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
History of chess by the common public, and even the courtly society, which continued to enjoy the now-prohibited chess tournaments uninterrupted. The pieces, which had been nonrepresentational in Islamic countries (see piece values in shantranj), changed shape in Christian cultures. Carved images of men and animals reappeared. The shape of the rook, originally a rectangular block with a V-shaped cut in the top, changed; the two top parts separated by the split tended to get long and hang over, and in some old pictures look like horses' heads. The split top of the piece now called the bishop was interpreted as a bishop's