Glossary of chess

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This page explains commonly used terms in chess in alphabetical order. Some of these have their own pages, like fork and pin . For a list of unorthodox chess pieces, see Fairy chess piece; for a list of terms specific to chess problems, see Glossary of chess problems; for a list of chess-related games, see List of chess variants.

Chess Strategy board game

Chess is a two-player strategy board game played on a checkered board with 64 squares arranged in an 8×8 grid. The game is played by millions of people worldwide. Chess is believed to be derived from the Indian game chaturanga sometime before the 7th century. Chaturanga is also the likely ancestor of the Eastern strategy games xiangqi, janggi, and shogi. Chess reached Europe by the 9th century, due to the Umayyad conquest of Hispania. The pieces assumed their current powers in Spain in the late 15th century; the modern rules were standardized in the 19th century.

A fairy chess piece, variant chess piece, unorthodox chess piece, or heterodox chess piece is a chess piece not used in conventional chess but incorporated into certain chess variants and some chess problems. Fairy pieces vary in the way they move. Because of the distributed and uncoordinated nature of unorthodox chess development, the same piece can have different names, and different pieces the same name in various contexts. Almost all are usually symbolised as inverted or rotated icons of the standard pieces in diagrams, and the meanings of these "wildcards" must be defined in each context separately. Pieces invented for use in chess variants rather than problems sometimes instead have special icons designed for them, but with some exceptions, many of these are not used beyond the individual games they were invented for.

This page explains commonly used terms in chess problems in alphabetical order. For a list of unorthodox pieces used in chess problems, see Fairy chess piece; for a list of terms used in chess is general, see Glossary of chess; for a list of chess-related games, see List of chess variants.

Contents

A

absolute pin
A pin against the king is called absolute since the pinned piece cannot legally move out of the line of attack (as moving it would expose the king to check). [1] Cf. relative pin .
active
Describes a piece that threatens a number of squares, or that has a number of squares available for its next move. It may also describe an aggressive style of play. [2] Antonym: passive .
Envelope used for the adjournment of a match game Efim Geller vs. Bent Larsen, Copenhagen 1966 Adjournment.JPG
Envelope used for the adjournment of a match game Efim Geller vs. Bent Larsen, Copenhagen 1966
adjournment
Suspension of a chess game with the intention to finish it later. It was once very common in high-level competition, often occurring soon after the first time control, but the practice has been abandoned due to the advent of computer analysis. [3] See also sealed move .
adjudication
A way to decide the result of an unfinished game. A tournament director, or an impartial and strong player, will evaluate the final position and assign a win, draw, or loss assuming best play by both players. [4]
adjust
See Touch-move rule. To adjust the position of a piece on its square without being required to move it. A player may only do this on their turn, and they must first say "I adjust", or the French equivalent J'adoube. [5]
advanced pawn
A pawn that is on the opponent's side of the board (the fifth rank or higher). An advanced pawn may be weak if it is overextended, lacking support and difficult to defend, or strong if it cramps the enemy by limiting mobility. An advanced passed pawn that threatens to promote can be especially strong. [6]
advantage
A better position with the chance of winning the game. Evaluation factors can include space, time, material, and threats. [2]
Alekhine vs. Nimzowitsch, 1930
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Alekhine's gun
A special form of battery in which a queen backs up two rooks on the same file. [7]
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Algebraic notation
algebraic notation
The standard way to record the moves of a chess game, using alphanumeric coordinates for the squares. [8]
amateur
Any player whose main occupation is not chess. [9] The distinction between professional and amateur is not very important in chess as amateurs may win prizes, accept appearance fees, and earn any title, including World Champion. [9] [10] In the 19th century, "Amateur" was sometimes used in published game scores to conceal the name of the losing player in a Master vs. Amateur contest. It was thought to be impolite to use a player's name without permission, and the professional did not want to risk losing a customer. [10] See also NN .
analysis
The study of a game or a position, in order to evaluate the quality of the moves and various other aspects of the game or position. At the end of a game, the players will often do an analysis of the game. Cf. post-mortem . [2]
annotation
Written commentary on a game or a position using words, chess symbols or notation. [2]
announced mate
A practice, common in the 19th century, whereby a player would announce a sequence of moves, believed by him to constitute best play by both sides, that led to a forced checkmate for the announcing player in a specified number of moves (for example, "mate in five"). [11]
antipositional
A move or a plan that is not in accordance with the principles of positional play. [12] Antipositional is used to describe moves that are part of an incorrect plan rather than a mistake made when trying to follow a correct plan. Antipositional moves are often pawn moves; since pawns cannot move backwards to return to squares they have left, their advance can create irreparable weaknesses. [13]
Anti-Sicilian
An opening variation that White uses against the Sicilian Defense (1.e4 c5) other than the most common plan of 2.Nf3 followed by 3.d4 cxd4 4.Nxd4 (the Open Sicilian). Some Anti-Sicilians include the Alapin Variation (2.c3), Moscow Variation (2.Nf3 d6 3.Bb5+), Rossolimo Variation (2.Nf3 Nc6 3.Bb5), Grand Prix Attack (2.Nc3 Nc6 3.f4 g6 4.Nf3 Bg7 and now 5.Bc4 or 5.Bb5), Closed Sicilian (2.Nc3 followed by g3 and Bg2), Smith–Morra Gambit (2.d4 cxd4 3.c3), and Wing Gambit (2.b4). [14]
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Arabian mate
A checkmate that occurs when the knight and rook trap the opposing king in a corner. [15]
arbiter
See International Arbiter .
Armageddon game
A game that is guaranteed to produce a decisive result, because if there is a draw it is ruled a victory for Black. In compensation for this White is given more time on the clock. Often White is given six minutes, and Black five. This format is typically used in playoff tiebreakers when shorter blitz games have not resolved the tie. [16]
artificial castling
Refers to a maneuver of several separate moves by the king and by a rook where they end up as if they had castled. Also known as castling by hand. [17]
attack
An aggressive action on a part of the chessboard, or to threaten the capture of a piece or pawn. [18] See also counterattack , discovered attack , double attack , mating attack , and minority attack . Antonym: defense .
Example of attraction
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White wins with 1.Rd7+! The black king is attracted away from the defense of the black queen with a skewer.
attraction
A type of decoy involving a sacrifice of a minor or major piece on a square next to the enemy king, forcing the king to abandon the defense of another square. For example (see diagram), the black queen has interposed to block a check from the white queen, and White can check the king from the opposite direction to win the queen. [19]
automaton
An automaton is a self-operating machine. In chess, it refers to chess-playing machines that were in fact hoaxes and under the control of hidden human players. Automatons stirred up great interest in the 18th and 19th centuries and inspired early thoughts of the possibility artificial intelligence. By far, the most famous chess-playing "automaton" was The Turk, whose secret of human control was kept for a very long time. The first true automaton El Ajedrecista was created by Leonardo Torres y Quevedo.

B

B
Symbol used for the bishop when recording chess moves in English. [20]
back rank
A player's first rank (the one on which the pieces stand in the starting position); White's back rank is Black's eighth rank, and vice versa. [21] Also called first rank or home rank.
back-rank mate
A checkmate delivered by a rook or queen along a back rank from which the mated king is unable to move because it is blocked by friendly pieces (usually pawns) on the second rank. [21] Also called back-row mate.
back-rank weakness
A situation in which a player is under threat of a back-rank mate and, having no time/option to create an escape for the king, must constantly watch and defend against that threat, for example by keeping a rook on the back rank. [21]
backward pawn
A pawn that is behind a pawn of the same color on an adjacent file and that cannot be advanced with the support of another pawn. [22]
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White has a bad bishop, Black has a good bishop (Evans & 1967:66).
bad bishop
A bishop that is hemmed in by the player's own pawns. [23] See also good bishop .
bare king
A position in which a king is the only man of its color on the board. [24]
Basque chess
A chess competition in which the players simultaneously play each other two games on two boards, each playing White on one and Black on the other. There is a clock at both boards. It removes the bonus in mini-matches of playing White first. Basque chess was first played in the 2012 Donostia Chess Festival in the Basque Country, Spain. [25] Also called Basque System.
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A pair of white rooks are aligned along their battery, ready to do some action.
battery
To double rooks on a file, or to place a bishop and a queen on a diagonal. [18] In chess problems, battery refers to an arrangement of two pieces in line with the enemy king on a rank, file, or diagonal so that if the middle piece moves a discovered check (or a threat other than a check) will be delivered. [26]
BCF
British Chess Federation, the former name of the English Chess Federation. [27] See ECF .
BCM
An abbreviation for the British Chess Magazine. [28]
BCO
An abbreviation for the 1982 openings reference book Batsford Chess Openings, by Raymond Keene and Garry Kasparov. The second edition (1989) is often called BCO-2. [29] Cf. ECO and MCO .
best play
The theoretical absolute and ideal best moves from any given position. [30]
Charousek vs. Maroczy, 1895
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The white bishop is doing the work of a pawn and has no bigger prospects.
big pawn
A bad bishop stuck behind its own pawns and defending themeffectively doing the work of a pawn. [31]
bind
A strong grip or stranglehold on a position that is difficult for the opponent to break. A bind is usually an advantage in space created by advanced pawns. The Maróczy Bind is a well-known example. [32] See also squeeze .
bishop
Chess bishop icon.png
bishop pair
The player with two bishops is said to have the bishop pair. Two bishops are able to control the diagonals of both colors. In open positions, two bishops are considered to have an advantage over two knights, or a knight and a bishop. [18] Also called the two bishops.
bishop pawn
Or bishop's pawn. A pawn on the bishop's file, i.e. the c-file or f-file. Sometimes abbreviated "BP". [33]
bishops on opposite colors
Or bishops of opposite colors. A situation in which one player has only a light-square bishop remaining while the other has only a dark-square bishop remaining. In endgames, this often results in a draw if there are no other pieces (only pawns), even if one side has a material advantage of one, two or even three pawns, since the bishops control different squares (see Opposite-colored bishops endgame). In the middlegame, however, the presence of opposite-colored bishops imbalances the game and can lead to mating attacks, since each bishop attacks squares that cannot be covered by the other. [34]
black
The dark-colored squares on the chessboard are often referred to as "the black squares" even though they are often some other dark color. Similarly, "the black pieces" are sometimes actually some other (usually dark) color. [35] See also white .
Black
The designation for the player who moves second, even though the pieces ("the black pieces") are sometimes actually some other (usually dark) color. [36] See also White and first-move advantage .
blind chess
See Kriegspiel .
blindfold chess
A form of chess in which one or both players are not allowed to see the board. [37]
blind pigs
A pair of rooks on the opponent's second rank are referred to as "pigs" as they tend to devour pawns and pieces, and "blind pigs" if they cannot find the mate. [38]
blitz chess
[from German: Blitz, "lightning"] A fast form of chess with a very short time limit, usually 3 or 5 minutes per player for the entire game. With the advent of electronic chess clocks, the time remaining is often incremented by 1 or 2 seconds per move. [39]
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Black has a solid light-square blockade. White's bishop cannot challenge Black's minor pieces.
blockade
The placement of a piece directly in front of an enemy pawn, where it obstructs the pawn's advance, and hinders the movements of the other enemy pieces. The enemy pawn provides some shelter to the piece that is blocking it, thereby protecting it from attacks by enemy pieces. A blockade is most effective against passed or isolated pawns. The ideal piece to use as a blockader is the knight. This strategy was famously formulated by Aron Nimzowitsch in 1924. [40] [41]
blocked position
A position where both sides are constrained from making progress, typically by interlocking pawn chain(s) dividing the available space into two camps. [42] See also closed game .
blunder
A very bad move, an oversight (indicated by "??" in notation). [18]
board
1.  See chessboard .
2.  An assignment in team chess, e.g. first board, second board, etc.
board one
See first board .
Schulder vs. Boden, London 1853
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Boden's Mate
Boden's Mate, named for Samuel Boden, is a checkmate pattern in which the king, usually having castled queenside, is checkmated by two crisscrossing bishops. Immediately prior to delivering the mate, the winning side typically plays a queen sacrifice on c3 or c6 to set up the mating position. [43]
book draw
An endgame position known to be a draw with perfect play. Historically this was established by reference to chess endgame literature, but in simplified positions computer analysis in an endgame tablebase can be used. [44]
book move
An opening move found in standard reference books on opening theory. A game is said to be "in book" when both players are playing moves found in the opening references. A game is said to be "out of book" when the players have reached the end of the variations analyzed in the opening books, or if one of the players deviates with a novelty (or a blunder). [45]
book win
An endgame position known to be a win with perfect play. Historically this was established by reference to chess endgame literature, but in simplified positions (currently seven pieces or fewer) computer analysis in an endgame tablebase can be used. [46]
break
A move that gains space and therefore freedom of movement, or the opening of a blocked position by the advance or capture of a pawn. [47]
breakthrough
Penetration of the opponent's position, or destruction of the defense, often by means of a sacrifice. [18]
brevity
[chiefly British] See miniature .
brilliancy
A game that contains a spectacular, deep and beautiful strategic idea, combination, or original plan. [47]
brilliancy prize
A prize awarded at some tournaments for the best brilliancy played in the tournament. [48]
Bronstein delay
A time control method with time delay, invented by David Bronstein. When it becomes a player's turn to move, the clock waits for the delay period before starting to subtract from the player's remaining time. [49]
Bughouse chess Bughouse game animation.gif
Bughouse chess
bughouse chess
A popular chess variant played with teams of two or more. [50]
building a bridge
Making a path for a king in the endgame by providing protective cover against checks from line pieces. A well-known example is the Lucena position. [51]
bullet chess
Each side has 1 minute to make all their moves. [52]
bust
A refutation of an opening, an opening line, a tactic, or a previously published analysis. [53] [54]
bye
A tournament round in which a player does not have a game, usually because there are an odd number of players. A bye is normally scored as a win (1 point), although in some tournaments a player is permitted to choose to take a bye (usually in the first or last round) and score it as a draw (½ point). [54]

C

Caissa, the patron goddess of chess (Fratta, 18th century) Caissa.jpg
Caïssa, the patron goddess of chess (Fratta, 18th century)
Caïssa
Known as the goddess or muse of chess, whose name is taken from a nymph in a 1763 poem, Caïssa or The Game at Chess, by Sir William Jones. [55]
calculate
To plan a series of moves and considering possible responses, without actually moving the pieces. [18]
candidate move
A move that seems good upon initial observation of the position, and that warrants further analysis. [56]
Candidates Match
A knockout match in the Candidates Tournament. [57]
Candidates Tournament
A tournament organised by the FIDE, the third and last qualifying cycle of the World Chess Championship. The participants are the top players of the Interzonal tournament plus possibly other players selected on the basis of rating or performance in the previous candidates tournament. The top ranking player(s) qualify(ies) for the world championship. [58]
can-opener
The plan of attacking a kingside, sometimes a fianchetto position, by advancing the h-pawn with the intention of opening a file near the defender’s king. [59]
capped piece
A particular piece with which one player attempts to deliver checkmate. Agreeing to play with a capped piece provides the stronger player an extra challenge, thereby conferring upon himself a handicap. When the capped piece is a pawn, it is called a pion coiffé [from French, "capped pawn"]. [60]
capture
A move by a pawn or piece that removes from the board the opponent’s pawn or piece. The capturing piece then occupies the square of the captured piece (except in the case of a capture that is done en passant ). [61]
castling
A move in which the king and a rook are moved at the same time. It moves the king from the center to a flank where it usually is safer, and it develops the rook. It is the only time two pieces are moved in a turn. Castling can be done on either the kingside (notated 0-0) or the queenside (0-0-0). Castling cannot be done in reply to a check, nor if either the king or rook has already moved. [62] [63]
castling into it
A situation where one side castles and a result is that the king is in more danger at the destination than on the initial square, either immediately or because lines and diagonals can be more readily opened against it. [64]
castling long
Castling queenside; in chess notation: 0-0-0. [62]
castling short
Castling kingside; in chess notation: 0-0. [62]
casual game
See friendly game .
category of a tournament
The category of a tournament is a measure of its strength based on the average FIDE rating of the participants. The category is calculated by rounding up the number: (average rating  2250) ÷ 25. So each category covers a 25-point rating range, starting with Category 1 which spans ratings between 2251 and 2275. A Category 18 tournament has an average rating between 2676 and 2700. [65]
CC
An abbreviation sometimes used for correspondence chess.
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The center squares are marked "×".
center
Or centre. The four squares in the middle of the board. [66] See also expanded center . Sometimes short for pawn center . A king "in the center" can refer to an uncastled king on a center file.
center file
Or centre file. The king's file (e-file) or queen's file (d-file).
center pawn
Or centre pawn. A pawn on the king's file (e-file) or queen's file (d-file). [67]
central file
See center file .
centralization
Moving a piece or pieces toward the center of the board, where they will not only control the center, but their influence will extend to other areas. Pieces are best placed near the center of the board, because they increase their power and maneuverability. Knights in particular benefit from being centralized. [68] Antonym: decentralization. [69]
central pawn
See center pawn .
cheapo
Slang for a primitive trap, often set in the hope of swindling a win or a draw from a lost position. [70] Also called cheap shot.
check
A direct attack on the king by an enemy man. The attacked king is said to be in check. There are only three possible immediate responses to a check: capturing the attacking piece, moving the king to an unattacked square, or interposing a piece between the attacker and the king. In casual games a player usually announces "check", however this is not a requirement in tournament games. [71]
checkmate
A position in which a player's king is in check and the player has no legal move (i.e. cannot move out of or escape the check). A player whose king is checkmated loses the game. [72] Often shortened to mate.
chess blindness
The failure of a player to see a good move or danger that should normally be considered obvious. The term was coined by Siegbert Tarrasch. Similar to Kotov syndrome. [73]
chessboard
The chequered board used in chess, consisting of 64 squares (eight rows by eight columns) arranged in two alternating colors, light and dark. [74]
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A chess clock
chess clock
A device made up of two adjacent clocks and buttons, keeping track of the total time each player takes for their moves. Immediately after moving, the player hits their button, which simultaneously stops their clock and starts their opponent's. The picture shown displays an analogue clock where the term flag fall originates. Modern clocks are digital. [75]
chessmen
The movable figures placed on the board in a game of chess. Includes both pieces and pawns. [76] Singular: chessman.
chess notation
See notation .
chess opening
See opening .
chess problem
Also called composition .
A wooden chess set and board ChessStartingPosition.jpg
A wooden chess set and board
chess set
The thirty-two pieces required for a game, plus a chessboard.
chess variant
A chess-like game played using a board, pieces, or rules different from standard chess. [77]
Chess960
Chess960 (also known as Fischer Random Chess) is a variation of the game invented and advocated by Bobby Fischer. The pieces and pawns have their normal moves, but the setup of pieces on the first rank is random, except that two rules must be followed: the king must be placed on a square between the rooks, and the bishops are placed on squares of opposite color. Black's pieces are placed opposite White's. The random setup can be established by dice toss, computer program, playing cards, or other methods. Castling may be done; the special Chess960 rules governing castling incorporate the normal castling in classic chess. [78] [79]
chop wood
Slang for capturing or exchanging pieces. [80] See also wood .
classical
1.  An opening system geared towards forming a full pawn center. Classical ideas were challenged by hypermodern ideas. [66]
2.  A game using a longer time control such as 40/2; the opposite of fast chess categories such as rapid, blitz or bullet. [81]
classical bishop sacrifice
See Greek gift sacrifice .
clearance
Removal of piece from a square, rank, file or diagonal so that another piece may use it. It often involves sacrificing the piece that unblocked the position. [82]
clock move
In a game played clock move, a move is considered completed only after the clock is pressed. For example, one could touch a piece, then move a different piece—as long as the player has not pressed their clock button. This way of playing is uncommon but can be seen in casual games or blitz games. [83]
clock time
Time (consumed or remaining) on the chess clock, in a tournament game. [84]
closed file
A file on which White and Black each have a pawn. [85]
closed game
A closed game has few open lines (files or diagonals). It is generally characterized by interlocking pawn chains, cramped positions with few opportunities to exchange, and extensive maneuvering behind lines. Such a game may evolve and later become an open game . [86] See also positional play .
Closed Game
A Closed Game is a particular opening that begins with the moves 1.d4 d5. It is also known as a Double Queen's Pawn Opening or Double Queen's Pawn Game. [87] See also Open Game and Semi-Open Game .
closed tournament
A tournament in which only invited or qualifying players may participate, as opposed to an open tournament . Also called invitational tournament.
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The Blackburne Shilling Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4?!), an example of coffeehouse play
coffeehouse
Adjective used to describe a move, player, or style of play characterized by risky, positionally dubious play that sets traps for the opponent. The name comes from the notion that one would expect to see such play in skittles games played in a coffeehouse or similar setting, particularly in games played for stakes or blitz chess. The Blackburne Shilling Gambit is a typical example of coffeehouse play. [88]
color
Or colour. The white or black pieces, and the white or black squares. The actual pieces and squares may be other colors, usually light and dark, but they are referred to as white and black. [76] See White and Black in chess.
combination
A sequence of moves, including forced moves, and often involving a sacrifice, to gain an advantage. [66]
compensation
That which is gained in return for a sacrifice or some other action. If material is sacrificed there may be a gain in development, or if a minor piece is exchanged for two or three pawns, the pawns would be the compensation. [89]
computer move
A term for a move that seems likely to have been played by a computer rather than a human, because the move seems counterintuitive, or seems not to make immediate sense, or seems to eventually make sense, but not until far into the future of the game. Computer moves seem to be what they are: moves based on the brute force of millions of calculations, and not based on intuition, aesthetics, or emotion. A computer move would overlook a dramatic capture that might cause an opponent to resign on the spot in favor of an obscure move that may eventually turn out to be only slightly better. At one time the term was used disparagingly, but the definition has evolved as computers have improved. It is a term that is occasionally used to suggest that a player has been assisted by a computer. [90] [91]
confirmation bias
The tendency of a chess player analyzing a position to find a candidate move, and then look for variations that support that first move rather than looking for superior variations. [92]
connected passed pawns
Passed pawns on adjacent files. These are considered to be unusually powerful (often worth a minor piece or rook if on the sixth rank or above and not properly blockaded) because they can advance together. [66] See also connected pawns .
connected pawns
Refers to two or more pawns of the same color on adjacent files. [68] Cf. isolated pawns .
connected rooks
Two rooks of the same color on the same rank or file with no pawns or pieces between them. Connected rooks are usually desirable. Players often connect rooks on their own first rank or along an open file. [93] See also doubled rooks .
consolidation
The improvement of a player's position by the reposition of one or more pieces to better square(s), typically after a player's attack or combination has left their pieces in poor positions or uncoordinated. [94]
continuation
See variation .
control
When a player’s pawn, piece or pieces guard a square, or squares, or a file, or a rank in such a way that the territory can be advantageously used; and the opponent is prevented from using the territory. [95]
control of the center
Having one or more pieces that attack any of the four center squares; an important strategy, and one of the main aims of openings. [96]
cook
In chess problems , an unintended duplicate solution, or a refutation. [97] See also Glossary of chess problems#cook.
corr.
An abbreviation for correspondence game.
correspondence chess
Chess played at a long time control by long-distance correspondence. Traditionally correspondence chess was played though the post; today it is usually played over a correspondence chess server or by email. Typically, one move is transmitted in every correspondence. [98]
corresponding squares
Corresponding squares are pairs of squares such that when a king moves to one square, it forces the opponent's king to occupy the other square in order to hold the position. If the opponent's king cannot move to the required square it is zugzwang and a disadvantage. Corresponding squares usually occur in pawn endgames. The theory of corresponding squares has developed to include complex calculations based on math-like formulas. [99] Also called related squares. Cf. opposition .
counterattack
An attack that responds to an attack by the opponent. [100]
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The Falkbeer Countergambit (1.e4 e5 2.f4 d5), a gambit response to the King's Gambit
countergambit
A gambit offered by Black, for example the Greco Counter Gambit, usually called the Latvian Gambit today (1.e4 e5 2.Nf3 f5?!); the Albin Countergambit (1.d4 d5 2.c4 e5); and the Falkbeer Countergambit (1.e4 e5 2.f4 d5). An opening need not have "countergambit" in its name to be one, for instance the Benko Gambit (1.d4 Nf6 2.c4 c5 3.d5 b5); the Englund Gambit (1.d4 e5?!); the Budapest Gambit (1.d4 Nf6 2.c4 e5); the Blackburne Shilling Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4?!); and many lines of the Two Knights Defense (e.g. 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 and now 4...Bc5!? [the Wilkes–Barre Variation or Traxler Counterattack]; 4...Nxe4?!; 4...d5 5.exd5 Na5 6.Bb5+ c6 [the main line]; 4...d5 5.exd5 Nd4 [the Fritz Variation]; and 4...d5 5.exd5 b5 [the Ulvestad Variation]) are all examples of countergambits. [101]
counterplay
The defending side's own aggressive action. [102]
country move
A disparaging term for a move considered unsophisticated, especially an unnecessary single-step advance of the rook's pawn in the opening. The term was popular in London in the late 19th century. [103]
cover
To protect a piece or control a square.
cramped
Having limited mobility in a position. [104]
critical position
The moment in a game or opening when the evaluation shows that things are about to change, either towards an advantage for one player, or towards equality; a wrong move can be disastrous. [102]
critical square
See key square .
cross-check
A cross-check is a check played in reply to a check, especially when the original check is blocked by a piece that itself either delivers check or reveals a discovered check from another piece. [105]
crosstable
An arrangement of the results of every game in a tournament in tabular form. The names of the players run down the left side of the table in numbered rows. The names may be listed in order of results, alphabetically, or in pairing order, but results order is most common. The columns are also numbered, each one corresponding to the player in the same numbered row. Each table cell records the outcome of the game between the players on the intersecting row and column, using 1 for a win, 0 for a loss, and ½ for a draw. (In a double round-robin tournament each cell contains two entries, as each pair of players plays two games alternating White and Black.) Every game is recorded twice, once from the perspective of each player. The diagonal cells that correspond to the player playing himself are marked with a * or × or other symbol since they are not used. [106] For examples see Hastings 1895 chess tournament, Nottingham 1936 chess tournament, and AVRO tournament.
crush
Slang for a quick win, especially an overwhelming attack versus poor defensive play. A crushing move is a decisive one.

D

dark-square bishop
One of the two bishops that moves only on the dark squares. In the initial position, White's dark-square bishop is on c1; Black's is on f8. [36] Often shortened to dark bishop [69] or DSB. Cf. light-square bishop .
dark squares
The 32 dark-colored squares on the chessboard, such as a1 and h8. A dark square is always located at a player's left-hand corner. [36] Cf. light squares .
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A dead draw by means of insufficient material. King versus king and bishop will not ever lead to checkmate.
dead draw
A drawn position in which neither player has any realistic chance to win. A dead draw may refer to a position in which it is impossible for either player to win (such as insufficient material), or it may refer to a simple, lifeless position that would require a major blunder before either side would have a chance to win. [107]
decoy
This is a tactic used to lure a piece to a particular square. [108]
defense
1.  A move or plan to meet the opponent's attack. [102]
2.  Part of the name of openings played by Black; e.g. the Scandinavian Defense, King's Indian Defence, English Defence, etc. [102]
deflect
The inverse of a decoy. Whereas a decoy involves luring an enemy piece to a bad square, a deflection involves luring an enemy piece away from a good square; typically, away from a square on which it defends another piece or threat. Deflection is thus closely related to overloading. [109]
Wouter Mees at a demonstration board WouterMeesRotterdam1991.jpg
Wouter Mees at a demonstration board
demonstration board
A large standing chess board used to analyze a game or show a game in progress. Johann Löwenthal invented the demonstration board in 1857. [110]
descriptive notation
A system of recording chess moves, used primarily in the English and Spanish speaking countries until the 1980s. Descriptive notation is based on natural language descriptions of chess moves rendered in abbreviated form, for example "pawn to queen's bishop's fourth" is rendered as "P-QB4". Now replaced by the standard algebraic notation. [111]
desperado
A piece that seems determined to give itself up, typically to bring about stalemate or perpetual check. Also a threatened piece that sacrifices itself for the maximum compensation possible. [112]
development
The movement of non-pawn pieces in the opening from their original squares to squares where they can be more active. Development of one's pieces is one of the objectives of the opening phase of the game. [108]
diagonal
A line of squares of the same color touching corner to corner, along which a queen or bishop can move. [113]
discovered attack
An attack made by a queen, rook or bishop when another piece or pawn moves out of its way. [108]
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Once the e4-bishop moves, it is discovered check by the rook.
discovered check
A discovered attack to the king. This occurs when a player moves a piece, resulting in another piece putting their opponent's king in check. [114]
domination
A situation that occurs in games and in endgame studies when a piece is attacked and appears to have a number of destination squares, but the squares are guarded and the piece cannot avoid being captured. [115]
double attack
Two attacks made with one move: these attacks may be made by the same piece (in which case it is a fork ); or by different pieces, for example in a discovered attack when the moved piece also makes a threat. [108]
double check
A check delivered by two pieces at the same time. A double check necessarily involves a discovered check. By its nature a double check cannot be met by interposing a defending piece in the line of attack, or by capturing an attacker; when subjected to a double check, the attacked king must move, which makes the double check especially powerful as an attacking tactic. [116]
doubled pawns
Two pawns of the same color on the same file; generally considered a weakness due to their inability to defend each other. [113]
doubled rooks
A powerful configuration in which a player's two rooks are placed on the same file or rank with no other men between them. They defend each other and attack along the shared file or rank, as well as two additional ranks or files. The configuration can be especially decisive in the endgame. [117]
draw
A game that ends without victory for either player. Most drawn games are draws by agreement. The other ways that a game can end in a draw are stalemate, threefold repetition, the fifty-move rule, and insufficient material. A position is said to be a draw (or a "drawn position" or "theoretical draw") if either player can, through correct play, eventually force the game into a position where the game must end in a draw, regardless of the moves made by the other player. A draw is usually scored as ½ point, although in some matches only wins are counted and draws are ignored. [108]
draw by agreement
A game that is ended by both players accepting a draw. [118] See also resign .
draw death
Hypothetical scenario whereby elite-level chess players, aided by modern computer analysis, become so good that they never make mistakes, leading to endless drawn games (since chess is widely believed to be drawn with best play from both sides). [119]
drawing line
An opening variation that commonly ends in a draw. [120] See also Collection of drawing lines.
drawing weapon
An opening line played with the intent of drawing the game. [121]
drawish
An adjective describing a position or game that is likely to end in a draw. [122]
draw odds
A type of chess handicap where one player (Black in an Armageddon game) only has to draw in order to win the match. [123]
draw offer
A proposal by a player to the opponent that the game be drawn by agreement. [124]
dynamism
A style of play in which the activity of the pieces is favored over more positional considerations, even to the point of accepting permanent structural or spatial weaknesses. Dynamism stemmed from the teachings of the Hypermodern school and challenged the dogma found in more classical teachings, such as those put forward by Wilhelm Steinitz and Siegbert Tarrasch. [125]

E

eat
To remove the opponent's piece or pawn from the board by taking it with one's own piece or pawn. [126] [127] See also capture .
ECF
The English Chess Federation (ECF) is the governing chess organisation in England and is one of the federations of the FIDE. It was known as the British Chess Federation (BCF) until 2005 when it was renamed.
ECO
The Encyclopaedia of Chess Openings (ECO), a standard and comprehensive chess opening reference. Also a classification system (ECOcode) for openings that assigns an alphanumeric code from A00 to E99 to each opening.
edge
An edge is a small but meaningful advantage in the position against one's opponent. It is often said White has an edge in the starting position, since White moves first (see First-move advantage in chess). [128]
Elo rating system
The Elo rating system is a method for calculating the relative skill levels of chess players, named after Arpad Elo. Since 2012, FIDE publishes a monthly international chess rating list using the Elo system. [129]
endgame
The third and last phase of the game, when there are few pieces left on the board. The endgame follows the middlegame. [129]
endgame tablebase
A computerized database of endgames with a small number of pieces, providing perfect play for both players, and thus completely solving those endgames. By 2012, tablebases have been calculated for all positions with up to seven pieces. [130]
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After 1.d4 c5 2.d5 e5, White can play 3.dxe6, capturing the e-pawn en passant on the next move only. The white pawn is placed on e6, and the black pawn on e5 is removed from the board.
en passant
[from French, "in the act of passing"] The rule that allows a pawn that has just advanced two squares to be captured by an enemy pawn that is on the same rank and adjacent file. The pawn can be taken as if it had advanced only one square. Capturing en passant is possible only on the next move. [131]
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The pawn on e4 is en prise.
en prise
[from French, "in a position to be taken", [132] [133] often italicized] En prise describes a piece or pawn exposed to a material-winning capture by the opponent. This is either a hanging piece, an undefended pawn, a piece attacked by a less valuable attacker, or a piece or pawn defended insufficiently. For instance, 1.e4 Nf6 2.Nf3? leaves White's e-pawn en prise. [134]
epaulette mate
A checkmate position where the king is blocked on both sides by its own rooks. [135]
EPD
An abbreviation for Extended Position Description.
equalize
Or equalise. To reach a position where the players have equal chances of winning, referred to as equality. In the opening, because White has the advantage of the first move, the immediate goal for Black is to achieve equality. [136]
escape square
See flight square .
evaluation
Or simply eval. The analysis of a position. A computer or engine evaluation is a means of assigning a number value to a position, based not on intelligence, but on algorithms, which vary from engine to engine and depend on engine strength. Engine evaluations have foibles and imperfections even when functioning as designed. If an engine describes a position as +2.50, the plus sign (+) indicates the position is favorable to White; a minus sign (−) indicates the position is favorable to Black. The number can correspond to the approximate value of pieces, although engines use other factors besides material. The notation +2.50 indicates that White is ahead by two and one-half pawns. The notation +M4 indicates that White can force checkmate in four moves. [137] [138] [139] Cf. analysis .
exchange
To swap or trade pieces by capture. Usually the pieces are of equal value (i.e., rook for rook, knight for knight, etc.), or of bishop for knight (two pieces that are considered approximately equal in value). [140] Also called even exchange.
exchange, the
The advantage of a rook over a minor piece (knight or bishop). The player who captures a rook for a minor piece is said to have "won the exchange", the player who has lost the rook has "lost the exchange". An exchange sacrifice is giving up a rook for a minor piece. [134]
exchange variation
This is a type of opening in which there is an early, voluntary exchange of pawns or pieces. [141]
exhibition
Chess games played for the public in various formats and for various purposes, often to promote the game, or a particular match or player, or as a fundraiser. An exhibition may pit two masters against each other, and normally use chess clocks. In a simultaneous exhibition, one player takes on a number opponents at once, and it is often not timed. A blindfold exhibition is the same but more challenging, since the exhibitor plays without seeing the boards. [142]
expanded center
The central sixteen squares of the chessboard. [143]
exposed king
A king lacking pawns to shield it from enemy attack. [144]
Extended Position Description
A Forsyth–Edwards Notation derivative format that contains the position on the chessboard, but not the game. It is primarily used to test chess engines. [145] Abbr. EPD.

F

family fork
A knight fork that simultaneously attacks the enemy king (giving check), queen, and possibly other pieces. Also known as a "family check". [146]
FAN
An abbreviation for figurine algebraic notation, which substitutes symbols for letters to represent piece names (e.g. ♘f3 instead of Nf3). [147]
fast chess
A form of chess in which both sides are given less time to make their moves than under the normal tournament time controls. See also: rapid chess , blitz chess , bullet chess .
FEN
An abbreviation for Forsyth–Edwards Notation.
FGM
An abbreviation for the FICGS Grandmaster title.
fianchetto
To develop a bishop to the board's longest diagonal on the file of the adjacent knight (b2 or g2 for White; b7 or g7 for Black). The Italian word ("little flank") is pronounced "fyan-ketto". [148]
FICGS Grandmaster
A correspondence chess title calculated by the FICGS (Free Internet Correspondence Games Server) organization. [149]
FIDE
The World Chess Federation (Fédération Internationale des Échecs), the primary international chess organizing and governing body. The abbreviated name FIDE is nearly always used in place of the full name in French. [150]
FIDE Master
A chess title ranking below International Master. [151] Abbr. FM.
fifty-move rule
A draw may be claimed if no capture or pawn move has occurred in the last fifty moves by either side. [152]
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The f-file
file
A column of the chessboard. A specific file can be named either using its position in algebraic notation, a–h, or by using its position in descriptive notation. For example, "f-file" and "king bishop file" both denote the squares f1–f8 (or KB1–KB8 in descriptive notation). [150]
fingerfehler
[from German, "finger mistake"] An error caused by unthinkingly touching the wrong piece or releasing a piece on the wrong square, forcing the player to move that piece in accordance with the touch-move rule. [153]
first board
In team chess, the player who is assigned to face the strongest opponents. Also called top board and board one. Second board faces the next strongest players, followed by third board, and so on. Generally board assignments must be made before the competition begins and players may not switch boards, although reserve players are often allowed as substitutes.
first-move advantage
The slight (by most accounts) advantage that White has by virtue of moving first. [150]
first player
The expression "the first player" is sometimes used to refer to White.
first rank
See back rank .
Fischer delay
A time control method with time delay, invented by Bobby Fischer. When it becomes a player's turn to move, the delay is added to the player's remaining time. [154]
Fischer Random Chess
See Chess960 .
five-minute chess
See blitz chess .
flag
Part of an analogue chess clock, usually red, that indicates when the minute hand passes the hour. To "flag" someone means winning the game on the basis of the opponent exceeding the time control. [150]
flank
The queenside a-, b-, and c-files; or the kingside f-, g-, and h-files. Distinguished from the center d-file and e-file. [155] Also called wing.
flank opening
An opening played by White and typified by play on one or both flanks. [156]
flight square
A square to which a piece can move, that allows it to escape attack. [146] Also called escape square. See also luft .
FM
An abbreviation for the FIDE Master title.
Fool's mate Fools mate animation.gif
Fool's mate
Fool's mate
The shortest possible chess game ending in mate: 1.f3 e5 2.g4 Qh4# (or minor variations on this). [157]
forced mate
A sequence of two or more moves culminating in checkmate that the opponent cannot prevent. [158]
forced move
A move that is the only one that does not result in a serious disadvantage for the moving player. Forced can also be used to describe a sequence of moves for which the player has no viable alternative, for example "the forced win of a piece" or "a forced checkmate". In these cases the player cannot avoid the loss of a piece or checkmate, respectively. [157]
forced win
A win guaranteed by a series of forcing moves.
forcing move
A move that presents a threat and limits the opponent's responses. [159]
forfeit
Refers to losing the game by breaking rules, by absence or by exceeding the time control (forfeit on time). [160]
fork
A simultaneous attack by a single piece on two (or more) of the opponent's pieces (or other direct target, such as a mate threat). When the attacker is a knight the tactic is often specifically called a knight fork. Some sources state that only a knight can give a fork and that the term double attack is correct when another piece is involved, but this is by no means universal usage. [5]
Forsyth–Edwards Notation
A standard notation for describing a particular board position of a chess game. The purpose of FEN notation is to provide all the necessary information to restart a game from a particular position. [161] [162] Abbr. FEN.
fortress
In endgame theory, a fortress is an impenetrable position which, if obtained by the side with a material disadvantage, may result in a draw due to the stronger side's inability to make progress. [163]
friendly game
A game that is not played as part of a match, tournament, or exhibition. Often the game is not timed, but if a chess clock is used rapid time controls are common. The term refers only to the circumstances in which the game is played, not the relationship between the players or the intensity of the competition. [164] Also called casual game.

G

gambit
A sacrifice (usually of a pawn) used to gain an early advantage in space or time in the opening. [5]
game clock
A synonym for chess clock .
game score
Often shortened to score. The record of a game in some form of notation, usually algebraic notation. In over-the-board tournaments, the game score is recorded on a score sheet. [165]
gardez
[from French: gardez la reine!, "Protect the Queen!"] An announcement to the opponent that their queen is under direct attack, similar to the announcement of "check". This warning was customary until the early 20th century. [166]
GM
An abbreviation for Grandmaster. [167]
God
Metaphorically, a hypothetical player who always plays perfectly. [168]
good bishop
A bishop that has greater mobility, because the player's own pawns are on squares of color opposite to that of the bishop. [169] See also bad bishop .
Grandmaster
The highest title a chess player can attain (besides World Champion). Awarded by FIDE, it cannot be taken away. [170] Abbr. GM.
grandmaster draw
A game in which the players agree to a quick draw. Originally it referred to such games between grandmasters, but the term can now refer to any such game. [170]
Greek gift sacrifice
A typical sacrifice of a bishop by White playing Bxh7+ or by Black playing ...Bxh2+ against a castled king to initiate a mating attack. Also known as the classical bishop sacrifice. [171]

H

half-open file
A file on which only one player has no pawns. [172] Also called a semi-open file.
handicap
See odds .
hanging
Unprotected and exposed to capture. A hanging piece may also be said to be en prise. [170]
hanging pawns
Two pawns of the same color on adjacent files, with no pawns of the same color on the files either side of them. The term is used almost exclusively for pawns on the c- and d-files, and usually for two pawns on the same rank (side by side). They can be a strength, a weakness or neutral - depending on the position. They typically serve as an attacking rather than as a defensive asset. [170]
Harry
A nickname for the h-pawn, sometimes occurring in the expression, "Harry the h-pawn". [173] [174]
hauptturnier
German word that is freely translated as "candidates tournament". In the early part of the 20th century, it was necessary for ambitious European amateurs to win a succession of prizes in small tournaments before they could progress to a higher level of competition. The creation of the hauptturnier enabled the process to become more formalized, and they became a regular feature of the major German chess congresses. Winning such an event conferred the title of 'Master of the German Chess Federation', and this, in turn, could be used to gain admittance to prestigious international tournaments. Some of the best players in chess history, such as Emanuel Lasker and Siegbert Tarrasch, secured their Master titles and advanced their chess careers in this way. [175]
heavy piece
See major piece .
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The dots indicate holes. (Evans, 1967)
hole
A square that is inside or near a player’s territory that cannot be controlled by a pawn. It is a gap in a player’s pawn configuration, and especially dangerous when the hole is close to the center or near the king. A knight landing on a hole may be part of an attack. An example of a hole is e4 in the Stonewall Attack. [176]
home rank
Rank one for White; rank eight for Black. [177] See back rank .
horizontal line
See rank .
Horwitz vs. Harrwitz,
London 1846, rd. 10, 0–1 [178]
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After 30.Qe2. Black's Horwitz bishops are aimed at White's kingside. [179]
Horwitz bishops
A player's light-square and dark-square bishops placed so that they occupy adjacent diagonals, creating a potent attack. Also called raking bishops, and sometimes Harrwitz bishops. [180] [181]
human move
A move a human would make, as opposed to the kind of move that only a computer would make. [182]
Hutton pairing
A pairing technique invented in 1921 by George Dickson Hutton for matching teams of players in which only one game is required per player. Has been used regularly for correspondence team events and for matches between many teams conducted on one day. [183] Also called jamboree pairing.
hypermodernism
A school of thought that prefers controlling the center with pieces from the flanks as opposed to occupying it directly with pawns. Major proponents of hypermodernism included Réti and Nimzowitsch. [184] See also classical .

I

ICCA
See International Correspondence Chess Federation .
ICCF
An abbreviation for the International Correspondence Chess Federation. [185]
ICS
An abbreviation for Internet chess server.
IGM
An abbreviation for the older term International Grandmaster. The modern usage is Grandmaster (GM).
illegal move
A move that is not permitted by the rules of chess. An illegal move discovered during the course of a game must be corrected. [186]
illegal position
A position in a game that is a consequence of an illegal move or an incorrect starting position; a position that is impossible to reach by any sequence of legal moves. [186]
IM
An abbreviation for the International Master title. [187]
imbalance
Any difference between the positions of White and Black. An imbalanced position is one where White and Black both have unique advantages. Conversely, a balanced position may be drawish. [184]
inaccuracy
A move that is not the best, but not as bad as a blunder. [187]
inactive
See passive .
increment
Refers to the amount of time added to each player's time before each move. For instance, rapid chess might be played with "25 minutes plus 10 second per move increment", meaning that each player starts with 25 minutes on their clock, and this increments by 10 seconds after (or before) each move, usually using the Fischer Delay method. [39] See Time control#Compensation (delay methods).
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In the KID Fianchetto Variation (1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 0-0 5.Bg2 d6 6.0-0), both sides have Indian bishops.
Indian bishop
A fianchettoed bishop, characteristic of the Indian defenses, the King's Indian and the Queen's Indian. [188]
Indian defense
An opening that begins 1.d4 Nf6. Originally used to describe queen's pawn defenses involving the fianchetto of one or both black bishops, it is now used to describe all Black defenses after 1.d4 Nf6 that do not transpose into the Queen's Gambit. [189]
initiative
The ability to make attacking moves, and force the course of play. It is an aspect of time. The attacking player has the initiative, and the defending player attempts to seize it. [190]
innovation
A synonym for theoretical novelty .
insufficient material
An endgame scenario in which all pawns have been captured, and one side has only its king remaining while the other has only its king, a king plus a knight, or a king plus a bishop. A king plus bishop versus a king plus bishop with the bishops on the same color is also a draw, since neither side can checkmate, regardless of play. Situations where checkmate is possible only if the inferior side blunders are covered by the fifty-move rule. [191] See Draw (chess)#Draws in all games.
interference
The interruption of the line or diagonal between an attacked piece and its defender by interposing a piece. [190]
intermediate move
See zwischenzug .
intermezzo
See zwischenzug .
International Arbiter
A tournament official who arbitrates disputes and performs other duties such as keeping the score when players are under time pressure.
International Correspondence Chess Federation
The International Correspondence Chess Federation (abbr. ICCF) was founded in 1951 to replace the International Correspondence Chess Association (ICCA). [185]
International Grandmaster
Abbr. IGM. The original name of the FIDE title now simply called Grandmaster (GM).
International Master
A chess title that ranks below Grandmaster but above FIDE Master. Abbr. IM.
International Woman Master
Obsolete name for Woman International Master.
Internet chess server
An external server that provides the facility to play, discuss, and view chess over the Internet. Abbr. ICS.
interpose
To move a piece between an attacking piece and its target, blocking the line or diagonal of attack. Interposing is not possible if the attacker is a knight, king, or pawn, thus only possible in case of attacking rooks, bishops, or queens. Interposing a piece is one of the three possible responses to a check. [5]
Interzonal tournament
A tournament organised by the FIDE starting from the 1950s to 1993. It was the second qualifying cycle of the World Chess Championship. The participants were selected from the top players of the Zonal tournaments. The top ranking players qualified for the Candidates Tournament. Since 1998 the winners of the zonal tournaments have played short matches against each other over a few weeks in a knockout-style competition to determine who is eligible for the Candidates Tournament.
intuition
A way of thinking that looks for the winning strategy not by calculating, but by a feeling or a hunch, that may be prompted subconsciously while studying the position, its visual patterns and dynamics, or by one’s memory of previous experience. [192]
IQP
An abbreviation for isolated queen pawn. See also isolani .
irregular opening
In early 19th-century chess literature, all openings that did not begin with either 1.e4 e5 or 1.d4 d5 were classified as "irregular". As opening theory developed and many openings previously considered "irregular" became standard (e.g. the Sicilian Defence), the term gradually became less common. Opening books today are more likely to describe debuts such as 1.b4 (the Sokolsky Opening) as "uncommon" or "unorthodox". [193]
isolani
Refers to a d-pawn with no pawns of the same color on the adjacent c-file and e-file, and is a synonym for isolated queen pawn (abbr. IQP). The term was coined by Nimzowitsch, who considered the isolani as a weapon of attack in the middlegame but an endgame weakness; he considered the problem of hanging pawns to be related. [194] See also Pawn structure#Queen's Gambit – Isolani.
isolated pawn
A pawn with no pawn of the same color on an adjacent file. [195]
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Italian bishops in the Giuoco Piano
Italian bishop
A white bishop developed to c4 or a black bishop developed to c5. A bishop so developed is characteristic of the Italian Game. In the Giuoco Piano both players have Italian bishops. The Italian bishop stands in contrast to the "Spanish" bishop on b5 characteristic of the Ruy Lopez. "Italian" may be used as an adjective for an opening where one or both players have Italian bishops. [196]

J

j'adoube
(from French, "I adjust", pronounced  [ʒa.dub] ) See Touch-move rule. A player says "j'adoube" as the international signal that he or she intends to adjust the position of a piece on the board without being subject to the touched piece rule. The verb adouber, literally "to dub" (raise to the knighthood) is rarely used in contemporary French outside of this context. A local language equivalent, e.g. "I am adjusting" is generally acceptable. [5]

K

K
Symbol used for the king when recording chess moves in English. [20]
key square
1.  An important square.
2.  In pawn endings, a square whose occupation by one side's king guarantees the achievement of a certain goal, such as the promotion of a pawn or the win of a pawn. [191]
KGA
The King's Gambit Accepted opening.
KGD
The King's Gambit Declined opening.
KIA
The King's Indian Attack opening.
kibitz
As a spectator, making comments on a chess game that can be heard by the players. Kibitzing on a serious game while it is in progress (rather than during a post-mortem) is a serious breach of chess etiquette. [197]
kick
Attacking a piece, often a knight, with a pawn, so that it will move. Kicking a piece may lead to gaining a tempo, or may force the opponent to concede control of key squares. [197]
KID
The King's Indian Defence opening.
king
Chess king icon.png
king bishop
Or king's bishop. The bishop that is on the kingside at the start of the game. The terms king knight and king rook are also used. Sometimes abbreviated "KB", "KN", and "KR", respectively. [76]
king hunt
A sustained attack on the enemy king that results in the king being driven a far distance from its initial position, typically resulting in its checkmate. Some of the most famous games featuring king hunts are Edward Lasker–Thomas, Polugaevsky–Nezhmetdinov, and Kasparov–Topalov. [198]
king knight
Or king's knight. The knight that is on the kingside at the start of the game. The terms king bishop and king rook are also used. Sometimes abbreviated "KN", "KB", and "KR", respectively. [76]
king pawn
Or king's pawn. A pawn on the king's file, i.e. the e-file. Sometimes abbreviated "KP". Also king bishop pawn (KBP), king knight pawn (KNP), and king rook pawn (KRP) for a pawn on the f-, g-, or h-file, respectively. [76]
king pawn opening
An opening that begins 1.e4. Also called king's pawn opening.
king rook
Or king's rook. The rook that is on the kingside at the start of the game. The terms king bishop and king knight are also used. Sometimes abbreviated "KR", "KB", and "KN", respectively. [76]
kingside
Or king's side. The side of the board (half-board) the kings are on at the start of the game (the e- through h-file), as opposed to the queenside . [33] Also called king's wing.
king walk
A consecutive series of king moves designed to bring the king to a safer square. For example, if a player has castled kingside but the opponent has sacrificed a piece to destroy the kingside pawn cover, they may choose to walk the king over to the queenside to shelter behind the queenside pawns. [199] See also King walk.
knight
Chess knight icon.png
knight pawn
Or knight's pawn. A pawn on the knight's file, i.e. the b-file or g-file. Sometimes abbreviated "NP". [76]
Example of a knight's tour Knight's tour anim.gif
Example of a knight's tour
knight's tour
A puzzle that challenges a person to set a knight on an empty chessboard, and make the piece move around (as it moves in a chess game), but to visit every square only once. The knight’s tour is the most well known of a variety of “tours” and puzzles based on chess pieces. A "closed" tour (also known as a "re-entrant tour") ends on the same square on which it began and needs 64 moves. An "open" tour ends on a different square and needs only 63 moves. [200]
knockout tournament
See Single-elimination tournament. A tournament conducted as a series of matches in which the winner of each match advances to the next round and the loser is eliminated. Well-known chess tournaments held in the knockout format include London 1851 and the 2007 Chess World Cup. Cf. round-robin tournament and Swiss tournament .
Kotov syndrome
This phenomenon, described by Alexander Kotov in his 1971 book Think Like a Grandmaster, can occur when a player does not find a good plan after thinking long and hard on a position. The player, under time pressure, then suddenly decides to make a move that he has hardly thought about at all, and it may not be a good move for that reason. [201]
Kriegspiel
[from German, "war game"] Kriegspiel is a chess variant played by two opponents who can only see their own board, and one monitoring umpire who makes the moves of both players on a neutral board. It requires three chess sets and boards. The players make their moves based on limited information from the umpire. It was introduced in 1898. It is sometimes referred to as blind chess, not be confused with blindfold chess. [202]
Kt
The symbol sometimes used for the knight when recording chess moves in descriptive notation, mainly in older literature. An N is used instead in algebraic notation and in later descriptive notation to avoid confusion with K, the symbol for the king. [20]

L

laws of chess
The rules of chess. [203]
lightning chess
A form of chess with an extremely short time limit, either blitz chess or bullet chess. [204]
light-square bishop
One of the two bishops that moves only on the light squares. In the initial position, White's light-square bishop is on f1; Black's is on c8. [191] Often shortened to light bishop. [205] Cf. dark-square bishop .
light squares
The 32 light-colored squares on the chessboard, such as h1 and a8. [206] Cf. dark squares .
line
1.  A sequence of moves, usually in the opening or in analyzing a position.
2.  An open path for a piece (queen, rook, or bishop) to move or control squares. [204]
line piece
A piece whose movement is defined to be along straight lines of squares (i.e. the rook, bishop, and queen). [207]
liquidation
See simplification .
long diagonal
One of the two diagonals with eight squares (a1–h8 or h1–a8). [208]
long-range piece
A bishop, rook, or queen.
loose piece
A piece vulnerable to opponent attacks because it is undefended and cannot easily be withdrawn or supported. [209]
loose position
A position vulnerable to opponent attacks because it is overextended or its pieces are uncoordinated.
losing a tempo
See tempo .
loss
A defeat for one of the two players, which may occur due to that player being checkmated by the other player, resigning, exceeding the time control, or being forfeited by the tournament director. In chess, a zero-sum game, this results in a win for the other player. [210]
Lucena position
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White wins by 1.Rd1+ Ke7 2.Rd4! Ra1 3.Kc7 Rc1+ 4.Kb6 Rb1+ 5.Kc6 Rc1+ 6.Kb5 Rb1+ 7.Rb4 and the pawn queens.
Lucena position
A well-known rook and pawn versus rook endgame position in which the player with the extra pawn can force a win by cutting off the opponent's king and placing a rook on the 4th rank in order to block the opponent's rook checks, thereby allowing the pawn to queen. [51]
luft
[from German, "air"] Space made for a castled king to give it a flight square to prevent a back-rank mate. Usually luft is made by moving a pawn on the second rank in front of the king. [211] See also flight square .

M

main line
The principal, most important, or most often played variation of an opening. [212]
majority
A larger numbers of pawns on one flank opposed by a smaller number of the opponent's; often a player with a majority on one flank has a minority on the other. [213]
major piece
A queen or rook, also known as a heavy piece. [214] The primary distinction of major pieces versus minor pieces is that major pieces are capable of checkmate with only their own king for support, as the enemy king is unable to step across the ranks and files they control. On an otherwise empty board, a major piece can move from any square to any other square in at most two moves.
man
A piece or a pawn, when the term piece is used as exclusive of pawns. [215]
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