Chess

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This article is about the Western board game. For other chess games or other uses, see Chess (disambiguation).

Chess
From left, a white king, black rook and queen, white pawn, black knight, and white bishop
Players	2
Setup time	Under one minute
Playing time	Casual games without time control last usually 10–60 minutes
Random chance	None
Skills required	Tactics, Strategy

Chess is a recreational and competitive game played between two players. Sometimes called Western chess or international chess to distinguish it from its predecessors and other chess variants, the current form of the game emerged in Southern Europe during the second half of the 15th century after evolving from similar, much older games of Indian and Persian origin. Today, chess is one of the world\'s most popular games, played by millions of people worldwide in clubs, online, by correspondence, in tournaments and informally.

The game is played on a square chequered chessboard with 64 squares arranged in an eight-by-eight square. At the start, each player (one controlling the white pieces, the other controlling the black pieces) controls sixteen pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. The object of the game is to checkmate the opponent\'s king, whereby the king is under immediate attack (in "check") and there is no way to remove it from attack on the next move.

The tradition of organized competitive chess started in the sixteenth century. The first official World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; Viswanathan Anand is the current World Champion. Theoreticians have developed extensive chess strategies and tactics since the game\'s inception. Aspects of art are found in chess composition.

One of the goals of early computer scientists was to create a chess-playing machine, and today\'s chess is deeply influenced by the abilities of current chess programs and by the possibility to play online. In 1996, a match between Garry Kasparov, then World Champion, and a computer proved for the first time that machines are able to beat even the strongest human players.

Pieces at the start of a game and a chess clock.

Initial position. First row: rook, knight, bishop, queen, king, bishop, knight, and rook. Second row: pawns.

Contents 1 Rules 2 History 2.1 Predecessors 2.2 Origins of the modern game (1450–1850) 2.3 Birth of a sport (1850–1945) 2.4 Post-war era (1945 and later) 3 Place in culture 3.1 Pre-modern 3.2 Modern 4 Notation for recording moves 5 Strategy and tactics 5.1 Fundamentals of strategy 5.2 Fundamentals of tactics 5.3 Opening 5.4 Middlegame 5.5 Endgame 6 Chess composition 7 Competitive play 7.1 Organization of competitions 7.2 Titles and rankings 8 Mathematics and computers 9 Psychology 10 Variants 11 See also 12 Notes 13 References 14 Further reading 15 External links

Rules

Moves of a king

positions after kingside (White) and queenside (Black) castling

Moves of a rook

Moves of a bishop

Moves of a queen

Moves of a knight

Moves of a pawn

Pc6 can move to c7 or take either black rook; Ph5 can take en passant Pg5 if the last Black move was g7-g5

Main article: Rules of chess

For a simple demonstration of the gameplay, see sample chess game.

Chess is played on a square board of eight rows (called ranks and denoted with numbers 1 to 8) and eight columns (called files and denoted with letters a to h) of squares. The colors of the sixty-four squares alternate and are referred to as "light squares" and "dark squares". The chessboard is placed with the light squares at the players\' right, and the pieces are set out as shown in the diagram, with each queen on its own color.

The pieces are divided, by convention, into White and Black sets. Each player, referred to by the color of his pieces, begins the game with sixteen pieces: these comprise one king, one queen, two rooks, two bishops, two knights and eight pawns. White moves first. The colors are chosen either by a friendly agreement, by a game of chance or by a tournament director. The players alternate moving one piece at a time (with the exception of castling, when two pieces are moved simultaneously). Pieces are moved to either an unoccupied square, or one occupied by an opponent\'s piece, capturing it and removing it from play. With one exception (en passant), all pieces capture opponent\'s pieces by moving to the square that the opponent\'s piece occupies.

When a king is under immediate attack by the opponent\'s pieces, the king is said to be in check. When in check, only moves that result in a position in which the king is not in check are permitted. The player must not make any move that would place his king in check. The object of the game is to checkmate the opponent; this occurs when the opponent\'s king is in check, and there is no way to remove the king from attack.

Each chess piece has its own style of moving.

• The king can move only one square horizontally, vertically, or diagonally. Once in every game, each king is allowed to make a special move, known as castling. Castling consists of moving the king two squares towards a rook, then placing the rook immediately on the far side of the king. Castling is only permissible if all of the following conditions hold:The rules of chess. Retrieved on 2008-01-07.

1. The player must never have moved either the king or the rook involved in castling;
2. There must be no pieces between the king and the rook;
3. The king may not currently be in check, nor may the king pass through squares that are under attack by enemy pieces. As with any move, castling is illegal if it would place the king in check.
4. The king and the rook must be on the same rank (to exclude castling with a promoted pawn, described later).

• The rook moves any number of vacant squares vertically or horizontally (it is also involved in the king\'s special move of castling);
• The bishop moves any number of vacant squares in any direction diagonally. Note that a bishop never changes square color, therefore players speak about "dark-squared" or "light-squared" bishops, depending on the color of square on which the bishop resides. Alternatively, bishops may be identified as a "queen bishop" or a "king bishop", depending on whether they are next to the queen or the king when on their home square.
• The queen can move any number of vacant squares diagonally, horizontally, or vertically;
• The knight can jump over occupied squares and moves two spaces horizontally and one space vertically or vice versa, making an "L" shape. A knight in the middle of the board has eight squares to which it can move. Note that every time a knight moves, it changes square color.
• Pawns have the most complex rules of movement:The F.I.D.E. Laws Of Chess. Retrieved on 2008-01-07.

• A pawn can move forward one square, if that square is unoccupied. If it has not yet moved, the pawn has the option of moving two squares forward, if both squares in front of the pawn are unoccupied. A pawn cannot move backward.
• When such an initial two square advance is made that puts that pawn horizontally adjacent to an opponent\'s pawn, the opponent\'s pawn can capture that pawn en passant as if it moved forward only one square rather than two, but only on the immediately subsequent move.
• Pawns are the only pieces that capture differently than they move. They can capture an enemy piece on either of the two spaces adjacent to the space in front of them (i.e., the two squares diagonally in front of them), but cannot move to these spaces if they are vacant.
• If a pawn advances all the way to its eighth rank, it is then promoted (converted or "queened") to a queen, rook, bishop, or knight of the same color. In practice, the pawn is almost always promoted to a queen.

With the exception of the knight, pieces cannot jump over each other. One\'s own pieces ("friendly pieces") cannot be passed if they are in the line of movement, and a friendly piece can never replace another friendly piece. Enemy pieces cannot be passed, but they can be "captured". When a piece is captured (or taken), the attacking piece replaces the enemy piece on its square (en passant being the only exception). The captured piece is thus removed from the game and may not be returned to play for the remainder of the game.However, a captured piece is often used as a "new" piece, following the promotion of a pawn. The new piece is nevertheless regarded distinct from the original captured piece; it is simply used for convenience. Moreover, the player\'s choice by promotion is not restricted to pieces that have been captured previously. World Chess Federation. FIDE Laws of Chess. Retrieved 9 December 2006. The king cannot be captured, only put in check. If a player is unable to get the king out of check, checkmate results, with the loss of the game.

Chess games do not have to end in checkmate — either player may resign if the situation looks hopeless. Games also may end in a draw (tie). A draw can occur in several situations, including draw by agreement, stalemate, threefold repetition of a position, the fifty move rule, or a draw by impossibility of checkmate (usually because of insufficient material to checkmate).

Besides casual games without exact timing, chess is also played with a time control, mostly by club and professional players. If a player\'s time runs out before the game is completed, he automatically loses. The timing ranges from long games played up to seven hours to shorter rapid chess games lasting usually 30 minutes or one hour per game. Even shorter is blitz chess with a time control of three to fifteen minutes for each player and bullet chess (under three minutes).

The international rules of chess are described in more detail in the FIDE Handbook, section Laws of Chess.World Chess Federation. FIDE Laws of Chess. Retrieved 30 November 2006.

History

Predecessors

Main article: Origins of chess

Iranian chess set, glazed fritware, twelfth century. New York Metropolitan Museum of Art.

Chess originated in India,Murray, H.J.R. (1913). A History of Chess. Benjamin Press (originally published by Oxford University Press). ISBN 0-936317-01-9.  where its early form in the 6th century was chaturanga, which translates as "four divisions of the military"-- infantry, cavalry, elephants, and chariots, represented respectively by pawn, knight, bishop, and rook. In Persia around 600 the name became shatranj and the rules were developed further. Shatranj was taken up by the Muslim world after the Islamic conquest of Persia, with the pieces largely retaining their Persian names. In Spanish "shatranj" was rendered as ajedrez and in Greek as zatrikion, but in the rest of Europe it was replaced by versions of the Persian shāh ("king").

Knights Templar playing chess, Libro de los juegos, 1283.

The game reached Western Europe and Russia by at least three routes, the earliest being in the 9th century. By the year 1000 it had spread throughout Europe.Hooper and Whyld, 144-45 (first edition) Introduced into the Iberian Peninsula by the Moors in the 10th century, it was described in a famous 13th century manuscript covering shatranj, backgammon, and dice named the Libro de los juegos.Sonja Musser Golladay\'s English Translation of Alfonso X\'s Book of Games. Retrieved 11 December 2006

Another theory, championed by David H. Li, contends that chess arose from the game xiangqi, or at least a predecessor thereof, existing in China since the 2nd century BC.Li, David H. (1998). The Genealogy of Chess. Premier Pub. Co. ISBN 0-9637852-2-2. 

Origins of the modern game (1450–1850)

Original Staunton chess pieces by Nathaniel Cook from 1849

Around 1200, rules of shatranj started to be modified in southern Europe, and around 1475, several major changes rendered the game essentially as it is known today.Hooper and Whyld, 144-45 (first edition) These modern rules for the basic moves had been adopted in ItalyDavidson (1981), p. 13–17 and in Spain.Calvo, Ricardo. Valencia Spain: The Cradle of European Chess. Retrieved 10 December 2006 Pawns gained the option of advancing two squares on their first move, while bishops and queens acquired their modern abilities. This made the queen the most powerful piece; consequently modern chess was referred to as "Queen\'s Chess" or "Mad Queen Chess".An analysis from the feminist perspective: Weissberger, Barbara F. (2004). Isabel Rules: constructing queenship, wielding power. University of Minnesota Press. ISBN 0-8166-4164-1.  P. 152ff These new rules quickly spread throughout western Europe, with the exception of the rules about stalemate, which were finalized in the early nineteenth century.See History of the stalemate rule.

This was also the time when chess started to develop a corpus of theory. The oldest preserved printed chess book, Repetición de Amores y Arte de Ajedrez (Repetition of Love and the Art of Playing Chess) by Spanish churchman Luis Ramirez de Lucena was published in Salamanca in 1497.Calvo, Ricardo. Valencia Spain: The Cradle of European Chess. Retrieved 10 December 2006 Lucena and later masters like Portuguese Pedro Damiano, Italians Giovanni Leonardo Di Bona, Giulio Cesare Polerio and Gioachino Greco or Spanish bishop Ruy López de Segura developed elements of openings and started to analyze simple endgames.

François-André Danican Philidor, eighteenth century French chess Master

In the eighteenth century the center of European chess life moved from the Southern European countries to France. The two most important French masters were François-André Danican Philidor, a musician by profession, who discovered the importance of pawns for chess strategy, and later Louis-Charles Mahé de La Bourdonnais who won a famous series of matches with the British master Alexander McDonnell in 1834.Louis Charles Mahe De La Bourdonnai. Chessgames.com. Retrieved 30 November 2006. Centers of chess life in this period were coffee houses in big European cities like Café de la Régence in ParisMetzner, Paul (1998). Crescendo of the Virtuoso: Spectacle, Skill, and Self-Promotion in Paris during the Age of Revolution. Berkeley: University of California Press. ISBN 0-520-20684-3.  Online version and Simpson\'s Divan in London.Bird, Henry Edward. Chess History and Reminiscences. Retrieved 10 December 2006

As the nineteenth century progressed, chess organization developed quickly. Many chess clubs, chess books and chess journals appeared. There were correspondence matches between cities; for example the London Chess Club played against the Edinburgh Chess Club in 1824.London Chess Club. Chessgames.com. Retrieved 30 November 2006. Chess problems became a regular part of nineteenth century newspapers; Bernhard Horwitz, Josef Kling and Samuel Loyd composed some of the most influential problems. In 1843, von der Lasa published his and Bilguer\'s Handbuch des Schachspiels (Handbook of Chess), the first comprehensive manual of chess theory.

Birth of a sport (1850–1945)

The "Immortal Game", Anderssen-Kieseritzky, 1851

The first modern chess tournament was held in London in 1851 and won, surprisingly, by German Adolf Anderssen, relatively unknown at the time. Anderssen was hailed as the leading chess master and his brilliant, energetic — but from today\'s viewpoint strategically shallow — attacking style became typical for the time. World Title Matches and Tournaments - Chess history. worldchessnetwork.com Sparkling games like Anderssen\'s Immortal game or Morphy\'s Opera game were regarded as the highest possible summit of the chess art.Burgess, Graham, Nunn, John and Emms, John (1998). The Mammoth Book of the World\'s Greatest Chess Games. Carroll & Graf Publishers. ISBN 0-7867-0587-6. , p. 14.

Deeper insight into the nature of chess came with two younger players. American Paul Morphy, an extraordinary chess prodigy, won against all important competitors, including Anderssen, during his short chess career between 1857 and 1863. Morphy\'s success stemmed from a combination of brilliant attacks and sound strategy; he intuitively knew how to prepare attacks.Shibut, Macon (2004). Paul Morphy and the Evolution of Chess Theory. Courier Dover Publications. ISBN 0-486-43574-1.