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
Chess piece relative value minor pieces are usually better than a queen because of their greater mobility, and the extra pawn is not important enough to change the situation . Three minor pieces are almost as strong as two rooks . Two minor pieces plus two pawns are almost always as good as a queen. Two rooks are better than a queen and pawn . Many of the systems have a 2-point difference between the rook and a minor piece, but most theorists put that difference at about points, see The exchange (chess)#Value of the exchange. In open positions, a rook plus a pair