Chess Glossary

This glossary defines chess terminology used on this site and elsewhere in the chess world. Items in italics refer to terms defined elsewhere in the glossary. Chess terms from other languages are indicated.



Action: A USCF-rated Game/30 tournament. See: time control.

Activity: The potential action of the pieces on the chessboard.

Adjourned game: A tournament game that has been paused to be resumed at another time. See: sealed move.

Algebraic Notation: The most common form of chess notation used today. The chessboard is a grid with eight vertical files lettered a through h, and eight horizontal ranks numbered 1 through 8. Each square is named by a letter and number, e.g. b2 or f7.

Angstgegner: An unpleasant opponent against whom a player has particularly poor results. Implied is that on paper, one player should not have such a lopsided score over the other; psychological factors are at work. Against this person, one feels snakebitten. Similar terms: bête noire, bogeyman, nemesis, problem opponent. (German)

Arbiter: An official who supervises FIDE-rated tournaments. There are three official categories of arbiter, in ascending order: National Arbiter, FIDE Arbiter, and International Arbiter.

Armageddon: The last (or only) game of a tiebreak playoff, usually a blitz game. White starts the game with more time than black (e.g., 5 minutes to 4 minutes), but Black is declared the winner in the event of a draw.

Annotations: Notes about chess games, usually containing variations and commentary.

Anti-draw rules: Stipulations in tournament rules that aim to ensure “fighting chess.” Some examples include players not being allowed to agree a draw before move 30, or all draw offers needing to be made through the Arbiter. See also: Sofia rules.

ARO: Average rating of opponents.

Associate National Tournament Director (ANTD): A USCF Tournament Director who has directed the following types of events can, in general, apply for ANTD:

    • Ten tournaments expected to draw more than 100 players (some subsitutions are allowed)
    • Three tournaments that awarded $1,000+ in prizes
    • One team or individual-team tournament with at least 50 players
    • One round robin or two quick round robin tournaments with six or more players with an average rating of at least 1400
    • Chief Assistant to a National Tournament Director at a tournament expected to draw 300+ players and award $5,000+ in prizes

The applicant needs to score 80% on an essay exam. ANTDs are certified for six-year renewable terms.

Attack: A piece or pawn in position to capture an enemy unit on a future turn. This may or may not cause the opponent distress. See also: threat.



Backward pawn: A non-isolated pawn that cannot be protected by a neighboring pawn if it advances.

Battery: The combined action of two straight-line pieces on a single file, rank, or diagonal. The three possibilities are queen and rook, queen and bishop, or two rooks.

Berger tables: Reference tables that assign round robin pairings based on start numbers. Named after Austrian master Johann Berger (1845-1933).

Suppose we have a round robin with 10 players; i.e. each player contests 9 total games, one against every other entrant. The players randomly draw start numbers. These numbers have nothing to do with rating or title.

    • Players who draw numbers 1 through 5 receive five White games and four Black games.
    • Player 1 gets White in the first two rounds; Player 6 gets Black in the first two rounds.
    • Player 2 gets White in rounds 3-4; Player 7 gets Black in rounds 3-4.
    • Player 3 gets White in rounds 5-6; Player 8 gets Black in rounds 5-6.
    • Player 4 gets White in rounds 7-8; Player 9 gets Black in rounds 7-8.
    • Player 5 gets White in all odd-numbered rounds; Player 10 gets Black in all odd-numbered rounds.
    • Player 10 stays on Board 1 the entire event; the other players move around.

Best game prize: A prize awarded to the game adjudged to be the highest quality in a tournament; in contrast to the traditional brilliancy prizes, the games with the flashiest combinations are not always chosen. It is also possible for both players to share a best game prize in a well-played draw. See also: brilliancy prize.

Bishop pair: Having both bishops as opposed to having a bishop and a knight, or two knights. This is considered an advantage in most positions. Since both players begin with two bishops, it really applies when a bishop for knight exchange has taken place. See also: minor exchange.

Blitz: A game of chess where each player has a total of ten minutes or less of thinking time. FIDE blitz regulations require each player to have at least three minutes of thinking time. Blitz games are rated separately from rapid games and standard games.

Blockade: Placing a piece in the path of an enemy pawn to keep it from advancing.

Blunder: A very bad move that changes the evaluation of a position from winning to drawing, drawing to losing, or winning to losing.

Brilliancy: A game featuring attractive combination play, often a miniature. This game may or may not actually win a brilliancy prize.

Brilliancy prize: A game awarded a special prize at a tournament. Historically, brilliancy prizes were awarded to games featuring stunning combinations. See also: best game prize.

Bronstein delay: A timing mode named after 1951 World Championship Challenger David Bronstein (1924-2006). A player’s clock begins to run, and after completing their move seconds are added back to their time, as with increment. However, if the player does not use all of their bonus seconds, they only receive what they used. Therefore, a player can never have more time than they started with.

Buchholz: A tiebreak commonly used in Swiss-system tournaments calculated by summing the total scores of a player’s opponents. Modified versions include Median Buchholz, Buchholz Cut-1, etc. Also called Solkoff.

Bughouse: A chess variant with two teams of two players playing on neighboring boards. White on Team A faces black on Team B, and white on Team B faces black on Team A. Since each player’s opponent has the same color as their teammate, every unit captured by a player is given to his or her partner. You can play a move on your board, or place a unit captured by your partner on your board instead. There are two restrictions: pawns cannot be placed on the 1st or 8th rank, and a unit cannot capture from off the board. When victory is achieved on one board (by checkmate or a win on time) both games end immediately. Also called siamese chess.

Bullet: A game with 1 minute total for each player, possibly including a 1-second increment.

Burstein System: An alternative to the FIDE Dutch System for pairing Swiss-System tournaments; players in a score group are ranked by their Sonneborn-Berger, Buchholz, and Median tiebreaks before pairing. Named for Almog Burstein (born 1950), an Israeli International Arbiter and International Organizer.

Bye: A game for which a player is not assigned an opponent.

    • In a round robin tournament with an odd number of players, one player will get a bye every round worth 0 points.
    • In a Swiss-system tournament, an odd number of players to be paired will result in one player being assigned a bye worth 1 point. This will usually be the player with the lowest rating having the lowest score, but not an unrated player.
    • A player can request a bye for any round they do not wish to play. This bye can count for either 0 points or ½ point depending on the rules of the tournament.



Caissa: The goddess of chess.

Candidate: There are two very different definitions:

    • A participant in a Candidates Tournament or series of Candidates Matches.
    • The unblocked pawn in a pawn majority. It is not a passed pawn, but a pawn the player hopes to advance in order to create one.

Candidate move: A move a player considers making on their turn.

Candidate Master (CM): FIDE and USCF award this title differently:

    • FIDE: A playing title available to any player who achieves a FIDE rating of at least 2200.
    • USCF: A playing title automatically earned when a player achieves a USCF rating of at least 2000 and five Candidate Master norms (usually requiring a performance rating of 2200+).

Candidates Matches: A series of elimination matches that decides the Challenger among eight Candidates. Eight players play four matches in the quarterfinal, four winners play two matches in the semifinal, and two players play a match in the Candidates Final. This system was in place from the 1964 through 1993 World Championship cycles, and returned for one cycle in 2011.

Candidates Tournament: A round robin tournament to decide the Challenger of the upcoming World Championship Match. Used for the 1948 through 1963 Championship cycles, it returned in 2013 and is the current system.

Capture: The act of removing an enemy unit from the chessboard. To do this, you must make a legal move with one of your pieces or pawns to a square occupied by an enemy piece or pawn. When you do, your unit takes over the square and the enemy unit is removed from the board. But see: en passant.

Castling: A special move where the king and a rook move on the same turn. More details here.

Category: The classification of a round robin tournament based on the average rating of its players, in 25 point bands. Category 1 is 2251-2275, Category 2 is 2276-2300 … Category 19 is 2701-2725, etc. Used in FIDE and ICCF events.

Center: The four centermost squares on the chessboard (d4, d5, e4, and e5).

Challenger: The opponent of the titleholder in a World Championship Match. A player normally becomes the Challenger by winning a Candidates Tournament or a series of Candidates Matches.

Check: An attack on the king by an enemy piece or pawn. A player must get their king out of check before doing anything else. If this is not possible, the result is checkmate.

Checkmate: A player’s king is attacked with no way to save him. The game ends immediately.

Chess Life: The official monthly magazine of the USCF.

Chess Life for Kids: The official bi-monthly magazine of the USCF, for players age 12 or under.

Chess 960: A variant where the king, queen, rooks, bishops, and knights start in one of 960 possible configurations, chosen at random. There are two restrictions: bishops must start on opposite colors as in standard chess, and the king must start between both rooks. The white and black pieces mirror each other. Also called Fischer Random Chess or Shuffle Chess. Example:

Chess clock: The timing device used in chess tournaments. It consists of two linked timers; as one timer runs, the other is stopped. See: time control.

Chess Informant: The English name of Serbian chess publisher Šahovski Informator and its flagship product. Established in 1966 and published quarterly, Chess Informant contains hundreds of high-level games, combinations, and endgames. Šahovski Informator also created the ECO opening classification system, and the symbolic notation that is universal today.

Class: 200-point bands that estimate a player’s skill based on USCF rating. Class E is 1000-1199, Class D is 1200-1399, Class C is 1400-1599, Class B is 1600-1799, and Class A is 1800-1999.

Class player: A player rated below 2000 USCF.

Closed file: A file containing one or more pawns of both colors.

Closed game: A game beginning with 1.d4 d5.

Closed tournament: An invitation-only tournament, usually held as a round robin with a small group of players. In many countries this is how the final of the national championship is conducted, with the players qualifying through various means.

Club Tournament Director: The initial level of certification for USCF Tournament Directors, obtained by reading the USCF rulebook and signing a form promising to abide by USCF rules. These TDs can be Chief TD of events expected to draw less than 50 players. Club TDs are certified for three-year renewable terms.

Color complex: A group of squares of one color. A weak color complex is a group of squares of one color that cannot be defended by pawns, making it possible for the opponent to establish pieces there.

Combination: A series of moves involving sacrifices that leads to a positive result for the player initiating it. Common goals are checkmate, a gain of material, or pawn promotion.

Compensation: The non-material benefit a player receives for a sacrifice. This may include a strong attack, a passed pawn, a safer king, etc.

Composer: A person who creates a chess problem or study.

Composition: A problem or study not from an actual game.

Conditions: Financial or other compensation of value given to a player competing in a tournament that is not contingent upon their results.

Cook: A flaw in the intended solution of a problem or study.

Correspondence chess: Games played via postal mail, email, or web server over a long period of time. Correspondence games can last for years: a typical time control for ICCF is 10 moves in 50 days.

Counterplay: Threats and ideas that fight against an opponent who has the initiative.

Cross-pin: A piece pinned on two different lines simultaneously. Also called a double pin.

In the game Kortschnoj—Udovcíc, Leningrad 1967 shown below, White has just played 23.Qg4-h4, creating a cross-pin against the Black bishop on e7. Capturing the Qh4 is illegal, while capturing the Bb4 exposes the Qd8 to capture.

Cumulative of opposition: The combined cumulative scores of a player’s opponents. See: cumulative score.

Cumulative score: The sum of a player’s round-by-round scores in a tournament. Example: a player who, in a four-round tournament, wins their first two games, loses the third, and wins the fourth would have a cumulative score of 1+2+2+3 = 8.



Decoy: A tactical idea where an enemy piece is drawn to a certain square during a combination. Also called attraction or enticement.

Default time: The amount of time after the start of a round before a late player is forfeited.

    • FIDE: 0 minutes. The regulations of an event may specify otherwise. See zero-tolerance rule.
    • USCF: 60 minutes or until a player’s time runs out, whichever comes first. The regulations of an event may specify otherwise.

Defend: To protect a piece or a square under attack or that might come under attack.

Deflection: A tactical idea where an enemy piece is forced away from a certain square during a combination.

Delay: Each player receives a set amount of free time on each move before their chess clock starts to run, usually 5 or 10 seconds. See also: Bronstein delay.

Descriptive Notation: An old style of chess notation, mostly obsolete today. More details here.

Desperado: A piece that cannot avoid capture takes the most valuable enemy piece or pawn it can, before being lost.

Development: Bringing pieces from their starting squares into battle.

DGT: Digital Game Technology, the Dutch company founded in 1992 that makes electronic chess sets, clocks, and other equipment that has become the standard at international tournaments.

Diagonal: Straight lines of the same color (light or dark) running along the chess board.

Direct title: A FIDE title earned by achieving a specified place or level of performance in a World or Continental Championship. Every playing title (GM, IM, WGM, WIM, FM, WFM, CM, and WCM) can be earned in this way.

Discovered attack: One piece moves and reveals another friendly piece that creates an attack.

Discovered check: One piece moves and reveals another friendly piece that gives check to the enemy king.

Domination: Said of pieces that cannot safely move because they will be lost through capture or a tactical idea such as a fork or skewer. This theme appears often in the endgame study.

Double attack: One move creates an attack on two targets at the same time. These targets can be vulnerable pieces and/or important squares.

Double bishop sacrifice: A thematic sacrifice of a bishop against h7/h2 and g7/g2 leading to a king hunt. Also called Lasker’s Combination, from the game Lasker-Bauer, 1889, shown below:

Double check: One piece moves and reveals another friendly piece, and both pieces check the enemy king simultaneously. The only way to escape a double check is to move the king, if possible. All double checks are also discovered checks, but the reverse is not necessarily true.

Doubled pawns: Two pawns of the same color on the same file.

Draw: A tied game. Each player scores ½-point. Draws can occur in the following ways:

    • Agreement: The players can agree on a draw.
    • Insufficient material: Neither side has sufficient material remaining to deliver checkmate (for example, King vs. King, no pawns; King and Bishop vs. King, no pawns; or King and Knight vs. King, no pawns).
    • 50 move rule: One player claims a draw after 50 consecutive moves (for White and Black) are played without a pawn move or capture having taken place.
    • Triple occurrence of position: One player claims a draw by stating their intention to make a move that will cause an identical position to occur on the board for a third time in the game; the occurrences need not be consecutive.
    • Both players run out of time on the clock.

Draw odds: A draw is as good as a win in deciding the winner of a competition.

    • In fixed-length World Championship matches through 2004, the Champion retained their title if the score was tied at the conclusion of all games. Since 2004, a playoff is contested in the event of a drawn match.
    • In the championship match of some team events, the higher-ranked team after preliminary competition may receive draw odds.
    • In an Armageddon tiebreak game, White receives extra time, while Black receives draw odds.

Dual-rated: An USCF-rated game with a sudden death time control of at least 30 minutes but not exceeding 60 minutes. Such games are both standard– and quick-rated.

Dubov System: An alternative to the FIDE Dutch System for pairing Swiss-System tournaments; players in a score group are ranked by their average rating of opponents (ARO) before pairing. Named for Eduard Dubov (1938-2018), a Russian International Arbiter and mathematician.

Dutch System: The default pairing algorithm for FIDE-rated Swiss-system tournaments. It is very strict: under its rules a different Arbiter or pairing software should generate identical pairings. Other more rarely-used pairing systems include the Burstein, Dubov, and Lim systems.



ECO: The Encyclopedia of Chess Openings. First published by Šahovski Informator in the 1970s, it divides chess openings into five volumes: A, B, C, D, and E. Within each volume are 100 codes, numbered 00 through 99: A00-A99, B00-B99, C00-C99, D00-D99, and E00-E99.

    • Volume A: Mostly includes Flank Openings like the English and Reti Openings, and irregular openings not included in other volumes (for example: 1.f4 and 1.g4).  You can also find the Dutch, Modern Benoni, Benko Gambit, and even some Queen Pawn Games here.
    • Volume B: Semi-open games except the French Defense. B00-B09 explores the Scandinavian, Alekhine’s Defense, the Pirc and Modern Defenses, and others. B10-B19 is the Caro-Kann. B20-B99 covers the Sicilian Defense.
    • Volume C: C00-C19 is the domain of the French Defense. C20-C99 covers the open games. WIthin this territory, C60-C99 includes all Ruy Lopez lines.
    • Volume D: The book for most closed games, plus the Grunfeld Defense.
    • Volume E: This is the place to find most of the Indian Defenses including, among others, the Catalan, Nimzo-Indian, Queens Indian, and King’s Indian.

Elo: The rating system and unit of rating points used by FIDE. Named for Arpad Elo (1903-1992), Hungarian-American chess master and physics professor. The first official FIDE rating list was published in January 1971. Elo ratings have also gained popularity outside of chess.

Endgame: The final part of the game; a tipoff that the endgame has been reached is that the kings play an active role in the game.

En passant: A special method of pawns capturing enemy pawns. More details here. (French)

En prise: Said of a piece or pawn vulnerable to capture. (French)

Entry point: A square vulnerable to invasion, particularly by an enemy rook or queen.

Established rating: In USCF, a rating calculated in the normal way once a player has played 26 rated games.

Exchange: The act of trading pieces.

Exchange, the: A trade of rook for bishop or rook for knight.

Expert: In USCF, a player who has achieved an established rating of 2000 or higher.



Fairy chess: A branch of chess composition where some of the Laws of Chess are changed; for example, in the movements of the pieces.

FederationThe FIDE country a player represents in internationally-rated tournaments. This is usually, but not necessarily, the country a player was born in or lives in.

Fianchetto: For White: b2-b3 and Bc1-b2, or g2-g3 and Bf1-g2; for Black: …b7-b6 and …Bc8-b7, or …g7-g6 and …Bf8-g7. Developing a bishop in this way places it in position to control one of the long diagonals. (Italian)

FIDE: Féderacion Internationale des Échecs or International Chess Federation, established 1924. (French)

FIDE Arbiter (FA): A title allowing arbiters to supervise most FIDE-rated events. It is earned by achieving three FA norms, attending a seminar and passing an exam. See: International Arbiter.

FIDE Master (FM): A playing title available to any player who achieves a FIDE rating of 2300.

File: The eight vertical columns lettered a, b, c, d, e, f, g, h running up and down the board called “a-file,” “b-file,” etc.

Fischer: A timing mode where a player gets a predetermined number of seconds added to their clock after they complete each move. Named for Bobby Fischer (1943-2008), World Chess Champion 1972-1975. Also called bonus or increment.

Flank Opening: An opening that does not begin with 1.e4 or 1.d4, and does not transpose back into open, closed, semi-open, or semi-closed game territory.

Floor: In USCF, a rating level that a player can never drop below, no matter their results. A floor is usually calculated by setting the last two digits of a player’s highest-achieved rating to zero and then subtracting 200 points. The minimum rating is 100, and there are floors in 100-point increments from 1200 to 2100. But see Original Life Master. Examples:

    • Highest rating: 1400. Floor: 1200.
    • Highest rating: 1399. Floor: 100.
    • Highest rating: 2412 (with <300 games over 2200). Floor: 2100.
    • Highest rating: 2312 (with 300+ games over 2200). Floor: 2200.

Fork: A single unit attacks two or more targets at the same time.



Gambit: An opening sacrifice of one or more pawns and/or pieces for compensation, usually in the form of accelerated development or a quick attack on the enemy king.

Grandmaster (GM): The highest playing title that can be earned in chess. It can be earned as a direct title, but typically requires a player to achieve three GM norms and a 2500 Elo rating.

Greek gift: A thematic sacrifice of a bishop against h7/h2 leading to a king hunt. Also called classic bishop sacrifice or Greco sacrifice.



Half-open file: A file containing pawns of only one color. Also called semi-open file.

Hanging pawns: Two pawns standing side-by-side with no friendly pawns on neighboring files. These pawns control several important squares, but are also vulnerable to attack.

Helpmate: A chess problem where Black moves first and both players make moves that help bring about a checkmate of the Black king, with White making the final move.

Hole: A square in enemy territory that cannot be controlled by one of their pawns. This is often a central square in front of a backward pawn. Also see outpost.

Hort system: A method for awarding money prizes where half of the prize money among tied players is split equally, while the other half is awarded based on mathematical tiebreaks. Named after Czech-German grandmaster Vlastimil Hort (born 1944).

Horwitz bishops: Two bishops of the same color attacking adjacent light and dark diagonals. Named for Bernhard Horwitz (1807-1885), a German chess master and study composer.

House player: A player not registered for a tournament available to face a competitor assigned a 1-point bye.

Hybrid: A tournament where the games are played and timed on an internet chess server, but the players are supervised in-person by arbiters at their locations.



ICCF: International Correspondence Chess Federation. The governing body for correspondence chess, sanctioned by FIDE. Unlike over-the-board chess, there are no restrictions on outside assistance in ICCF play, including computer usage.

Illegal move: A move not allowed by the laws of chess. The player must take back their move and make a different one with the same piece (if possible). In a tournament, the opponent gets an extra two minutes added to their chess clock. In FIDE events, the game is lost by a player who makes two illegal moves in the same game.

In-between move: See: Intermediate Move.

Increment: A set amount of time added to a player’s clock after the completion of each move. Also called bonus or Fischer mode.

Indian Defense: A semi-closed game typically starting with 1.d4 Nf6. The name comes from a common pattern of development in Indian chess. Examples include the King’s Indian Defense, Queen’s Indian Defense, Grünfeld Defense, Nimzo-Indian Defense, and Catalan Opening.

Individual-Team tournament: A Swiss-system tournament where the scores of players from the same school or team are pooled. An unlimited number of players may enter, but only a certain number of scores are counted towards a team’s score, usually the best 3 or 4. Pairings attempt to avoid players from the same team facing each other.

Initiative: Controlling the flow of the game, usually by continuously making threats and forcing your opponent to respond to them.

International: A tournament open to players from any federation, for FIDE rating. Title norms are often available as well. Entry may be restricted to players with a certain minimum rating.

International Arbiter (IA): The highest title for arbiters, allowing them to supervise all FIDE-rated events. It can be earned by FIDE Arbiters achieving four IA norms.

International Master (IM): The second-highest playing title that can be earned in chess. It can be earned as a direct title, but typically requires a player to achieve three IM norms and a 2400 FIDE rating.

International Organizer (IO): The title allowing a person to be Chief Organizer of an official FIDE event. It requires three organizer norms, attending a seminar, and passing an exam.

Interference: Placing a piece in between one enemy piece and another enemy piece that defends it on a rank, file, or diagonal. See also: Novotný.

Intermediate move: A reply to an opponent’s threat that takes higher priority, forcing them to respond. Usually a check or capture, such moves can be unexpected and often win immediately.

Intermezzo: See: Intermediate Move. (Italian)

Interzonal: From 1948-1993, one or more tournaments in the World Championship cycle that determined which players advanced to the Candidates Tournament or Candidates Matches.

Isolani: An isolated d-pawn, usually referenced in the middlegame. Also called IQP (from Isolated Queen Pawn, a vestige of Descriptive Notation).

Isolated pawn: A pawn that has no friendly pawns on neighboring files.

Isolated pawn couple: A would-be isolani that has gained the protection of a pawn on c6/c3.



J’adoubeThis is announced by a player to his or her opponent before adjusting a piece not centered on its square. Without saying “J’adoube” or “I adjust” before touching a piece, the touch move rule applies. (French)

JaVaFo: The most popular engine used by major tournament management software to create pairings under the FIDE Dutch System. Authored by Italian International Arbiter Roberto Ricca, the name “JaVaFo” combines the names of Ricca’s nieces and nephews Johanna, Victoria, and Francesco.

Junior tournament: An event for players under 21 years of age.



K-factor: The coefficient multiplied by the value of (Wins – Win expectancy) to produce rating change for a player. If a player scores more points than expected based on their rating and opponents’ ratings, this value is positive and they gain points. If they score less than expected, this value is negative and they lose points.

In FIDE Standard Chess:
K=40 for new players who have completed less than 30 games; and players under 18 years of age also rated below 2300.
K=20 for players rated below 2400.
K=10 for players who have reached 2400; upon reaching 2400, a player’s K remains 10 for life, even if their rating drops below 2400.

Key: The solution to a composition.

King hunt: An attack that forces the enemy king to run far from his shelter.

King’s field: The squares around a kingside castling position often targeted by the opponent.

Kingside: The half of the board where the kings start the game.

Knockout tournament: An elimination tournament where half the field is reduced each round until there is one winner.

Koya: A tiebreak that counts victories against opponents who have won more than 50% of their games. Typically used only for round robin tournaments, it is named for Indian chess promoter and FIDE Vice-President Ummer Koya (1951-2020).



Laws of Chess: The official rules of chess as approved by FIDE.

Lever: A pawn advance setting up an exchange of pawns that opens space for other pieces. This term was popularized by Austrian International Master and International Arbiter Hans Kmoch (1894-1973) in his book Pawn Power in Chess (1959). See also: pawn break.

Lim System: An alternative to the FIDE Dutch System for pairing Swiss-System tournaments; players in the Median score group are paired last.

Local Tournament Director: A Club Tournament Director who has directed at least three tournaments totalling 50 or more players, while serving as Chief TD of at least one of these events, can apply for Local TD. This requires passing an exam with a score of 80%. Local TDs are certified for four-year renewable terms.

Luft: An escape square for a castled king to avoid checkmate on the back rank. (German)



Major piece: A queen or a rook. Also referred to as heavy piece.

Match (Individual): A series of games between two players.

    • Fixed-length match: decided when one player scores more than 50% the total number of games. They are always scheduled for an even number of games, giving each player the same number of White and Black games.
    • Unlimited match: decided when one player scores a certain number of wins. Draws do not count. Examples include the World Championship Matches of 1927, 1978, and 1984. All of these were “first to six wins,” but lasted 34, 32, and 48 games respectively.

Match (Team): A set of games played between two teams on multiple boards simultaneously. One team wins if they score ½-point more than 50% of the total number of games. The match is drawn if both teams score the same amount of points.

Material: The pieces and pawns in your army, or those that you have captured.

Maximummer: A chess problem with the stipulation that Black (or both players) must make the geometrically longest move on each turn.

Merge: Two or more groups of players combined into one who compete for the same prizes. This is used in large Swiss-system tournaments with more than one schedule.

Middlegame: The part of a chess game between the opening and the endgame where the main “action” often takes place.

Miniature: A game won in 25 moves or less.

Minor exchange: An exchange of bishop for knight. While both pieces are roughly equal in value, the bishop is usually considered slightly stronger on average. See also: bishop pair.

Minority attack: An attack by a player on a flank where they have less pawns. Often, the absence of a pawn gives them use of an additional open or half-open file.

Minor piece: A bishop or a knight. Also referred to as light piece.

Mutual zugzwang: See: reciprocal zugzwang.



National Arbiter: The entry level title for arbiters. NAs are certified by their National Federation and can serve as Chief Arbiter of non-World, non-Continental level events that do not award title norms.

National event: A USCF event that awards a national title. In addition to the U.S. Championship and U.S. Women’s Championship, there are dozens of other National tournaments restricted by age or other criteria. Examples:

    • National Elementary Championship (open to players in Pre-K through 6th grade)
    • U.S. Amateur Team Championship (open to teams with an average rating of <2200)
    • U.S. Armed Forces Championship (open to military personnel)
    • U.S. Blind Championship (open to legally blind players)
    • U.S. Class Championship (one section for each class: E, D, C, B, A, Expert, and Master)
    • U.S. Junior Championship (invitational event for the top players Under 21 years of age)
    • U.S. Senior Championship (invitational event for the top players Over 50 years of age)

National Master (NM): A USCF lifetime title earned by a player who achieves an established rating of 2200 or higher.

Nationals: Colloquially, this refers to scholastic National events.

National Tournament Director (NTD): The highest level of Tournament Director certification in the USCF. A TD who has directed the following types of events can, in general, apply for NTD:

    • 15 tournaments expected to draw more than 100 players (some subsitutions are allowed)
    • Three tournaments that awarded $1,000+ in prizes
    • One team or individual-team tournament with at least 50 players
    • One round robin or two quick round robin tournaments with six or more players with an average rating of at least 1400
    • Chief Assistant to a National Tournament Director at a tournament expected to draw 300+ players and award $5,000+ in prizes
    • Chief Assistant to a National Tournament Director at one or more National events.

The applicant needs to score 80% on an essay exam. NTDs are certified for life.

NN: An unknown or unnamed player, it is an abbreviation for nomen nescio. (Latin)

Notation: The recording of moves in a game. The most common and internationally-recognized method of chess notation used today is Algebraic Notation.

Norm: A qualifying performance at a tournament needed for a FIDE title. Chess titles requiring norms in ascending order, for different areas of chess:

    • Over-the-board chess: Woman International Master (WIM), Woman Grandmaster (WGM), International Master (IM), Grandmaster (GM)
    • ICCF: Correspondence Chess Expert (CCE), Correspondence Chess Master (CCM), International Master (IM), Senior International Master (SIM), Grandmaster (GM)
    • Arbiter: FIDE Arbiter (FA), International Arbiter (IA)
    • Organizer: International Organizer (IO)

Norm tournament: An event created with the specific goal of providing opportunities for players to earn a title norm. Players seeking International Master or Grandmaster norms pay an entry fee, while IMs (in an IM norm tournament) or GMs (in a GM norm tournament) are given conditions to participate. Normally held as round robins, small Swiss-system events can also create norm opportunities.

Novelty: A new move played for the first time in an important tournament. Also called a Theoretical Novelty, or TN.

Novotný: A theme where a White piece interferes with two differently-moving Black pieces, jamming their lines of communication. Either piece that captures the unit hinders its colleague. Named after Czech composer Antonín Novotný (1827-1871), it usually only appears in problems. See also: Plachutta.



Olympiad: The most important team tournament open to all FIDE countries. The first edition was held in 1927. Since 1950 the Chess Olympiad has been held every even-numbered year except 2020.

Open file: A file with no pawns on it.

Open game: A game beginning with 1.e4 e5.

Opening: The first part of the game where both sides develop their armies.

Open tournament: A tournament (or section of a tournament) open to players of any rating, as well as unrated players.

Opposition: When the two kings are standing vertically, horizontally, or diagonally an odd number of squares apart, the side not having the move possesses the opposition. This means the enemy king must eventually move aside and allow his opponent to invade his territory. Particularly important in endgames with only kings and pawns.

Organizer: The person or group of people responsible for the smooth operation of a tournament. They procure the playing site, equipment, and arbiters. They also invite the players and ensure their comfort and good playing conditions. See also: International Organizer.

Original Life Master: In USCF, a player who has played at least 300 tournament games with a rating of 2200 or higher (the games need not be consecutive). OLMs receive a certificate from USCF and have a permanent floor of 2200; this is the only way to achieve a 2200 floor.

Outpost: A square in the opponent’s half of the board where a player can establish a piece supported by a pawn and incapable of being attacked by an enemy pawn. See also: hole.

Overprotection: A strategic concept championed by Aron Nimzowitsch (1886-1935). A key center pawn is protected many times to prevent a freeing pawn break and cramp the enemy position.

Over-the-Board (OTB): A game played in person on a physical chessboard, and not online or by correspondence. See also: hybrid.



Pairings: The listing of all matchups in a given round. It usually includes ratings of the players, and sometimes other information such as current score and team if any.

Passed pawn: A pawn with no enemy pawns in front of it, either on the same or an adjacent file. As a passed pawn advances there are no pawns that can either block it (same file) or capture it (adjacent file).

A passed pawn protected by a friendly pawn is called a protected passed pawn, two passed pawns on adjacent files are called connected passed pawns, and one or more passed pawns near the edge of the board are called outside passed pawns.

Pawn break: A pawn advance intended to provoke pawn exchanges to free pieces.

Pawn chain: A diagonal line of pawns, each protected by the pawn behind it. The rearmost pawn is called the base of the chain, and the foremost pawn is called the head of the chain.

Pawn majority: A greater number of pawns for one player on the kingside or queenside.

Pawn nail: A solitary pawn on the opponent’s 6th/3rd rank that cramps their position.

Pawn promotion: A pawn reaching the end of the board becomes a new piece. More details here.

Pawn storm: Two or more pawns rushing in unison down a flank. Also called pawn phalanx.

Performance rating: An estimate of a player’s skill level in a tournament based on the ratings of their opponents and results against them.

Perpetual check: Said of a position where one side can infinitely check the opposing king, not allowing that side to make any progress towards victory. Normally the players agree to a draw when a perpetual is evident, but there is no claim of “perpetual check.” The draw can be brought about by a claim of triple occurrence of position or the 50-move rule.

Piece fist: A mass of pieces grouped together in an attack on the enemy king.

Pin: A straight-line piece (bishop, rook, or queen) attacks an enemy piece. If that enemy piece were to move, a more valuable piece behind it would then be under attack.

    • Absolute pin: the king is the rear piece, so the pinned piece is not allowed to move, as that would place the king in check.
    • Relative pin: a piece other than the king is behind the pinned piece; a player can move the pinned piece, but may lose material.

Plachutta: A theme where a White piece interferes with two similarly-moving Black pieces, jamming their lines of communication. Either piece that captures the unit hinders its colleague. Named after Slovenian composer Josef Plachutta (1827-1883), it usually only appears in problems. See also: Novotny.

Playing Area: The portion of the playing venue where play takes place, as well as bathrooms, refreshment areas, and smoking areas. Players are normally not allowed to leave the playing area without permission from the arbiter.

Playing Venue: The physical location of a tournament, including the playing area and non-playing areas. Example: the hotel where an event is held.

Playoff: An over-the-board contest to break a tie among tied players. Commonly used to determine a clear tournament winner, or to decide an indivisible prize such as qualification for a future event.

Post-mortem: Analysis of a just-completed game by the two contestants, and possibly others.

ProblemA chess composition with a starting position unlikely to appear in a real game.

Problem child: A bishop imprisoned behind its own pawn chain. An example is black’s light-squared bishop in the Queen’s Gambit Declined, shown below:

Prophylaxis: Preventive measures taken against an enemy plan before it can be initiated.

Provisional rating: An estimated rating for a player who has not yet played enough rated games to earn an established rating.



Quad: Short for quadrangular. A round-robin tournament with four players. More details here.

Queenside: The half of the board where the queens start the game.

Quick: A USCF-rated time control where each player has more than 10 but less than 30 minutes total thinking time for the game, taking into account delay or increment. Quick games are rated separately from blitz games and standard games.

Quickplay Finish (QPF): The final phase of a FIDE-rated standard or rapid game not using an increment, where all moves must be completed in a finite amount of time. Mostly obsolete today because of the near-universal use of increment in FIDE events.



Rapid: A FIDE-rated time control where each player has more than 10 but less than 60 minutes total thinking time for the game. Rapid games are rated separately from blitz games and standard games.

Rank: The eight horizontal rows, numbered 1 through 8, on the board. They are named “1st rank,” “2nd rank,” etc.

Rating: A numerical estimate of a player’s skill level. Each country has its own rating system. International (FIDE) ratings are based on the Elo rating system.

Reciprocal Zugzwang: A situation in which both White and Black would be in zugzwang were it their turn to move. Also called mutual zugzwang. See also: zugzwang.

Re-entry: A player who withdraws from a tournament and starts again fresh for an additional fee, sometimes receiving ½-point byes for unplayed games. This gives the player a chance to improve their score. Also called restart option.

Reloader: A tactic where a player forces an exchange of his attacker for a defender, so that a second attacker can replace its colleague with powerful effect.

Resign: A player gives up, resulting in a win for the opponent. This ends the game immediately.

Resumption: The continuation of an adjourned game. This may take place on the same or different day from when a move was sealed and the game paused.

Rook lift: A rook is raised to beyond its pawn rank in order to be transferred to another file for action against the opponent, where the rook is not blocked by its own pawns.

Round robin: A tournament where each player plays one or more games against every other player in the event; also known as a circular or all-play-all tournament.



Sacrifice: A player intentionally gives up material in return for some other benefit.

Scheveningen tournament: A team tournament where every member of Team A plays one or more games against every member of Team B.

Schiller System: Named for American FIDE Master and International Arbiter Eric Schiller (1955-2018), this is a variation of the Scheveningen tournament. Usually, instead of two teams, there are four teams with three players each. Each player faces the nine competitors not on their own team.

The point is that one of the four teams will be comprised of three Grandmasters, who will play against the other nine players. This gives nine players a chance to score a GM norm, as 1/3 of a player’s opponents must be GMs to earn such a norm.

Scholastic tournament: A tournament for players in primary or secondary school. In the United States, scholastic tournaments are for players in grades K-12, or some portion thereof.

Score group: Players with the same score in a Swiss-System tournament. When possible, players with the same score are paired against each other.

Sealed move: A tournament game is to be adjourned. With their clock running, the player on move decides their next move and writes it down on their scoresheet without playing it on the board; the opponent doesn’t know which move has been chosen. The arbiter or tournament director then seals both players’ scoresheets in an envelope and retains custody of it. This envelope also contains the current board position, clock times, player names, and time/place of the resumption. The players are free to use any assistance in analyzing the game between the adjourment and resumption. Adjournments and the need to seal moves is exceedingly rare nowadays with sudden death time controls, but there are unusual circumstances where this archaic practice comes in handy, even today.

Second: An assistant to a player during a tournament, compensated by the player. Normally they help the player analyze games and prepare for future opponents.

Semi-closed game: A game beginning with 1.d4 where black does not play 1…d5.

Semi-open game: A game beginning with 1.e4 where black does not play 1…e5.

Senior tournament: An event for players over 50 years of age. Sometimes these events have separate sections for players over 65 years of age, as well.

Senior Tournament Director (SrTD): A USCF Tournament Director who has directed five tournaments of at least four rounds expected to draw 50-99 players, and at least ten total tournaments totalling 400 or more players can, in general, apply for Senior TD. This requires passing an exam with a score of 80%. Senior TDs are certified for five-year renewable terms.

Silli System: Named for Italian Armando Silli (1917-1987), it is a method of pairing non-round robin correspondence chess tournaments with large fields.

Simultaneous exhibition: Often shortened to “simul.” One player plays separate games against more than one, and typically dozens, of opponents at the same time. The person giving the simul is usually a much stronger player than his or her opponents. Simuls can have different variants, as well:

    • Blindfold simul: The player does not have sight of a board and their opponents’ moves are relayed to him or her orally. The player communicates their own moves orally, and may or may not actually wear a blindfold.
    • Clock simul: The player has the same total amount of time for all of their games as each opponent has individually.
    • Tandem simul: Two or more simul givers take turns making moves on each board.

Skewer: A straight-line piece (bishop, rook, or queen) attacks an enemy piece. If that enemy piece moves, a less valuable piece behind it can then be captured.

Smothered mate: A king trapped by his own pieces is given checkmate by an enemy knight. Also called the Lucena Mate or Philidor’s Legacy.

Sofia rules: A regulation introduced in the M-Tel Masters tournaments held in Sofia, Bulgaria from 2005-2009. Draw offers are prohibited before move 30 without permission of the Arbiter. See also: anti-draw rules.

Sonneborn-Berger: A tiebreak traditionally used for round robin tournaments. It is calculated by adding the scores of all opponents a player defeated, plus half the scores of all opponents a player drew.

Space: The amount of territory on the chess board occupied by a player’s pawns.

Spectator: A person watching a tournament game. Another person playing a game of their own becomes a spectator when watching other games.

Stalemate: A player cannot make a legal move with any piece or pawn, but is not in check. The game immediately ends in a draw.

Standard: Rated games with 60 minutes or more total thinking time for each player.

Standings: A list of players in the tournament ranked by score and then by tiebreak criteria.

Start number: A player’s initial ranking number before a tournament begins.

    • In a round robin, they are typically drawn randomly one or more days before the start of the first round.
    • In a Swiss-system tournament, they are sorted by rating from highest to lowest.

Staunton pattern: The general design of chess pieces standard in international tournament play. Named for Howard Staunton (1810-1874), an English chess master.

Strong square: A important post that cannot be assailed by enemy pawns. A notable type of strong square is an outpost.

StudyA chess composition with a starting position that could plausibly appear in a game.

Sudden death: The final (or only) time control for a game. The players do not receive any more main thinking time for the rest of the game.

Super tournament: A round robin tournament wiith elite players. There is no formal definition, but a reasonable guideline is an event with an average FIDE rating of 2700 or higher. Sometimes written as “supertournament.”

Swindle: A deep trap sprung by a player in a losing position; if successful it can score an unexpected draw or even win. Sometimes called a Marshall Swindle after Frank Marshall (1877-1944), the longtime United States Champion who became known for employing them.

Swiss Gambit: Said of a player who loses or draws against a weaker player early in a Swiss tournament, but then finishes highly in the standings. By losing or drawing early on, their lower score provided them with lower-scoring, lower-rated opponents for the rest of the event. Peers who finished with a similar score but did not lose or draw early likely faced tougher opponents throughout the event.

Swiss Manager: This tournament management software developed by Heinz Herzog is widely used for major international events.

SwissSys: Tournament management software developed by Thad Suits, popular in the United States.

Swiss-system: A non-elimination tournament with more players than rounds. Swisses can accomodate hundreds of players if necessary. Various algorithms can be used to decide who each player is paired with every round. More details here.



Tarrasch’s Rule: There are two such rules, named for Siegbert Tarrasch (1862-1934). A medical doctor by training, he was for decades was one of the world’s leading players and teachers.

    • In rook endgames: a player’s rook is best placed behind passed pawns, whether their own or the opponent’s.
    • In evaluating a position: if one piece is badly placed, the entire position is bad.

Team tournament: An event with matches played on multiple boards. It can be conducted as a round-robin, Scheveningen, or Swiss.

Tempo: Time in chess measured in moves (turns), and not chess clock time.

Thematic tournament: An event where all games must begin with a certain series of moves. Such events are not rated.

Threat: The intention to play a move that will cause the opponent problems. This move could be a capture that wins material, checkmate, or the promotion of a pawn, for example.

Tiebreaks: Mathematical algorithms and/or playoffs used to decide tournament final placings among tied players or teams. The tiebreaks to be used in an event are announced in advance. More details here.

Time control: The timing rules for the game. A player who runs out of time normally loses the game. Examples:

    • Game/30: each player has 30 minutes for the entire game.
    • 90/40′; SD/30′ +30″: two time controls. Each player has 90 minutes to complete their first 40 moves. If the game hasn’t ended by move 40, each player gets an additional 30 minutes to make all remaining moves. +30″ indicates a 30-second increment for the entire game.

Time pressure: A player has little time remaining to complete all moves in the current (or only) time control. The player is forced to play faster and possibly make mistakes in order to not lose the game by running out of time.

Touch-move rule: A player who deliberately touches one of his or her pieces must move it if legal. A player who deliberately touches an enemy piece or pawn, must capture it if possible. See: J’adoube.

Tournament Director (TD): An official who supervises chess tournaments in the United States.

    • Chief TD: The head of the directing staff who is ultimately responsible for all decisions. In smaller events, the Chief TD may be the only TD.
    • Backroom TD: A TD responsible for making pairings. Also called Computer TD.
    • Floor TD: A TD responsible for making rulings and solving disputes in the playing area.

Tournament Life Announcement (TLA): A classified ad featured in the Tournament Life section of Chess Life magazine.

Transposition: An identical position that can be reached by more than one move order.

Triple-Block: A type of correspondence chess time control that leads to games concluding by a certain date. Each player starts the game with a specified amount of time and accumulates time for each move they make up to, say, move 50. At that point, they receive no added time for any further moves until the end of the game.

Triple Occurrence of Position: If an identical position is reached for the third (or more) time, a player can claim a draw to the Arbiter or Tournament Director. This position need not be reached on consecutive moves. Also called three-fold repetition of position.

Twin: The pieces and pawns in a composition are shifted one or more files to the left or right, or one or more ranks up or down.



Underpromotion: Promoting a pawn that has reached the end of the board to a rook, bishop, or knight, and not a queen.

Unplayed game: A game not played in a tournament. This could be the result of a bye, forfeit, or withdrawal.

Unrated: A player who does not have an official rating. This does not mean the player has a rating of zero; in USCF, for example, the lowest possible rating is 100. Often displayed on a wall chart or standings as “UNR.”

USCF: United States Chess Federation. Founded in 1939 it is the governing body for chess in the United States.



Variant: A game using a chess board and chess pieces, but played under different rules from standard chess. Examples: Bughouse, Chess 960.

Variation: A possible line of play. Different branches of openings are usually called variations.

Varma tables: Created by Indian chess organizer and former All India Chess Federation President B. Varma (1929-2013), these tables modify normal Berger round-robin pairings to avoid certain players or teams meeting in the final rounds of an all-play-all event. A high-profile use of Varma tables is the Candidates Tournaments, where players from the same country play each other in the first round(s) of each half of the event.

Virtual opponent: A method of assigning a score to a player with unplayed games for use in mathematical tiebreak calculations. See: Buchholz.



Wall chart: A listing of all players in a Swiss system tournament sorted by rating from highest to lowest. It also displays the opponents each player faced, their color in the game, and the result.

Weak pawn: A pawn incapable of being defended by a friendly pawn. These include backward pawns and isolated pawns, and can also include doubled pawns.

Weak square: A square incapable of being defended by a friendly pawn. A notable type of weak square is a hole.

Windmill: A tactic with repeated discovered checks where the piece that uncovers its partner captures enemy units each time it creates the discovery. Also called mill or see-saw.

WinTD: Tournament management software developed by Tom Doan, popular in the United States.

Withdraw: To drop out of a tournament before all of your scheduled games. This can be done at any time in a Swiss by informing the arbiter or director, but is prohibited in a round-robin.

Woman Candidate Master (WCM): A playing title available to any female player who achieves a FIDE rating of at least 2000.

Woman FIDE Master (WFM): A playing title available to any female player who achieves a FIDE rating of at least 2100.

Woman Grandmaster (WGM): The highest female-only playing title that can be earned in chess. It can be earned as a direct title, but typically requires a player to achieve three WGM norms and a 2300 Elo rating.

Woman International Master (WIM): The second-highest female-only playing title that can be earned in chess. It can be earned as a direct title, but typically requires a player to achieve three WIM norms and a 2200 Elo rating.

World Cup: A large event held as a series of knockout matches where the finalists earn a spot in the next Candidates Tournament. From 1997 through 2004, the current World Cup format was the FIDE World Championship.

Players can qualify by rating, as a top finisher in zonal tournament, through a Continental Championship, or through a nomination by the Organizer or FIDE President.

In a 128-player World Cup, the players are sorted by rating and then paired top against bottom: 1 vs. 128, 2 vs. 127, etc. Each match is two games, played on consecutive days. Matches tied 1-1 have rapid tiebreaks played on the following day. Thus, each round is three days. Players who win their matches 2-0 or 1½-½ get a rest on “tiebreak day.” The final is typically a Best-of-4 match.

There is an Open World Cup and Women’s World Cup (usually 64 players).



X-Ray: A tactic where a piece attacks an enemy unit from behind, and is indirectly defended by a friendly piece in front of the enemy on the same file, rank, or diagonal.



Youth tournament: An event for players under 18 years of age.



Zeitnot: See: Time Pressure(German)

Zero-tolerance rule: A player not present in the playing area at the start of a round is forfeited. Zero minutes is the default time for FIDE-rated events. An Organizer not wanting zero-tolerance to apply must specify a default time in their event regulations (e.g., 30 minutes or 60 minutes).

Zonal: The championship tournament of a zone. One or more winners qualify to a further stage in the World Championship cycle.

Zone: A region of the chess world, as determined by FIDE.

    • Zone 1: Europe
    • Zone 2: Americas (including North and South)
    • Zone 3: Asia (including Oceania)
    • Zone 4: Africa

Canada (2.2), China (3.5), India (3.7), Russia (1.6), Ukraine (1.9), and the United States (2.1) are single-zone countries. Zone 2.3.5 (Caribbean nations) consists of 20 countries, the most of any zone.

Zugzwang: Any possible move a player makes will worsen their position. Reciprocal zugzwang or mutual zugzwang means that either player would be in zugzwang if they are on move. (German)

Zwischenzug: See: Intermediate Move. (German)