Bishop (chess)

A bishop (unicode|♗,unicode|♝) 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. In algebraic notation the starting squares are c1 and f1 for White's bishops, and c8 and f8 for Black's bishops.

The canonical chessmen are now dated back to Howard Staunton and the Staunton chess set. The piece's deep groove symbolizes a bishop's (or abbot's) mitre. The groove originates from the original Indian form of the piece, an elephant (the groove represented the elephant's tusks). This groove was interpreted differently in different countries as the game moved to Europe; in France, for example, the groove was taken to be a jester's cap, hence in France the bishop is called "fou" (the fool).

The bishop's move

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Initial placement of the bishops.chess diagram|=
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The black bishop can move to any of the squares marked by a black dot. The white bishop can move to any square marked by a white dot or capture the black pawnThe bishop has no restrictions in distance for each move, but is limited to diagonal movement. Bishops cannot jump over other pieces. A bishop captures by occupying the square on which an enemy piece sits.

The bishops may be differentiated according to which wing they begin on, i.e. the "king's bishop" and "queen's bishop". As a consequence of its diagonal movement, each bishop always remains on either the white or black squares, and so it is also common to refer to them as "light-squared" or "dark-squared" bishops.

Comparison to other pieces

versus rook

A rook is generally worth about two pawns more than a bishop. The bishop has access to only half of squares of the board, whereas all squares of the board are accessible to the rook. A rook on an empty board always attacks fourteen squares, whereas a bishop attacks no more than thirteen and as few as seven, depending on how near it is to the center. A king and rook can force checkmate against a lone king, while a king and bishop cannot.

versus knight

In general bishops are approximately equal in strength to knights, but depending on the game situation either may have a distinct advantage.

Less experienced players tend to underrate the bishop compared to the knight because the knight can reach all squares and is more adept at forking. More experienced players understand the power of the bishop, but a more sophisticated understanding is required harvcol|Mednis|1990|p=2.

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A rare example of a bishop fork occurs after 12...Nxe4?, when the forking 13.Bd5! wins material after, "e.g.", Nxg3 14.Bxc6+ Qd7 15.Bxd7+ Kxd7 16.fxg3.

Bishops generally gain in relative strength towards the endgame as more pieces are captured and more open lines are available for them to operate. When the board is empty, a bishop can influence both wings simultaneously, whereas a knight would need a few moves to do so. In an open endgame, a pair of bishops is decidedly superior to either a bishop and a knight, or to two knights. A player possessing a pair of bishops has a strategic weapon in the form of a long-term threat to trade down to an advantageous endgame.

In certain positions a bishop can by itself lose a move (see triangulation and tempo), while a knight can never do so. The bishop is capable of skewering or pinning a piece, while the knight can do neither.

On the other hand, in the opening and middlegame a bishop may be hemmed in by pawns of both players, and thus be inferior to a knight which can hop over them. Furthermore, on a crowded board a knight has many opportunities to fork two enemy pieces. While it is technically possible for a bishop to fork, practical opportunities are rare. One such example occurs in the position at right, which arises from the Ruy Lopez: 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 b5 6.Bb3 Be7?! 7.d4 d6 8.c3 Bg4 9.h3!? Bxf3 10.Qxf3 exd4 11.Qg3 g6 12.Bh6!

Game use

Good bishop and bad bishop

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style="padding: 0.5em 0; text-align: left;" | After White's 23rd move of Krasenkow vs. Zvjaginsev, FIDE World Chess Championship 2004A player with only one bishop should generally place their pawns on squares of the color that the bishop cannot move to. This allows the player to control squares of both colours, allows the bishop to move freely among the pawns, and helps fix enemy pawns on squares on which they can be attacked by the bishop. Such a bishop is often referred to as a "good" bishop.

Conversely, a bishop which is impeded by friendly pawns is often referred to as a "bad bishop" (or sometimes, disparagingly, a "tall pawn"). However, a "bad" bishop need not always be a weakness, especially if it is outside its own pawns' pawn chains. Even if the bad bishop is passively placed, it may serve a useful defensive function, a well-known quip from GM Mihail Suba is that "Bad bishops protect good pawns." [Discussions on the strength of bishops is covered e.g. in "The Art of Planning, part 2" by Jeremy Silman published in the July 1990 issue of Chess Life. Suba's quote is mentioned e.g. in "Secrets of Modern Chess Strategy, Advances Since Nimzowitsch" by John Watson.]

In the position from the game Krasenkow versus Zvjaginsev, [ [http://www.chessgames.com/perl/chessgame?gid=1292300 Krasenkow versus Zvjaginsev] at ChessGames.com] a thicket of black pawns hems in Black's bishop on c8, so Black is effectively playing with one piece fewer than White. Although the black pawns also obstruct the white bishop on e2, it has many more attacking possibilities, and thus is a good bishop vis-a-vis Black's bad bishop. Black resigned after another ten moves.

Fianchetto

A bishop may be "fianchettoed", for example after moving the g2 pawn to g3 and the bishop on f1 to g2. This can form a strong defense for the castled king on g1 and the bishop can often exert strong pressure on the long diagonal (here h1-a8). A fianchettoed bishop should generally not be given up lightly, since the resulting holes in the pawn formation may prove to be serious weaknesses, particularly if the king has castled on that side of the board.

There are nonetheless some modern opening lines where a fianchettoed bishop is given up for a knight in order to double the opponent's pawns, for example 1.d4 g6 2.c4 Bg7 3.Nc3 c5 4.d5 Bxc3+!? 5.bxc3 f5, a sharp line originated by Roman Dzindzichashvili. Giving up a fianchettoed queen bishop for a knight is usually less problematic. For example, in Karpov-Browne, San Antonio 1972, after 1.c4 c5 2.b3 Nf6 3.Bb2 g6?!, Karpov gave up his fianchettoed bishop with 4.Bxf6! gxf6 5.Nc3, doubling Black's pawns and giving him a hole on d5. [ [http://www.chessgames.com/perl/chessgame?gid=1035250 Chess game of Anatoly Karpov vs Walter Shawn Browne, 1972] at ChessGames.com]

Endgame

An endgame in which each player has only one bishop, one controlling the dark squares and the other the light, will often result in a draw even if one player has a pawn or sometimes two more than the other. The players tend to gain control of squares of opposite colors, and a deadlock results. In endgames with same-colored bishops, however, even a positional advantage may be enough to win harvcol|Mednis|1990|pp=133-34.

Bishops on opposite colors

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H. Wolf vs. P. Leonhardt, 1905.
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Draw with either side to moveEndgames in which player has only one bishop (and no other pieces) and the bishops are on opposite colors are often drawn, even when one side has an extra pawn or two. Many of these positions would be a win if the bishops were on the same color.

The position from Wolf versus Leonhardt (see diagram), shows an important defensive setup. Black can make no progress, since the white bishop ties the black king to defending the pawn on "g4" and it also prevents the advance ... f3+ because it would simply capture the pawn – then either the other pawn is exchanged for the bishop (an immediate draw) or the pawn advances (an easily drawn position). Otherwise the bishop alternates between the squares "d1" and "e2" Harvcol|Müller|Lamprecht|2001|p=118.

If two pawns are connected, they normally win if they reach their sixth rank, otherwise the game may be a draw (as above). If two pawns are separated by one file they usually draw, but win if they are farther apart Harvcol|Fine|Benko|2003|pp=184-204.

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Efim Bogoljubov vs. Max Bluemich, 1925.
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__|__|__|kl|__|__|__|__|=|Position after 28 ... Kf8In some cases with more pawns on the board, it is actually advantageous to have the bishops on opposite colors if one side has weak pawns. In the 1925 game of Efim Bogoljubov versus Max Bluemich, (see diagram) White wins because of the bishops being on opposite colors making Black weak on the black squares, the weakness of Black's isolated pawns on the queenside, and the weak doubled pawns on the kingside Harvcol|Reinfeld|1947|pp=80-81. The game continued [ [http://www.chessgames.com/perl/chessgame?gid=1030793 Chess game Efim Bogoljubov vs Max Bluemich, 1925] at ChessGames.com]

:29. Kd2 Ke7:30. Kc3 f6:31. Kd4 Be6:32. Kc5 Kd7:33. Kb6 g5:34. Kxa6 Kc7:35. Bb6+ Kc8:36. Bc5 Kc7:37. Bf8 f5:38. Bxg7 f4:39. Bf6 f3:40. gxf3 exf3:41. Bxg5 Bxh3:42. Bf4+ 1-0

Wrong rook pawn

With a bishop, a rook pawn may be the wrong rook pawn, depending on which color of square the bishop resides. This results in some positions being drawn which otherwise would be won.

History

The bishop was originally an "alfil". In the Persian form of chess, the bishop could move one or two squares diagonally. In the Moslem form it could leap two squares along any diagonal, and could jump over a piece that was adjacent to it on a diagonal. As a consequence of this rule, each bishop could only move to sixteen squares and no bishops could attack each other. The bishop acquired its current move in the 16th Century harvcol|Davidson|1981|pp=13-14.

ee also

* Bishop and knight checkmate
* Chess endgame
* Chess piece
* Chess piece point value
* Opposite colored bishops endgame
* Rules of chess
* Staunton chess set

Notes

References

*citation
last=Barden|first=Leonard|authorlink=Leonard Barden
year=1980
title=Play better CHESS with Leonard Barden
publisher=Octopus Books Limited|isbn=0-7064-0967-1|page=10
ISBN status=May be invalid - please double check

*citation
last=Brace|first = Edward R.
year=1977
title=An Illustrated Dictionary of Chess
publisher=Hamlyn Publishing Group
isbn=1-55521-394-4
pages=34–35
ISBN status=May be invalid - please double check

*citation
last=Davidson|first=Henry
year=1981
title=A Short History of Chess (1949)
publisher=McKay
id=ISBN 0-679-14550-8

*Citation
surname1=Fine|given1=Reuben|authorlink1=Reuben Fine
surname2=Benko|given2=Pal|authorlink2=Pal Benko
year=2003
title=Basic Chess Endings (1941)
publisher=McKay
id=ISBN 0-8129-3493-8
*citation
last = Mednis| first = Edmar | authorlink = Edmar Mednis
title = Practical Bishop Endings
publisher = Chess Enterprises
year = 1990
id = ISBN 0-945470-04-5
isbn = 0945470045
*Citation
surname1=Müller|given1=Karsten|authorlink1=Karsten Müller
surname2=Lamprecht|given2=Frank|authorlink2=Frank Lamprecht
year=2001
title=Fundamental Chess Endings
publisher=Gambit Publications
id=ISBN 1-901983-53-6
isbn=1901983536
author=Karsten Muller, Frank Lamprecht,
*Citation
surname1=Reinfeld|given1=Fred|authorlink1=Fred Reinfeld
year=1947
title=Reinfeld on the End-game in Chess
publisher=Dover Publications