Fidelity Ultimate Chess Challenge

The Fidelity Ultimate Chess Challenge is a chess video game released for the Atari Lynx by Telegames in 1991. Players can either play one player vs the game engine or two players (using the same console). The game engine uses the experience of Fidelity Electronics, makers of various chess computers and elaborates the Master rated (2325 Elo) chess program. It uses the program of the 6502 programs (Sensory 9—Excellence) series.

The program has 17 levels of play. Eight of them are time based level setting the average response time from 5 seconds (level time 1) to 4 minutes (level 8). The eight following levels restrict the program ability to lookahead. For example, level depth 1 restricts the program to a lookahead of 1 ply or 1 half move, level depth 2 restricts the computer's lookahead to 2 plies or 2 half moves, and so on to level depth 8. The 17th level is an infinite level, the computation can either be stopped by the user or by the finding of a forced mate.