Checkmate (frequently shortened to mate) is a situation in chess (and in other boardgames of the chaturanga family) in which one player's king is threatened with capture (in check) and there is no way to meet that threat. Delivering checkmate is the ultimate goal in chess: a player who is checkmated loses the game (the king is never actually captured – the game ends as soon as the king is checkmated). In practice, most players resign an inevitably lost game before being checkmated.
If a king is under attack but the threat can be met, then the king is said to be in check, but is not in checkmate. If a player is not in check but has no legal move (that is, no valid move that would not put the king in check), the result of the game is stalemate, and the game ends in a draw. (See Rules of chess.)
Origin of the word
The term checkmate
is an alteration or Hobson-Jobson
of the Persian
phrase "Shāh Māt" which means, literally, "the King is ambushed" (or "helpless" or "defeated"). It does not literally mean "the King is dead", although that is a common misconception, as chess reached Europe via the Islamic world, and Arabic māta
مَاتَ means "died", "is dead".
Moghadam traced the etymology of the word mate. It comes from a Persian verb mandan, meaning "to remain", which is cognate with the Latin word manco. It means "remained" in the sense of "abandoned" and the formal translation is "surprised", in the military sense of "ambushed" (not in the sense of "astonished"). So the king is in mate when he is ambushed, at a loss, or abandoned to his fate.
The term checkmate has come to mean in modern parlance an irrefutable and strategic victory.
A checkmate may occur in only two moves with all of the pieces
still on the board
(as in Fool's mate
, in the opening
phase of the game), in a middlegame
position (as in the Game of the Century
between Donald Byrne
and Bobby Fischer
), or after many moves with as few as three pieces in an endgame
Two major pieces
Two major pieces
) can easily force checkmate on the edge of the board, even without the help of their king. The process is to put the two pieces on adjacent ranks
and gradually force the king to the side of the board, where one piece keeps the king on the edge of the board while the other delivers checkmate .
In the first diagram, White checkmates easily by forcing the black king to the edge a rank at a time or a file at a time:
- 1. Qg5+ Kd4
- 2. Rf4+ Ke3
- 3. Qg3+ Ke2
- 4. Rf2+ Ke1
- 5. Qg1# (second diagram) .
The checkmate with two queens or with two rooks is similar .
Checkmate can be forced even away from the edge of the board with two rooks and a king, or with a queen, rook, and king, while two queens are able to force checkmate in the center without the help of the king.
Here are the common fundamental checkmates when one side has only his king
and the other side has only the minimum material
needed to force checkmate, i.e. (1) one queen
, (2) one rook
, (3) two bishops
on opposite-colored squares, or (4) a bishop and a knight
. The king must help in accomplishing all of these checkmates. If the superior side has more material, checkmates are easier .
The checkmate with the queen is the most important, but it is also very easy to achieve. It often occurs after a pawn has queened. The next most important one is the checkmate with the rook, and it is also very easy to achieve. The checkmates with the two bishops and with a bishop and knight are not nearly as important, since they only occur infrequently. The two bishop checkmate is fairly easy to accomplish, but the bishop and knight checkmate is difficult and requires precision.
King and queen
The first two diagrams show representatives of the basic checkmate positions with a queen
, which can occur on any edge of the board. Naturally, the exact position can vary from the diagram.
In the first of the checkmate positions, the queen is directly in front of the opposing king and the white king is protecting its queen. In the second checkmate position, the kings are in opposition
and the queen mates on the rank
) of the king. See Chess/The Endgame
for a demonstration of how the king and queen versus king mate is achieved.
With the side with the queen to move, checkmate can be forced in at most ten moves from any starting position, with optimal play by both sides, but usually fewer moves are required. . In positions in which a pawn has just promoted to a queen, at most nine moves are required . In this position, White checkmates by confining the black king to a rectangle and shrinking the rectangle to force the king to the edge of the board:
- 1. Qf6 Kd5
- 2. Qe7 Kd4
- 3. Kc2 Kd5
- 4. Kc3 Kc6
- 5. Kc4 Kb6
- 6. Qd7 Ka6
- 7. Qb5+ Ka7
- 8. Kc5 Ka8
- 9. Kc6 Ka7
- 10. Qb7# .
The superior side must be careful to not stalemate the opposing king, whereas the defender would like to get into such a position. There are two general types of stalemate positions that can occur, which the winning side must avoid .
King and rook
The first diagram shows the basic checkmate position with a rook
, which can occur on any edge of the board. The black king can be on any square on the edge of the board, the white king is in opposition to it, and the rook can check from any square on the rank or file (assuming that it can not be captured). The second diagram shows a slightly different position where the kings are not in opposition but the defending king must be in a corner.
With the side with the rook to move, checkmate can be forced in at most sixteen moves from any starting position . Again, see Chess/The Endgame for a demonstration of how the king and rook versus king mate is achieved.
In this position, White checkmates by confining the black king to a rectangle and shrinking the rectangle to force the king to the edge of the board:
- 1. Kd3+ Kd5
- 2. Re4 Kd6
- 3. Kc4! Kc6
- 4. Re6+ Kc7
- 5. Kc5 Kd7
- 6. Kd5 Kc7
- 7. Rd6 Kb7
- 8. Rc6 Ka7
- 9. Kc5 Kb7
- 10. Kb5 Ka7
- 11. Rb6 Ka8
- 12. Kc6 Ka7
- 13. Kc7 Ka8
- 14. Ra6# (second checkmate position)
There are two stalemate positions to watch out for: :
King and two bishops
Here are the two basic checkmate positions with two bishops
(on opposite-colored squares), which can occur in any corner. (Two bishops or more on the same color cannot checkmate.) The first is a checkmate in the corner. The second one is a checkmate in a side square next to the corner square. With the side with the bishops to move, checkmate can be forced in at most nineteen moves .
It is not too difficult for two bishops to force checkmate, with the aid of their king. Two principles apply:
- The bishops are best when they are near the center of the board and on adjacent diagonals. This cuts off the opposing king.
- The king must be used aggressively, in conjunction with the bishops.
In the position from Seirawan, White wins by first forcing the black king to the side of the board, then to a corner, and then checkmates. It can be any side of the board and any corner. The process is:
- 1. Ke2 Ke4 (Black tries to keep his king near the center)
- 2. Be3 Ke5 (forcing the king back, which is done often)
- 3. Kd3 Kd5
- 4. Bd4 Ke6
- 5. Ke4 Kd6 (Black tries a different approach to stay near the center)
- 6. Bc4 (White has a fine position. The bishops are centralized and the king is active.)
- 6... Kc6 (Black avoids going toward the side)
- 7. Ke5 Kd7 (Black is trying to avoid the a8 corner)
- 8. Bd5 (keeping the black king off c6)
- 8... Kc7
- 9. Bc5 Kd7
- 10. Bd6! (an important move that forces the king to the edge of the board)
- 10... Ke8 (Black is still avoiding the corner)
- 11. Ke6 (now the black king cannot get off the edge of the board)
- 11... Kd8
- 12. Bc6 (forcing the king toward the corner)
- 12... Kc8 (Black's king is confined to c8 and d8. The white king must cover a7 and b7)
- 13. Kd5 (13. Ke7? is stalemate)
- 14. Kc5 Kc8
- 15. Kb6 Kd8 (Now White must allow the king to move into the corner)
- 16. Bc5 Kc8
- 17. Be7! (an important move that forces the king toward the corner)
- 17... Kb8
- 18. Bd7! (the same principle as the previous move)
- 18... Ka8
- 19. Bd8 (White must make a move that gives up a tempo. This move is such a move, along with Bc5, Bf8, Be6, or Ka6.)
- 19... Kb8
- 20. Bc7+ Ka8
- 21. Bc6#, as in the first diagram in this section .
Note that this is not the shortest forced checkmate from this position. Müller and Lamprecht give a fifteen move solution, however it contains an inaccurate move by Black (according to endgame tablebases) . With optimal play by both sides, checkmate in this position requires seventeen moves. The longer variation is more instructive.
King, bishop and knight
This checkmate is the most difficult to force, because these two pieces cannot form a linear barrier to the enemy king from a distance. Also, the checkmate can be forced
only in a corner that the bishop controls.
Here are the two basic checkmate positions with a bishop and a knight, or the bishop and knight checkmate. The first position is a checkmate by the bishop, with the king in the corner. The second position is a checkmate by the knight, with the king in a side square next to the corner. Alternatively, the knight can be on c6 or d7 in the second position.
With the side with the bishop and knight to move, checkmate can be forced in at most thirty-three moves from any starting position , except those in which the defending king is initially forking the bishop and knight and it is not possible to defend both. However, the mating process requires accurate play, since a few errors could result in a draw either by the fifty move rule or stalemate.
Opinions differ as to whether or not or not a player should learn this checkmate procedure. James Howell omits the checkmate with two bishops in his book because it rarely occurs but includes the bishop and knight checkmate. Howell says that he has had it three times (always on the defending side) and that it occurs more often than the checkmate with two bishops . On the other hand, Jeremy Silman includes the checkmate with two bishops but not the bishop plus knight checkmate because he has had it only once and his friend John Watson has never had it . Silman says
...mastering it would take a significant chunk of time. Should the chess hopeful really spend many of his precious hours he's put aside for chess study learning an endgame he will achieve (at most) only once or twice in his lifetime?"
Two or three knights
It is impossible to force
checkmate with a king and two knights, although checkmate positions are possible (see the first diagram). In the second diagram, if Black plays 1... Ka8?
White can checkmate with 2. Nbc7#
, but Black can play 1... Kc8
and escape the threat. The defender's task is easy — he simply has to avoid moving into a position in which he can be checkmated on the next move, and he always has another move available in such situations .
In the third diagram, White can play 1. Nc6+ Ka8, but now if White plays 2. Nb5 threatening 3. Nc7#, Black is stalemated. It is sometimes possible to force checkmate with two knights against a pawn, because in some positions, having a pawn removes this stalemate defence.
Three knights and a king can force checkmate against a lone king within twenty moves . These situations are generally only seen in chess problems, since one or more of the knights must be a promoted piece, and there is very rarely a reason (e.g., avoidance of stalemate) to promote a pawn to anything other than a queen (see underpromotion).
Under some circumstances, two knights and a king can force checkmate against a king and pawn (or rarely more pawns). The winning plan, quite difficult to execute in practice, is to blockade the enemy pawn(s) with one of the knights, maneuver the enemy king into a stalemated position, then bring the other knight over to checkmate. (See Two knights endgame.)
Rare checkmate positions
In some rare positions it is possible to force checkmate with a king and bishop versus a king and pawn or a king and knight versus a king and pawn.
In the diagram showing Stamma's mate (named for Philipp Stamma
), White to move wins :
- 1. Nb4+ Ka1
- 2. Kc1 a2
- 3. Nc2#
White also wins if Black is to move first:
- 1. ... Ka1
- 2. Nc1 a2
- 3. Nb3#
This checkmate has occurred in actual games, see the game Nogueiras-Gongora
from the 2001 Cuban Championship
, which proceeded
- 81. Kc2 Ka1
- 82. Nc5 Ka2 (if 82... a2 then 83. Nb3#)
- 83. Nd3 (reaching the first position)
- 83... Ka1
- 84. Nc1 a2
- 85. Nb3#
Unusual checkmate positions
There are also positions in which a king and knight or can checkmate a king and a bishop, knight, or rook; or a king and bishop can checkmate a king with a bishop on the other color of squares, but the checkmate cannot be forced (see the diagrams for some examples). Nevertheless, it keeps these material
combinations from being ruled a draw
because of "insufficient mating material" or "impossibility of checkmate".
Articles on types of checkmates