A fork, an example of a double attack, is a special tactic that is a favorite of many players because one of their pieces attacks two or more pieces of an opponent at the same time. Usually, the opponent loses one of these pieces.
The attacking piece is known as the forking piece; the attacked pieces are known as the forked pieces. The goal is to win one of the forked pieces.
Games are often lost by players who have missed a potential fork that they could have made and gained a winning advantage. Similarly, players have often lost games when they could not identify how an opponent was setting up a potential fork.
Because an opponent may not be able to defend all the forked pieces at the same time, the attacker may be able to win material. A fork is even more forcing when the opposing king is placed in check, and the opponent has to take action to protect the king and avoid checkmate.
You may be surprised to realize that every piece that you have can be used to make a fork. Let’s illustrate how the queen, rook, bishop, knight, pawn, and even the king can be used to fork your opponent’s pieces.
A triple fork—the queen is attacking three pieces: two rooks and a knight. Because the queen has the ability to move like a bishop and a rook combined, it can be a powerful forking piece.
The rook can fork two pieces on the same rank or file.
When opposing pieces are on the same diagonal, a bishop often can create a fork by maneuvering between them.
Because the knight attacks up to eight squares, it is very adept at making forks.
Even a pawn can fork two opposing pieces.
Sometimes your opponent may even make a mistake that permits your king to fork two pieces.
Because knights can jump over other pieces, they are particularly adept at forking an opponent’s pieces. Except when a knight is attacking an opponent’s knight, it cannot be captured by the forked pieces. When one of the pieces that the knight is forking is an opponent’s king, the opponent is forced to capture the knight (if they can) or move the king because the check cannot be blocked by another piece.
Because the knight is a minor piece, it can often be traded with no restrictions. With a value of just three points, the knight can often be used in devastating forks that force exchanges to capture a piece with a higher value such as a rook (worth five points) or a queen (worth nine points). (Read about the values of chess pieces in the ChessKid article “Understanding The Value Of Chess Pieces.”)
When an opponent’s king and queen are attacked at the same time, particularly by a knight, the tactic is known as a royal fork.
A royal fork may cause an opponent to resign.
Head on over to Puzzle Themes, an option in the pull-down menu of Play, and choose “Fork / Double Attack” among the many themes. The puzzles that are presented to you will test your knowledge about forks.
In addition, you can learn more about forks by reviewing several problems in the ChessKid article "A Coach's Best 'Fork' Positions!"
You now know what a fork in chess is and why this tactic is so important. Learn more about creating forks by practicing puzzles on ChessKid so that you are well-prepared for your future games.