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
History of chess a disadvantage, as the other player would have a long period to analyze before having to make a reply when the game was resumed. Preventing access to a chess set to work out moves during the adjournment would not stop him from analyzing the position in his head. Various strange ideas were attempted, but the eventual solution was the "sealed move". The final move before adjournment is not made on the board but instead is written on a piece of paper which the referee seals in an envelope and keeps safe. When the game is continued after adjournment, the referee