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
The Morals of Chess chess to life and writes that foresight, circumspection and caution can be learnt from the game. After describing the effects chess can have on one's perception of life he describes a set of moral rules that a chess player should hold, including to not cheat and not disturb the opponent. Franklin suggests that the opponent be told about mistakes he makes, for example if he would lose a piece. The essay is one of the first texts about chess that was published in the United States; it appeared in the first chess-related book that was published in Russia in 1791.