Solving Orthodox Chess Problems

Since a long time, around 1973, I'm interested in chess problems, and how to solve them with the help of a computer program.

List of contents

What is a Chess Problem?

Posing a chess problem consists of The stipulation ``mate in N moves'' means, that the side to move shall do a key move, such that even with the best possible counter-play there will be a mate in (or before) move N.

What is so ``orthodox'' about it?

``White moves and mates in N moves'' is the classic stipulation. Later there have been invented more exotic stipulations.

An orthodox problem is restricted to those chess pieces which are also used for playing chess. Especially for chess problems there have been invented lots of other pieces, which move in funny ways. These are not considered to be orthodox.

Additionally, the chess board contents posed in an orthodox problem must be reachable in a legal chess game (although such a game need not make sense, legality is sufficient).

How does this relate to computers?

The task to solve a chess problem is exactly defined, with mathematical rigor. A proposed solution to a chess problem is either right or wrong, not good or bad. If the stipulation restricts the number of moves, then the task to solve a chess problem is even obviously limited.

Therefore, the task to solve chess problems is even more suited to computers and programming, than the task to play chess.

Programs to solve chess problems

Of course, all chess playing programs can be used to assist in problem solving. Many of them have special ``problem modes'', which solve orthodox problems. A drawback (for the problemist) is that they often do not find the shortest mate, or duals and cooks. Of course, for the analysis of real world chess games (not artificially constructed problems) that is no harm.

There are also some specialized mate finders and solvers, partially freeware and partially commercial products. "Freely available" normally means "for non-commercial purposes".

I will not try to list all commercially available products, or all freeware programs, but I list some link lists below.


These acronyms stand for Portable Game Notation, Extended Position Description and Forsyth-Edwards Notation. The former is used to denote complete games, while the latter two denote game or problem positions. They are especially useful for import and export to and from chess software.

You may download the PGN Standard titled "The Specification and Implementation Guide" by Steven J. Edwards, containing the description of all three: FGN, EPD and FEN.

Other resources (links) around chess problems

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$Date: 2014/12/22 17:04:53 $