Chess puzzle

A chess puzzle is a puzzle in which knowledge of the pieces and rules of chess is used to solve logically a chess-related problem. The history of chess puzzles reaches back to the Middle Ages and has evolved since then.

Usually the goal is to find the single best, ideally aesthetic move or a series of single best moves in a chess position, which was created by a composer or is from a real game. But puzzles can also set different objectives. Examples include deducing the last move played, the location of a missing piece, or whether a player has lost the right to castle. Sometimes the objective is antithetical to normal chess, such as helping (or even compelling) the opponent to checkmate one's own king.

Chess problems

While a chess puzzle is any puzzle involving aspects of chess, a chess problem is an arranged position with a specific task to be fulfilled, such as White mates in n moves. Chess problems are also known as chess compositions because the positions are specially devised, rather than arising from actual games. Chess problems are divided into orthodox and heterodox types, both covering a variety of genres.

Orthodox chess problems employ the standard rules of chess and involve positions that can arise from actual gameplay (although the moves to reach those positions may be unrealistic). The most common orthodox chess problem takes the form of checkmate in n moves. The positions are seldom similar to positions from actual play, and the challenge is not to find a winning move, but rather to find the (usually unique) move that forces checkmate as rapidly as possible.

Heterodox chess problems involve conditions that are impossible with normal play, such as multiple kings or chess variants, while fairy chess problems employ pieces not used in orthodox chess, such as the amazon (a piece combining the powers of the queen and the knight).

Tactical puzzles

Chess puzzles can also be regular positions from actual games, usually meant as training positions, tactical or positional, from all phases of the game (openings, middlegames and endings). These are known as tactical puzzles. They can range from a simple "Mate in one" combination to a complex attack on the opponent's king. Solving tactical chess puzzles is a very common chess teaching technique. Although it is unlikely that the same position will occur in a game the student plays, the recognition of certain patterns can help to find a good move or plan in another position.

Examples

This section uses algebraic notation to describe chess moves.

Unless otherwise stated, all puzzle positions illustrated arose in real games, and all puzzle sequences are top chess engine lines.^[a] All animations depict positions from the point of view of the side to play.

Puzzle 1

The solution is 1...Qf2!, attacking the f1-rook; 2.Rxf2 would blunder back-rank checkmate after 2...Rd1+. The rook's only safe square is g1, but after 2.Rg1, 2...Bc5 sets up a battery aimed at g1, and White cannot stop checkmate without moving the c1-bishop to connect the rooks. The only two squares available to the bishop are controlled by the black queen, however, thus the loss of the bishop is unavoidable from the start; White's best response is 2.Be3, giving up the bishop immediately.

Puzzle 2

The solution is 1.Ne6+!, unblocking White's h4-bishop and g1-rook. Black's f-pawn must guard the g6-bishop, preventing ...fxe6 in all variations; thus, if the black king moves after 1.Ne6+, then 2.Qxf6 leaves Black down a piece and in a mating net. White can force mate in less than 13 moves against any alternative to 1...Qxe6, which sacrifices material to blunt White's attack.

Mathematical chess problems

Some chess problems, like the eight queens puzzle or the knight's tour problem, have connections to mathematics, especially to graph theory and combinatorics. Many famous mathematicians have studied such problems, including Euler, Legendre, and Gauss. Besides finding a solution to a particular puzzle, mathematicians are usually interested in counting the total number of possible solutions, finding solutions with certain properties, and generalization of the problems to n×n or rectangular boards.

Notes

^ Engines and versions may vary; Stockfish NNUE can be assumed.

External links

[1] Engines and versions may vary; Stockfish NNUE can be assumed.

[a]