Fork (chess)
In chess, a fork is a tactic in which a piece attacks two or more pieces simultaneously. The attacker usually aims to capture one of the forked pieces, or threaten checkmate. The defender often finds it difficult to counter two or more threats in a single move.
A fork is most effective when it is forcing, such as when the king is put in check.
Apart from pawns on an outside file, any piece can fork, but knight forks are the most striking, since the knight is a minor piece and can be traded, and because except in the case of other knights, a knight cannot be captured by the piece it is threating.[1]
Since the queen is usually more valuable than the pieces it attacks, a queen fork gains material only when the pieces attacked are undefended or if one of them is the king and the other is undefended.
Terminology
A fork is also known as a double attack. The type of fork is named after the type of forking piece. For example, a knight fork. The attacked pieces are forked.[2] If the King is one of the attacked pieces, the term absolute fork is sometimes used. A fork not involving the enemy king is in contrast a relative fork.[3]
A fork of the king and queen, the highest material-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.[4] A knight fork of the enemy king, queen, and possibly other pieces is sometimes called a family fork or family check.
Game examples
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This example is from the first round of the FIDE World Chess Championship 2004 between Mohamed Tissir and Alexey Dreev.[5] 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.
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This example is from the ninth round of the Clarin GP Final between Guillermo Soppe and Fernando Braga.[6] After
- 40... Qh1+
White resigned. The only move is 41.Ke2 which enables a royal fork with 41...Nc3+, winning the queen.
Position after 4.Nc3. Black can play 4...Nxe4 since he has a fork trick.
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After 4...Nxe4 5.Nxe4 d5, White is forked and Black will regain a piece.
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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
- ^ "Fork in Chess - Chess Terms". Chess.com. Retrieved 2021-04-09.
- ^ "The Fork • lichess.org". lichess.org. Retrieved 2021-04-09.
- ^ https://www.chess-game-strategies.com/chess-fork.html
- ^ An example of a king, queen and double rook fork can be found in the 9th game in a September 2020 match between IM Eric Rosen and the Botez sisters that ended 9½-½. See Video on YouTube (Rosen's perspective) and Video on YouTube (the Botez' perspective).
- ^ "Tissir vs. Dreev, Tripoli 2004". Chessgames.com.
- ^ "Guillermo Soppe vs Fernando Braga, (1998)". Chessgames.com.