Glossary of Chess

Tabia or Tabiya: (from Arabic)
1. A position for the pieces from which a Shatranj game was started: piece movement in Shartanj was slow, hence games were possibly started from standard position, named Tabiyas, obtained by standard move sequences from the initial position.; 2. As extension: the final position of a well-known chess opening. The position (e.g. the Isolani) can be reached via different move sequences, even arising from different openings, and is usually considered prototypical in terms of strategic ideas.; 3. (from 2) The opening position from which two players familiar with each others' tastes begin play.
Tablebase: See Endgame tablebase.
Tactician: A player who specializes in tactical play, as distinguished from a positional player.
Tactics: Play characterized by short-term attacks and threats, often requiring extensive calculation by the players, as distinguished from positional play.
Takeback: Used in casual games when both players agree to undo one or more moves.
Tarrasch rule: Named after Siegbert Tarrasch, this refers to the general principle that rooks usually should be placed behind passed pawns, either yours or your opponent's.
TD: See Tournament director.
Tempo: An extra move, an initiative at development. A player gains a tempo (usually in the opening) by making the opponent move the same piece twice or defend an enemy piece. In the endgame, one may wish to lose a tempo by triangulation to gain the opposition. (Plural: tempos or tempi).
Text move: This term is used in written analysis of chess games to refer to a move that has been played in the game as opposed to other possible moves. Text moves are usually in bold whereas analysis moves are not.
Theme tournament: A tournament in which every game must begin with a particular opening specified by the organizers, for example the Budapest Gambit (1.d4 Nf6 2.c4 e5).
Theoretical Novelty (TN): A new move in the opening. Also called simply a "novelty".
Threat: A plan or move that, if left unattended, would result in an immediate depreciation of the opponent's position.
Threefold repetition: A draw may be claimed if the same position occurs three times with the same player to move, and with each player having the same set of legal moves each time (the latter includes the right to take en passant and the right to castle).
Tie-breaking in Swiss system tournaments: This refers to a number of different systems that are used to break ties, and thus designate a single winner, where multiple players or teams tie for the same place in a Swiss system chess tournament.
Time: Opportunities to make moves: similar meaning to tempo. A move that does not alter the position significantly is described as "wasting time", and forcing the other player to waste time is described as "gaining time".
Time control: The allowed time to finish a game, usually measured by a chess clock. A time control can require either a certain number of moves be made per time period (e.g., 40 moves in 2½ hours) or it can limit the length of the entire game (e.g., 5 minutes per game for blitz). Hybrid schemes are used, and time delay controls have become popular since the widespread use of digital clocks.
Time delay: A time control which makes it possible for a player to avoid having an ever-decreasing amount of time remaining (as is the case with sudden death). The most important time delays in chess are Bronstein delay and Fischer delay.
Time pressure or time trouble: Having very little time on one's clock (especially less than five minutes) to complete one's remaining moves. See Time control.
Top board: In team chess, the player who is assigned to face the strongest opponents. Also called first 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.
Touch-move rule: The rule requiring a player who touches a piece that has at least one legal move to move that piece (and, if the player moves the piece to a particular square and takes his hand off it, to move it to that square). Castling must be initiated by moving the king first, so a player who touches his rook may be required to move it, without castling. The rule also requires a player who touches an opponent's piece to capture it if possible. A player wishing to touch a piece to adjust its position on a square without being required to move it signals this intent by saying "J'adoube" or "I adjust". This way of playing is common in official games, in favour of clock move.
Tournament: A competition involving more than two players or teams, generally played at a single venue (or series of venues) in a relatively short period of time. A tournament is divided into rounds, with each round consisting either of individual games or matches in the case of knockout tournaments and team tournaments. The assignment of opponents is called pairing, with the most popular systems being round-robin and Swiss. Tournaments are usually referred to by combining the city in which they were played with the year, as in "London 1851", although there are well known exceptions such as "AVRO 1938".
Tournament book: A book recording the scores of all the games in a tournament, usually with analysis of the best or most important games and some background on the event and its participants. One well-known example is Bronstein's Zurich International Chess Tournament 1953. The less comprehensive tournament bulletin is usually issued between the rounds of a prestigious event, giving the players and world media an instant record of the games of the previous round. Individual copies may be bundled together at the conclusion of the event to provide an inexpensive alternative to the tournament book.
Tournament director (TD): Organizer and arbiter of a tournament, responsible for enforcing the tournament rules and the Laws of Chess. Also tournament controller (chiefly British).
Transposition: Arriving at a position using a different sequence of moves.
Trap: A move which may tempt the opponent to play a losing move. See also Swindle.
Trébuchet: A position of mutual zugzwang in which either player would lose if it is their turn to move.
Triangulation: A technique used in king and pawn endgames (less commonly seen with other pieces) to lose a tempo and gain the opposition.
Two bishops, The: "(The) two bishops". Synonym for: Bishop pair.