Chess strategy is the aspect of chess play concerned with evaluation of chess positions and setting goals and long-term plans for future play. While evaluating a position strategically, a player must take into account such factors as the relative value of the pieces on the board, pawn structure, king safety, position of pieces, and control of key squares and groups of squares. Chess strategy is distinguished from chess tactics, which is the aspect of play concerned with the move-by-move setting up of threats and defenses. Some authors distinguish static strategic imbalances, which tend to persist for many moves, from dynamic imbalances, which are temporary. This distinction affects the immediacy with which a sought-after plan should take effect. Until players reach the skill level of "master", chess tactics tend to ultimately decide the outcomes of games more often than strategy. Many chess coaches thus emphasize the study of tactics as the most efficient way to improve one's results in serious chess play.
In chess, a pin is a tactic in which a defending piece cannot move out of an attacking piece's line of attack without exposing a more valuable defending piece. Moving the attacking piece to effect the pin is called pinning; the defending piece restricted by the pin is described as pinned. Only a piece that can move any number of squares along a horizontal, vertical, or diagonal line can pin. Any piece can be pinned except the king. The pin is one of the most powerful chess tactics.
Algebraic notation is the standard method for recording and describing the moves in a game of chess. It is based on a system of coordinates to uniquely identify each square on the board. It is used by most books, magazines, and newspapers.
This glossary of chess explains commonly used terms in chess, in alphabetical order. Some of these terms have their own pages, like fork and pin. For a list of unorthodox chess pieces, see Fairy chess piece; for a list of terms specific to chess problems, see Glossary of chess problems; for a list of named opening lines, see List of chess openings; for a list of chess-related games, see List of chess variants; for a list of terms general to board games, see Glossary of board games.
The zwischenzug is a chess tactic in which a player, instead of playing the expected move, first interposes another move posing an immediate threat that the opponent must answer, and only then plays the expected move. It is a move that has a high degree of "initiative". Ideally, the zwischenzug changes the situation to the player's advantage, such as by gaining material or avoiding what would otherwise be a strong continuation for the opponent.
In the game of chess, interference occurs when the line between an attacked piece and its defender is interrupted by sacrificially interposing a piece. It is a chess tactic which seldom arises, and is therefore often overlooked. Opportunities for interference are rare because the defended object must be more valuable than the sacrificed piece, and the interposition must itself present a threat. Huczek defines interference as a tactic involving blocking moves that obstruct lines of attack. This definition may be expanded by including blocking moves that disrupt lines of defense.
In chess, a tactic is a sequence of moves that each makes one or more immediate threats – a check, a material threat, a checkmating sequence threat, or the threat of another tactic – that culminates in the opponent's being unable to respond to all of the threats without making some kind of concession. Most often, the immediate benefit takes the form of a material advantage or mating attack; however, some tactics are used for defensive purposes and can salvage material that would otherwise be lost, or to induce stalemate in an otherwise lost position.
In chess, en passant describes the capture by a pawn of an enemy pawn on the same rank and an adjacent file that has just made an initial two-square advance. The capturing pawn moves to the square that the enemy pawn passed over, as if the enemy pawn had advanced only one square. The rule ensures that a pawn cannot use its two-square move to safely skip past an enemy pawn.
In chess and similar games, check is a condition that occurs when a player's king is under threat of capture on the opponent's next turn. A king so threatened is said to be in check. A player must get out of check if possible by moving the king to an unattacked square, interposing a piece between the threatening piece and the king, or capturing the threatening piece. If the player cannot remove the check by any of these options, the game ends in checkmate and the player loses. Players cannot make any move that puts their own king in check.
In chess, a pure mate is a checkmate position such that the mated king is attacked exactly once, and prevented from moving to any of the adjacent squares in its field for exactly one reason per square. Each of the squares in the mated king's field is attacked or "guarded" by one—and only one—attacking unit, or else a square which is not attacked is occupied by a friendly unit, a unit of the same color as the mated king. Some authors allow that special situations involving double check or pins may also be considered as pure mate.
In chess, a queen sacrifice is a move that sacrifices a queen in return for some compensation, such as a tactical or positional advantage.
In chess, a sacrifice is a move that gives up a piece with the objective of gaining tactical or positional compensation in other forms. A sacrifice could also be a deliberate exchange of a chess piece of higher value for an opponent's piece of lower value.
The Exchange Variation of the Ruy Lopez is a chess opening that begins with the moves:
The Accelerated Dragon is a chess opening variation of the Sicilian Defence that begins with the moves:
In chess, a flight square or escape square is a safe square to which a piece, especially a king, can move if it is threatened.
In chess, an exchange or trade of chess pieces is a series of closely related moves, typically sequential, in which the two players capture each other's pieces. Any type of pieces except the kings may possibly be exchanged, i.e. captured in an exchange, although a king can capture an opponent's piece. Either the player of the white or the black pieces may make the first capture of the other player's piece in an exchange, followed by the other player capturing a piece of the first player, often referred to as a recapture. Commonly, the word "exchange" is used when the pieces exchanged are of the same type or of about equal value, which is an even exchange. According to chess tactics, a bishop and a knight are usually of about equal value. If the values of the pieces exchanged are not equal, then the player who captures the higher-valued piece can be said to be up the exchange or wins the exchange, while the opponent who captures the lower-valued piece is down the exchange or loses the exchange. Exchanges occur very frequently in chess, in almost every game and usually multiple times per game. Exchanges are often related to the tactics or strategy in a chess game, but often simply occur over the course of a game.
In chess, a skewer is a tactic in which a long range attacker attacks two targets on the same rank, file or diagonal; and is similar to a pin. A skewer is often considered to be the opposite of a pin; the supposed difference is that in a skewer, the more valuable piece is the one under direct attack and the less valuable piece is behind it. The opponent is compelled to move the more valuable piece to avoid its capture, thereby exposing the less valuable piece which can then be captured. However, this is not quite a full and accurate understanding of a skewer, because two pieces of equal value can be subjected to a skewer. For example, two bishops standing on the same rank or file can be skewered by a rook; or two rooks on the same diagonal can be skewered by a bishop. Only line pieces can skewer; kings, knights, and pawns cannot.
The following outline is provided as an overview of and topical guide to chess:
Brinkmate is the situation in which an unavoidable checkmate sequence will be created by the player's next move.
Many basic tactics of shogi are similar to those of chess tactics, involving forks, pins, removing the defender and other techniques, all of which are considered very strong when used effectively.
