# Question
Title: What alternatives are there to Chess Position Trainer?
CPT is software for testing (among other things) one's opening repertoire knowledge.

I'm wondering if there are any other similar pieces of software I should consider.

# Answer
> 4 votes
You can use Listudy (disclaimer I own that site) for exactly that. I created Listudy to train my own repertoire by playing against it. For this spaced repetition is used so the training is always working on the moves you're weakest on. You can upload your own repertoire in form of a PGN or import studies from Lichess. You can look here for example studies: https://listudy.org/en/studies/search

And best of all, Listudy is free and open source: https://github.com/ArneVogel/listudy

# Answer
> 3 votes
Bookup/Chess Openings Wizard, Chess Opening Trainer (which had a PC version too) and Chess Position Trainer are some of the main options, but just for completeness sake:

Chessbase lets you add 'training annotation' to moves in a game, so when you switch on training, it will hide the continuation, and quiz you.

Lucas Chess now lets you set up a Personal Opening Guide, and then test it via Learn Tactics by repetition.

SCID has a 'find best move' feature.

Heuristic Opening Repertoire Specialist & Trainer (H.O.R.S.T.) allows you to "train variations by using a training assistant."

Jan Kaan's Bookbuilder has a "book training module."

# Answer
> 3 votes
I like the online chesstempo beta opening manager and trainer. I have read on the facebook page of chess position trainer, that chess position trainer 6 is coming this year. I aspect a lot from this software.

Lucas Chess has some interesting repertoire making functions. Like importing best moves or all best moves from a bin book, for one collar. You can export the openings to pgn but I have noticed that there is an error and there are many threefold and more-fold repetitions in the games. You can solve this by importing the pgn in chess position trainer and export to pgn again. I also like Hiarcs Chess explorer. You can sort games for one player by opening name. So you can make repertoires for it. You can edit the player name in a text editor or in Chess Assistant.

# Answer
> 2 votes
The very commercial Bookup (also goes by the name Chess Openings Wizard) is probably the big contender for the PC.

I believe there are a few phone apps that help with this as well like the Chess Opening Trainer (iPhone)

# Answer
> 1 votes
As I see this question six years after you ask it, I can now answer with the online tool **Chessable** ( https://www.chessable.com/ ).

It sells courses and whole books turned into courses, but it also still allows uploading your own courses as PGN. And then it lets you train them like Chess Position Trainer does.

It isn't as smart about transpositions as CPT is (just plays lines), but that has its advantages as well as its disadvantages.

---
Tags: software, memorization
---


# Question
Title: From a full board to a pawn endgame in the shortest possible number of half-moves
Is any game known where all the pieces (except the pawns) are still on the board, and where a piece (not a pawn!) is captured at each half-move, leading to a pawn endgame?

In other words, is there a game where a "full" board is transferred to a pawn endgame in only 14 half-moves?

Here a game where the tranformation is made in 16 half-moves:

```
[Event "URS-ch26"]
[Site "Tbilisi"]
[Date "1959.??.??"]
[Round "15"]
[White "Kortschnoj, Viktor"]
[Black "Geller, Efim P"]
[Result "1-0"]
[ECO "E69"]
[PlyCount "83"]
[EventDate "1959.??.??"]
[EventType "tourn"]
[EventRounds "19"]
[EventCountry "URS"]
[Source "ChessBase"]
[FEN ""]

1. d4 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 O-O 5. Nc3 c6 6. e4 d6 7. Nge2 e5 8. O-O
Nbd7 9. b3 exd4 10. Nxd4 Nc5 11. h3 Re8 12. Re1 a5 13. Rb1 Nfd7 14. Be3 h5 15.
Qd2 Ne5 16. Red1 Qe7 17. Kh1 Bf8 18. Re1 Bg7 19. Re2 Qc7 20. f4 Ned7 21. Bg1
Nf6 22. Nc2 b6 23. Ree1 Bb7 24. Nd4 Re7 25. Re2 Rae8 26. Rbe1 Ncxe4 27. Nxe4
Nxe4 28. Rxe4 Rxe4 29. Rxe4 Rxe4 30. Bxe4 c5 31. Bxb7 Qxb7+ 32. Qg2 Qxg2+ 33.
Kxg2 Bxd4 34. Bxd4 cxd4 35. Kf3 Kg7 36. Ke4 Kf6 37. Kxd4 Kf5 38. Ke3 Ke6 39.
Ke4 Kd7 40. f5 g5 41. Kd5 Kc7 42. g4 1-0

```

# Answer
> 3 votes
Such a game more than likely doesn't. The game that you give is amazing enough in that 16 already exists. Without access to a database, however, I don't know for sure. Perhaps someone could try to do that, and search in one or two. But again, more than likely it doesn’t exist due to the extreme conditions and setup that a real game would have to arrive at the do it, not to mention that there are two minds involved.

Just for fun, as a related note that isn't an answer, here is the fastest possible game with such a sequence.

```
[Title "me, chess.stackexchange.com 7/3/2020, Non-Unique Proof Game in 15.0 Moves"]
[FEN ""]

1. e3 e6 2. Qf3 Qf6 3. Qxb7 Qxb2 4. Be2 Be7 5. Nf3 Nf6 6. O-O O-O 7. h3 h6 8. Kh2 Kh7 9. Qxa8 Qxa1 10. Qxb8 Qxb1 11. Qxc8 Qxc1 12. Qxf8 Qxf1 13. Qxe7 Qxe2 14. Qxf6 Qxf3 15. gxf3 gxf6

```

# Answer
> 1 votes
I have made a search on pawn endgames in my database, and here is the definite answer! 21 full moves, it really cracked me up to see it hahahaha.

http://view.chessbase.com/cbreader/2020/7/3/Game1044992468.html

By the way your above example is not 16 half-moves (that would be 8 full moves). It's 34 full moves.

Cheers!

---
Tags: pawn-endgame, captures, records
---


# Question
Title: How often do grandmasters miss checkmate?
Although top players are extremely good at finding checkmate, the number of permutations of moves in just 3 moves can be hundreds of thousands, and the farther out the possible mate (e.g. mate in 4, mate in 5), the more permutations are possible; so it is understandable that a checkmate will sometimes be missed by top players.

Engine analysis of past grandmaster games would reveal missed checkmates - what percent of classical games did/does a grandmaster miss a checkmate?

# Answer
Probably more often than people realize.

There have been several notable instances where GMs (even world champions) have missed simple mates in one.

From my own experience, when I analyze my games the engine frequently will point out some ridiculous 25 move forced mate. In a game, I'm not going to take the time to calculate something like that out if I have a very clear, simple and direct win. Maybe it takes a couple of moves longer but who cares?
> 24 votes

# Answer
It really depends on what counts as a missed checkmate. In Blitz we occasionally see a missed mate in 1. In slower games, mates in a few moves are rarelly missed. But the problem is that sometimes long mate sequences will be "intentionally missed", as the player will go for a solid advatange that guarantees victory rather than calculate a 15-move long line that leads to mate but could be wrong. Does this really count? You're probably mating anyway but 20 moves further down the line.

If we refer exclusively to missing forced mates that lead to not winning the game, I'd say they're few and far between
> 18 votes

# Answer
I agree with the answers above, however, there are actually some cases where GMs missed mate-in-ones in classical chess while not in time trouble. If memory servers right, I have read about that a few years back on chess.com's news page, but I cannot find the article right now.

The main reason is the following: Player A only needs a draw (to outright win the tournament or advance in a knockout tournament, for instance) and has calculated a quite long forced line leading to a perpetual or stalement. Then these forced moves are blitzed out and the mate-in-one is missed.

Of course, this still happens only rarely, but the percentage of easy mates missed by GMs *while having lots of time* is probably farther away from 0 than one might first expect.
> 7 votes

# Answer
This depends entirely your horizon for what you consider a missed mate. Is there any upper bounds on the number of moves required? Would you consider a "mate in 53" to be a missed mate, even if no one, human or computer, had the computational power to actually find such a mate (but maybe in 100 years a computer could show a forced mating sequence from that position)?

Assuming that you would consider a missed "mate in 53" to be a missed mate, then the answer is that no one can give you a precise number, for the simple reason that no one can determine which situations contain such a mate. There does, however, exist a theoretical answer: the number of missed mates by a player in any game is precisely the number of instances in which that player had a winning position at one time but later the position became drawn or lost. The key insight is that a forced mate exists if and only if one of the players has a won position, even if the horizon for that forced mate is so far out as to be effectively impossible to compute.

You could probably get a reasonable estimate for the number of missed mates in a given game by running the game through a good chess engine and setting an appropriate cutoff evaluation, where any evaluation above that score is considered a won position for that player and any evaluation below that score is considered a draw or a loss. Since a pawn is generally considered enough to win, a score like 1.0 or 1.1 might be a reasonable choice. The number of missed mates would then be the number of times the computer evaluation crossed that cutoff line from high to low -- e.g., if the evaluation was 1.4 one move and .6 the next, quite probably the player moved from a won position to a drawn position, missing a theoretical forced mate. The downside to this method is that it is sensitive to the cutoff evaluation chosen, the engine accuracy, and the engine stability. Possible very sensitive, as it is quite possible to imagine a situation where a sequence of player moves or engine analysis at different depths fluctuate frequently over the chosen value in a narrow range, leading to large uncertainty as to whether the current move does in fact represent a change from won to drawn or vice-versa. Similarly it is quite possible that one engine evaluates a position as above the cutoff while a different engine deems it below.

A precise answer is clearly impossible, but if people are interested and time permits, I might try running a grandmaster game or two through my engine and see what results come out.
> 6 votes

---
Tags: engines, checkmate, statistics, grandmaster
---


# Question
Title: Why do some (many!) grandmasters play the opening so slowly?
I know it is never good to memorize opening lines and play them without understanding the plans and ideas, but still, I see so many grandmasters play moves from #5 to around #10 so slowly as if they've never seen the position before. But we know that they have, and furthermore the positions has been played in literally thousands of games by others. Are they trying to decide which of the moves that are in their repertoire to play? Or are they trying to fully absorb the plans, even though they've already studied the plans at home? Or are they trying to recall the variations that they studied at home but might have forgotten? What's going on in their heads during their slow play in the first 10 moves?

# Answer
Remember that they've usually spent a few hours before the game to prepare against this particular opponent: reviewed which openings the opponent plays and what his weaknesses are, chose what kind of opening to play today, made a guess which variations are likely to occur and made a plan based on that, et cetera. He always plays the same against 1.e4 and I have a nice idea against that line, maybe play that today even though it's not my main move? In that other line, he recently won spectacularly against a strong opponent but I have an improvement early on, he probably hasn't looked at it too closely...

Of course, the opponent has done the same.

If everything goes exactly as expected, the moves go very fast. But usually at least one side goes for a surprise, and then the exact preparation is out of the window, and they have to rely on the general preparation. He suddenly goes 1.e4, maybe I should go for a secondary defense? But I know my main one so well... Or: he suddenly goes for the French! What have I played against this recently, should I avoid those lines? What other lines are there that he probably isn't that good at? *Why* is he playing this?

The moves and variations themselves are very familiar at that point, but there's still the metagame of choosing the right opening against this opponent.
> 9 votes

# Answer
Thinking long in the early phase can have psychological reasons. The grandmaster thinks how he can play against a particular player to exploit the opponents weaknesses, or tries to surprise the opponent somehow.

But in some cases, the opponent plays rare variants. Not all playable openings occur at grandmaster level and perhaps the opponent tried to come up with a surprise.

Even a grandmaster does not know EVERY sensible position possible after about 5 moves, only the most common ones, or those they play regular.
> 4 votes

# Answer
Knowing the plays -- and knowing the player, are not the same. On any given day a player might play differently, and you must control the tempo of a game to see how the player responds; meaning it's not just about playing slow, but about controlling the pace of the game.
> 2 votes

# Answer
Reshevsky once took a full hour for his first move.

No reason for it. Sometimes GMs play the opening slow.

I would guess that it is to ensure they do not make a silly mistake or fall into a trap early that would lose the game.
> 2 votes

---
Tags: opening, grandmaster
---


# Question
Title: Are there any grandmasters who always play until checkmate?
Are there any high-level players who are either known for playing games out until the bitter end or have done so in famous circumstances? Is this considered poor etiquette (I'd imagine it would be rude to force a master to play out a simple king+queen vs. king checkmate)?

# Answer
> 11 votes
To become Grandmaster, you must win many tournament games. They take many hours, sometimes multiple games per day, or many days in a row. Tournaments are exhausting. If you are tired then you make mistakes, and making mistakes means you don't play at the required level to become Grandmaster.

Players who always waste a lot of time by playing on until checkmate instead of resting aren't very likely to become Grandmaster.

# Answer
> 9 votes
Sometimes the grandmasters will play out the K+B+N vs K endgame, so as to have their opponent 'prove' they are capable of carrying out the somewhat tricky mate.

As it turns out, it may be worth playing to the bitter end in this case. There are some examples of even grandmasters failing to deliver the checkmate! Here's a recently semi-famous one from a game played during womens FIDE Grand Prix tournament in Geneva, 2013. Showing only the relevant part; whole game can be replayed here: http://www.chessgames.com/perl/chessgame?gid=1716505

**Note: At the time of the game, Anna Ushenina was Women's World Champion!**

```
[White "Anna Ushenina"]
[Black "Olga Girya"]
[fen "8/8/8/8/B7/2NK4/8/k7 w - - 0 1"]

1. Nd1 Ka2 2. Bc2 Ka1 3. Kc3 Ka2 4. Bb3+ Ka1 5. Ne3 Kb1 6. Nc2 Kc1 7. Ba2 Kd1 8. Nd4 Ke1 9. Kd3 Kf2 10. Bd5 Kg3 11. Ke3 Kg4 12. Be4 Kg5 13. Kf3 Kf6 14. Kf4 Kg7 15. Kg5 Kf7 16. Kf5 Kg7 17. Bd5 Kh6 18. Ne6 Kh7 19. Kf6 Kg8 20. Nf4+ Kh8 21. Be4 Kg8 22. Nh3 Kh8 23. Ng5 Kg8 24. Nf7 Kf8 25. Bh7 Ke8 26. Bf5 Kf8 27. Nh6 Ke8 28. Nf7 Kf8 29. Ne5 Kg8 30. Ng6 Kh7 31. Be6 Kh6 32. Bg8 Kh5 33. Ne5 Kh4 34. Kf5 Kg3 35. Bc4 Kf2 36. Kf4 Ke1 37. Ke3 Kd1 38. Bd3 Kc1 39. Nc4 Kd1 40. Nb6 Kc1 41. Na4 Kd1 42. Be4 Kc1 43. Bd3 Kd1 44. Nb2+ Kc1 45. Nc4 Kd1 46. Bg6 Kc1 47. Bf5 Kd1 48. Nb6 Kc1 49. Na4 Kd1 50. Nb2+ Kc1 51. Nc4 Kd1 52. Kd3 Kc1 53. Kc3 Kd1 54. Bd3 1/2-1/2

```

# Answer
> 4 votes
Only in exceptional cases, a grandmaster plays until the mate. If the mate is beautiful, or if he is very angry about himself, or just as a joke. But normally, they rather resign one move before mate than being checkmated.

In many cases, grandmasters resign too early, with only a pawn down at a full board or with a bad piece. Nakamura often plays games out, but he resigns in totally hopeless positions.

In short, a grandmaster is rarely checkmated. And I am pretty sure, that there is no master ALWAYS playing to the mate, unless perhaps in a blitz or lightning game.

# Answer
> 4 votes
Here is an example of a master playing on 2 queens down in the British Championship http://streathambrixtonchess.blogspot.co.uk/2010/01/ray-could-play-iv.html

# Answer
> 2 votes
They should play on if the other person in in time trouble. Or if the other player is tired or not feeling well. Mistakes happen. And in blitz you should never resign for any reason.

# Answer
> 1 votes
GMs do not wait for themselves to take the effort for total annihilation . They resign long way back when they feel the Position does not have to offer anything . In Classical Chess the above stands True but in Blitz sometimes they might wait for the Checkmate to happen .

---
Tags: checkmate, etiquette
---


# Question
Title: Is there any better play than the 3-move mate?
I know how to cause a checkmate in three moves. Are there any better ones? I've been told that there is a two move one but, I have never found someone who can do it. Is it just a legend that has happened once or twice?

# Answer
There is a two-move mate: the *Fool's Mate*. However, it requires White to be, as the name implies, extremely foolish!

```
[FEN ""]
1.g4 e5 2.f3 Qh4#

```

As you can see, this mate relies on White advancing pawns without any regard for his King's safety. There's no way to *force* a two move checkmate (if there were, Chess would be an awfully boring game!).

As to whether it's ever occurred in real (master) play, I can't find any record of it, though the Wikipedia article mentions Teed vs. Delmar, 1896, where a very similar mate is delivered a few moves later.
> 4 votes

# Answer
You can NOT cause a mate in 3 or 2 or any low number.

If the other player is truly stupid or messing with you then it might be possible to mate in 2 for black but white to do it would take 2½
> 1 votes

---
Tags: checkmate, history
---


# Question
Title: Compiling Stockfish to disable own castling while allowing opponent castling
For artistic purposes, I would like to create and study engine games in which only one side is able to castle.

For this, I need to compile a version of Stockfish which never castles, and doesn't consider its own castling in its calculations, whereas calculates with castling for the opponent.

I have gone through the types.h file and found the following:

```
enum MoveType {
  NORMAL,
  PROMOTION = 1 << 14,
  ENPASSANT = 2 << 14,
  CASTLING  = 3 << 14
};

enum CastlingRights {
  NO_CASTLING,
  WHITE_OO,
  WHITE_OOO = WHITE_OO << 1,
  BLACK_OO  = WHITE_OO << 2,
  BLACK_OOO = WHITE_OO << 3,

  KING_SIDE      = WHITE_OO  | BLACK_OO,
  QUEEN_SIDE     = WHITE_OOO | BLACK_OOO,
  WHITE_CASTLING = WHITE_OO  | WHITE_OOO,
  BLACK_CASTLING = BLACK_OO  | BLACK_OOO,
  ANY_CASTLING   = WHITE_CASTLING | BLACK_CASTLING,

  CASTLING_RIGHT_NB = 16
};

```

**What can I do to disable castling in moves and calculations of Stockfish?**

# Answer
There is no need to compile your own version of Stockfish for this. Instead you can just start from a position that omits castling rights for one side or the other. The FEN for the initial position without castling rights for White is

`rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w kq - 0 1`

and the FEN for the initial position without castling rights for Black is

`rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1`

The FEN can be entered into Stockfish using the UCI command

`position fen FEN`

where `FEN` should be replaced by the FEN in question.
> 10 votes

# Answer
Without reviewing the complete code (which is probably humongous), it is difficult to give a proven right answer.

However, it should work if you replace the lines for the black castling possibilities by `BLACK_00 = 0, BLACK_000 = 0,` (or respectively for the white, if you want). This should lead to all tests in the code returning 'black castling not possible', which is the intention.
> 2 votes

---
Tags: engines, stockfish, programming, computer-chess, castling
---


# Question
Title: How do I apply moves (bitboard) and continue searching? My current attempt is throwing a strange error!
## Explanation

I have a list of all possible current moves in a position. At each node, I want to then generate all possible moves and continue. The problem is that my code is modifying the list of moves in the node above. At least I think this is the case!

I am open to completely changing the way I handle moves, as I feel this isn't very efficient since I have a struct for every move.

## Output

This is the current output.

```
PS D:\Users\kmont\Desktop\ChessEngine> dotnet run
Number of moves at depth 1 is 4. It is White's turn.
Number of moves at depth 2 is 4. It is Black's turn. Previous move was knight to a3
Unhandled exception. System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
    at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
    at System.Collections.Generic.List`1.Enumerator.MoveNext()
    at Program.search(Int32 depth, Board board, String prevMove) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 55
    at Program.search(Int32 depth, Board board, String prevMove) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 60
    at Program.Main(String[] args) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 33

```

## Code

The Move Struct:

```
public struct Move{
    public Piece.Type pieceType;
    public UInt64 piece;
    public UInt64 moveTo;
    public int color;

    public bool quiet;
    public UInt64 capturedPiece;
    public int capturedColor;
}

```

Search function:

```
public static void search(int depth, Board board, string prevMove = "nothing"){

    // If at the end of the tree, return.

    depth++;
    if (depth == maxDepth) return;

    Console.Write("Number of moves at depth {0} is {1}. It is {2}'s turn.", depth, board.allMoves.Count, board.color == 0 ? "White" : "Black");
    if (prevMove != "nothing") Console.WriteLine(" Previous move was knight to " + prevMove);
    else Console.WriteLine("");

    // Uncomment below line for a list of all possible moves.
    //if (true) foreach (Board.Move move in board.allMoves) Console.WriteLine(String.Format("    {0} {1} on square {2} can move to {3}.", move.color == 0 ? "White" : "Black", move.pieceType.ToString(), help.square(move.piece), help.square(move.moveTo)));

    foreach (Board.Move move in board.allMoves){
        Board newBoard = board;
        newBoard.color = 1 - board.color;
        initialiseBoard(newBoard);
        newBoard = makeMove(newBoard, move);
        search(depth, newBoard, help.square(move.moveTo));
    }
}

```

Make move function:

```
public static Board makeMove(Board board, Board.Move move){

    string moveColor = move.color == 0 ? "White" : "Black";
    string boardColor = board.color == 0 ? "White" : "Black";
    string pmove = help.square(move.moveTo);
    //Console.WriteLine(String.Format("    Making {0} move {2}: It is {1}'s turn.", moveColor, boardColor, pmove));

    Board toReturn = board;
    // Remove piece from board
    if (toReturn.color == 0 & move.color == 0){
        if (move.pieceType == Piece.Type.Knight){
            toReturn.WhiteKnightsBitboard &= ~move.piece; // Get rid of piece on board
            toReturn.WhiteKnightsBitboard |= move.moveTo; // Add piece to board
        }
    }
    else if (toReturn.color == 1 & move.color == 1){
        if (move.pieceType == Piece.Type.Knight){
            toReturn.BlackKnightsBitboard &= ~move.piece;
            toReturn.BlackKnightsBitboard |= move.moveTo;
        }
    }

    Game.node++; // To count nodes
    return toReturn;

}

```

Initialise Board function:

```
static void initialiseBoard(Board board){
    BoardOperations.updatePieces(board); // Sets all pieces and finds empty squares
    board.generateAttackSquares(board);  // Finds white knight moves and puts them into board.allMoves
}

```

# Answer
> 5 votes
The issue may be here:

```
Board newBoard = board;

```

This creates a new variable, but it doesn't actually create a new `Board`. `board` and `newBoard` are pointing to the exact same `Board` object. So, when your code changes anything in `newBoard`, it also changes it in `board`, and when it changes, you get this error.

What you may want to do is make an actual copy of `board`, so when you change it, it doesn't change the original.

---
Tags: engines, programming, bitboard
---


# Question
Title: Typical Good Bishop vs. Bad Bishop endgame - how to decide if stronger side has a definite win
Black here has 3 weak pawns; if any one of them falls - he will very likely lose the game as well. If he lets White king break through via c4-c5(d5) - White will also likely win. c5 pawn is a passed pawn, but is not going anywhere. Evaluations like "White is better" are not precise enough - is it possible via analysis to prove that White definitely wins? Or that Black definitely holds? Variations or plans for both sides are welcome.

White to move:

```
2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 64

```

# Answer
> 11 votes
With new analysis from user AlwaysLearningNewStuff, we can conclude this is a win for white,

The first critical position appears after `1.Be2 Kb7`.

```
      [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

       1.Be2 Kb7

```

Black defends everything at the moment, but the only moves that keep the position are `Kb7-a7-b7`. A simple triangle maneuver puts black in zugzwang.

```
     [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

       1.Be2 Kb7 2.Kd2 Ka7 3.Kc2 Kb7 4.Kc3

```

Now black is in *zugzwang* and loses. The following lines illustrate this:

```
[FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

1.Be2 Kb7 2.Kd2 Ka7 3.Kc2!+- Kb7 4.Kc3 ( 4...Ka7 5.Bc4 Be8 ( 5...Bg6 6.Be6 Kb7 7.Kc4 Kc6 8.Bd5+ Kd6 9.Bb7+- Bf7+ 10.Kd3 )( 5...Bxc4 6.Kxc4 Kb7 7.Kxc5+- ) 6.Be6 Bg6 7.Kc4 Kb7 8.Kxc5+- )( 4...Bg6 5.Bf3+! Kc7 6.Kc4 Kd6 7.Bb7+- Bf7+ 8.Kd3 )( 4...Be8 5.Kc4 Kc6 6. Bf3+ Kd6 7.Bb7+- Bf7+ 8.Kd3 ) c4! 5.Kd4! ( 5.Bxc4? Bxc4 6.Kxc4 Kc6= ) 5...Kc7 ( 5...Kc6? 6.Bxc4 Bxc4 7.Kxc4+- )( 5...Kc8? 6.Bxc4+- Bxc4 7.Kxc4 Kc7 8.Kc5 ) 6.Bf3! Kc8 7.Bd1!!+- Kc7 ( 7...Kd7 8.Bc2! Be6 9.Ke5+-)( 7...Kb7? 8.Bc2! Be6 9.Ke5 Bd7 ( 8... Bg8 9.Bxf5+- ) 10.Kd5!+- ) 8.Bc2! Be6 9.Ke5 Kd7 ( 9...Bd7 10.Kd5!+- ) 10.Bd1! Bf7 11.Kxf5 Kd6 12.Kf6!+-

```

The important idea is that after `4...c4!` White uses `6.Bf3!` to restrict Black king. After `6...Kc8` White repositions Bishop on `c2` with the move `7.Bd1!!` so the decisive *zugzwang* can be achieved. After `12.Kf6!` the rest is a matter of technique.

The analysis is kept as brief as possible in order to preserve space, since the rest of the winning moves can be easily found with an engine.

# Answer
> 2 votes
This resembles another position referred to as the "Iron Duke." Based on my knowledge of the *other* position, I'd say that Black can draw.

The reason is that all the potential entry points (on the fourth rank) for the white king are either occupied or "covered" by Black. There is a (blocked) White pawn on a4, b4 and d4 are covered by the Black pawn on c5, c4 is covered by the Black bishop, e4 and g4 are covered by Black pawns, and f4 and h4 have (blocked) White pawns. The Black bishop can continue to cover c4 while moving along the diagonal to protect whatever pawn White's bishop attacks (except for the one on a6, which the king can protect).

If White tries for an exchange of Bishops on c4, the Black K "toggles" between c6 and d6, and the White king still can't break through.

Black *can* lose by moving his c pawn or wrongly moving his bishop. But as the position now stands, White can't force a win. Neither can Black for that matter. If he moves his (passed) c pawn, he has losing chances.

# Answer
> 1 votes
Analysis with Houdini 6.02 signal a win for White(+4.53)at d= 41/103 after more than a quarter hour of analysis. The winning method is complicated though , and White should start with 1 Bg2. Thanks. A demo (analysis included for pure curiosity in my program )with New Engine gives + 5.58 at d= 56 , which confirms the endgame is slowly winning for White.

---
Tags: analysis, endgame, bishops, bishop-endgame
---


# Question
Title: Is this the position from TCEC Season 18, Game 80 a win or a draw?
This position from move 42 of TCEC Season 18 Game 80, with Black to move. Is it a win or a draw?

```
[FEN "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

```

# Answer
The key point in this endgame is that the bishops are of opposite colours. It is a trivial draw. White is a pawn up but with nothing more than barely competent play by black, white will never be able to advance his pawns. The black king can never be moved from b7 and the black bishop can take station on the diagonal between c6 and h1 making the pawn move c6 impossible. Black will also play h5 at some stage leaving him with only the g6 pawn to protect. The f6 pawn is an irrelevance.

To be able to win an opposite coloured bishop endgame one player has to have two passed pawns separated by a minimum number of files. That isn't the case here. The problem for the side with the extra pawns is that the opposing king and bishop can always blockade the colour of the bishop and the attacking bishop cannot help.
> 3 votes

# Answer
## Is it a win or a draw?

The position from the diagram is a dead draw.

**How can White win?**

```
[Title "White wins with queenside pawns"]
[StartFlipped "0"]
[fen "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1...Bg4 2. f5 {No matter how Black captures the pawn, White plays Bb2 and gets the f6 pawn} Bxf5 3. Kb5 Bg4? {I am just setting up the winning position for White, proper defense shall be demonstrated in a separate diagram} 4. c6+ Kb8 5. Bf4+ {That was the point of f5, to vacate f4 square for the bishop}  Kc8 6. b7+ Kd8 7. b8=Q+ 1-0

```

There are only two ideas that can make White win on the kingside:

```
[Title "White wins with h-pawn"]
[StartFlipped "0"]
[fen "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1...Bg4 2. Bb2 Bd7 3. Bxf6 Bc6? 4. h5!+- {With Black king tied to the queenside, only bishop is left to defend, which is why Black may not take, because White king will help the f-pawn to queen, forcing Black to give up the bishop. White bishop easily stops Black's passed h-pawn} Bf3 5. h6 g5 {Sooner or later, Black will have to play this move in order to defend the h-pawn} 6. Bxg5! 1-0

```

Similar idea looms in the air:

```
[Title "White wins with f-pawn"]
[StartFlipped "0"]
[fen "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1...Bg4 2. Bb2 Bh5? 3. Bxf6 Bg4 4. Be7 Bf3 5. Kb4 Bg2 6. Kc4 Bf3 7. Kd4 Bh1 8. Ke5 Bg2 9. Kf6 Bf3? 10. Kg5 Bh5? 11. f5 {Black loses bishop if he takes the f-pawn, otherwise f-pawn promotes to Queen} 1-0

```

**How can Black hold? What are his plans?**

Black needs to:

1. stop f-pawn from moving
2. stop h-pawn from moving
3. stop queenside pawns from rolling

Points 1 and 2 are easily achieved with the pawns placed on g6 and h5. Bishop then needs to be on the b1-h7 diagonal once White plays Kg5 and there will be no way for White to break through. To be ultra safe, we will keep Black's bishop as further away as possible from the White king.

Point 3 is achieved by keeping the bishop on h1-a8 diagonal.

The only question remains if White can somehow overburden Black pieces with piece maneuvers, namely with the king. Bishop is faster than the king, so Black just needs to shuffle the bishop on the relevant diagonal.

Let us put this all together:

```
[Title "Black holds comfortable draw"]
[StartFlipped "0"]
[fen "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1...Bd7! {Now White can not perform the queenside pawn roller described earlier} 2. Bb2 h5! {No more h5 ideas} 3. Kb4 Bc6! {Flexibly posting the bishop, so he can shuffle on the required diagonals. F-pawn is irrelevant} 4. Bxf6 Bh1 5. Kc4 Bg2 6. Kd4 Bh1 7. Ke5 Bg2 8. Be7 Bh1 9. Kf6 Be4! {As long as White king attacks the g6 pawn we defend it by shuffling on the b1-h7 diagonal} 10. Ke5 Bh1 {Once White king abandons the g6 pawn, Black switches the bishop back to the h1-a8 diagonal} 11. f5 gxf5 12. Kxf5 Bf3! {Now we just shuffle on the d1-h5 diagonal} 13. Kg5 Bd1 14. Kf5 Be2 15. Ke5 Bf3! {Remember, as soon as White king moves away from the kingside pawns we switch back to h1-a8 diagonal to block the queenside pawns} 16. Kd6 Bh1 1/2-1/2

```

Black can play like this forever, he will simply shuffle between the relevant diagonals as shown in this example. White has nothing in this endgame.

If you have any questions leave a comment, I will gladly reply.
> 2 votes

# Answer
It is rather easy to just chuck this position into a chess engine to determine the result, but let's try to manually to improve our analysis skills.

Clearly, White is up one pawn with two connected passed pawns. These pawns are threatening to check agter White moves their king to b5, and push dawn the Black king to do so. But these pawns are easily neutralized by Black's light square bishop since the pawn's checking square is protected by it, The Black king can now sit and blockade the pawns, like so.

```
[FEN "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1... Be4

```

White's kingside threats are easy to counter and therefore not a threat at all. Now we can turn our eye to Black's queenside majority. Black can make a passed pawn no matter what White does, but it will never be of any use due to White's dark-squared bishop.

```
[FEN "8/1k5p/1P3pp1/K1P2b2/5P1P/8/8/2B5 b - - 0 1"]

1... Be4 2. Kb5 h6 3. Be3 g5 4. fxg5 hxg5 5. hxg5 fxg5 6. Bxg5 *

```

Neither side can advance their pawns for promotion because of the opposite colored bishops. White can try ideas such as protecting their kingside pawns with their bishop and moving their king to the queenside, but Black will always be able to force the exchange of pawns on the queenside before than.

The end effect is that the pawns are practically non-existent, leaving an opposite colored bishop endgame with only kings and them on the board, which are always are a draw, unless a FIDE player runs out of time of course.

All in all, **the position is a draw.**
> 1 votes

---
Tags: draw, bishop-endgame
---


# Question
Title: Carlsen - Ghaem, why does Black want to do e5?
I am watching videos about the London system, and one example they use is this game.

```
[Title "Carlsen-Ghaem, Baku 2016"]
[FEN ""]

1. d4 d5 2. Nf3 Nf6 3. Bf4 e6 4. e3 Bd6 5. Bg3 c5 6. c3 Nc6 7. Nbd2 Bxg3 8. hxg3 Qd6 9. Bb5 Bd7

```

after 8. ... Qd6, the guy explaining the video says that Black is preparing to move e5, so White moves 9. Bb5 to avoid that. What is Black's plan with that move?

# Answer
With ...e5, Black:

1. Opens a diagonal for the c8-bishop, and
2. Fights for central control.

Both of these adhere to chess principles, so planning for ...e5 is a very natural thing for Black.
> 4 votes

# Answer
My thinking is that Black's long-term problem is being saddled with a bad Bishop, his pawns on white squares limit it's scope so try for Ne7 and hope for the exchange.

If Black allows BxN the White's Ne5 looks strong.

The dilemma for Black set by Carlsen: do I risk castling into the open h file, do I plan to castle Q side or do I wait until White makes his intentions re castling clear?
> 1 votes

# Answer
e5 would be a mistake here. I get that it frees up the bad bishop but black is going to be left with a worse pawn structure no matter how that plays out. Black's play is on the queenside.
> 0 votes

---
Tags: opening, london-system
---


# Question
Title: How much time it takes before searching for tactical themes becomes a subconscious process?
I would really like to have that ability.So how to achieve that?

# Answer
> 7 votes
It is a bit like for example learning to play the piano. At first as a beginner you look at the keys and where your fingers are going. With increasing practice, and remember even a great piano virtuoso(*) will still practice every day, your thought patterns become better organised and you later play with your fingers seemingly doing the thinking for you. (*) The great Artur Rubinstein practised several hours each day: he said that if he did not do this he would detect a decline in his performances.

For each player the speed that this happens will vary.

I find playing through lots of master games is most helpful. I try to read any annotations and play through some of the variations given in the analysis.

At first I was slow and cumbersome but after a while this improved.

The secret is consistent practice.

Every day without fail set yourself the task of playing through 1 to 20 games. Little by little patterns of play will be absorbed and you will find yourself subconsciously playing better moves. By the end of a month you will have played through 30 to 600 master games. By the end of a year you will have played through 350 to 7000!

Create for yourself a concrete set of steps for each game. I used to have them typed on a card and reviewed the steps before each tournament game. After a while they become second nature.

Two phases: 1. It is your opponents move. 2. It is your move.

I can elaborate these steps if it is of interest.

---
Tags: tactics
---


# Question
Title: Are there any inherent problems with point-symmetric random chess?
The regular setup of chess is *mirror-symmetric:* If you mirror the positions of all figures on the equator of the board (between the fourth and fifth rank) and swap the colours, nothing changes. It is also almost *point-symmetric* or *rotational-symmetric:* If you reflect the positions on the centre of the board (or equivalently rotate the board by 180°) and swap the colours, only kings and queens will swap their positions.

By contrast, in Chess 960 a.k.a. Fisher random chess, opening positions are mirror-symmetric by construction, but in general far from point-symmetric. Now, suppose I want to introduce a Chess 096, where white’s setup is determined like in Chess 960, but black’s setup point-mirrors white’s. Castling rules would be point-symmetric as well. A possible starting position would be this:

```
rnnkbqrb/pppppppp/8/8/8/8/PPPPPPPP/BRQBKNNR w KQkq - 0 1

```

Like in regular Chess or Chess 960, the only imbalance is that white has the first move – unlike for example, if white and black’s starting positions were randomised independently. My question is: Are there any inherent gameplay problems with these point-symmetric starting conditions? For example, does this tilt the balance of the game?

# Answer
Consider the following initial position:

```
[FEN "rkqnnbbr/pppppppp/8/8/8/8/PPPPPPPP/RBBNNQKR w - - 0 1"]

```

By putting the kings on opposite sides of the board, you've more or less introduced an opposite-side-castling situation, without anyone having castled.

Let's say White starts throwing his queenside pawns forward towards Black's king. In this position, this can be done without compromising his own king's safety, as it's on the other side of the board. What are Black's responses?

* Launch his own attack by throwing pawns towards White's king. But given the symmetrical nature of the position, it seems inevitable that White's attack will hit first.
* Castle long, to the side White's king is on. This runs into several difficulties. There are a lot of pieces in the way - there's no real way to do so before move *nine*. Black will have to move two pawns on the "long" side to get his bishops out, which may weaken his castled position, while White technically wouldn't have to move any pawns to castle over there (and White's king is already "there" even if he doesn't castle at all.) Also, if we're going to keep symmetry, Black's king should end up on the f-file (it's a long castle, after all) while White's will be on the g-file.
* Leave his king over there, and defend. This may work, although it doesn't seem ideal.

Also note that the queenside attack doesn't have to start on move 1; it can be delayed a few moves to establish a center first.

Overall, it seems to me that this variation may increase White's advantage, especially in scenarios like this example where the kings are very far apart.
> 7 votes

# Answer
Look at 'normal chess', but with rotational symmetry.

```
[FEN "rnbkqbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1"]

```

I haven't analyzed this opening much, so I may be missing some concrete lines that make this game degenerate. Barring that, I suspect this version of chess offers a few advantages over normal chess.

* Much less opening theory is available/known for this position, allowing for more over-the-board creative play.
* The most common castling combination in chess is that both players castle kingside, in part because there are fewer pieces in the way. If both players castle 'kingside' in this variant, they have castled on opposite sides, which often leads to more aggressive, 'asymmetric' middlegame play and more decisive results.
* For white, putting early pressure on c7 here is harder than putting pressure on f7 in normal chess. Normally, 1. e4 is considered aggressive because it releases both the light squared bishop (which threatens f7) and the queen. Here, we need to move both the d2 and e2 pawns to let both those pieces out. The same also applies to black for threatening f2. I suspect this leads to fewer 'sharp' openings (if the opening theory was worked out).

Lets try playing 'normal' openings and see how they compare...

* 1. e4 e5 2. Nf3: Usually black has to defend the e5 pawn, but here it is already defended by the queen, so black has more options. Further, 2..Nc6 is a common response, which is still valid here and has the added advantage of making progress toward castling 'kingside'.
* 1. d4 d5 c4 : The queen's gambit feels pretty strong. It seems to have the aggressive advantage of the king's gambit in normal chess, but without the danger of moving the f2 pawn.
* 1. c4 : For the same reason as above, the English opening seems strong.
* 1. g3 d5 2. Bg2 Nf6 seems stronger for white than it normally is, but by no means dominant.
> 5 votes

---
Tags: chess-variants, chess960
---


title: Is this endgame winnable for White?

text:
# Question
Title: Is this endgame winnable for White?
Playing White against a computer, I reached this position (White to move):

```
[fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

```

White has a queenside pawn majority, but Black's king is closer to the action, and its knight has the idea of Nd4-c2. I played this position through to the end about a dozen times, and usually only managed to draw: Black was able to pick up my queenside pawns, and even in lines where I got one of Black's kingside pawns in compensation, the position was still drawn. A couple of times I did manage to push the queenside pawns and win, but I didn't keep track of exactly what I did and it's possible the engine made a defensive error (it was set at a fairly easy level). So what should White's plan be in this position? Does White have a win here, or is this a draw?

# Answer
> 8 votes
## EDITED ( January 7th, 2014 ):

Based on the member *shivsky*'s comments I have edited the entire solution.

---

> Does White have a win here, or is this a draw?

Yes it is won for White.

> So what should White's plan be in this position?

At first, I wanted to provide an answer with `1.a4` and simply force the win, but I do not have computer strong enough to analyze the variations I come up with, so my conclusions can not be 100% true.

I do not think that you can achieve much by creating the *passed pawn* immediately, at least my engine shows some convincing defensive lines.

And again you were right-even if you trade queen side pawns for his king side pawn, he might still draw.

My engine shows some lines where `1.a4` continuation allows you to get `f7` pawn for your queen side pawns-giving White an advantage, but I strongly believe you can **not** win since all the pawns are at one side and Black's Knight can do a good job at defending and blocking.

Being strong endgame player, I must say that I do not like `1.a4` anyway.

## ANSWER:

Your only chance is to **deaden** the position and to win by using your queen side pawns to **distract his pieces from defending king side**, when your pieces could invade there and get enough material to enforce queening. You need to **start the action at the right moment**.

`1.Kf1` can achieve that, when you could freely maneuver into the favorable setup which will create passed pawn and win.

**TO CLARIFY MY ANSWER:**

I have tested this line with the engine to see if there is a valid defense, and engine could find none.

I have tried to find one myself and `1. ...Nh4` was the best try I could find.

It is the only way to prevent White from activating his king ( if Black allows that then its game over ) and the idea is to harass White's King side pawns so Black could play f6 + g5 + Nf5 hoping to achieve something like this:

```
[fen "8/8/p3kp2/5npp/PPN4P/3K2P1/5P2/8 w - - 0 1"]

1. hxg5 fxg5

```

This would give him some counter-play ( he threatens to queen with `h4` ) and would provide him a chance to exchange all king side pawns.Then he could try to catch the queen side pawn ( `a6` pawn will 100% be exchanged for the `b5`-White has to play it at some point ) or to sacrifice the Knight for a pawn ensuring the draw.

This is how I would try to save the game as Black, but White can refute this plan:

```
[fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

1.Kf1 Nh4 2.g3 Nf3 3.h4 Nh2+ 4.Ke2 Ng4 5.f3 Nh6 6.Ne3!

```

This move restricts the Knight completely refuting the above plan.Without the ability to create counter-play Black is simply lost-White creates the queen side *passed pawn* distracting one or both of Backs pieces and then wins by taking all of Blacks pawns on the king side.

**HOW TO EXACTLY WIN THIS:**

First rule of endgames-**king is extremely powerful piece-use it!**

Second rule-of all the available moves that can implement your plan always play those **that make the least commitment**. This gives you the **flexibility** to adapt when **position changes in its character drastically**.

The `1.a4` continuation breaks both rules, as it neglects the king and forces the matters-which **unnecessarily** sharpens the game and **provides Black with counter-play based on his strong King**.

In endgames you need to **slow down the pace** and see the **whole picture**. Raw calculation here is useless if you do not have a **clear plan**.

To create a plan, we always start with the analysis of the position. Yours is sufficiently good for a start so let us go from there:

> White has a queenside pawn majority, but Black's king is closer to the action, and its knight has the idea of Nd4-c2.

Third rule in endgames-in order to win, most of the time you will have to create **at least two DISTANT** weaknesses in the opponents camp ( if they are close then opponent might defend successfully ). Here we already have one-extra pawn on the queen side.

Our pawn structure is healthy-we have no pawn weaknesses on queen or king side ( doubled/isolated pawns... ).

The weakest piece in our setup is our king and that is our only weakness.

Our Knight is A MONSTER! This piece alone actually won this endgame! He is ideally posted-he can aid in creation of a passed pawn, he can attack on the queen side, he **restricts** the opposing Knight and King, he can harass the king side pawns if black king abandons them and he can defend our king side. WHAT A BEAUTIFUL PIECE! A HERO!

Now let us see what Black has:

Black's king IS active as you have correctly noticed, but he is **badly placed**-he needs to be closer to the center to balance the lack of a pawn at queen side ( e6 would be nice )-and that is something you have missed.

Black's knight is OK, he is posted well, but is **decentralized** which **limits his actions**-he can only attack on the king side at the moment.

Black has no pawn weaknesses, but is a pawn down. He also has started to **probe** the king side since h-pawn has advanced and can be supported with he knight and a king. He should try to create counter-play there, **since he has no time to attack the queen side**.

Let us see the entire picture:

**Black's pieces are misplaced** ( you missed this fact and this is important to notice ), they **need** 1 or 2 moves to centralize them selves ( **they must do this in order to hold queen side** ), and will spend **even more moves** to organize a defense/create counter attack.

**This will give White enough time to activate his king.**

Now we see the first phase of our plan-improve the king's position.

The second part should be about **creating the second weakness**-this **type** of endgame is well known and the usual plan is to create passed pawn on the queen side to distract king/knight/both and then to use our extra pieces to break through on the king side.

You saw what happens when Black tries to generate counter-play on the king side, now let us see what happens when he tries to centralize his pieces so he can attack on the queen side:

```
 [fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

 1.Kf1 Nd4 2.Ke1 Ke6 3.Kd2 Kd5 4.Kd3

```

At this point Black is in zugzwang, and no matter what he plays, White will simply parry his threats and eventually play `a4` fulfilling the plan described above. Let us just see one sample continuation so you "get the feel":

```
 [fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

 1.Kf1 Nd4 2.Ke1 Ke6 3.Kd2 Kd5 4.Kd3 Nc6 5.Ne3+ Ke5 6.Kc4 f5 7.a4 f4 8.Nd5 g5 9.Nc7 Nb8 10.b5 axb5+ 11.axb5 Kd6 12.b6 Kc6 13.Nd5 Nd7 14.Kd4 Nxb6 15.Nxb6 Kxb6 16.Ke5

```

And White wins. The queen side pawn majority did its job-it has distracted the knight, and eventually the king from defending the king side which was exploited with White's last move.

One thing I must mention is the usage of *zugzwang*. At certain point Black did manage to centralize his pieces, but so did White. At that moment everything boils down to small nuances and here it is White knight that saved the day-by restricting both king and knight he enabled the creation of *zugzwang* after which the creation of the passed pawn was easy.

Notice also, how the activity of the Black's pieces just wasn't good enough for a draw, since they were badly misplaced and notice how that gave White the time to improve his own king.

I think that this is enough for you to understand how to win this alone, so set up the position on your computer and try to win this time.

Good luck!

Best regards and a Happy New Year!

# Answer
> 4 votes
It's technical, but white wins in this position. White's plan should be to execute typical "outside passed pawn" tactics:

1. Activate King!
2. Play with zugzwang

The idea is that white threatens to attack on both flanks with pawn advances. Black can't stop two threats at the same time because the battlefield is too big.

Without the knights it would be easier, but with the knights it is a bit harder. With a bishop, rook or queen the plan becomes quite difficult to execute because these pieces can defend both flanks at the same time.

Here are two sample solutions:

```
[fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

1. Kf1 Nd4 (1...Ke6 2. Ke2 Nh6 3. Ne3 Ng4 4. Nxg4 hxg4 5. Kd3 Kd5 6. h3 gxh3 7. gxh3
Kc6 8. Kc4 Kd6 9. f4 Kc6 10. a4 Kb6 11. Kd5 Kc7 12. Kc5 Kb7 13.Kd6 1-0)
2. Ke1 g5 3. Kd2 Nf5 4. a4 Ke6 5. Kd3 Nh4 6. Ne3 f5 7. Kc4 f4 8. Nd5
Nxg2 9. a5 f3 10. b5 Kd6 11. bxa6 Nf4 12. a7 Nxd5 13. a8=Q Nc7 14. Qxf3 g4 15.
Qf6+ Kd7 1-0

```

A more detailed explanation on this type of position is given here: http://www.mark-weeks.com/aboutcom/aa03g19a.htm

# Answer
> 2 votes
These moves were selected by Stockfish running on a decent 2-core CPU at 30 minutes per move. While Stockfish is a fine engine, computers aren't great at the end game, so I expect that there could be some improvements.

```

[fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

1.Kf1 Ke6 2.Ke2 Kd5 3.Kd3 Ne7 4.a4 Nc8 5.Ne3+ Kc6 6.Nf5 g6 7.Nd4+ Kc7 8.Nb3 h4 9.Nc5 Kb6 10.Nd7+ Kc6 11.Ne5+ Kd5 12.Nxf7 Nd6 13.Nxd6 Ke6 14.Ne4 *

```

...and it's lights-out for Black.

What we see here for the first 7 half-moves are both players centralizing their Kings and preparing for a skirmish on the Queenside. Black's 4th move looks to be a clunker though it is still about bringing the Knight to the Queenside. What's happening here is that White is taking the slack out of the Queenside and limiting Black's response. This makes additional calculation easier.

White punishes `4...Nc8` by a series of Knight moves that harass the Black King, which must stay near the Queenside. A fork develops and Black loses material without compensation on the Kingside. Black can honorably resign after White's 11th move, IMO.

After `13.Nxd6` there are no good moves and Stockfish goes wonky. It hardly matters - Black is done.

The strategies in the position are: 1. Black will try to equalize on the Queenside 2. White will be willing to surrender two pawns for one pawn on the Queenside, as long as the Black King is misplaced (decoyed!) to the rim. White's King can then run amok on the Kingside.

To answer the OP's question, yes this is winnable. First, it looks to me like White can win with proper play. Second, unless you're playing at a very high level, nearly every position is winnable - you just have to capitalize on the opponent's mistakes. Chess is a game about outwitting your opponent, not making perfect moves.

Final edit - I don't see a variation where Black can force a draw. White's extra pawn forces Black to make decisions that are fatal in the long term.

# Answer
> 0 votes
Analysis with Houdini 6.02

```
[fen "8/5pp1/p4k2/5n1p/1PN5/P7/5PPP/6K1 w - - 0 1"]

1.Kf1 Nd4 2.Ke1 Ke6 3.Kd2 h4 4.a4 Kd7 5.Kd3 Nc6 6.Kc3 Kc7 7.f4 Ne7 8.Ne3 Ng6 9.Nd5+ Kd6 10.Kd4 Nf8 11.Ne3 Ne6+ 12.Ke4 Kd7 13.Ke5 Nd8 14.Kd4 Kc6 15.Nf5 Ne6+ 16.Ke5 Nf8 17.Ke4 Nd7 18.Nxg7 Nb6 19.Ke5 Nxa4 20.Nf5 Nb2 21.Kd4 Kb5 22.Kc3 Nd1+ 23.Kb3 Nf2 24.Nd6+ Kc6 25.Nxf7 Kd5 26.Ka4 h3 27.g3 Ng4 28.Ka5 Nxh2 29.Ng5 Kc4 30.Nxh3 Ng4 31.Ng5 Nf6 32.Nf3 Nd5 33.Ne5+ Kd4 34.Nc6+ Ke4 35.Kxa6 Kf3 36.b5 Kxg3

```

Mate in 21 according to Nalimov tablebases , starting with f5. Two iterations of 20 and 15 minutes.

---
Tags: endgame, knights, knight-endgame
---


# Question
Title: Why do some strong players play 5... Be4 in Caro Kann, Tal Variation?
```
[FEN ""]
1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 { B12 Caro-Kann Defense: Advance Variation, Tal Variation } h6 5. g4 Be4 6. f3 Bh7  7. e6 Nf6

```

What is the point of the intermediate move 5...Be4 before retreating by ...Bh7? It was played by very strong players, including Ding Liren (against MVL) and Hikaru Nakamura (against Mikhail Antipov).

If the point is to provoke f3, it seems to me that White is not unhappy to play f3 and control e4, as Black might play 6... Nf6 next, which is indeed a good move in these positons.

If the point is to disallow Nf3 in positions when White pushes e6 and Black takes with exf, it does not achieve that, as Black wasted one tempo on the bishop retreat Bf5-e4-h7 and White can also waste a tempo by playing f2-f3-f4 and then Nf3.

It does weaken g3, which Black could try to exploit with 7...Qd6, but after exf+ Kxf7 White can once again push f4 without feeling bad about wasting a tempo.

# Answer
> 6 votes
White probably intends to play e6 anyway, to launch an attack against the light squares. Whether Black takes this Pawn or allows exf7, White will want to play Nf3-e5 as part of his followup, and if f3 has been provoked, he will need to play f3-f4, losing another tempo and obstructing his dark Bishop.

# Answer
> 5 votes
> If the point is to disallow Nf3 in positions when White pushes e6 and Black takes with exf, it does not achieve that, as Black wasted one tempo on the bishop retreat Bf5-e4-h7 and White can also waste a tempo by playing f2-f3-f4 and then Nf3.

There is an error in your tempo-count.

If Black plays Bf5-e4-h7 instead of Bf5-h7, he loses one tempo.

If White plays f2-f3 followed by f3-f4 and Ng1-f3 instead of directly Ng1-f3, he loses **two** tempi.

Having the pawn on f4 instead of f2 may be useful in some lines (provides control of e5, might be followed by f5 or g5 in tactical skirmishes) or harmful in others (e4 is weakened, the Bc1 will find it harder to reach an active spot), but in any case it is not what White would like to spend on tempo at that point on in such a sharp position.

Indeed, After 6...Be4 7.f3, most often White doesn't follow with f3-f4 and find other ways to develop his Ng1 (e.g. through h3 and f4).

---
Tags: opening, caro-kann
---


title: Queen placement in the Dragon

text:
# Question
Title: Queen placement in the Dragon
```
[FEN ""]
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 g6 5.Nc3 Bg7 6.Be3 Nf6 7.f3 O-O 8.Bc4 e6 9.O-O a6

```

Here is a line from a game of mine. I made the movee 10. Qd3, but my computer program says Qd2 would have been a much better move. Why is that?

# Answer
> 12 votes
One of Black's development plans will include moves like Nd7 intending Ne5 hitting the Q and Bishop if the Q is on d3. This will cost White an important tempo in this dynamic opening.

Black's plans revolve around control of the c4 square hoping to place a piece on this square. Depending on White's particular move order Black may play b5, Bb7, Nd7, Nb6, Nc4, Rc8.

To counter this Q side action of Black, White needs to get active on the K side: Qd2 allows the B to h6 plan to exchange off the key defensive Black B. In due course after completing development White can plan a pawn storm against the B King.

# Answer
> 11 votes
Qd2 is used in these lines to support the Be3, which is typically played to h6 to exchange for the Bg7, followed by a pawn attack on the king-side.

# Answer
> 4 votes
Without giving a long, drawn out explanation, the simple answer is that you're decreasing the mobility of the queen. The queen only has three legal moves from d3 and all of them waste time. Qd2 loses a tempo since you could have played Qd2 the move before. Same with Qe2. Qd1 wastes two moves.

The value of moves comes from the value of the pieces and the value of the pieces comes from their mobility.

# Answer
> 2 votes
The queen on d2 allows for a future Bh6 exchanging the bishops and preparing a h4-h5 push with a strong attack for White.

With Qd3, you are exposing it to attack (...Nc6-e5 is a typical maneuvre in this type of posiiton). You also prevent your bishop from going to c4 which is a typical square where it's placed.

Also note that Black's ...e6 is a very bad move, as it does nothing to further development, weakens the d6 square and prevents the c8 bishop from developing to e6.

---
Tags: opening, theory, sicilian-defense, sicilian-dragon
---


# Question
Title: Did Stockfish blunder a drawn position against Leela here?
I don't see how you can defend both pawns at once if the bishop is located on the f8 square. Where did Stockfish go wrong in this game?

```
[FEN "5B2/3k4/2p4p/4n1r1/8/2R5/6K1/8 w - - 0 1"]

```

# Answer
Welcome!

I am not 100% sure of what your are asking.

Are you saying that Stockfish missed a draw by playing Bf8 as shown in the diagram ie there was some other move that could have drawn?

Or are you saying Stockfish missed a drawing line later.

Or are you asking in general where Stockfish went wrong in the game?

If you look at the evaluations then Stockfish seemed to assess itself as losing many moves earlier. Leela on the other hand thought her position better for quite some time but not necessarily a forced win.

In the lead up to your diagrammed position Stockfish I think is lost and has been for quite a long while. The Black pawns are wide apart making the defensive Bishop's task very hard. The White K has to keep an eye on one of the pawns whilst the White Rook keeps an eye on the other pawn whilst at the same time trying to harrass and keep out the Black K with checks.

Black has to manoevre carefully but will always be able to shepherd the c Pawn down to the queening square.

I think Stockfish made a strategic error with 40. Ng2 allowing Leela to swap her bad Bishop and get a position with the "Petrosian Knight" verses Stockfish's bad Bishop. After this swap Leela's Q invaded, Stockfish's position deteriorated leaving a difficult defensive task.

Apologies if I have missed your point.
> 7 votes

---
Tags: analysis, endgame
---


# Question
Title: Is there any other notation system other than algebraic notation?
Other than the current coordinate notations used in chess, are there any other notations that anybody knows about? I am looking for anything that does not employ the coordinate system like naming all squares or any other sharp ideas.

# Answer
Other than the algebraic nomenclature: Two off the top of my head are

Correspondence chess used 1:1 to 8:8 to label the squares.

Descriptive notation predated algebraic: 1. P-K4 P-K4 2. KN-B3 QN-B3 and so on.
> 11 votes

# Answer
Older players such as myself (I'm 83) learned with descriptive notation. Descriptive notation names the files based upon the piece standing originally on the 1st rank square, e.g. the QB file for what is the "c" file in Algebraic and the Q file for the Algebraic "d" file.

I preferred it to Algebraic, which became popular later on, since I found it easier to record the moves during a game or to follow the written moves on a scoresheet or in a magazine or book without a board. It is, as the name implies, more descriptive of the move. The downside was that you had to count from both sides of the board, e.g. my KB3 as White was Black's KB6 and vice versa, i.e. Black's KB3 was White's KB6, etc.
> 7 votes

---
Tags: terminology, notation
---


title: Wwhy was f5 played here?

text:
# Question
Title: Wwhy was f5 played here?
```
[FEN "r1b1k2r/3pnpbp/pp2p1p1/2q3B1/3pPP2/1B1P4/PPP1N1PP/R2Q1RK1 b k - 0 1"]

```

In this position, f5 was played. The reasoning is that Black's king is still in the center, so if White decides to start a kingside attack the king can just to run to safety. But this doesn't make any sense! Black could just castle after the move. Am I missing something?

# Answer
Black could castle, but that doesn't make the king any safer! White could follow with f5 0-0 Qd2, threatening both f6 and Bh6.

Anyway even if Black could castle that doesn't make f5 a bad move (the only downside being the e5 square becoming a bit weak)
> 5 votes

---
Tags: analysis, middlegame
---


title: Checkmate without check beforehand

text:
# Question
Title: Checkmate without check beforehand
```
[Title "fucccommies-Diam0ndJake, chess.com, 7/8/2020"]
[FEN ""]

1. e4 e5 2. Nf3 Nf6 3. d4 Nc6 4. d5 Nd4 5. c3 Nxf3+ 6. Qxf3 Be7 7. Bb5 O-O 8. O-O c6 9. dxc6 bxc6 10. Bc4 d5 11. exd5 cxd5 12. Rd1 Qb6 13. Be3 Qb7 14. Bxd5 Nxd5 15. Rxd5 g6 16. Na3 Bxa3 17. bxa3 Qb2 18. Rad1 Qxa2 19. Ra5 Qb3 20. Rxe5 Bb7 21. Qf6 Qxd1#

```

In this game, I which my opponent and I played poorly, I ended up winning without a check at all before the checkmate. Can anyone help me understand when checkmates can happen without a check?

# Answer
Assuming you are Black, you *have* checked your opponent - your Queen on d1 is putting his King on g1 in check (and checkmate).

**Edit**: assuming Rewan Demontay's reading of your question is correct, then there's no stipulation that you have to check your opponent before checkmate. You can see this in well-known short checkmates, e.g. Scholar's mate. 1. e4 e5 2. Bc4 Bc5 3. Qh5 Nf6?? 4. Qx7# is checkmate without checking first.
> 8 votes

---
Tags: theory, checkmate, check
---


# Question
Title: Have there been computer-vs-computer chess games exceeding 493 moves?
From a FIDE Online Arena Facebook post (which appears copy/pasted from elsewhere), I'm interested in the part in bold:

> (Image of a chess board with two kings and no pawns nor pieces omitted.)
>
> This was the position after 91.Kxb8 in the game NewRival1816 - Faile06 in a computer tournament in 2001. According to the rule, the game should have been stopped as a draw here, but this rule apparently wasn't implemented ... **493 moves is a new world record**, ...

I find it hard to believe this is up-to-date, but I didn't immediately find examples to indicate otherwise (e.g. `long computer chess games` didn't give anything relevant).

**Question**: Have there been computer-vs-computer chess games exceeding 493 moves?

For this to be meaningful, I insist that both engines were actually playing "good moves", i.e., moves that both engines thought maximized its score. Or in other words, the engines were actually playing chess, and not trying to maximize the length of the game.

# Answer
> 3 votes
Tim Krabbe discusses this in his website (see section 328).

It's an old post - dating to 2006 - so it's certainly possible. However 2006 was also a long time ago. Since then engines have gotten more familiar with the rules, and all the top engines I'm aware of are aware of the 50-move rule. 493 moves is very long, but it should still be fairly trivial to get longer games if one just got engines to play and never adjudicate (see example). All one has to do is set some very short time control and play a billion games, and eventually a game will get there.

Games played in tournaments is a different matter, with a necessarily small sample size. In that case I think it's quite likely that 493 moves is the longest on record. It's about 100 moves longer than the next-longest games I'm aware of.

Caveat: the 493-move game wouldn't happen under real tournament rules since the 75-move rule would've been invoked to force a draw.

---
Tags: computer-chess, records
---


# Question
Title: What is the piece value heuristic in atomic chess?
In regular chess a queen is worth 9, rook 5, knight 3, etc. What is the equivalent heuristic in atomic chess?

# Answer
The answer is, as expected, "it depends". To answer directly first, 2016 Atomic World Championship (AWC) winner, tipau, put the values as:

> Pawn - 1 Knight - 1.5 Bishop - 1.5 Rook - 3 Queen - 6

As a somewhat strong player myself (two top-8 finishes in the AWC) who has extensively analysed atomic chess endgames, I would tend to agree.

The king has no value, but outside of stopping passed pawns in endgames and a few other special zugzwang compositions, it is almost useless.

---

Now to go deeper into the topic, do note that the **piece values change during the game**. General experience would give the following points to support the piece values:

* In an endgame, a minor piece is only slightly more than a pawn; if one side has *N* pawns + 1 minor piece while the other side has *N+1* pawns, the side with the minor piece has a slight advantage (which may not be enough to win, depending on the position).
* In the middlegame, a minor piece is worth more than a pawn, but usually less than two pawns.
* A rook is generally worth more than a minor piece, especially when there are more open files for invasion. A minor piece + pawn can compensate for a rook in the endgame though, generally forcing the side with the rook to take a draw by perpetual check.
* Knights are generally better than bishops in the very early opening and endgame, but not in the middlegame.
* The bishop pair is much stronger than the knight pair or a knight + bishop.
* The queen's value is hard to pin down. Depending on the position, she can be worth less than B+N, or more than R+B+N+P, as seen in several common opening lines. It largely depends on the solidity of both sides' positions.
* Factors like piece activity, pawn structure, passed pawns and other non-material considerations also matter in any given position.

I would therefore recommend using the following rules of thumb instead of exact point values:

* B ~ N (depends)
* N/B slightly \> P
* B+B \> 2 minors
* R \> N/B
* R ~ N/B + P
* R \> P+P
* R \< B+N
* Q somewhere between B+N and R+B+N+P
> 10 votes

---
Tags: point-value, atomic-chess
---


# Question
Title: Are aggressive attacking and tactical playeing the same?
What's the difference? Both look same to me.

# Answer
They are related, but probably not the same. If you play an opening like the King's Indian you are probably an aggressive, attacking player, but you may rely more on the understanding of the position than on tactical tricks.

Similarly, there are certain types of position where accurate calculation is required but with defensive purposes.

Aggressive and attacking are probably harder to distinguish, though!
> 10 votes

---
Tags: tactics, attack, aggressive-play
---


# Question
Title: What percentage of the time does White win in the Lomonosov tablebase?
Studies show a slight advantage for White for having the first move. In the tablebase of trillions of 7-piece endgames, **with White to move**, how many of **those** endgames end up as wins, how many as losses, and how many as draws for White? And what are the numbers for 6, 5, 4, etc piece endgames?

# Answer
> 12 votes
As I do not have access to the full Lomosonov tablebases, here is an answer based on the Syzygy tablebases, which are available online in machine-readable format. I interpret your question as "how often does the **side to move** win, lose or draw". As the Syzygy tablebases only include positions where White has material advantage, we have to add the statistics with White to move to the statistics with Black to move.

## You are going to be disappointed

It seems that there are actually more positions in which the side to move loses. The reason seems to lie in the positions with large material imbalance. For example, consider KQQQQQvK. If you check that link, you will see that:

* with **White to move**, there are **37 099 315 080** winning positions for White (see "histogram":"white":"wdl":"2", the format is explained here)
* with **Black to move**, there are **334 280 290 500** winning positions for White (losing positions for Black), which is about 9 times more! (see "histogram":"black":"wdl":"-2")

The reason for this is that, in KQQQQQvK, most of the positions are checks or checkmates. These positions are legal with Black to move, but illegal with White to move. This strongly biases the statistics to the point that the non-moving side (White) actually has more winning positions than the moving side.

I wrote a Python program to count the wins, draws and loses of the side to move for 3 to 7 pieces. Here are the results. In the spirit of open source/reproducible research, the source code is also included below. As these results are somewhat surprising, I will be happy to be informed of possible mistakes I may have made.

```
3- to 7-man Syzygy tablebases
Total positions: 945907910147154
Side to move loses: 439240886147124 (46.4359%)
Side to move loss saved by 50-move rule: 1405811609374 (0.1486%)
Draws: 124655757593757 (13.1784%)
Side to move win saved by 50-move rule: 1511382741156 (0.1598%)
Side to move wins: 379094072055743 (40.0773%)

3-man Syzygy tablebases
Total positions: 367868
Side to move loses: 99222 (26.9722%)
Side to move loss saved by 50-move rule: 0 (0.0000%)
Draws: 166126 (45.1591%)
Side to move win saved by 50-move rule: 0 (0.0000%)
Side to move wins: 102520 (27.8687%)

4-man Syzygy tablebases
Total positions: 143702885
Side to move loses: 48712335 (33.8980%)
Side to move loss saved by 50-move rule: 0 (0.0000%)
Draws: 45850555 (31.9065%)
Side to move win saved by 50-move rule: 0 (0.0000%)
Side to move wins: 49139995 (34.1956%)

5-man Syzygy tablebases
Total positions: 32612482961
Side to move loses: 12895319023 (39.5411%)
Side to move loss saved by 50-move rule: 38951980 (0.1194%)
Draws: 7248043033 (22.2248%)
Side to move win saved by 50-move rule: 33205648 (0.1018%)
Side to move wins: 12396963277 (38.0129%)

6-man Syzygy tablebases
Total positions: 6170694290902
Side to move loses: 2634258815181 (42.6898%)
Side to move loss saved by 50-move rule: 8110268813 (0.1314%)
Draws: 1075100392347 (17.4227%)
Side to move win saved by 50-move rule: 7817500373 (0.1267%)
Side to move wins: 2445407314188 (39.6294%)

7-man Syzygy tablebases
Total positions: 939704459302538
Side to move loses: 436593683201363 (46.4607%)
Side to move loss saved by 50-move rule: 1397662388581 (0.1487%)
Draws: 123573363141696 (13.1502%)
Side to move win saved by 50-move rule: 1503532035135 (0.1600%)
Side to move wins: 376636218535763 (40.0803%)

```

## Source code

```
import json
import numpy as np

fd=open('stats.json')

wdl_keys=('-2', '-1', '0', '1', '2')
wdl=np.zeros((5, 5), dtype=np.uint)

data=json.load(fd)

for key, value in data.items():
    n_pieces=len(key)-1
    for i_wdl in range(5):
        # add WDL data for White to move
        wdl[n_pieces-3, i_wdl]+=value['histogram']['white']['wdl'][wdl_keys[i_wdl]]
        # add WDL data for Black to move
        wdl[n_pieces - 3, i_wdl] += value['histogram']['black']['wdl'][wdl_keys[i_wdl]]

total_positions=np.sum(wdl)
total_wdl=np.sum(wdl, axis=0)
print('3- to 7-man Syzygy tablebases')
print('Total positions: {:d}'.format(total_positions))
print('Side to move loses: {:d} ({:.4f}%)'.format(total_wdl[0], 100.0*float(total_wdl[0])/float(total_positions)))
print('Side to move loss saved by 50-move rule: {:d} ({:.4f}%)'.format(total_wdl[1], 100.0*float(total_wdl[1])/float(total_positions)))
print('Draws: {:d} ({:.4f}%)'.format(total_wdl[2], 100.0*float(total_wdl[2])/float(total_positions)))
print('Side to move win saved by 50-move rule: {:d} ({:.4f}%)'.format(total_wdl[3], 100.0*float(total_wdl[3])/float(total_positions)))
print('Side to move wins: {:d} ({:.4f}%)'.format(total_wdl[4], 100.0*float(total_wdl[4])/float(total_positions)))

positions=np.sum(wdl, axis=1)
for i_pieces in range(5):
    print()
    print('{:d}-man Syzygy tablebases'.format(i_pieces+3))
    print('Total positions: {:d}'.format(positions[i_pieces]))
    print('Side to move loses: {:d} ({:.4f}%)'.format(wdl[i_pieces, 0], 100.0 * float(wdl[i_pieces, 0]) / float(positions[i_pieces])))
    print('Side to move loss saved by 50-move rule: {:d} ({:.4f}%)'.format(wdl[i_pieces, 1], 100.0 * float(wdl[i_pieces, 1]) / float(positions[i_pieces])))
    print('Draws: {:d} ({:.4f}%)'.format(wdl[i_pieces, 2], 100.0 * float(wdl[i_pieces, 2]) / float(positions[i_pieces])))
    print('Side to move win saved by 50-move rule: {:d} ({:.4f}%)'.format(wdl[i_pieces, 3], 100.0 * float(wdl[i_pieces, 3]) / float(positions[i_pieces])))
    print('Side to move wins: {:d} ({:.4f}%)'.format(wdl[i_pieces, 4], 100.0 * float(wdl[i_pieces, 4]) / float(positions[i_pieces])))

```

---
Tags: endgame, statistics, tablebases
---


# Question
Title: How often do grandmasters fail to mate soon when mate in five or less is possible?
The recent question, How often do grandmasters miss checkmate? , turned out to be a bit broad. This question asks about a simple subset of that one, which I hope can be answered with some precision.

How often do grandmasters miss an opportunity for a mate in five or less? Since it matters little if the exact move sequence is followed,I will allow a slightly longer series of moves to be considered not a miss. Consider it a "miss" if twice as many moves (ten) are played before the win,or if there is no win.

Consider classical, over-the-board games.

# Answer
Let me count the reasons.... It all depends!

And there is no way to answer your question exactly.

GMs do not play by your arbitrary evaluation method. They play to win or possibly to not lose. While their tactics are usually very good , missing a mate in 5 while winning the game is more important to them.

Depending on how they feel, how much clock time they have, whether they fear their might be a killer move by opponent they missed if they tried, they will go with what they see as the clearest win no matter how many moves (unless time pressure requires them to win faster as in a SD game with a long difficult endgame vs somehow winning it faster like that mate in 5).
> 6 votes

---
Tags: checkmate, statistics, grandmaster
---


# Question
Title: Simplest plan to stop my queen from getting trapped
It's reasonably common for my opponents in blitz to fall into the following trap in the opening.

```
[FEN ""]
1. e4 Nc6 2. d4 e5 3. d5 Nce7 4. f4 Ng6 5.f5 Qh4+ 6. g3 Qxe4+ 7. Qe2 Qxh1 8. Nf3

```

This position should be an easy win, but I find myself often getting in trouble with my queen getting trapped after white develops and castles queenside. Is there a simple plan to safely extract the queen? I don't mind giving back a minor piece to simplify the position.

# Answer
> 10 votes
I don't think that this is an easy win at all. In fact it is not clear who is the trapper and who is the "trappee". To close the trap, White has no need even to develop. He can simply play Kd2!! followed by Bg2. This refutes, for example, N6e7.

The only defence that I can see starts with 8..e4! 9.Qxe4+ Kd8! 10.fxg6 hxg6. Without analysing further White has a lot of compensation. However, this is all moot. Instead of the adventurous 7..Qxh1, Black has simply 7..Qxf5 with two extra Pawns and no real problems.

# Answer
> 2 votes
cant make comments yet: Do you want to keep the Queen or do you want to have a winning position?

```
 [fen ""]

 1. e4 Nc6 2. d4 e5 3. d5 Nce7 4. f4 Ng6 5. f5 Qh4+ 6. g3 Qxe4+ 7. Qe2 Qxh1 8. Nf3 *

```

Leaves you with Rook, Knight and a Rook for the Queen.

---
Tags: opening-traps, nimzowitsch-defense
---


# Question
Title: Seeking GM-level coverage of a typical pawn structure
I was wondering if there is a top level coverage of plans for Black in the below pawn structure:

```
[fen "8/pp3ppp/2p2p2/8/3P4/8/PPP2PPP/8 w - - 0 1"]

```

Or this one:

```
[fen "8/pp3ppp/2p2p2/8/2PP4/8/PP3PPP/8 w - - 0 1"]

```

I know similar ones arise from Caro-Kann, but have also seen it in many other openings where White plays Bxf6.

Computer claims equality, or a slight edge, but I would like to "hear an opinion" from top GMs if possible.

# Answer
Vallejo has a great series (Spanish only) in chess24 about the Caro-Pirc, which covers this particular structure. Note that the dynamics of positions with those two pawn structures are probably very different from one another (a ...c5 break by Black would have a very different impact on each case. Similar ofr the pressure on the semi-open d file)

"Engine claims equality" does not make much sense when referring to the pawn structure itself, since many different factors will determine the actual evaluation of a given position.
> 6 votes

---
Tags: pawn-structure
---


# Question
Title: As we come out of lockdown, how much FIDE rated chess was played in June 2020?
I asked a similar question about chess during lockdown. Now that some countries are coming out of lockdown and chess is resuming FIDE has published data for June.

NB I looked at May data and as far as I could tell FIDE just repeated the April tournament data with updates from federations for corrections to previous data and new registrations but no new tournament data. The June data does contain new tournament data.

What does the June data tell us about chess coming out of lockdown?

Specifically:

1. How many games (or half-games) of FIDE rated chess (standard, rapid and blitz) were played in June, by country?
2. How many players from which countries played FIDE rated chess (standard, rapid and blitz) in June?
3. How does this compare with the same data for June 2019 for total game counts and total player counts? (Break down by country would be too much)

These statistics should give us some idea what progress is being made and how much further we have to go to get back close to normal.

# Answer
I downloaded the latest July 2020 rating list and loaded the data into my database and ran a few queries.

First one to show the number of players who played standard, rapid or blitz per federation sorted by standard players descending. I also included the number of active players in the federation to give an idea of which federations were more active. I excluded federations where the number of players playing was less than 4 on the grounds that they were likely living and playing in other federations. That still gave an impressive list of 33 federations which look as if they are back playing chess.

Code ActivePlayers Standard Rapid Blitz
CZE 10838 2543 17 16
SVK 6704 1357 54 0
SWE 5331 449 1 0
CRO 7654 351 14 54
GRE 20595 338 0 0
DEN 5496 134 0 0
SRB 7436 112 75 69
ISR 4104 96 0 1
NOR 5165 93 0 0
POL 21407 85 38 40
HUN 7928 80 6 1
LAT 2758 69 86 99
MNE 822 69 0 0
SUI 3170 66 6 1
BUL 3038 60 1 0
ISL 1842 36 54 60
FIN 1308 36 0 0
LTU 3813 32 59 22
SLO 4320 31 44 82
NCA 712 23 0 39
GER 22613 22 1 2
EST 1517 22 0 6
BEL 5602 14 0 1
RUS 68077 8 3 1
ITA 18332 6 10 1
AUT 5640 4 2 0
UKR 11853 4 2 22
FRA 55783 4 1 2
TUR 36523 4 0 0
ESP 45444 4 0 1
IRQ 1515 2 47 0
THA 1082 0 14 0
KGZ 2688 0 10 0

What stands out as quite remarkable in that list is that over 20% of Czech and Slovak active players played last month!

Next a query to show the sum of standard players, rapid players and blitz players.

That gave for June 2020:

Standard = 6171
Rapid = 551
Blitz = 524

By comparison for June 2019:

Standard = 35708
Rapid = 18712
Blitz = 10569

Two things stand out

1. More than 60% of standard chess played in June 2020 was played in the Czech and Slovak republics
2. Standard accounted for far more of the chess played in June 2020 than in June 2019.

Next a query to show the sum of standard+rapid+blitz games per federation. Here is the top 20. Click on the federation link to see the list of tournaments reported for that federation in June 2020:

Code Total Standard Rapid Blitz
CZE 16002 7899 100 204
SVK 4848 2424 132 0
LAT 2625 599 672 1427
SRB 2097 435 560 1227
CRO 2074 719 80 636
GRE 1834 917 0 0
SLO 1663 138 300 1387
POL 1221 441 401 339
HUN 1213 601 8 11
SWE 1108 554 7 0
ISL 869 93 330 683
NOR 776 388 0 0
DEN 754 377 0 0
LTU 714 230 404 254
BUL 708 354 9 0
MNE 606 303 0 0
NCA 575 167 0 241
SUI 503 246 36 11
EST 354 144 0 66
ISR 319 155 0 9

The sum of games for June 2020:

Standard = 17562
Rapid = 3774
Blitz = 6844

For comparison the same figures for June 2019:

Standard = 247057
Rapid = 148693
Blitz = 121143

Digging deeper into the data for the Czech republic, you can see the tournaments reported for
June 2020 for the Czech Republic here and for
June 2019 for the Czech Republic here

43 Czech tournaments reported in June 2020 against 21 in June 2019. It looks very much like in June they aimed to catch up with all the matches and tournaments they missed during the lockdown.
> 3 votes

---
Tags: rating, fide, statistics
---


title: Beginners question: The double pawn

text:
# Question
Title: Beginners question: The double pawn
*Question:* Are there rules of thumb that every chess player should know about the double pawns?

# Answer
Since it hasn't been mentioned yet, I will also put that double pawns loses control of the squares infront of them.
> 1 votes

# Answer
Bad: They can't defend each other like adjacent pawns can.

Good: They give you an extra open file for your rooks.

Usually the bad outweighs the good, but there are a zillion exceptions. Most beginners are overly afraid of having doubled pawns.
> 8 votes

# Answer
Isolated double pawns are considered as weakness in general except rare occasions where they play a crucial role in defending important squares. There is no general rule of pawn islands with double pawns close to the centre and each case should be analyzed separately. These pawns are not considered as a weakness since they can either establish a strong centre or can be un-doubled easily.
> 4 votes

# Answer
There are two important things to note about doubled pawns.

1: They are good at defense.

2: They are bad at moving forward.

```

[fen "8/5p2/6p1/ppp5/5PP1/1P4P1/1P6/8 w - - 0 1"]

```

In this diagram from *A practical guide to Rook endgames* by Nikolay Minev. The author shows that on the kingside the extra doubled pawn is a weakness because White is not able to break through at any point. Highlighting their inability to play aggressively.

On the queenside however, the black pawns can get attacked more easily. What's more, when black plays either ...c4 or ...a4 white exchanges a pawn and black is left with weaker split pawns as a result. This underlines the defensive capability of doubled pawns.

So go forth and double your pawns if you know you are defending on that side!
> 2 votes

# Answer
Excellent discussion of doubled pawns by Gserper on chess.com Nov 2012. Botvinnik was first World-class player who liked doubled pawns. Kasparov noted Botvinnik loved to grab the center and was not hesitant to use doubled pawns to achieve that. He doubled pawns on central files, viz. c, d, e, f , never on extreme flank files. He usually advanced at least the lead pawn early. The pawns were used to control central squares and support outposts.

If **your pawns** may be doubled :

1. Avoid on flank files
2. Quite valuable to maintain an adjacent pawn.
3. Advance at least the lead pawn as soon as possible.
Cramped if they remain on 2nd & 3rd ranks.
4. Use to support outposts. Occupy adjacent open files with rooks.
5. Caution trading down. Doubled pawns weak in endgame.

If **opponents pawns** are doubled :

1. Blockade with pawn or piece ( Nimzowitsch )
2. Attack either pawn that is unguarded.
3. Don't hesitate to trade down.
> 2 votes

# Answer
Yes, there is a rule(s) of thumb that every chess player should know about doubled pawns.

> Avoid double pawns in pawn endings.

Double pawns prevent the ability for a pawn majority to create passed pawns in a pawn ending against perfect play. This is because the side without a doubled pawn will be able to create a passed pawn with their majority and the side with the doubled pawn will not (against perfect play).

Whereas most rule(s) of thumb concerning doubled pawns aren't necessarily critical (e.g. double pawns can open files, double pawns can strengthen influence in the center (see Botvinnik-Sorokin 1931), etc), not following the above rule of thumb can lose you the game. Therefore, every chess player should know this rule of thumb about doubled pawns.
> 0 votes

---
Tags: theory, strategy, beginner, doubled-pawn
---


title: Fairy chess: KNNvK

text:
# Question
Title: Fairy chess: KNNvK
I just wondered: can K + 2 nightriders force a mate against bare K? (A nightrider can make an unlimited number of knight moves in any direction - it cannot change direction partway through its move.)

# Answer
The Wikipedia page on the Nightrider contains an example from T. R. Dawson, published in the British Chess Magazine in 1925, where a king, knight and nightrider force a mate against a lone king. I guess a similar procedure would work for two nightriders, but you have to be a little more careful to avoid stalemate.
> 8 votes

# Answer
See my book Fairy chess endings on an n x n chessboard (2017), p. 345 and 414. The ending of king + two nightriders against bare king on board 8x8 is won for the stronger side and the longest win has 22 moves. Also the ending king + knight + nightrider against king is a general win, see page 395.
> 2 votes

---
Tags: chess-variants, knight-endgame, unorthodox-pieces
---


# Question
Title: Could two kings force checkmate against a lone king?
I was looking at minimal combinations of material needed to force checkmate (K+R, Q+B, R+N+N, etc). You end up with a sort of threshold of how much material is needed, and that sort of assigns a strength to the king. But that made me wonder if K+K is sufficient material to force checkmate. Obviously this is normally impossible, but in the hypothetical endgame where white has two kings and black has one (and make the obvious loosenings of the restrictions on moving into check), could the two kings force checkmate against the one king?

Alternatively, one could think of it as white having a king and a fairy chess piece that moves exactly like a king. Is this enough material to force checkmate?

# Answer
If these are two real kings, it is not possible. This is because one requirement of checkmate is that the black king is in check which cannot be achieved with any of the white kings, since it would put the white king in check.

If you say that white has only one king and a nonstandard chess piece that moves exactly like a king (i.e. this piece can be put next to the enemy king), then yes, it seems possible and quite easy to mate the black king.

For example, put the king and “king” for on c3 and f3, and the black king on d5. As you can see the two kings almost cover the whole 4th rank. Pushing the black king to the side of the board and into the corner is quite easy, e.g. if black starts with 1... Ke5, 2. Kc4 Kd6 3. Kf4 Ke6 4. Kc5. Once you have the black king around the corner you put white's real king on c6 and give checkmate with the "king", the piece that moves like a king but really isn’t one, on g7.

Here is a demonstration of said strategy in the replayer. Remember, white’s standard king is on b2 and their other “king” is on f3!

```
[FEN "8/8/8/3k4/8/5K2/1K6/8 w - - 0 1"]

1. Kc3 Ke5 2. Kc4 Kd6 3. Kf4 Ke6 4. Kc5 Kd7 5. Kf5 Ke7 6. Kc6 Ke8 7. Kf6 Kd8 8. Kf7 Kc8 9. Ke8 Kb8 10. Kd8 Ka8 11. Kb6 Kb8 12. Kdc7+ Ka8 13. Kcb7#

```
> 20 votes

# Answer
A King and a Man (or commoner; i.e., a non-royal King) can mate a lone King. The longest distance to mate on a standard 8x8 board is 18 moves.

The result quoted above was obtained by H.G. Muller in 2008, see this coment on chessvariants.com: http://www.chessvariants.com/index/listcomments.php?id=28770
> 18 votes

# Answer
Non-royal king is a combination of \[0,1\] leaper (wazir) and \[1,1\] leaper (fers) and in fairy chess called a erlking. About erlking, see my book Fairy chess endings on an n x n chessboard (2017), page 545.

The ending of king + erlking against bare king on board 8x8 is won for the stronger side and the longest win has 18 moves. Also the ending of two erlkings against king is a general win and the longest win has 16 moves.
> 4 votes

---
Tags: endgame, checkmate, chess-variants, kings, unorthodox-pieces
---


title: Why is Qf3 better than Nf3?

text:
# Question
Title: Why is Qf3 better than Nf3?
I am training with an app and have played about 10 games in my life, most years apart. However, now I became interested in the game.

I have this situation:

```
[FEN "4kbnr/p2npppp/1p6/4P3/q2N4/P6P/1PPP1P1P/RNBQ1RK1 w k - 0 1"]

```

I was going to move Nf3, thereby moving the knight to (temporary) safety, protecting the e5 pawn, and having the queen additionally protect knight. However, the app wants me to make the move Qf3.

The only advantages I see to that are d eveloping the queen and having a more versatile queen instead of a knight control centre

But it seems like this should easily cost me the knight. So, can you help me realise why the app is right?

# Answer
It comes with the threat of **Qa8+**, which forces black to return the knight.

And white is up material, so exchanges are good.
> 22 votes

# Answer
Welcome Ludi!

As RemcoG points out, Qf3!

This is an example of a zwischenzug or "intermediate or interpolated move". Often a surprise move or an unexpected move. Black thinks you are forced to attend to your attacked knight, but you have a surprise in store!

But, how would you come to consider such moves?

Your knight is attacked as you point out, so the first thought is to either defend it or to move it to safety.

However a useful thought pattern in chess is: I have found a good move, but is there an even better one?

This skill comes about from developing sight-of-the-board.

You can develop this skill by practise. A quick scan should allow you to notice several general things:

1. You are the exchange and two pawns up.
2. Your king is a bit exposed but your opponent does not have any effective threat against you king.
3. Your opponent's king is in a precarious position: a check delivered on a8 or c8 by either a rook or queen would be checkmate! Any threat to do this cannot be ignored so one thought is: can any of my pieces attack either of those squares? It leads you to Qf3!

This general scan of the board routinely can be done when it is your opponent's move. Then when it is your turn to move you already have a useful framework to decide on a specific move.
> 10 votes

# Answer
Qf3 threatens the king with Qa8 on the next move. Your oppenent could capture your knight and defend with Nb8 afterwards, but this will cost him a knight as well (and also a bishop or an exchange of queens), so he won't capture your knight.

Always keep in mind that there are four possible defences if one of your pieces is under attack:

1. Move the piece to safety, preferably somewhere where it's still dangerous. Don't retreat.
2. If the attacking piece is more valuable than yours, back it up and make it an exchange.
3. Move a cheaper piece into the line of fire and block the attack, preferably making it an exchange as well.
4. Press and unrelated attack, which forces the opponent to defend his pieces instead of attacking yours.

In your example, all four defences are available. You can move the knight to safety with Nf3, back it up with c2, block the attack with b3 or press an unrelated attack with Qf3. Qf3 is the best option, because it puts you in a great position, forces the opponent to waste a tempo defending his king, and you can still protect your knight with c2 of b3 afterwards. Retreating the knight to Nf3 is the worst option.
> 3 votes

# Answer
1. a general rule is to solve problems with devolopment, here your problem is your N is under attack and you threat QA8+
2. the threat of QA8 is very dangerous and is winning.
> 1 votes

---
Tags: analysis, beginner
---


# Question
Title: Why is Bd6 better than Be7, Bc5 and Bb4?
```
[FEN "r1bqkb1r/p4ppp/2p2n2/3p4/8/2N5/PPP1BPPP/R1BQK2R b KQkq - 1 9"]

```

Be7 protects knight from getting pinned, Bc5 pins the pawn on f2 after Whites, castles, and Bb4 pins the knight.

Whats logic behind Bd6? (It also can't be a battery in future via Qc7 because of 1... Kh1 2. Bxh2 g3, and the bishop will be trapped.)

# Answer
> 9 votes
Part of the problem with Bc5 is that they can respond with Na4, which threatens the bishop and grabs the tempo. Be7 isn't great because its range is inhibited by the knight and it impedes the kingside rook's power on the e file after you castle. Bd6 is nice because it is protected by the pawns, the bishop can be retreated to b8 or c7 while still controlling either of the second longest diagonals. I'm a 1500 rated player, so take that into account.

# Answer
> 5 votes
Bd6 is the most active square. No, there's not an immediate threat but it does attack h2 which could turn into something later.

Be7 is too passive. It's not smart to "protect against pins" that haven't even happened yet. There's lots of unpin combinations that actually lead to the pinning side being worse. Also, white can't really capitalize on a pin since the knight can't come to e4 or d5. Lastly, the bishop on e7 blocks the open e-file which could turn into a strong attack if white doesn't castle quickly.

Bc5 isn't that bad but after white castles the bishop isn't doing much.

Bb4 doesn't do much either. Normally you would play Bb4 to control the e4 square but white isn't threatening anything there. You could double the c-pawns but that doesn't really do anything. White will just play c4 at some point and end up with a slightly better position because of the 2 bishops.

# Answer
> 5 votes
Bd6 has two big advantages that haven't been mentioned. The first is that it protects the b8 square for your rook. Your rook naturally belongs on the half-open file, and White really wants to play Bf4 to keep you from doing that. (You can put your bishop on d6 later if that happens, but you've wasted a tempo and exchanging bishops makes it easier for the white knight to establish itself at c5.) The second is that, later in the game, e5 will likely be a very powerful square for the bishop. (Or sooner, if White tries Bg5.)

# Answer
> 4 votes
e7 is a very passive square for the bishop. Since White is expected to castle on the kingside, there is no reason not to prefer ...Bd6 over ...Be7. The pin on the f6 knight is not too much of a problem precisely because a ..Bc7, ..Qd6 continuation is always on the table.

...Bb4 has a similar problem as ...Be7 because after 0-0 the bishop is doing nothing on b4 (exchanging it for the knight would not be a great idea)

This leaves us with the options ...Bd6 and ...Bc5. I don't have a clear idea of which one is better but ...Bd6 seems more natural to me for an attack on h2. I guess ...Bd6 allows Black to push the central pawns if needed, but leaving them on c6 and d5 is probably best. I don't think the pin on the f2 pawn is that relevant as White will probably never try to play f4 in this position. Anyway I wouldn't say ...Bc5 is an inferior move.

# Answer
> 1 votes
1. when the pawns are on c6 and d5 that means that your dark bishop is your best bishop
2. after c6 and d5 the dark square around them are weak and the bishop takes control of those square.
3. the bishop on e7 is not controling alot of square on c5 and b4 it can get kicked around with a3 b4 or Na4. I am 2100 take that into account.

---
Tags: analysis, bishops, pins, bad-bishop, candidate-move
---