Captures

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Home * Chess * Moves * Captures

Captures are tactical moves changing material balance where an opponent piece is removed from the board as part of the completion of the move. This is either done by moving a piece to a square, which is occupied by the opponent captured piece - or as a special case of pawn takes pawn, en passant.

Winning captures are those with least valuable aggressor of most valuable victim, where even a recapture would win material, and captures of pieces en prise, that is the union of undefended (hanging) pieces, as well as pieces defended inadequately. A static exchange evaluation might be applied to determine a victim is en prise or not. Equal captures are exchanges of equal valued pieces. Winning, as well as equal captures are subject of quiescence search. Some programs extend captures or recaptures under certain conditions, i.e. material becomes close to the root score again.

Capture Generation

With mailbox like square centric board representations, capture generation requires a so called blocker loop, while bitboards rely on attack generation and intersection with the set of opponent pieces.

Six times Take Five

Capture Best case Worst case
capturing with the pawn
pxQ winning queen pawn for queen
pxR winning rook pawn for rook
pxB winning bishop pawn for bishop
pxN winning knight pawn for knight
pxP winning pawn exchanging pawns
capturing with the knight
nxQ winning queen knight for queen
nxR winning rook winning the exchange
nxB winning bishop exchanging minors
nxN winning knight exchanging minors
nxP winning pawn losing knight for pawn
capturing with the bishop
bxQ winning queen bishop for queen
bxR winning rook winning the exchange
bxB winning bishop exchanging minors
bxN winning knight exchanging minors
bxP winning pawn losing bishop for pawn
capturing with the rook
rxQ winning queen rook for queen
rxR winning rook exchanging rooks
rxB winning bishop losing exchange
rxN winning knight losing exchange
rxP winning pawn losing rook for pawn
capturing with the queen
qxQ winning queen exchanging queens
qxR winning rook losing queen for rook
qxB winning bishop losing queen for bishop
qxN winning knight losing queen for knight
qxP winning pawn losing queen for pawn
capturing with the king, always winning captures
kxQ winning queen
kxR winning rook
kxB winning bishop
kxN winning knight
kxP winning pawn

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