Pin (chess) Pin (chess) In chess, a pin is a situation brought on by an attacking piece in which a defending piece cannot move without exposing a more valuable defending piece on its other side to capture by the attacking piece. Moving the attacking piece to bring on the pin is called pinning; the defending piece so restricted is described as pinned. Only pieces that can move an indefinite number of squares in a horizontal, vertical, or diagonal line (i.e. bishops, rooks, and queens) can pin. Kings, knights, and pawns cannot pin. Any piece can be pinned except the king, since the
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