Undermining (chess) Undermining (chess) Undermining (also known as removal of the guard, or removing the defender) is a chess tactic in which a defensive piece is captured, leaving one of the opponent's pieces undefended or under-defended. The opponent has the unpalatable choice of recapturing or saving the undefended piece. A possible response is to sacrifice the piece whose defense was undermined before capturing the piece which just took the defender. Kramnik–Topalov in the seventh round of the 2004 Linares chess tournament reached the diagrammed position with White to play. The black knight on a4 is defended only by the black pawn on
Chess piece each of the two players begins with the following sixteen pieces in a standard game: The rules of chess prescribe the types of move a player can make with each type of chess piece. Each piece type moves in a different way. During play, the players take turns moving one of their own chess pieces. Pieces other than pawns capture in the same way that they move. A capturing piece replaces the opponent piece on its square, except for an "en passant" capture. Captured pieces are immediately removed from the game. A square may hold only one piece at any