Greater Peoria Chess Foundation

The Greater Peoria Chess Foundation is a 501(c)3 non profit organization dedicated to encouraging chess in our community and school systems. Chess helps students to develop many life skills that will help them as they navigate with challenges that lay ahead.


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). Cf. relative pin.

Active Piece: 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. Antonym: passive.

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. 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.

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.

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.

Advantage: A better position with the chance of winning the game. Evaluation factors can include space, time, material, and threats.

Alekhine's GunA special form of battery in which a queen backs up two rooks on the same file.

Algebraic Notation: The standard way to record the moves of a chess game, using alphanumeric coordinates for the squares, a-h for the files and 1-8 for the ranks on the 8x8 board.

Analyze: Where one or more players make moves on a board to try to determine what is the best continuation.

AntipositionalA move or a plan that is not in accordance with the principles of positional play.[13] 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.

Appeal: Normally a player has the right to appeal against a decision of the Arbiter, Tournament Director or Organizer.

Arabian Mate: A checkmate that occurs when the knight and rook trap the opposing king in a corner.

Arbiter: (FIDE) The person(s) responsible for ensuring that the rules of a competition are followed. In US tournaments this person is called the Tournament Director.

Arbiter’s Discretion: There are man instances in the Laws of Chess where the arbiter must use his judgment in the same way an umpire or referee in other sports.

Armageddon: 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.

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.

Assistant: A person who may help the smooth running of the competition in various ways. An asistant will report to the Tournament Director or Organizer.

Attack: A piece is said to attack an opponent’s piece if the player’s piece can legally make a capture on that square.

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, 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.

B: Symbol used for the bishop when recording chess moves in English. Other languages may use other symbols, for example, the German word for the piece is Laufer and Germans would use the letter L.

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. Also called 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. This is also sometimes referred to as a 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.

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.

Bad Bishop: A bishop that is hemmed in by the player's own pawns. See also good bishop.

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. Also called Basque system.

Battery: To double rooks on a file, or to place a bishop and a queen on a diagonal. 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.

Big Pawn: A Bad Bishop stuck behind its own pawns and defending them—effectively doing the work of a pawn.

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. See also squeeze.

Bishop: The Chess Piece that only moves diagonally. Bishops are line pieces and so they can move from one edge of the board to another but they have a weakness in that they can never change colors to attack pawns or pieces of the other color.

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. Also called the two Bishops.

Bishop Pawn: A pawn on the bishop's file, i.e. the c-file or f-file. Sometimes abbreviated "BP". Also called bishop's pawn.

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.

Black: There are 16 dark-colored pieces and 32 squares called black. Or 2. When capitalized, this also refers to the player of the black pieces.

Blitz: A game where each player’s thinking time is 10 minutes or less. [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.

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.

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. See also closed game.

Blunder: A very bad move, an oversight, a move that the player knows not to make but plays without adequate thought. (indicated by "??" in notation).

Board: Short for chessboard. The playing area of the game.

Boden's Mate: is named for Samuel Boden. It 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. Can also be called the Crossfire Mate.

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 now be used.

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).

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 six pieces or fewer) computer analysis in an endgame tablebase can be used.

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. Also see Pawn Break.

Breakthrough: Penetration of the opponent's position, or destruction of the defense, often by means of a sacrifice.

Brevity: Name for a very short game of 20 moves or less. [chiefly British] See miniature.

Brilliancy: A game that contains a spectacular, deep and beautiful strategic idea, combination, or original plan.

Brilliancy Prize: A prize awarded at some tournaments for the best brilliancy played in the tournament.

Bronstein Delay, Bronstein Mode: 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. See Delay Mode.

Bughouse Chess: A toxic chess variant played with teams of two or more where pieces are exchanged between boards. Instead of trying to find the best move in a position, the players are encouraged to wistful fantasies of what they could do if only they had a few more specially useful pieces.

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.

Bullet Chess: Each side has 1 minute to make all their moves.

Bust: A refutation of an opening, an opening line, a tactic, or a previously published analysis.

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).

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.

Calculate: To plan a series of moves and considering possible responses, without actually moving the pieces.

Candidate Move: A move that seems good upon initial observation of the position, and that warrants further analysis.

Candidates Tournament: A tournament organized 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. The winner of the Candidates Tournament then plays a match with the reigning World Champion for the title.

Capture: Where a piece is moved from its square to a square occupied by an opponent’s piece, the latter is removed from the board. In notation written as x or left out. Older forms of notation used : instead of x.

Castling: A King move, the only King move of more than 1 square and the Rook is then placed on the opposite side of the King. Neither King nor Rook may have been previously moved. The King may not be in check or pass through check when castling. In notation 0-0 is King-side castling, 0-0-0 Queen-side castling, each 0 for an empty square between the King and Rook.

Castling Long: Castling queenside; in chess notation: 0-0-0.

Castling Short: Castling kingside; in chess notation: 0-0.

Casual Game: A game played without tournament rules or with modifcations agreed to by the payers. 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. 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.

CC: An abbreviation sometimes used for Correspondence Chess.

Cellphone: Usually forbidden in the playing area. See Mobile Phone.

Centralisation: 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.

Center: The four squares in the middle of the board.

Center Pawn: A pawn on the king's file (e-file) or queen's file (d-file).

Central Pawn: A central pawn may include pawns in the larger 4x4 16 square center.

Check: Where a king is attacked by one or more of the opponent’s pieces. When in check a player's only legal response is to get out of check. There are 3 ways out of check - move the King to a safe square, capture the checking piece, or block the attacker if it is a line piece. In notation use + after writing the checking move.

Checkmate: Where the king is attacked and cannot parry the threat. There are 3 possible ways out of check - move, capture & block. If none of these saves the King it is Checkmate. In notation ++ or #.

Chessboard: The 8x8 grid on which the game is played consisting of 64 squares (eight rows called ranks by eight columns called files) arranged in two alternating colors, light and dark.

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 presses their button, which simultaneously stops their clock and starts their opponent's. Analogue clocks where originally used and as the hand passed the 12 it would raise a flag which would fall once the hand began its downward motion. This is the origin of the term flag fall. Modern clocks are digital.

Chess Set: The 32 pieces used in a game of chess on the chessboard.

Chess960: Also called Fischer Random Chess, A variant of chess where the back-row pieces are set up in one of the 960 distinguishable possible positions. The pieces and pawns all have their normal moves, but the setup of pieces on the first rank is random, except that a few rules must be followed: the king must be placed on a square between the rooks, the bishops are placed on squares of opposite color, and Black's pieces are placed opposite White's.

Claim: The player may make a claim to the arbiter under various circumstances.

Classical Chess: 1. An opening system geared towards forming a full pawn center. Classical ideas were challenged by hypermodern ideas. 2. A game using a longer time control such as 40/2; the opposite of fast chess categories such as rapid, blitz or bullet.

Classical Bishop Sacrifice: See Greek gift sacrifice for explanation.

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.

Clock: One of the two time displays on a chess clock which tracks the time usage of one of the players.

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. Tournament games are all played by touch move rules.

Clock Time: Time (consumed or remaining) on the chess clock, in a tournament game.

Closed File: A file on which White and Black each have a pawn.

Closed Game: 1. 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. See also positional play. 2. 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. See also Open Game and Semi-Open Game.

Coffeehouse Chess: 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.

Color 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. Sometimes squares of a particular color can become weak due to the absence of a needed Bishop. See White and Black in chess.

combination: A sequence of moves, including forced moves, and often involving a sacrifice, to gain an advantage.

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.

Completed Move: Where a player has made his move and then pressed his clock. A completed Move should be distinguished from a committed move.

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.

Connected Pawns: Refers to two or more pawns of the same color on adjacent files. Connnected pawns can forma chain and protect each other. 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. 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

Contiguous Area: An area touching but not actually part of the playing venue. For example, the area set aside for spectators.

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 usually by having more attackers on the square than the opponent.

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.

Cook: In chess problems, an unintended duplicate solution, or a refutation.

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.

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. Also called related squares. Cf. opposition.

Counterattack: An attack that responds to an attack by the opponent. Of the 5 ways to answer an attack (move, capture, block, defend, counterattack), the counterattack is often the best.

Counter-gambit: 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 counter-gambits.

Counterplay: The defending side's own aggressive action. When the opponent is controlling the board the best response is counterplay.

cramped: Having limited mobility in a position. Often the best way out of a cramped position is the exchange of pieces to open squares for your remaining pieces.

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. The flex point between winning and losing.

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.

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. 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.

Cumulative (Fischer) Mode: Where a player receives an extra amount of time (often 30 seconds) prior to each move. Also called Increment.

Dark Square Bishop: One of the two bishops that moves on the dark squares, situated on c1 and f8 in the initial position. Both White and Black start with a dark 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 near left hand corner.

Dead Position: 1. Where neither player can mate the opponent’s king with any series of legal moves. For example when only Kings remain on the board. 2. 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 def 1 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.

Decoy: This is a tactic used to lure a piece to a particular square.

Default Time: The specified time a player may be late without being forfeited. Some international tournaments use zero-tolerance for tardiness. In USCF the standard is one hour (or until time runs out if a faster time limit is being used) unless announced before the tournament.

Defense: 1. A move or plan to meet the opponent's attack. 2. Part of the name of openings played by Black; e.g. the Scandinavian defense, King's Indian defense, English defense, etc.

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.

Delay (Bronstein) Mode: Both players receive an allotted "main thinking time". Each player also receives a "fixed extra time" with every move. The countdown of the main thinking time only commences after the fixed extra time has expired. Provided the player presses his clock before the expiration of the fixed extra time, the main thinking time does not change, irrespective of the proportion of the fixed extra time used.

Demonstration Board: A display of the position on the board where the pieces are moved by hand for demonstration to onlookers.

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 four" is rendered as "P-QB4". Now replaced by the standard algebraic notation. Some books still in circulation use Descriptive Notation

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.

Development: To develop means to move 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.

Diagonal: A straight line of squares of the same color, running from one edge of the board to an adjacent edge.

Disability: A condition, such as a physical or mental handicap, that results in partial or complete loss of a person's ability to perform certain chess activities. Persons with disabilities are often provided special accommodations to compensate for the disability.

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.

Displaced Piece: (FIDE) to put or take pieces from their usual place. For example, a pawn from a2 to a5; a rook partway between d1 and e1; a piece lying on its side; a piece knocked onto the floor.

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.

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.

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.

Doubled Pawns: Two pawns of the same color on the same file; generally considered a weakness due to their inability to defend each other.

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.

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.


Draw Line: An opening variation that commonly ends in a draw.

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.

Dynamic Play: A style of play in which the activity of the pieces is favoured 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.

E-cigarette: device containing a liquid that is vaporised and inhaled orally to simulate the act of smoking tobacco. Prohibited in tournaments.

ECO: The Encyclopaedia of Chess Openings (ECO), a standard and comprehensive chess opening reference. Also a classification system (ECO code) for openings that assigns an alphanumeric code from A00 to E99 to each opening.

Edge: An edge is a small but meaningful advantage (less than a Pawn) 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).

Elo Rating System: The Elo rating system is a method for calculating the relative skill levels of chess players, named after Arpad Elo. The Elo system has been used by the USCF since 1960 and by FIDE since 1970 and since 2012, FIDE publishes a monthly international chess rating list using the Elo system.

En passant: The pawn capture of a pawn that has moved two squared and has passed a pawn that could capture had it moved only one square. In notation, either e.p. or just show the normal capture on the square the capturing pawn sits on after the move.

En Prise: [from French, "in a position to be taken", 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.

Epaulette Mate: A checkmate position where the king is blocked on both sides by its own rooks.

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.

Escape Square: A safe square where the King can find refuge when attacked. See flight square.

Exchange: 1. 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 almost equal in value); this is also called an "even exchange". 2. 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.

Exchange Variation: This is a type of opening in which there is an early, voluntary exchange of pawns or pieces.

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.

Expanded CenterThe central sixteen squares of the chessboard. Also sometimes called central squares.

Explanation: (FIDE) A player is entitled to have a rule or ruling explained.

Family Fork: A knight fork that simultaneously attacks the enemy king (giving check), queen, and possibly other pieces. Also known as a "family check".

Fair Play: (FIDE) Whether justice has been done has sometimes to be considered when an arbiter finds that the Laws are inadequate and a judgment call must be made. Cheating is not permitted even in cases not directlt covered by the rules.

FEN: An abbreviation for Forsyth–Edwards Notation. FEN is used with PGN files to indicate a position other than the starting position.

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".

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.

FIDE Master: A chess title ranking below International Master.[150] 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. See also 50 Move Rule.

File: A vertical column of eight squares on the chessboard.

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.

First Board: In team chess, the player who is assigned to face the strongest opponents. Also called top board. 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.

Fischer Delay or Fischer Mode: Where a player receives an extra amount of time (often 30 seconds) prior to each move. Also called Increment or Cumulative Mode.

Flag: The indicator that displays when a time period has expired. Originally 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.

Flag-fall: Where the allotted time of a player has expired.

flank opening: An opening played by White and typified by play on one or both flanks (sides of the board).

Flight Square: A square to which a piece can move, that allows it to escape attack. Also called escape square. See also luft.

Fool's mate: The shortest possible chess game ending in mate: 1.f3 e5 2.g4 Qh4# (or minor variations on this).

Forced Mate: A sequence of two or more moves culminating in checkmate that the opponent cannot prevent.

Forced Move: A move that is the only one which 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.

Forcing Move: A move that presents a threat and limits the opponent's responses. Usually a check or capture.

Forfeit: To lose the right to make a claim or move. Or 2. To lose a game because of an infringement of the Laws.

Forfeit: Refers to losing the game by breaking rules, by absence or by exceeding the time control (forfeit on time).

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. GPCF usage is a Fork is only given by non-line pieces (King, Pawn or Knight) and line pieces (Bishop. Rook or Queen) give Double Attacks

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.Also see 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.

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. Also called casual game.

Gambit: A sacrifice (usually of a pawn) used to gain an early advantage in space or time in the opening.

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. See also bad bishop.

GPCF: Abrev for Greater Peoria Chess Federation or Greater Peoria Chess Foundation. The Foundation is a 501(c)3 organization which sponsors this site and provides incentives and encouragement to local schools and students. The Federation sponsors local tournaments and meets every Monday night.

Grandmaster: The highest title a chess player can attain (besides World Champion). It is a title awarded by FIDE. It cannot be taken away. The title was originally given to eight players who might qualify as world champion in the early 1900s. Today we have over a thousand GMs in the world. 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 is now used to refer to any such game drawn without eral effort on either players part.

Greek Gift Sacrifice: Also known as the classical bishop sacrifice, it is a typical sacrifice of a bishop by White playing Bxh7+ or Black playing Bxh2+ against a castled king to initiate a mating attack.

Half Open File: A file on which only one player has no pawns.

Handicap: For physical disability, see Disability; for a handicap game see Odds.

Hanging: Unprotected and exposed to capture. A hanging piece may also be said to be en prise.

Hanging Pawns: Two friendly pawns on adjacent files, with no further friendly pawns 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 are typically an attacking rather than a defensive asset.

Hypermodern: A school of thought that prefers controlling the center with pieces from the flanks as opposed to occupying it directly with pawns. Two major proponents of hypermodernism were Réti and Nimzowitsch.[182] See also Classical and Dynamic.

ICAAbrev for Illinois Chess Association

IESAAbrev for Illinois Elementary School Association

IESAAbrev for Illinois High School Association

I adjust: Said before adjusting a piece on its square on the chessboard. See j’adoube.

Illegal: A position or move that is impossible because of the Laws of Chess.

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.

Impairment: See disability.

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. See Time control#Compensation (delay methods).

Indian Bishop: A fianchettoed bishop, characteristic of the Indian defenses, the King's Indian and the Queen's Indian.

Indian Defense: An opening that begins 1.d4 Nf6. Originally used to describe queen's pawn s 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.

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.

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. 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.

Intermediate move: See zwischenzug.

Intermezzo: See zwischenzug.

Intervene: To involve oneself in something that is happening in order to affect the outcome.

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 defense), 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".

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. See also Pawn structure#Queen's Gambit – Isolani.

Isolated Pawn: A pawn with no pawn of the same color on an adjacent file.

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.

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.

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.

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. Penalties may be assessed against the kibitzer or even a player.

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.

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.

Kingside: The vertical half of the board on which the king stands at the start of the game.

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.

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.

Legal Move: A move made according to the Laws of Chess. See FIDE Article 3.10a.

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 building a bridge by placing a rook on the 4th rank in order to block the opponent's rook checks, thereby allowing the pawn to queen.

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. See also flight square.

Made: (FIDE) A move is said to have been ‘made’ when the piece has been moved to its new square, the hand has quit the piece, and the captured piece, if any, has been removed from the board. The move is made but not completed until the chess clock button has been pushed stopped the players clock and starting the opponent's clock.

Main Line: The principal, most important, or most often played variation of an opening.

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. Often the player with a pawn majority can force a passed pawn to win the game.

Major Piece. A piece of high value, a Rook or Queen.

Maróczy Bind: A bind on the light squares in the center, particularly d5, obtained by White by placing pawns on c4 and e4. Named for Géza Maróczy, it originally referred to formations arising in some variations of the Sicilian Defense, but the name is now also applied to similar setups in the English Opening and the Queen's Indian Defense. It was once greatly feared by Black but means of countering it have been developed since the 1980s and earlier.

Master: Loosely, a strong chess player who would be expected to beat most amateurs. It may also refer to a formal title such as International Master or National Master. Standards vary, but a master will usually have an Elo rating of over 2200.

Match: A competition between two individuals or two teams. A match may be the entire competition, or it may be a round in a knockout tournament or team tournament. A chess match always consists of at least two games, and often many more.

Mate: Abbreviation of checkmate.

Material: All of a player's pieces and pawns on the board. The player with pieces and pawns of greater value is said to have a "material advantage". When a player gains a material advantage they are also said to be "winning material". See Chess piece relative value.

Materialism: A playing style characterized by a willingness to win material at the expense of positional considerations. Chess computers are often materialistic.

Mating Attack: An attack aimed at checkmating the enemy king.

Mating Net: A position or series of moves that leads to forced mate.

MCO: Modern Chess Openings, a popular chess opening reference. Often the edition is also given, as in MCO-14, the 14th edition. Cf. ECO.

Middlegame: The part of a chess game that follows the opening and comes before the endgame, beginning after the pieces are developed in the opening. This is usually roughly moves 20 through 40.

Miniature: A short game (usually no more than 20 to 25 moves), for example: 1.e3 e5 2.Qf3 d5 3.Nc3 e4 4.Qf4?? Bd6! and White resigned in NN–Künzel (1900, Europe) because the queen is trapped. However, a significant minority of authors include games up to 30 moves. Usually only decisive games (not draws) are considered miniatures. Ideally, a miniature should not be spoiled by an obvious blunder by the losing side. A miniature may also qualify as a brilliancy. The Opera game is a famous example. Sometimes called a brevity [chiefly British]. See al

Minor Exchange The exchange of a bishop for a knight.

Minority Attack: An advance of pawns on the side of the board where one has fewer pawns than the opponent, usually carried out to provoke a weakness.

Minor Piece. A 3 point piece, a Bishop or Knight.

Mobile Pawn Center: Pawns on central squares able to advance without becoming weak.

Mobile Phone: Cellphone. A player may not have a mobile phone in his possession in a FIDE tournament, may not have it turned on in a US tournament.

Monitor: An electronic display of the position on the board.

Move: 1. 40 moves in 90 minutes, refers to 40 moves by each player. Or 2. having the move refers to the player’s right to play next. Or 3. White’s best move refers to the single move by White.

Move-counter: A device on a chessclock which may be used to record the number of times the clock has been pressed by each player.

Move Order: The sequence of moves one chooses to play an opening or execute a plan. Different move orders often have different advantages and disadvantages. A plan that uses certain moves, can sometimes be improved by making the identical moves but in a different sequence. See transposition. If you think you have a tactic but it doesn't work, try to change the move order.

Mysterious Rook Move: Coined by Nimzowitsch to refer to the placing of a rook on closed file in anticipation that the opponent is going to open the file. This move may either achieve a position with a rook on an open file, or it may alternatively hinder the opponent's intentions (prophylaxis). The meaning of the word has since expanded to refer to any rook move that appears to have a hidden purpose.

NN: No Name. Traditionally used in game scores to indicate a player whose name is not known. The origin is uncertain. It may be an abbreviation of the Latin phrase nomen nescio ("name unknown"). It was often used in the 19th century when the losing player would be embarrassed by being the subject of another's good moves.

Norm: A standard of competitive performance that is required in order for a chess player to be awarded one of several titles, such as Grandmaster, International Master, or Woman Grandmaster, etc. The chess organization, such as FIDE, that awards the titles, will established specifically what a norm is. For example a candidate might achieve a norm if they play in a tournament and face a certain number of grandmasters, and then have a certain number of wins in that tournament against players that are above a certain rating, and so on. If the candidate then collects a certain number of norms, three for example, they will win a grandmaster title. The details that define a norm can be obtained from the chess organization, and the details will change from time to time.

Normal Means: Playing in a positive manner to try to win; or, having a position such that there is a realistic chance of winning the game other than just flag-fall.

Notation: Any method of recording chess moves, allowing games to be later published, replayed and analyzed. The most common notation today is algebraic notation, which is used internationally. Formerly descriptive notation was standard in English language publications. There are also systems of notation for recording chess positions without the use of diagrams, the most common of which is Forsyth–Edwards Notation (FEN).

Octopus: A strongly positioned knight in enemy territory. A knight on e6 reaches out in eight directions, like the eight tentacles of an octopus.

Odds: This refers to the stronger player giving the weaker player some sort of advantage in order to make the game more competitive. It may be an advantage in material, in extra moves, in time on the clock, or some combination of those elements. Since the advent of the chess clock, time odds have become more common than material odds.

Olympiad: An international team chess tournament organized biennially by FIDE. Each team represents a FIDE member country.

Open File: A file on which there are no pawns. A file on which only one player has no pawns is said to be half-open.

Open Game: 1. A game in which exchanges have opened files and diagonals, and there are few pawns in the center, as opposed to a closed game. 2. Any opening that begins with the moves 1.e4 e5. Examples of Open Games include the Ruy Lopez, the Giuoco Piano, the Danish Gambit, and many others. The Open Game is also referred to as a Double King's Pawn Opening or Double King's Pawn Game.

Opening: The beginning phase of the game, roughly the first dozen moves, but it can extend much farther. In the opening players set up their pawn structures, develop their pieces, and usually castle. The opening precedes the middlegame.

Opening Innovation: A synonym for theoretical novelty.

Opening Preparation: Home study and analysis of openings and defenses that one expects to play, or meet, in later tournament or match games. In high-level play, an important part of this is the search for theoretical novelties that improve upon previous play or previously published analysis.

Opening Repertoire: The set of openings played by a particular player. The breadth of different players' repertoires varies from very narrow to very broad.

Opening System: An opening that is defined by one player's moves and that can be played generally regardless of the moves of the opponent, with the goal of reaching a desired type of middlegame position. Sometimes several different move orders are possible. Examples include the Colle System and Hippopotamus Defense.

Open Lines: Unobstructed files and diagonals. See also open game.

Open Tournament: A tournament where anyone can enter, regardless of rating or invitation. Cf. closed tournament.

Opposite Color Bishops: See bishops on opposite colours.

Opposition: A situation in which two kings stand on the same rank, file or diagonal with one empty square between them. The player to move may be forced to move the king to a less advantageous square. Opposition is a particularly important concept in endgames. Cf. corresponding squares.

Organizer. The person responsible for the venue, dates, prize money, invitations, format of the competition and so on.

outpost: An outpost is a square protected by a pawn that is in or near the enemy's stronghold. Outposts are a favourable position from which to launch an attack, particularly using a knight.

Outside Passed Pawn: A passed pawn near the edge of the board and not in the path of threats from the opponent's pawns. In the endgame, such a pawn can constitute a strong advantage, because it threatens to promote, and it also diverts the opponent's forces to restrain its advance.

Overextended: An overextended position results when a player has advanced pawns too far into his opponent's side without sufficient support. The premature advance can leave weaknesses in the player's camp or the advanced pawns themselves may be weak ("overextended pawns").

Overloaded: A piece that has too many defensive duties. An overloaded piece can sometimes be deflected, or required to abandon one of its defensive duties.

Overprotection: The strategy of protecting an important pawn or square more than is apparently necessary. This serves to dissuade the opponent from attacking that point, and the latent power of the "over protectors" assembled around an important point, is a significant threat that can bear fruit at a small tactical change in the position. Aron Nimzowitsch coined the term and was a proponent of overprotection.

Over the Board: 1. A game played face-to-face with the opponent, as opposed to a remote opponent as in online chess or correspondence chess. 2. Analysis carried out during a game in real time (not necessarily a face-to-face game) as opposed to during preparation. Finding accurate moves over the board is harder than finding them with computer assistance in one's own time. "I looked up the gambit Smith played and there's a line that refutes it, but I couldn't find it over the board." Abbr. OTB.

Overworked: A synonym for overloaded.

Pairing: The assignment of opponents in a tournament. The most common pairing methods used in chess tournaments are round-robin and the Swiss system.

Passed Pawn: A pawn that has no pawn of the opposite color on its file or on any adjacent files on its way to queening.

Passive: Describes a piece or pawn that is inactive and able to move to or control relatively few squares, or a position without possibilities for attack. or counterplay. Antonym: active.

Passive Sacrifice: The sacrifice of a piece, by moving a different piece, leaving the sacrificed piece under attack.

Pattern Recognition: A part of chess thinking that involves remembering and recognizing certain recurring aspects large and small, visual and dynamic. It is a kind of thinking that gives an advantage to a player with great experience. It is distinct from the intellectual activity of calculation. It uses intuitive thinking that is familiar to humans, but is foreign to computers. It can be developed by studying chess puzzles. It has been studied by Adriaan de Groot, and other scientists, who have attempted to discover how chess players think.

Patzer: A weak chess player (from German: patzen, "to bungle"). See also woodpusher.

Pawn and Move: A type of odds game, common in the 18th and 19th centuries, in which the superior player plays Black and begins the game with one of their pawns, usually the king bishop pawn, removed from the board; plus White gets an extra move at the start.

Pawn Break: A pawn move that attacks an enemy pawn in order to open up lines and/or challenge the opponent's pawn structure. See also break.

Pawn Center: A player's pawns in the center of the board. Pawns on the squares adjacent to the center may also be considered part of the pawn center. Having an strong pawn center was considered absolutely essential until the hypermodern school introduced some new ideas. See King's Indian Defense, Four Pawns Attack for an example of an opening leading to an extended pawn center.

Pawn Chain: Two or more pawns of the same color diagonally linked. A pawn chain’s weakest point is the base, because it is not protected by another pawn. See pawn structure.

Pawn Island: A group of pawns of one color on consecutive files with no other pawns of the same color on an adjacent file. A pawn island consisting of one pawn is an isolated pawn.

Pawn Majority: See majority.

Pawn Race: A situation where both opponents are pushing a passed pawn in effort to be first to promote.

Pawn Skeleton: See pawn structure.

Pawn Storm: An attacking technique where a group of pawns on one wing is advanced to break up the Defense.

Pawn Structure: The placement of the pawns during the course of a game. As pawns are the least mobile of the pieces and the only pieces unable to move backwards, the position of the pawns greatly influences the character of the game.

Penalties: The arbiter may apply penalties in ascending order of severity.

Performance Rating: A number reflecting the approximate rating level at which a player performed in a particular tournament or match. It is often calculated by adding together the player's performances in each individual game, using the opponent's rating for a draw, adding 400 points to the opponent's rating for a win, and subtracting 400 points from the opponent's rating for a loss, then dividing by the total number of games. For example, a player who beat a 2400-rated player, lost to a 2600, drew a 2500, and beat a 2300, would have a performance rating of 2550 (2800 + 2200 + 2500 + 2700, divided by 4).

Perpetual Check: When a player puts the opponent in check, and the check could be repeated endlessly, the game will be declared a draw by repetition. The expression is often shortened to perpetual. This tactic can be resorted to as a form of insurance in a losing position.

PGN: An abbreviation for Portable Game Notation. PGN encoded games are readable by both computers and people and so has become the universal way of sharing games between computers. Games can be typed by hand using only a simple text editor.

Philidor position Usually refers to an important chess endgame that illustrates a drawing technique when the defender has a king and rook versus a king, rook, and pawn. It is also known as the third rank defence, because of the importance of the rook on the third rank cutting off the opposing king. It was analyzed by Philidor in 1777.[263] See also Rook and pawn versus rook endgame.

Piece: 1. One of the 32 figurines on the board. Or 2. A queen, rook, bishop or knight.

Pin: When a piece is attacked but cannot legally move, because doing so would expose the player’s own king to the attack; or when a piece is attacked and can legally move out of the line of attack, but such a move would expose a more valuable piece (or an unprotected piece) to capture. See absolute pin and relative pin.

Plan: A strategy employed in a specific position to optimize a player's advantages while minimizing the impact of positional disadvantages. Frank Marshall famously said a bad plan is better than no plan.

Playable: Said of an opening, a position, or move that gives the person playing it a tenable position.

Playing Area: The place where the games of a competition are played.

Playing Venue: 1. The only place to which the players have access during play, 2. The building hosting the event.

Points: Normally a player scores 1 point for a win, ½ point for a draw, 0 for a loss. An alternative is 3 for a win, 1 for a draw, 0 for a loss.

ply: Term mainly used in computer chess to denote one play of either White or Black. Thus equal to half a move.

Poisoned Pawn: An unprotected pawn that, if captured, causes positional problems or material loss.

Poisoned Pawn Variation: A variation of the Najdorf Variation of the Sicilian Defense, where some players call White's pawn on b2 a poisoned pawn since capturing it is very dangerous for Black.

Portable Game Notation: This is a popular computer-processible ASCII format for recording chess games (both the moves and related data). Abbr. PGN.

Positional Play: Play based on strategy, on gaining and exploiting small advantages, and on analyzing the larger position, rather than calculating the more immediate tactics.

Positional Sacrifice: A sacrifice in which the lost material is not regained via a combination, but instead gains positional compensation. These typically require deep positional understanding and are often overlooked by computers. Also known as a true sacrifice, as opposed to a pseudo sacrifice or sham sacrifice.

Post Mortem: Analysis of a game after it has concluded, typically by one or both players and sometimes with spectators (kibitzers) contributing as well. A player who has just lost the game thanks to a dubious move has the chance to win the post-mortem by finding a better one.

Prepared Variation: A well-analyzed novelty in the opening that is not published but first used against an opponent in competitive play.

Press the Clock: The act of pushing the button or lever on a chess clock which stops the player’s clock and starts that of his opponent.

Promotion: Where a pawn reaches the eighth rank and is replaced by a new Queen, Rook, Bishop or Knight of the same color.

Prophylaxis: A strategy that frustrates and protects against an opponent's plan or tactic for fear of the consequences. See also blockade, overprotection, and mysterious rook move.

Protected Passed Pawn: A passed pawn that is supported by another pawn.

QGA: Abrev. The Queen's Gambit Accepted Opening.

QGD: Abrev. The Queen's Gambit Declined Opening.

Quad: A round-robin style tournament among four players, where each participant plays every other participant once.

Queen: 1. The Chess Piece. 2. As in to queen a pawn, meaning to promote a pawn to a queen. 2.

Queenside: The vertical half of the board on which the queen stands at the start of the game.

Quick Chess: US definition of a game played at Game/30 or faster.

Quickplay Finish: (FIDE) The last part of a game where a player must complete an unlimited number of moves in a finite time. Also called sudden death.

Quiet Move: A move that does not attack or capture an enemy piece.

Rank: A horizontal row of eight squares on the chessboard.

Rapid Chess: A game where each player’s thinking time is more than 10 minutes, but less than 60.

Repetition: 1. A player may claim a draw if the same position occurs three times. 2. A game is drawn if the same position occurs five times. The 5 time repetition must be called internationally, may be called by the TD in the US.

Resigns: Where a player gives up, rather than play on until mated.

Rest Rooms: Toilets should be located before the start of play.

Result: Usually the result is 1-0, 0-1 or ½-½. In exceptional circumstances both players may lose (Double Forfeit), or one score ½ and the other 0. For unplayed games the scores are indicated by +/- (White wins by forfeit), -/+ (Black wins by forfeit), -/- (Both players lose by forfeit).

Regulations of an Event: Permitted variations in the rules set by the organizers of an event which must be stated ahead of time.

Sealed Move: Where a game is adjourned the player seals his next move in an envelope. Not used with Sudden Death time controls.

Scoresheet: A paper sheet with spaces for writing the notation of the moves. This may also be electronic.

Screen: An electronic display of the position on the board.

Spectators: People other than arbiters or players viewing the games. This includes players after their games have been concluded.

Standard Chess: A game where each player’s thinking time is at least 60 minutes.

Steward: In IESA and IHSA chess tournaments the persons enforcing the rules in the playing area are called stewards.

Square of Promotion: The square a pawn lands on when it reached the eighth rank.

Square of the Pawn An imaginary square made of several individual squares where one side is the distance from the pawn to the queening square. If the opponent's King can step into that square he can catch the pawn in a simple race.

Time Control: 1. The regulation about the time the player is allotted. For example, 40 moves in 90 minutes, all the moves in 30 minutes, plus 30 seconds cumulatively from move 1. Or 2. A player is said ‘to have reached the time control’, if, for example he has completed the required 40 moves in less than 90 minutes.

Time Period: A part of the game where the players must complete a number of moves or all the moves in a certain time. A time control may consist of more than one time period.

Touch Move: The rule that states if a player touches a piece with the intention of moving it, he is obliged to move it.

Tournament Director (TD) The official in charge of tournament play. There may be multiple directors: pairings director (in charge of making pairings), multiple floor directors (in charge of enforcing the rules on the playing floor) and the Chief Tournament Director who is ni charge of all areas covered by the rules during the tournament. There may also be multiple assistant directors reporting to the Chief TD. NOTE: in IESA and IHSA events the Floor Directors are called Stewards.

Vertical: The 8th rank is often thought as the highest area on a chessboard. Thus each file is referred to as "vertical".

White: 1. There are 16 light-colored pieces and 32 squares called white. Or 2. When capitalized, this also refers to the player of the white pieces.

Zero tolerance: Where a player must arrive at the chessboard before the start of the playing session. Players not arriving on time are forfeited.

50 Move Rule: A player may claim a draw if the last 50 moves have been completed by each player without the movement of any pawn and without any capture.

75 Move Rule: The game is drawn if the last 75 moves have been completed by each player without the movement of any pawn and without any capture. The draw must be called by the arbiter in international tournaments but may be called in US tournaments at the discretion of the Tournament Director.