Skewer (chess)
Encyclopedia
In chess
, a skewer (or X-ray attack
) is an attack upon two pieces in a line and is similar to a pin
. In fact, a skewer is sometimes described as a "reverse pin"; the difference is that in a skewer, the more valuable piece is in front of the piece of lesser or equal value. The opponent is compelled to move the more valuable piece to avoid its capture, thereby exposing the less valuable piece which can then be captured (see chess piece relative value). The long-range pieces (queen
, rook
, and bishop
) can skewer.
). In a relative skewer, the piece under attack is not a king, to the side being skewered is not obligated under the rules to move the piece.
is skewered by the black bishop. This is an absolute skewer, because the rules of chess compel White to get out of check (if possible). After White chooses one of the handful of legal moves available, Black will capture the white queen.
Because the skewer is a direct attack upon the more valuable piece, it is generally a much more powerful and effective tactic than the pin. The victim of a skewer often cannot avoid losing material (though it may be possible if, for example, either piece can give check, thereby forcing the skewering side to move out of check instead of being able to capture either piece, or if it is possible to move a less valuable piece in the way); the only question is which material will be lost. The skewer occurs less often than the pin in actual play. When it does occur, however, it is often decisive.
and Rafael Vaganian
, White sacrifices
a bishop to win a queen by a skewer. White has just moved 51. Be5+. If Black moves 51...Kxe5 to avoid the immediate loss of the queen, 52.Qc3+ wins the queen by a skewer. Black resigned in this position .
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
, a skewer (or X-ray attack
X-ray (chess)
In chess, the term X-ray or X-ray attack is sometimes used as a synonym for skewer. The term is also sometimes used to refer to a tactic where a piece either indirectly attacks an enemy piece through another piece or pieces or defends a friendly piece through an enemy piece.The second usage is...
) is an attack upon two pieces in a line and is similar to a pin
Pin (chess)
In chess, a pin is a situation brought on by an attacking piece in which a defending piece cannot move without exposing a more valuable defending piece on its other side to capture by the attacking piece...
. In fact, a skewer is sometimes described as a "reverse pin"; the difference is that in a skewer, the more valuable piece is in front of the piece of lesser or equal value. The opponent is compelled to move the more valuable piece to avoid its capture, thereby exposing the less valuable piece which can then be captured (see chess piece relative value). The long-range pieces (queen
Queen (chess)
The queen is the most powerful piece in the game of chess, able to move any number of squares vertically, horizontally, or diagonally. Each player starts the game with one queen, placed in the middle of the first rank next to the king. With the chessboard oriented correctly, the white queen starts...
, rook
Rook (chess)
A rook is a piece in the strategy board game of chess. Formerly the piece was called the castle, tower, marquess, rector, and comes...
, and bishop
Bishop (chess)
A bishop is a piece in the board game of chess. Each player begins the game with two bishops. One starts between the king's knight and the king, the other between the queen's knight and the queen...
) can skewer.
Details
Skewers can be broken down into two types: absolute and relative. In an absolute skewer, the king is in check so the check must be dealt with (under the rules of chessRules of chess
The rules of chess are rules governing the play of the game of chess. While the exact origins of chess are unclear, modern rules first took form during the Middle Ages. The rules continued to be slightly modified until the early 19th century, when they reached essentially their current form. The...
). In a relative skewer, the piece under attack is not a king, to the side being skewered is not obligated under the rules to move the piece.
Relative skewer
In this diagram, with Black to move, the black queen is skewered by White's bishop. To avoid capture of the queen, Black must move the queen, and on the next move, White can capture the rook. This is a relative skewer; Black is likely to move the queen, which is more valuable than the rook—but the choice is still available.Absolute skewer
In this diagram, with White to move, the white kingKing (chess)
In chess, the king is the most important piece. The object of the game is to trap the opponent's king so that its escape is not possible . If a player's king is threatened with capture, it is said to be in check, and the player must remove the threat of capture on the next move. If this cannot be...
is skewered by the black bishop. This is an absolute skewer, because the rules of chess compel White to get out of check (if possible). After White chooses one of the handful of legal moves available, Black will capture the white queen.
Because the skewer is a direct attack upon the more valuable piece, it is generally a much more powerful and effective tactic than the pin. The victim of a skewer often cannot avoid losing material (though it may be possible if, for example, either piece can give check, thereby forcing the skewering side to move out of check instead of being able to capture either piece, or if it is possible to move a less valuable piece in the way); the only question is which material will be lost. The skewer occurs less often than the pin in actual play. When it does occur, however, it is often decisive.
Example from game
In this 1989 game between Nigel ShortNigel Short
Nigel David Short MBE is an English chess grandmaster earning the title at the age of 19. Short is often regarded as the strongest English player of the 20th century as he was ranked third in the world, from January 1988 – July 1989 and in 1993, he challenged Garry Kasparov for the World Chess...
and Rafael Vaganian
Rafael Vaganian
Rafael Artemovich Vaganian, also transliterated Vahanyan is an Armenian chess grandmaster known for his sharp tactical style of play...
, White sacrifices
Sacrifice (chess)
In chess, a sacrifice is a move giving up a piece in the hopes of gaining tactical or positional compensation in other forms. A sacrifice could also be a deliberate exchange of a chess piece of higher value for an opponent's piece of lower value....
a bishop to win a queen by a skewer. White has just moved 51. Be5+. If Black moves 51...Kxe5 to avoid the immediate loss of the queen, 52.Qc3+ wins the queen by a skewer. Black resigned in this position .
External links
- Chess Tactics Repository - Skewers - Collection of chess problems involving skewers