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
Fairy chess piece Thus, the ferz is now considered a non-standard chess piece. Chess enthusiasts still often like to try variations of the rules and in the way pieces move. Pieces which move differently from today's standard rules are called "variant" or "fairy" chess pieces. Fairy chess pieces usually fall into one of three classes, although some are hybrids. Compound pieces combine the movement powers of two or more different pieces. An ("m","n")-leaper is a piece that moves by a fixed type of vector between its starting and destination squares. One of the coordinates of the vector 'start square – arrival square' must