“Zwischenzug” is a German term that translates to “intermediate move” in English. It is a chess tactic that refers to the practice of making a move that forces the opponent to respond in a specific way, in order to gain an advantage. The move is often unexpected and can catch the opponent off guard, resulting in a gain of material or a better position.
One of the most famous examples of a zwischenzug is the “Immortal Game” between Adolf Anderssen and Lionel Kieseritzky in 1851, where Anderssen sacrificed his queen to set up a zwischenzug that resulted in checkmate.
The tactic is often used in the endgame, when the number of pieces on the board is limited and the opportunities for tactics are fewer. The zwischenzug can be used to create a discovered attack, where a piece is moved out of the way to reveal an attack on an opponent’s piece. It can also be used to create a fork, where a piece attacks two or more opponent’s pieces at the same time.
The zwischenzug can also be used in the middle game to gain a tempo, where a move is made that forces the opponent to move the same piece twice in a row. This can be used to gain time to develop pieces or to create a weakness in the opponent’s position.