The exchange (chess) The exchange (chess) The exchange in chess refers to a situation in which one player loses a minor piece (i.e. a bishop or knight) but captures the opponent's rook. The side which wins the rook is said to have "won the exchange", while the other player has "lost the exchange", since the rook is usually more valuable. Alternatively, the side that has won the rook is "up the exchange", and the other player is "down the exchange". The opposing captures often happen on consecutive moves, although this is not strictly necessary. It is generally detrimental to lose the exchange, although
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