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
Capablanca Chess starting positions are protected by at least one piece. There are also variants of Capablanca Chess that do not use the standard 10×8 board. Grand Chess is a popular variant invented by Dutch game designer Christian Freeling in 1984. It uses Capablanca Chess pieces upon a larger, 10×10 board. In 2007 Grandmaster Yasser Seirawan devised a variant (called Seirawan chess), which adds the two pieces to the standard game in a different manner. The player, after moving a piece (for example, a bishop) from the first , may immediately place either of the two pieces on the bishop's square. If