Castling - AbsoluteAstronomy.com

Castling is a special move in the game

Game

A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...

of chess

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...

involving the king

King (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...

and either of the original rooks

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...

of the same color. It is the only move in chess (leaving aside promotion

Promotion (chess)

Promotion is a chess rule describing the transformation of a pawn that reaches its eighth rank into the player's choice of a queen, knight, rook, or bishop of the same color . The new piece replaces the pawn on the same square and is part of the move. Promotion is not limited to pieces that have...

) in which a player moves two pieces at the same time. Castling consists of moving the king two squares towards a rook on the player's first rank, then moving the rook onto the square over which the king crossed. Castling can only be done if the king has never moved, the rook involved has never moved, the squares between the king and the rook involved are not occupied, the king is not in check, and the king does not cross over or end on a square in which it would be in check. Castling is one of the rules of chess

Rules 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...

and is technically a king move .

The notation

Chess notation

Chess notation is the term for several systems that have developed to record either the moves made during a game of chess or the position of the pieces on a chess board. The earliest systems of notation used lengthy narratives to describe each move; these gradually evolved into terser systems of...

for castling, in both the descriptive

Descriptive chess notation

Descriptive notation is a notation for recording chess games, and at one time was the most popular notation in English-speaking and Spanish-speaking countries , . It was used in Europe until it was superseded by abbreviated algebraic notation, which was introduced by Philipp Stamma in 1737...

and the algebraic

Algebraic chess notation

Algebraic notation is a method for recording and describing the moves in a game of chess. It is now standard among all chess organizations and most books, magazines, and newspapers...

systems, is 0-0 with the kingside rook and 0-0-0 with the queenside rook. (In PGN

Portable Game Notation

Portable Game Notation is a computer-processible format for recording chess games ; many chess programs recognize this extremely popular format due to its being stored in plain text.-History:...

, O-O and O-O-O are used instead.) Castling on the kingside is sometimes called castling short and castling on the queenside is called castling long; the difference being based on whether the rook moves a short distance (two squares) or a long distance (three squares) .

Castling is in most European languages other than English known as 'rochieren/rochada/roque/arrocco' or some other derivative of the same root (from which also the English word 'rook' is derived), while the local adjectives meaning 'long' and 'short' are used in those countries to refer to 'queenside/kingside castling'. Castling was added to European chess in the 14th or 15th century and did not develop into its present form until the 17th century. The Asian versions of chess do not have such a move.

Requirements

Castling is permissible if and only if all of the following conditions hold :

The king has not previously moved.
The chosen rook has not previously moved.
There are no pieces between the king and the chosen rook.
The king is not currently in check.
The king does not pass through a square that is under attack by enemy pieces.
The king does not end up in check (true of any legal move).
The king and the chosen rook are on the same rank.

Conditions 4 through 6 may be summarized with the more memorable phrase "One cannot castle out of, through, or into check."

It is a common mistake to think that the requirements for castling are even more stringent than the above. To clarify:

The king may have been in check previously, as long as it is not in check at the time of castling.
The rook involved in castling may be under attack.
In queenside castling, the square next to the rook involved may be under attack. (Kingside castling is not legally possible when the square next to the rook involved is under attack: Because only two squares separate the king and the king's rook, the king would be moved to that square and thereby be placed in check.)

Strategy

Castling is an important goal in the early part of a game, because it serves two valuable purposes: it moves the king into a safer position away from the center of the board, and it moves the rook to a more active position in the center of the board (it is even possible to checkmate

Checkmate

Checkmate is a situation in chess in which one player's king is threatened with capture and there is no way to meet that threat. Or, simply put, the king is under direct attack and cannot avoid being captured...

with castling).

The choice as to which side to castle often hinges on an assessment of the trade-off between king safety and activity of the rook. Kingside castling is generally slightly safer, because the king ends up closer to the edge of the board and all the pawns on the castled side are defended by the king. In queenside castling, the king is placed closer to the center and the pawn on the a-file is undefended; the king is thus often moved to the b-file to defend the a-pawn and to move the king away from the center of the board. In addition, queenside castling requires moving the queen; therefore, it may take slightly longer to achieve than kingside castling. On the other hand, queenside castling places the rook more effectively – on the central d-file. It is often immediately active, whereas with kingside castling a tempo

Tempo (chess)

In chess, tempo refers to a "turn" or single move. When a player achieves a desired result in one fewer move, he "gains a tempo" and conversely when he takes one more move than necessary he "loses a tempo"...

may be required to move the rook to a more effective square.

It is common for both players to castle kingside, and rare for both players to castle queenside. If one player castles kingside and the other queenside, it is called opposite castling. Castling on opposite sides usually results in a fierce fight as both players' pawns are free to advance to attack the opposing king's castled position without exposing the player's own castled king. An example is the Dragon Variation

Sicilian Defence, Dragon Variation

In chess, the Dragon Variation is one of the main lines of the Sicilian Defence and begins with the moves:The name "Dragon" was first coined by Russian chess master and amateur astronomer Fyodor Dus-Chotimirsky who noted the resemblance of Black's kingside pawn structure to the constellation...

of the Sicilian Defence

Sicilian Defence

The Sicilian Defence is a chess opening that begins with the moves:The Sicilian is the most popular and best-scoring response to White's first move 1.e4...

.

If the king is forced to move before it has the opportunity to castle, the player may still wish to maneuver the king towards the edge of the board and the corresponding rook towards the center. When a player takes three or four moves to accomplish what castling would have accomplished in one move, it is sometimes called artificial castling

Artificial castling

In chess, artificial castling refers to a maneuver in which a king which has lost the right to castle, achieves a castled position in several normal moves, instead of the one special move.-Examples:...

, or castling by hand.

Tournament rules

Under the strict touch-move rules enforced in most tournaments

Chess tournament

A chess tournament is a series of chess games played competitively to determine a winning individual or team. Since the first international chess tournament in London, 1851, chess tournaments have become the standard form of chess competition among serious players.Today, the most recognized chess...

, castling is considered a king move. But under current US Chess Federation rules, a player who intends to castle and touches the rook first would suffer no penalty, and would be permitted to perform castling, provided castling is legal in the position. Still, the correct way to castle is to first move the king. As usual, the player's mind may change between all legal destination squares for the king until it is released. When the two-square king move is completed, however, the player has formally chosen to castle (if it is legal), and the rook must be moved accordingly. A player who performs a forbidden castling must return the king and the rook to their original places and then move the king, if there is another legal king move, including castling on the other side. If there is no legal king move, the touch-move rule does not apply to the rook .

It is also required by the official rules that the entire move be completed using only a single hand. Neither of these rules is commonly enforced in casual play, nor commonly known by non-competitive players .

The right to castle must be the same in all three positions for a valid draw

Draw (chess)

In chess, a draw is when a game ends in a tie. It is one of the possible outcomes of a game, along with a win for White and a win for Black . Usually, in tournaments a draw is worth a half point to each player, while a win is worth one point to the victor and none to the loser.For the most part,...

claim under the threefold repetition

Threefold repetition

In chess and some other abstract strategy games, the threefold repetition rule states that a player can claim a draw if the same position occurs three times, or will occur after their next move, with the same player to move. The repeated positions need not occur in succession...

rule.

Chess variants and problems

Some chess variant

Chess variant

A chess variant is a game related to, derived from or inspired by chess. The difference from chess might include one or more of the following:...

s, for example Chess960

Chess960

Chess960 is a chess variant invented and advocated by former World Chess Champion Bobby Fischer, originally announced on June 19, 1996 in Buenos Aires, Argentina. It employs the same board and pieces as standard chess, but the starting position of the pieces is randomized along the players' home...

, have modified castling rules to handle modified starting positions. Castling can also be adapted to large chess variants, like Capablanca chess

Capablanca chess

Capablanca chess is a chess variant invented in the 1920s by former World Chess Champion José Raúl Capablanca. It incorporates two new pieces and is played on a 10×8 board. Capablanca proposed the variant while World Champion, and not as a "sour grapes" rationalization after losing his title as...

, which is played on 10x8 board.

In chess problem

Chess problem

A chess problem, also called a chess composition, is a puzzle set by somebody using chess pieces on a chess board, that presents the solver with a particular task to be achieved. For instance, a position might be given with the instruction that White is to move first, and checkmate Black in two...

s, castling is assumed to be allowed if it appears possible, unless it can be proved by retrograde analysis

Retrograde analysis

In chess, retrograde analysis is a computational method used to solve game positions for optimal play by working backward from known outcomes , such as the construction of endgame tablebases. In game theory at large, this method is called backward induction...

that either the king or chosen rook has previously moved.

Notable examples

In this game between Yuri Averbakh
Yuri Averbakh
Yuri Lvovich Averbakh is a Soviet and Russian chess player and author. He is currently the oldest living chess grandmaster.-Life and career:...

and Cecil Purdy
Cecil Purdy
Cecil John Seddon Purdy was an Australian chess International Master and inaugural World Correspondence Chess champion. Purdy earned the Grandmaster title at Correspondence Chess in 1953...

, Black castled queenside. Averbakh pointed out that the rook passed over a square controlled by White and thought it was illegal. Purdy proved that the castling was legal since this applies only to the king, to which Averbakh replied "Only the king? Not the rook?" , .

Viktor Korchnoi
Viktor Korchnoi
Viktor Lvovich Korchnoi ; pronounced in the original Russian as "karch NOY"; Ви́ктор Льво́вич Корчно́й, born March 23, 1931 is a professional chess player, author and currently the oldest active grandmaster on the tournament circuit...

, in his 1974 Candidates final match with Anatoly Karpov
Anatoly Karpov
Anatoly Yevgenyevich Karpov is a Russian chess grandmaster and former World Champion. He was the official world champion from 1975 to 1985 when he was defeated by Garry Kasparov. He played three matches against Kasparov for the title from 1986 to 1990, before becoming FIDE World Champion once...

, famously asked the arbiter if castling was legal when the castling rook was under attack. The answer was in the affirmative, and Korchnoi ended up winning the game.

Three castlings occurred in the game between Wolfgang Heidenfeld
Wolfgang Heidenfeld
Wolfgang Heidenfeld was a chess player.Heidenfeld was born in Berlin. He was forced to move from Germany to South Africa because he was a Jew. There, he won the South African Chess Championship eight times, and he represented South Africa in the Chess Olympiad in 1958...

and Nick Kerins, in Dublin in 1973. Of course, the third one (the second one by White) was illegal. See this link, "Greatest number of castlings". The game is as follows:

1. e4 e6 2. d4 d5 3. Be3 Nf6 4. e5 Nfd7 5. f4 c5 6. c3 Nc6 7. Nf3 Qb6 8. Qd2 c4 9. Be2 Na5 10. 0-0 f5 11. Ng5 Be7 12. g4 Bxg5 13. fxg5 Nf8 14. gxf5 exf5 15. Bf3 Be6 16. Qg2 0-0-0 17. Na3 Ng6 18. Qd2 f4 19. Bf2 Bh3 20. Rfb1 Bf5 21. Nc2 h6 22. gxh6 Rxh6 23. Nb4 Qe6 24. Qe2 Ne7 25. b3 Qg6+ 26. Kf1 Bxb1 27. bxc4 dxc4 28. Qb2 Bd3+ 29. Ke1 Be4 30. Qe2 Bxf3 31. Qxf3 Rxh2 32. d5 Qf5 33. 0-0-0 Rh3 34. Qe2 Rxc3+ 35. Kb2 Rh3 36. d6 Nec6 37. Nxc6 Nxc6 38. e6 Qe5+ 39. Qxe5 Nxe5 40. d7+ Nxd7 0–1

Tim Krabbé
Tim Krabbé
Tim Krabbé is a Dutch journalist and novelist.Krabbé was born in Amsterdam. His writing has appeared in most major periodicals in the Netherlands. He is known to Dutch readers for his novel De Renner , first published in 1978...

composed a joke chess problem containing vertical castling (king on e1, promoted rook on e8). The loophole in the definition of castling upon which this problem was based was removed by the new requirement that the castling rook must occupy the same rank as the king.

Lasker game

In this game between Edward Lasker

Edward Lasker

Edward Lasker was a leading German-American chess and Go player. He was awarded the title of International Master of chess by FIDE. Lasker was an engineer by profession, and an author.-Background:...

and Sir George Thomas

George Alan Thomas

Sir George Alan Thomas, Bart. was a British badminton, tennis and chess player. He was twice British Chess Champion and a 21-time All-England Badminton champion. He also played in the semi-finals of the men's tennis doubles at Wimbledon in 1911...

(London 1912), Black had just played 17... Kg1. White could have checkmate

Checkmate

d by 18. 0-0-0# but instead played 18. Kd2#. (See Edward Lasker#Notable games.)

Prins versus Day

This game between Lodewijk Prins

Lodewijk Prins

Lodewijk Prins was a Dutch chess player and referee of chess competitions.Prins was awarded the International Master title in 1950, and was made an International Arbiter in 1960. In 1982 FIDE made him an honorary Grandmaster.Prins represented the Netherlands twelve times in all Chess Olympiads...

and Lawrence Day

Lawrence Day

Lawrence Day is a Canadian chess International Master, author, and journalist. He has represented Canada at 13 Chess Olympiads.- Early life :...

ended in a checkmate by castling:

31... 0-0-0# (see Lawrence Day#Notable chess games)

History

Castling has its roots in the "king's leap". There were two forms of the leap: (1) the king could move once like a knight

Knight (chess)

The knight is a piece in the game of chess, representing a knight . It is normally represented by a horse's head and neck. Each player starts with two knights, which begin on the row closest to the player, one square from the corner...

, and (2) the king could move two squares on his first move. The knight-move could be used early in the game to get the king to safety or later in the game to escape a threat. This second form was used in Europe as early as the 13th Century. In North Africa, the king was moved to a safe square by a two-step procedure: (1) the king moved to the second rank and (2) the rook moved to the king's original square and the king moved to the rook's original square .

Before the 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...

and 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...

acquired their current moves in the 16th Century they were weak pieces and the king was relatively safe in the middle of the board. When the bishop and queen got their current moves they became very powerful and the king was no longer safe on its original square since it can be attacked from a distance and from both sides. Castling was added to allow the king to get to a safer location and to allow rooks to get into the game earlier .

The rule of castling has varied by location and time. In medieval England, Spain, and France, the white king was allowed to jump to c1, c2, d3, e3, f3, or g1, if no capture was made, the king was not in check, and did not move over check. (The black king could move similarly.) In Lombardy, the white king could jump an additional square to b1 or h1 or to a2 (and equivalent squares for the black king). Later in Germany and Italy, the king move was combined with a pawn move.

In Rome from the early 17th century until the late 19th century, the rook could be placed on any square up to and including the king's square, and the king could be moved to any square on the other side of the rook. This was called "free castling".

In the Göttingen manuscript

Göttingen manuscript

The Göttingen manuscript is the earliest known work devoted entirely to modern chess. It is a Latin text of 33 leaves held at the University of Göttingen. A quarto parchment manuscript of 33 leaves, ff. 1–15a are a discussion of twelve chess openings, f. 16 is blank, and ff. 17–31b are a...

(ca. 1500) and a game published by Luis Ramirez de Lucena in 1498, castling consisted of two moves: first the rook and then the king.

The current version of castling was established in France in 1620 and England in 1640 .

In the 1811 edition of his chess treatise, Johann Allgaier

Johann Baptist Allgaier

Johann Baptist Allgaier was a German-Austrian chess master and theoretician. He was also the author of the first chess handbook in German – Neue theoretisch-praktische Anweisung zum Schachspiel .-About his biography:Relatively few details of his life are known...

introduced the 0-0 symbol. He differentiated between "0-0r" (r=right) and "0-0l" (l=left). The 0-0-0 symbol for queenside castling was added in 1837 by Aaron Alexandre

Aaron Alexandre

Aaron Alexandre was a Jewish German–French–English chess player and writer.Aaron Alexandre, a Bavarian trained as a rabbi, arrived in France in 1793. Encouraged by the French Republic's policy of religious toleration, he became a French citizen. At first, he worked as a German teacher and as...

. The practice was then accepted in the first edition (1843) of the Handbuch des Schachspiels
Handbuch des Schachspiels
Handbuch des Schachspiels is a chess book, first published in 1843 by Tassilo von Heydebrand und der Lasa. It was one of the most important opening references for many decades...

.