Fork (chess)

A fork is an example of a . The type of fork is named after the type of forking piece. For example, a fork by a knight is a knight fork. The attacked pieces are forked. If the king is one of the attacked pieces, the term absolute fork is sometimes used, while a fork not involving the enemy king is a relative fork. A fork of the king and queen, the highest -gaining fork possible, is sometimes called a royal fork. A fork of the enemy king, queen, and one (or both) rooks is sometimes called a grand fork. A knight fork of the enemy king, queen, and possibly other pieces is sometimes called a family fork or family check. ==Strategy==

While any piece can deliver a fork, knights are particularly effective as the forking piece because they cannot be captured by the non-knight pieces they attack, and as a they are less valuable than rooks and queens. Compared to forks by other pieces, a queen fork requires more specific conditions to be helpful due to the queen's higher value. A queen fork can often lead to material or positional gain, however, when the forked pieces are undefended, poorly coordinated, or when one piece is the king. ==Game examples==

This example is from the first round of the FIDE World Chess Championship 2004 between Mohamed Tissir and Alexey Dreev. After :33... Nf2+ 34. Kg1 Nd3 White resigned. In the final position the black knight forks White's queen and rook; after the queen moves away, Black will win the exchange. This example is from the ninth round of the Clarin GP Final between Guillermo Soppe and Fernando Braga. After :40... Qh1+ White resigned. The only move is 41.Ke2 which enables a royal fork with 41...Nc3+, winning the queen. In the Two Knights Defense (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6) after 4.Nc3, Black can eliminate White's e4-pawn immediately with :4... Nxe4 due to the fork trick :5. Nxe4 d5 regaining either the bishop or the knight. ==References==