Fork (chess)

In chess, a fork is a tactic in which a piece attacks multiple enemy pieces simultaneously. The attacker usually aims to capture one of the forked pieces. The defender often cannot counter every threat. A fork is most effective when it is forcing, such as when the king is put in check. A fork is a type of double attack.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

The white knight forks Black's king and rook. Black's pawn forks the white rooks.

A fork is an example of a double attack. 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.^[1] 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.^[2]

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. A knight fork of the enemy king, queen, and possibly other pieces is sometimes called a family fork or family check.^[3][4]

While any piece can deliver a fork, knights are particularly effective at creating forks because they cannot be captured by the pieces they attack, and as a minor piece they are less valuable than rooks and queens.^[5][6]

Compared to forks by other pieces, a queen fork requires more specific conditions to be helpful due to the queen's higher value. However, a queen fork can often lead to material or positional gain when the forked pieces are undefended, poorly coordinated, or when one piece is the king.^{[citation needed]}

Tissir vs. Dreev, 2004

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 33.Qe5–f4

This example is from the first round of the FIDE World Chess Championship 2004 between Mohamed Tissir and Alexey Dreev.^[7] 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.

Soppe vs. Braga, 1998

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 40.Nxe5

This example is from the ninth round of the Clarin GP Final between Guillermo Soppe and Fernando Braga.^[8] After

 40... Qh1+

White resigned. The only move is 41.Ke2 which enables a royal fork with 41...Nc3+, winning the queen.

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Position after 4.Nc3. Black can play 4...Nxe4 since he has a fork trick.

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h After 4...Nxe4 5.Nxe4 d5, White is forked and Black will regain a piece.

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.