the Immortal Zugzwang Game where Sämisch suffers this fate against Nimzowitsch.

For the progress itself, it's perfectly normal to use non-chess specific terminology here, e.g. you could say White was slowly getting strangled by Black in the game above.


Is it allowed to be an arbiter and have your kid playing in the same FIDE rated tournament? Recently, I participated in a FIDE-rated tournament where the (only) arbiter had their son playing in it. I find that very odd. Is it allowed? What if the arbiter favors their kid? What should be done?

The FIDE arbiters' Commission disapproves very strongly of arbiters playing in the same competition that they are arbiting in but does not ban it.

My own federation told me when I was still qualifying as an arbiter that I may not play in any tournament at the same time that I am arbiting a FIDE rated event. So, for instance if there was a FIDE rated tournament taking place alongside a national rated tournament then I may not play in the national rated tournament and arbit in the FIDE rated one. I am allowed to do the reverse.

The ECF, the federation running chess where I live now, does allow playing and arbiting in the same tournament whether FIDE rated or not.

From what I have written it should be clear that there is no problem whatsoever with every member of the chief arbiter's extended family playing in the same tournament that he or she is arbiting. Arbiters are required to be impartial and this applies whether it is with regard to family members, friends, lovers, bosses, work colleagues, etc., etc.

  What should be done?

The best advice I can give is to try not to be too paranoid. It will affect your chess playing and destroy your enjoyment of the game.


Meaning of winning percentage I was wondering about the exact meaning of winning percentage (white/draw/black) in database systems and how to use them for studying.

How are move order variations taken care of? For instance, if I go to a certain position, the winning percentage is only calculated from games which had this exact position on the board, right?
Let's say I look at a position from an opening which had been popular for many years. So there are lots of games in the database from those years with more or less equal percentage for black and white. Then at some point a novelty was found which gave a clear advantage for white, making the opening basically unplayable for black. As a consequence people stopped playing this opening and there are very few games in the database which show this big winning percentage for white. So if I look at some position before the novelty move, the winning percentage at that position will still show more or less equal percentages for white and black (because many pre-novelty-games get averaged with few novelty-games)?

Is this correct? If yes, IMO, the winning percentage is of rather limited use and should not be used when assessing a single position, without traversing and analyzing all the lines originating from that position.

Have there been attempts, to create a better (more useful for actual use) parameter than the "winning percentage"?

Winning percentages are quite useless not only because of novelties, but also because of general distribution of results. For example there is no meaningful average for line which is branching into (0,100,0) and (60, 0,40) later. I saw even more brutal examples like (55,0,45) branching on next black move into something like (100,0,0) and (0,20,80) which in original position seems like standard white advantage :D There is another problem that some lines are virtually always played by much weaker player. That can be reason why exchange Slav or 4 knights may in some books have positive score for black.

Engine evaluation / usage in corr games is in my opinion generally much closer to truth and count "N" can help you as well, even if this runs into novelty problem you pointed out. It has many drawbacks for evaluating human chess with many mistakes, but results graphs tells nothing of any value.


Can luck be used as a strategy in chess? Consider below games where white looses a clean rook quite early in the opening but fights on hoping that they will be lucky and escape. Lucky enough, they escape and win the clearly lost game.
[Event "Rated Blitz game"]
[Result "1-0"]
[Variant "Standard"]
[TimeControl "300+0"]
[ECO "B21"]
[Opening "Sicilian Defense: McDonnell Attack"]
[Termination "Normal"]
[Annotator "lichess.org"]
[FEN ""]

1. e4 c5 2. f4 { B21 Sicilian Defense: McDonnell Attack } d5 3. e5 Bf5 4. d3 d4 5. g4 Bd7 6. f5 e6 7. Qf3 Bc6 8. Qf2 Bxh1 9. Bg2 Bxg2 10. Qxg2 Nc6 11. Nd2 Qh4+ 12. Kf1 exf5 13. gxf5 Nh6 14. Ngf3 Qg4 15. Qh1 Qxf5 16. b3 Be7 17. Bb2 Nxe5 18. Re1 Bd6 19. c3 O-O 20. cxd4 cxd4 21. Kg2 Qg4+ 22. Kf2 Qf4 23. Re4 Nxd3+ 24. Ke2 Nxb2 25. Rxf4 d3+ 26. Ke3 Rfe8+ 27. Ne4 f5 28. Rh4 fxe4 29. Ng5 Nf5+ 30. Kd2 e3+ 31. Kc3 Be5+ 32. Kb4 Nxh4 33. Qd5+ Kh8 34. Nf7+ Kg8 35. Nh6+ { Black resigns. } 1-0

I have heard in the past that 'It is noble to resign' but if we fight on the stars may be aligned and luck come our way. Can we say that using luck may work as a strategy?

Whether or not to resign is a question of sportsmanship rather than strategy, I would argue. Just according to the rules, you are never forced to resign and can play on until you are checkmated. However, it is expected (to a certain degree) that you resign in a position that is "clearly" lost.
There is no definite definition when a position is "clearly" lost though. If I am down a rook against Magnus Carlsen, I would definitely resign, because the chances of Carlsen blundering and giving me an opportunity to turn the game are infinitesimally small. Similarly, if Carlsen were able to gain a pawn without me gaining any compensation for it, I might resign as well (especially if it were the endgame). Again, Carlsen is expected to turn this advantage into a win eventually, and hoping that he will make an unrealistic mistake would be poor sportsmanship. On the other hand, if I was playing an opponent of my strength level, then a single pawn advantage might not be enough for him to find the win (even though the game might be already lost at perfect play). Instead, I would continue playing against my opponent until he demonstrated that he is aware of how to utilize the advantage to create a win (e.g., by creating a passed pawn that I can only stop by sacrificing another piece).


What are the hardest pawnless endgames that go over the 50-move rule? I know two pawnless endgames that go over the 50-move rule.

King and 2 Bishops vs. King and Knight = 70 moves average.

King, Rook and Bishop vs. King and 2 Knights = 200 move average.

What others are there?

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

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

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

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


Berlin Defence or Petroff? Which one is the better drawing weapon?

Which one is harder to beat?

Which one is more solid?

Which opening should black pick if he/she doesn't want to lose?

If black needs a draw in the last round to win the tournament, which opening should black pick?

There no certain answer to your question. It depends.

An opening with a "drawish reputation" usually turns against the player who chooses it without having a deep knowledge of the opening itself.

That said, I think that both of these, if understood, can be a very hard match against a White player who desperately tries to win. But they're not easy to play.

In my opinion, as a 1. e4 player (so, with the "opponent's point of view"), the Berlin is quite solid but harder to play: Black has to find suitable squares for his pieces, and must play carefully to avoid White attacks.

As White, I am comfortable playing against the Petroff: for Black it's a little bit easier to play, but has many traps, and usually the Knight becomes an easy target for White pieces. Black will lose tempo while trying to defend it.

In conclusion, don't choose an opening only for its "drawish" reputation: this may be true only at higher levels, where players know very well almost every opening. At lower levels, on the contrary, the player who relies on a specific "drawish opening" in order to draw a game will find himself in trouble more often than not.


I played 2.f3 by accident! How do I save my position? So in a correspondence chess game, the opening is the standard 1.e4 e5.  I meant to play 2.Nf3 as always, but I completely misclicked and didn't realize until too late that I played f3 instead.  It's such a massive blunder in the opening that I almost feel like resigning here.  Is there a way for me to save my position?

[FEN ""]
1.e4 e5 2.f3

With 3. f4, you are playing the Latvian Gambit with colors reversed!

[FEN ""]
1. e4 e5 2. f3 Nf6 3. f4


Castling rule clarification A quote from Wikipedia for castling rule:

  the squares between the king and the rook involved are unoccupied

What if the squares are not occupied at this instance but an opponent piece was there before?

I tried on a computer chess game, it would not allow a castling move.

FIDE Article 3.8:

  (1) The right to castle has been lost:

  if the king has already moved, or
  with a rook that has already moved.

  (2) Castling is prevented temporarily:

  if the square on which the king stands, or the square which it must
  cross, or the square which it is to occupy, is attacked by one or more
  of the opponent's pieces, or
  if there is any piece between the king and the rook with which
  castling is to be effected.

The fact that a enemy piece previously occupied a square between the king and rook does not make castling illegal. Instead, there is probably some other reason why castling is not permitted.


Custom message for an online chess game I am trying to setup an online chess game that shows a custom message at the end of the match. The game would need to be setup as a human vs. the computer. Does anyone know of an online website that allows you to do this?

I just checked three of the major sites: Chess.com, Chess24.com, and Lichess.com, and none of them seem to support this.

This is close, but not just online, but The Internet Chess Club, aka ICC, lets you do this, but only using the newest client, "ICC for Windows".

Here are the instructions.

And here is a screenshot.


Why was this game drawn? So, I was having this game with my opponent (and losing), but anyways, here is the final position:

I checked the king with my knight on move 47 (i playing black). All of a sudden, the game was drawn by insufficient material rule. However, there was indeed a queen with my opponent there on the board. So, what exactly happened here?
Also take note that my opponent had no time on the clock, so practically, I should have won the game.

Chess.com, along with FIDE, awards the full point to your opponent if you run out of time, unless your opponent has insufficient material: not enough resources to feasibly carry out a win. This effectually concedes victory to both players, which is sensible since on the one hand, your opponent rendered you incapable, but on the other, you held him off until he had no time to finish you off.

However, Chess.com's definition of "insufficient material" differs from FIDE's Laws. Chess.com simply looks at your material. If you have lone K, KN, KB, or KNN, you have insufficient material. So in your case, your opponent ran out of time, but since they determine that you could not have checkmated him anyway, Chess.com split the point.

Whereas FIDE calculates all possible futures; if one legal series of moves results in checkmate against the player whose flag fell, flag-fall is a loss for that player:

  6.9
  Except where one of Articles 5.1.a, 5.1.b, 5.2.a, 5.2.b, 5.2.c applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

Just for kicks, let's see one of these legal series of moves wherein you checkmate your opponent.

[FEN "5Q2/8/8/8/2k2P2/6K1/4n3/8 w - - 0 0"]
[startflipped "1"]

1. Kg4 Kd4 2. Kg5 Ke4 3. f5 Nf4 4. f6 Kf3 5. Kh6 Kg4 6. Kh7 Kh5 7. Kg8 Kg6 8. Qe8+ Kh6 9. Kf8 Kh7 10. f7 Ng6#

That's why FIDE would count flag-fall to be a win for you. Chess.com does not. To be fair, that or any line resulting in victory for you is so far-fetched that in this case, it's hard to complain that you could feasibly have won.*

Sources: FIDE Laws of Chess, Article 6.9; Chess.com forums - list of threads with "insufficient" in the title.

*There are a couple positions, however, in which King and Knight can force a checkmate vs. King and Pawn. For example, there would be ample cause of complaint if Black purposely runs out of time in the following position:

[FEN "8/8/8/8/N7/p7/k2K4/8 w - - 0 0"]

1. Kc2 Ka1 2. Nc5 Ka2 3. Nd3 Ka1 4. Nc1 a2 5. Nb3#


Owen's Defence playability The Owen's defence is a chess opening which starts with 1. e4 b6!?. This opening is playable if Black can get a quick c7-c5 break, where he has a pawn on e6, b6, and then he pushes c7-c5.
However, Stockfish on 22ply depth disagrees, giving White a +0.89 advantage. This hardly seems playable, as White has almost the advantage of an extra pawn.
So there must be a reason for this evaluation. I think that White can somehow prevent the break, to get a full pawn center, but I can't find any way to do so without compromising my pawn structure.

It's completely playable below master level, probably playable to IM level and probably useful occasionally as a surprise weapon at GM level. Combined with the English defense it gives black a very solid opening repertoire with very little theory to learn. The only caveat would be to just be careful castling kingside into a strong attack.
22 ply is 11 moves. How many players below master level analyze 11 moves deep in their opening prep let alone over the board? If you can see two moves ahead you're better than most of the players out there and probably wouldn't be asking this question.
A .89 evaluation is literally nothing below GM level. Analyze your games with an engine. How many times do you see a swing bigger than .89 on a single move? I'm guessing at least once a game. And even if you do play near perfect chess how big a difference is there between that and the alternatives? I'm looking at the 365chess.com database. It has 1...b6 at .66 at a depth of 38. It has other mainstream openings like the French (.53), Pirc (.6) modern (.62), Alekhine's (.55) etc. You're literally talking about tenths and even hundredths of a pawn. It's absurd for players below master level to be talking about differences that small.


Do sacrifices work mostly for masters? Many beautiful and celebrated master games feature heavy sacrifices of material that result in checkmate, or at least the regaining of more material than was sacrificed. In most cases, the original sacrifices were soundly based on positional considerations.
How well do these tactics work for amateurs? Do many make "correct" sacrifices (from the master point of view) and then lose because of incorrect follow upsS? Do amateurs sacrifice at the "wrong" times (when positional considerations don't warrant it)? Or is it usually to be the case that if "someone is good enough to sacrifice (correctly), they're good enough to win?"

This happened once, I was white and had misplayed the opening:

[FEN "r1bq1rk1/ppp2p1p/3p2p1/2nPp2n/1PP1P3/2N1bP2/P2NB1PP/R1BQ1RK1 w - - 1 12"]

I thought that Kh1 would lead to a deadly black attack, so I sighed and played 12.Rf2. There followed 12...Qh4 13.Qe1 Qxf2+ 14.Qxf2 Bxf2+ 15.Kxf2, I had lost an exchange, the queens were off and I assumed I would be lost.

I then proceeded to blow black off the board -- black's rooks turned out to be completely useless, my pieces found great squares, and I won in 32. Of course there were also many more mistakes, according to the computer.

So if a completely unintentional sacrifice can work, then so can intentional sacrifices, right?

I believe that a good move is a good move. If a sacrifice gives compensation (in terms of great squares for pieces, or an attack, etc), then it does, regardless of the level of the players.

Yes, weaker players are more likely to make mistakes and lose the compensation. But guess what, they are also more likely to make mistakes without playing the sacrifice! Maybe the sacrifice is the best move, and not playing it is already a mistake.

  How well do these tactics work for amateurs? Do many make "correct" sacrifices (from the master point of view) and then lose because of incorrect follow up? Do amateurs sacrifice at the "wrong" times (when positional considerations don't warrant it)? Or is it usually to be the case that if "someone is good enough to sacrifice (correctly), they're good enough to win?"

This is hard to answer because at one hand, yes, of course weaker players are much more likely to screw it up, because that's what weaker players do, that's not really related to the move being a sacrifice. Weaker players will also play a conscious sacrifice less often, because it's easy to understand that you'll lose a piece, and less easy to understand that you get positional features in return that make up for it, or that the tactic actually does lead to a forced mate in 6. So most amateurs play it safe (but not all).

But if we assume the opponent is at the same level, so also an amateur, then I think sacrifices can be very effective at amateur because the opponent is also less likely to see them coming, and more likely to be confused by them.

So I don't think a general answer can be given, and think what matters is that a good move is a good move. Many moves gives up some type of advantage in return for another type, and sacrifices are just one example of that.

I think amateurs don't play them as often as they should, because of unnecessary fear.

Edit: I guess I need to add the whole game

[FEN ""]
[Date "2010.09.05"]
[Result "1-0"]
[WhiteElo "1927"]
[BlackElo "2040"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 O-O 5.Nf3 d6 6.Be2 Na6 7.O-O e5 8.d5 Nc5 9.Nd2 Bh6 10.f3 Nh5 11.b4 Be3+ 12.Rf2 Qh4 13.Qe1 Qxf2+ 14.Qxf2 Bxf2+ 15.Kxf2 Na6 16.Ba3 Nf4 17.Bf1 c5 18.dxc6 bxc6 19.Nb3 Rd8 20.Rd1 Bb7 21.Na5 Rab8 22.c5 Nc7 23.cxd6 Nb5 24.Bxb5 cxb5 25.Nxb5 Bxe4 26.Nxa7 Ra8 27.N7c6 Bxc6 28.Nxc6 Rxd6 29.Rxd6 Rxa3 30.Rd2 Nd3+ 31.Kf1 Nc1 32.b5 1-0


Carlsen vs. Nepo this morning, why didn't Nepo win the pawn? On move 19 Carlsen played Nd5. Why didn't Nepo win the pawn with Nxd5? If Bx, then Qxb4, or if px, then Qxb4 attacks the Bc4 still and Bxa6 then Nc5 and move the rook.

 [FEN ""]
 [Event "Tata Steel Rapid & Blitz"]
 [Site "Kolkata"]
 [Date "2019.11.22"]
 [Round "2.3"]
 [White "Carlsen, Magnus"]
 [Black "Nepomniachtchi, Ian"]
 [Result "1-0"]
 [ECO "B51"]
 [WhiteElo "2870"]
 [BlackElo "2773"]
 [PlyCount "87"]
 [EventDate "2019.??.??"]
 [EventType "blitz"]
 [WhiteTeam "Norway"]
 [BlackTeam "Russia"]
 [WhiteTeamCountry "NOR"]
 [BlackTeamCountry "RUS"]

  1. e4 c5 2. Nf3 d6 3. Bb5+ Nd7 4. d4 cxd4 5. Qxd4 a6 6. Be2 Ngf6 7. O-O e5 8. Qe3 Nc5 9. Nfd2 b5 10. c4 bxc4 11. Nc3 Bb7 12. Bxc4 Be7 13. b4 13... Ne6 14. Nb3 Rc8 15. Na5 Qd7 16. Qd3 O-O 17. Be3 Bd8 18. Nxb7 Qxb7 19. Nd5 Nc7 20. Nxf6+ Bxf6 21. Rab1 Rfd8 22. Rfd1 h6 23. f3 Qc6 24. Qb3 Qe8 25. a4 Rb8 26. b5 axb5 27. axb5 Ne6 28. b6 Bg5 29. Bf2 Nd4 30. Bxd4 exd4 31. Rxd4 Rdc8 32. b7 Rc5 33. Bd5 Qe7 34. Rc4 Qc7 35. Rxc5 dxc5 36. g3 Bf6 37. Kg2 Qe7 38. Qb6 Be5 39. Qc6 Kh7 40. f4 Bd4 41. Qc8 Qd6 42. Qf5+ Kh8 43. Kh3 Qa6 44. e5 1-0

The solution to that is much easier than it looks, and a fairly common type of position in practical play. After 19.Nd5! taking the nice outpost square, if black responds with 19…Nd5 then white can simply play 20.Bd5 Qb4, then Qxa6 just leaves black positionally lost despite even material. In positions like that where you have a rook behind the a-pawn, and the bishops both pointing at the queenside, the pawn on a2 is going to run fast and hard, and soon cost black heavy material.

  [FEN ""]

  1. e4 c5 2. Nf3 d6 3. Bb5+ Nd7 4. d4 cxd4 5. Qxd4 a6 6. Be2 Ngf6 7. O-O e5 8. Qe3 Nc5 9. Nfd2 b5 10. c4 bxc4 11. Nc3 Bb7 12. Bxc4 Be7 13. b4 13... Ne6 14. Nb3 Rc8 15. Na5 Qd7 16. Qd3 O-O 17. Be3 Bd8 18. Nxb7 Qxb7 19. Nd5 Nxd5? 20. Bxd5 Qxb4 21. Qxa6 {And from here, it is easy to see what kind of troubles black has.}


Drawing rules for time loss Let's say we have a few situations. White has all their pieces (hypothetically) and black has only:

N+K
B+K
N+N+K

If white were to run out of time, would each of these situations be a draw due to insufficient material? I'm wondering because let's say black were to have a forced checkmate with one of the above situations, could white deliberately lose on time and claim a draw?

lichess gets it wrong.

As it happens, White would lose all three games. With all white pieces still on the board, black has still "enough mating material" - it would actually help if White had no pieces at all!

I guess we all agree in the following position black is checkmate:

5k1K/5n1P/8/8/8/8/8/8 w - - 0 1

But this position can be reached from the examples shown. Even without pawns, it is still possible to checkmate for black:

2RKR3/5n2/3k4/8/8/8/8/8 w - - 0 1

Obviously, these cases are rather theoretical. But there are real-world situations (you need something like KRR vs KN, note that KQ vs KN is in fact drawn under that circumstances!) where this may apply. That is why the 10.2 rule (claiming draw with less than two minutes, now annex G) was established and why any higher-rated modern tournament will play with time increments.

There aren't many examples of asymmetric insufficient material. Most of the time, either both players or neither can win.

Edit: The relevant section of the rules is Article 6.9:

  Except where one of Articles 5.1.a, 5.1.b, 5.2.a, 5.2.b, 5.2.c
  applies, if a player does not complete the prescribed number of moves
  in the allotted time, the game is lost by that player. However, the
  game is drawn if the position is such that the opponent cannot
  checkmate the player’s king by any possible series of legal moves.

The common simplification "has not enough winning material" is not always a good one.


How do I know what squares I need to control in a given position? I'm never quite sure what squares I'm suppose to control, especially in positions that aren't official openings or unconventional openings?

The best way to know what needs to be done is  to grasp how the pawn structure in the center affects the course of the game.  Read "The Art of The Middle Game" by Alexander Kotov and Paul Keres.  Kotov's chapter explaining the five possible pawn centers and how to proceed is the finest source ever written on this topic.

Those possible centers are: open, closed, fixed, mobile, and dynamic.

An open center is where only one or no K or Q pawns are still on the board. Fast attacks on the K and Q files are required and
immediate castling for safety.
A closed center is where pawns lock in mutual pawn chains such that neither side can advance a central pawn.  Wing attacks become necessary and castling can be delayed.
A fixed center is where the two K pawns face each other so neither can advance and the Q pawns are off the board.  Or, the Q pawns exist in the same manner and the K pawns are gone.  Play will result where each side tries to place a piece(usually a Knight) on the strong point protected by the central pawn such that the piece cannot be attacked by an enemy pawn advance. This is called an advanced outpost and when it occurs, victory for that player is likely.
A mobile center is when one side has both central pawns and the opponent has none.  The constant threat of these pawns advancing keeps the enemy too busy defending and lacking time to mount a counter-attack.
A dynamic center exists when the other four possibilities have not yet been decided. You should try to play for the type of center that will be stronger for your side.

Finally, look at your central pawns. If the K pawn is further advanced, look to attack on that side or in the center.  When the Q pawn is further out, attack on the queen side.  Kotov can provide much more detail.  Read the book!


How to improve my blitz skills? As far as casual chess goes, I'm a fairly average player. Sometimes I win, sometimes I lose, but I'm generally able to avoid obvious blunders, think a move or a couple forward, etc.

However, since I've taken up chess, I've tried my skills in some local tournaments, and the scenario is always the same - I get put on a 10- or 15-minute clock, and either run out of time, panic, or blunder, and walk out with a straight row of zeroes. I even lose to my friends that I can easily beat when not on the clock.

So - should I look at blitz chess in a different light? Think differently? Or is it just "practice, practice, practice" and "don't be a slow thinker"?

Some things that have helped me get better are:

Counter-intuitively, continue to work hard on your slow game. The best speed game players in the world just happen to be the best slow game players.  When playing slow games, you are giving your brain more "soak time" to absorb patterns and really grind into positions, giving your analysis ("I takes, he takes, ... ") skills the necessary deliberate practice.
Time Management is key.  If you are playing blitz without a time delay/increment, then it is vital to play the clock first, board second. Playing the board makes sense until you hit your time allowance per move.  Then it is a matter of playing what you consider to be best and moving on. Play what makes him burn HIS clock, not yours. You're not painting a masterpiece, you're trying to win by any means necessary! Of course, with very strong opposition, you may need to do both ... but the clock trumps the position quite often, especially as you start getting into a time-crunch! Consider reading NM Heisman's famous Two Triggers Novice Nook ... might offer you a fresh perspective if you're ever hesitating to make a move or feel nervous that you might be wrong if you rush into things.
Get Good (or at least decent) at tactics.  You should have enough tactical patterns burned into your skull to recall 1-3 ply / single-motif shots in less than 3-5 seconds. Focus on breadth (covering a ton of basic 2-4 ply tactics) and do not waste time trying to solve 12-13 ply puzzles (as most tactics servers and puzzle books tend to lure you into!)
Practice closing out won games against a full-strength computer at insanely tough time-crunch controls (for e.g. start with basics such as KQ vs K in under a minute and work your way up to piece-up/two-pawns up type of won games)
To deal with nerves or panicking, put yourself way out of your comfort zone (as necessary!) by playing a lot of online-blitz against decent opposition.  This also allows you to try out a lot of different opening lines (some of these will want to become your pet lines / repertoire) quickly.


How do I determine the bye player in a Swiss tournament? The FIDE basic rules for Swiss systems mention:

(c) Should the number of players to be paired be odd, one player is unpaired. This player receives a pairing-allocated bye: no opponent, no colour and as many points as are rewarded for a win, unless the rules of the tournament state otherwise.
(d) A player who has already received a pairing-allocated bye, or has already scored a (forfeit) win due to an opponent not appearing in time, shall not receive the pairing-allocated bye.

However, who gets the bye is never spoken of. So my questions are, how do I determine the bye player:

in the first round, and
in other rounds?

I am looking for how FIDE deals with it, and not any other Swiss system.

Note:   Independently from the route followed, the assignment of the
  pairing-allocated bye (see C.2) is part of the pairing of the last
  bracket.

https://www.fide.com/component/handbook/?id=170&view=article

In simple terms, this means that the bye normally goes to one of the players currently tied for last place, but there may be complications if this conflicts with other rules (for example, if every player in the last bracket already got a bye).

It is not stated, but I think that it makes sense to give the bye to someone in the last bracket because that way the bye is least likely to influence who wins the tournament.


Free chess engine with a tablebase So I've downloaded Stockfish and the Arena GUI, but I'm having trouble getting any tablebase I download to either load into Arena, or be compatible with Stockfish.  Any suggestions?  I'm willing to download a different GUI if it is easy to get a tablebase loaded.

If your GUI allows custom UCI options (I think you can do it in Arena, but check its documentation), you should be able to add a syzygy path yourself. Otherwise, you may try the popular Deep Fritz GUI. Check this link:

http://talkchess.com/forum/viewtopic.php?t=50554&highlight=syzygy+deep+fritz


CPU v. GPU for chess engines GPUs are better at certain types of calculations, e.g. generating bitcoins and performing climate simulations.

Would chess engines benefit if they calculated with GPUs instead of CPUs?

Maybe some knowledgeable person can highlight the differences between the two and enlighten us as to whether GPUs are (un)suitable for the type of calculations that chess engines execute.

EDIT:

Few other points raised in http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=32317.

GPU not so good for recursion
GPU not so good for floating
GPU might work better for new machine-learning approach, but not the traditional engine algorithms

Original:

@Maxwell86 has already given excellent links and resources. Pay attention to the zeta-chess engine. It's a GPU chess engine. Unfortunately, GPU has not proven its usefulness in chess programming. In fact, the zeta chess engine project went absolutely nowhere.

GPU works very well on floating calculations and algorithms that can be paralleled. This requires independence. But if we look at a typical min-max (or alpha-beta) tree (used by every chess engine )

The right branch depends on the left branch. In particular, if we can get a cutoff (fail-high), we wouldn't even need to search the remaining nodes. Unfortunately, this is not something that a GPU can do efficiently. It's possible to write a GPU program for alpha-beta, but the GPU threads (known as kernels) will need to be paused to wait. Unlike a CPU, a GPU kennel can't just switch to something else ( a process known as thread-switch or even process-switch).

Our existing algorithm and engine knowledge was derived for the CPU world. The entire algorithm would need to be reinvestigated for the GPU. Unfortunately, there is not much interest and research on it.


What is the source of the house-rule 18-moves? In my area, most kids including me grew up with a very popular house-rule: After all the pieces of either of the players are removed besides the king, the opposing player has 18 moves to checkmate him. If he can't do that, the game is a draw.

The rule is popularly called 18-moves.

I have spent some time googling and have not found this rule anywhere.

Does anyone know a source for this rule and why it's so popular?

I grew up in Spain and we used a 20 "move rule" instead of 18.

We played exactly as you said, if a player is left with a single king, the other has to mate in 20 moves or less to win the game. However, this "rule" only applied in friendly matches and was never enforced in tournaments. Our coach made us play like this for several reasons:

It promotes critical thinking at an early stage, where you have to look for faster ways to checkmate your opponent than just queening your two remaining pawns and checkmate using the "staircase" method.
It avoids humiliating the opponent, since now promoting all the remaining pawns to minor pieces and playing around with the king is no longer an option. We were around 6 years old, so once you knew you had won  you wanted to enjoy it longer. This kind of demeaning behavior was discouraged.
It avoids elongating the game more than necessary. We trained without clocks, which could make us spend unnecessary time in trivial positions.

This practice then naturally extended to our friendly games, but we were well aware that this was not an official rule and that on tournaments the 50 move rule applied.


alpha-beta algorithm returns a value between alpha and beta inclusive? I am coding up a chess engine and using the alpha-beta algorithm for tree scanning. I ended up doing what they posted here:

int alphabeta(int depth, int alpha, int beta)
{
    move bestmove;
    if (game over or depth <= 0) return winning score or eval();
    for (each possible move m) {
        make move m;
        score = -alphabeta(depth - 1, -beta, -alpha)
        if (score >= alpha) { alpha = score; bestmove = m; }
        unmake move m;
        if (alpha >= beta) break;
    }
    return alpha;
}

It is stated that "The code above always returns alpha, beta, or a number between alpha and beta." In my calcs this is not true and I need it in order to implement aspiration search. I have seen many variants of the algorithm and tried a few but sometimes the return value falls outside the desired interval [alpha, beta].

Can anyone post C++ or pseudo-code of alpha-beta with that property?
Is it possible to prove that ?
Finally, it seems intuitive that the return value is an increasing function of alpha keeping beta fixed and similarly for beta. Is it true and is it provable? In my calcs this is not the case.
How big must be the window of aspiration search in order to ensure we have not pruned out the principal variation? If the return value falls between  alpha and beta will that suffice?

My usual reference is https://chessprogramming.wikispaces.com/Alpha-Beta#Implementation-Negamax%20Framework, which I believe is correct.

In your lecture slide, if score > beta ==> alpha = score ==> return alpha which is greater than beta. Thus, the claim looks incorrect to me.

You don't need to prove "increasing function of alpha" because any score less than alpha is a bad move for you, so you would ignore it.

Aspiration window width is a parameter and there is no definitive answer. You don't want it too big, or too small. You'll need to run tests...


Any ideas for this interesting problem? Any ideas for this interesting problem?

The black king threatens to escape via e4, so

8/2Q5/8/3k2K1/8/8/4NP2/8 w - - 3 13

1. f3 Ke6 {(forced)}
2. Nf4#

(sidenote: I'm really divided into putting the solution in a 'spoiler' block with >! (as is customary on Puzzles.SE)

   like this

and the current way, with a diagram to allow playback. It would be very nice if we could put the diagram inside the spoiler.)


Do "chess engine in the cloud" services exist? And if so, what interfaces can connect to them, and how do they do that?

I want to analyze with Lc0, but I don't have a computer with a GPU; I could rent one for a short time period at various cloud providers, but then I don't know what GUI I could use to talk to an engine running somewhere on the Internet.

Do e.g. Chessbase, Scid, Aquarium etc have a feature to work with engines running in the cloud?

Chessbase has this feature for subscribers. Basically you can analyse your games using their cloud based engine. If you have a powerful machine yourself you can also "rent out" your engine. More details here.

Here is an older article which includes a video explaining how it works and walks you through the process.


Sacrificing Bishop for Two Pawns against Queenside Castling Though queenside castling is less common, it is important enough to study. If your opponent has castled queenside, sometimes you have an opportunity to expose their King by sacrificing your Bishop for 2 pawns, as showed below. (I have removed other pieces from the board to avoid distraction.)

[FEN "2kr4/ppp5/8/8/8/4B3/8/4K3 w - - 0 1"]

1.Bxa7 b6 2.Bxb6 cxb6

What factors should one consider before deciding to offer this sacrifice? To put it another way, in what positions is this sacrifice favourable and in what positions would it be unfavourable?

Edit As per comment from xaisoft, I am posting a board with other pieces.

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 e5 2.d4 d6 3.Bc4 Nf6 4.Nf3 Nc6 5.dxe5 dxe5 6.Nxe5 Nxe5 7.Qe2 Bd7 8.Nc3 Qe7 9.Be3 O-O-O 10.Bxa7 b6 11.Bxb6 cxb6

I'd argue you never want to play such a bishop sacrifice if your opponent is willing to take it.

Therefore, I think your question is rather “when can I take the undefended ♟ a7”.

To answer this, I'd say you need

Either a defense on the bishop (with a rook or a knight)
Or a crushing attack if you can sacrifice it. A queen around, or a rook coming on the open c-file, with pieces supporting that are mandatory. If the king can't easily escape to e8, that's better.
Nothing better to do. That's just a far pawn, and it takes 2 tempi to take eat if you want to save your bishop. Your opponent need not take bigger of an advantage in the meantime, that you could defend from before taking the pawn.


Is it possible to win this endgame? [FEN "7r/1pk2p2/2p5/p5pp/3R2P1/1P3P1P/P5K1/8 w - - 0 1"]

Is it possible to win this endgame with either White or Black ?I know the Lucena and Philidor positions which are the first things that popped when I searched rook endgames. But how will that help me win these type of endgames? Is there a procedure?

Is it possible to win this endgame(either white or black)?

Of course either black or white could win this endgame. All it takes is one blunder by either side.
If what you meant to ask if either side can force a win, then the answer is "No". Black is a pawn up but white has a much more active rook and the black king is cut off on one side of the board by the white rook.
As Tarrasch is supposed to have said "All rook and pawn endgames are drawn". With best play this is also very probably drawn but best play is very rare for humans, particularly in the endgame and particularly when the clock is ticking.
Even if black succeeded in exchanging off pawns until left with king+rook+pawn versus king+rook it would likely still be drawn as long as white managed to keep the rooks on. Even with rooks off as well there are many positions where king+pawn would still be a draw against lone king.


Public higher-order endgame tablebases for *common* positions? It's easy for me to locate 6-piece tablebases online for free (e.g. lichess), and I know 7-piece tablebases exist (cf. Lomonosov tablebase), but I don't know of any easy way to access them.

However, I'm not really interested in all the weird positions like K4B vs KQ that a ≥7-piece tablebase would "honestly" have to include to be called as such. Haven't there been any restricted tablebases generated that only bother to include useful positions, such as e.g. KR vs. KR with more than a total of two pawns? Or is such a thing still technically infeasible?

(I realize that in theory, such a tablebase may not be 100% perfect, since calculations for common positions may be inextricably linked to those for uncommon ones; I would hope this issue could be circumvented with a minimum of resources spent brute forcing the uncommon positions and a minimum loss of accuracy for the common positions, but I could be wrong)

I understand where you are getting from. Unfortunately, it doesn't quite work like that. To generate a 7-man KRPPvKRP you would also need 7-man endgames for the promotion. You would need:

KRQPvKRP
KRQPvKRQ
KRQQvKRQ
KRBBvKRB
.......

Can you see, it's really not that easy to generate an endgame with a pawn, because that can transpose to another endgame with the same number of pieces.

We do have technology to generate Syzygy 7-piece, but you'd need a super-computer or a high-performance-computing to do it. Google can definitely do it if they want to. So far, nobody wants to cover the costs.


Guide to using a book I am currently twenty years old. I learned the rules of chess when I was eight and played on and off for a long time. However, I did not take it seriously. Recently after joining chess.com and trying out the tactics, as well as following grandmaster games and YouTube channels, I am interested in improving my skills.

As of now I am able to figure out tactics as well as calculate decently in situations where a few different permutations of exchanges or forks, 2 or 3 moves ahead, could take place. However, most text I see talk about pattern recognition and studying positions and tactics. Therefore I have obtained a copy of Susan Polgar's "Chess Tactics For Champions". I would like to know how I should go about using this book. I understand that it is quite comprehensive. But somethings I would like to get right the first time around are:

1) Should I make a conscious effort to remember positions presented in the book?

2) Should I make a conscious effort to identify patterns or relate positions other than the obvious differences? Or will I start to hone this skill automatically?

3) Should I try to set up a board and play on a few moves in cases where the objective is to get an advantage?

4) Should I keep in mind any trade-off between tactical advantages which may lead to immediate piece advantage versus positional advantage?

How you should use the book is really a matter of opinion, but I very much believe in immersion learning, so rather than do a few every day for a longer period, I believe that doing as many as you can in a shorter period of time is more beneficial. I have seen this play out in practice in both my progress, and in the progress of those, whom I have taught.

Therefore, I always say, that try and do at least 50 per day, spending no more than two minutes per move on each problem.

The whole point of pattern recognition is that you do not have to try to remember the specific positions you see in the book as you will likely never get those exact positions in your lifetime. What you will get in your games is certain elements of those games, the patterns", and by doing enough of these tactics exercises, you will start to remember them.

I just looked at the table of contents of the Polgar book, and it is well-organized. You want to stay within a certain type of tactic when you are studying, like doing pins for a while, and maybe later, forks, etc.

You should, and shouldn't, have to consciously identify the patterns. I think it will come naturally as you read that book, and MANY more tactics books after. Even if you become an "ordinary" Master, even then, your tactics will still always be helped by continued tactical practice.

I am not sure how number three relates, or really what you are asking, but in general, when doing tactics problems, I would not set up a board as it takes too long, and you want to start calculating in your head anyway.

A tactic can lead to either a material advantage, which I think is more common, or a positional advantage. You always need to be mindful of the evaluation at the end of a tactic, and ask if you are really better, and is there any trap at the end that you may have missed. If you have a tactic that can lead to either type of advantage, you have to weigh the pros and cons of each final position. I would say that, in general, material is more likely to be preferred, but there are definitely cases where I would not want the material, and would take the position.

For example, I recently answered a question here where the OP took the exchange. I would not have played the move 35...Ne3+ winning an exchange, and would have preferred to maintain the pressure. The short "tactical exchange" winning the exchange allowed white to use e4 as a blockading square for quite a while, whereas keeping the attacker would have probably led to more. The positional pressure was worth more, in my opinion. So this is an example of having a choice between material and position, and having to make a decision.