Exchange (chess) 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 value of piece(s) can be said to be "up the exchange" or "wins the exchange", while the opponent who captures the lower value of piece(s) is "down the exchange" or "loses the exchange". Exchanges occur very frequently in chess,
Pocket Mutation Chess Pocket Mutation Chess Pocket Mutation Chess is a chess variant invented by Mike Nelson in 2003. In this game a player can take a piece from the board and put it into a "pocket". The piece in the pocket can be put back on the board later. When placing the piece into the pocket the player can "mutate" the piece, i.e. change it to a different piece. The game is one of the "Recognized Chess Variants" at "The Chess Variant Pages". The starting position in this game is the same as in standard chess. Players make moves as in standard