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The Chess Variant Pages

Sneaky: A WinBoard Compatible Chess Engine that plays Cheapmate Chess

By Gary Baydo

Sneaky is a WinBoard compatible chess engine that plays Cheapmate Chess, a variant invented by Robert Price. In Cheapmate Chess all the rules of normal chess are observed, but in addition illegal moves that give legal mate are allowed. The zip file for this download contains Sneaky.exe and Sneaky.readme. Sneaky is based on Tom Kerrigan's TSCP chess engine source code.

Sneaky is a much better player than the Zillions versions that are available. This is partially due to the fact that in Zillions there is no (good) way to *test* for checkmate before a move is allowed. Consequently, Zillions must allow illegal illegal moves :-) and compensate by providing alternative ways of winning (or losing).

Although Sneaky can be played in a console window (a DOS box), it is much nicer to use the graphical frontend WinBoard. If you don't already have WinBoard installed on your computer, you can download it from That site also has additional information and links related to installing and using WinBoard.

There are a some other very good chess variant engines available that run under WinBoard: Sjeng and Sunsetter are two. Again, links to these may be found on Tim Mann's website at

As Tom Kerrigan would say, 'Share and enjoy!'

Download it:

Written by Gary Baydo.
WWW page created: August 9th, 2003.