AI Chess

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**AI Chess**, (A.I. Chess)
was [[Marty Hirsch|Marty Hirsch's]] first chess program and predecessor of [[MChess]]. AI Chess played the [[ACM 1988]], the [[WCCC 1989]] and the [[WMCCC 1989]] <ref>[[http://www.game-ai-forum.org/icga-tournaments/program.php?id=352|AI Chess' ICGA Tournaments]]</ref>.

=Description= 
given in the [[WCCC 1989]] booklet <ref>[[http://www.computerhistory.org/chess/full_record.php?iid=doc-434fea055cbb3|Kings Move - Welcome to the 1989 AGT World Computer Chess Championship.]] Edmonton, Alberta, Canada, Courtesy of [[Peter Jennings]], from [[The Computer History Museum]], [[http://archive.computerhistory.org/projects/chess/related_materials/text/3-1%20and%203-2%20and%203-3%20and%204-3.1989_WCCC/1989%20WCCC.062302028.sm.pdf|pdf]]</ref> :

{{A.I. Chess uses a fairly complicated algorithm combining full-width search, [[Selectivity|selective search]], and a "layered" [[Quiescence Search|quiscence search]] which behaves differently at different levels in the search tree. The program performs an [[Iterative Deepening|iterative]] full-width search using a modified form of the [[Principal Variation Search|Principal-Variation-Search]] (PVS) algorithm. On top of this, it does a combined selective/quiscence analysis. A.I. Chess has the unusual feature of sometimes re-searching a "[[Quiescent Node|quiscence node]]" with a full-width investigation.}}

{{The quiscence search incorporates a detailed "threat analysis" and therefore, the program spots may combinations long before a contrasting "[[Brute-Force|brute force]]" approach would find them. The gain (from needing less full-width plies) seems to exceed the loss in speed by a significant amount.}}

{{[[Evaluation|Position evaluation]] starts by considering if the side to move is threatened with [[Promotions|pawn promotion]], [[Check|check]], or [[Double Attack|double attack]], or has [[Trapped Pieces|trapped]], [[Pin|pinned]], or [[Skewer|skewered]] pieces. Penalties similar to swap-off scores are imposed if the position is too deep to merit a re-search. [[Score|Scores]] are then added for other [[Tactics|tactical patterns]], pressure on pieces and pawns, development, [[King Safety|King safety]], [[Passed Pawn|passed pawns]], [[Pawn Structure|pawn structure]], [[Outposts|outposts]], and [[Mobility|mobility]].}}

{{Some types of [[Endgame|endgame positions]] are scored differently, by [[Pattern Recognition|pattern recognition]] processing. The program is alert to simplifications, and to tactics involving passed pawns.}}

=Namesakes=
* [[http://www.cs.nott.ac.uk/~gxw/chess.html|AI Chess]] by [[Glenn Whitwell]], a [[Cpp|C++]] Chess Learning project in conjunction of a Computer Science Third Year Project from the [[http://en.wikipedia.org/wiki/University_of_Nottingham|University of Nottingham]]
* [[http://www.cs.cornell.edu/boom/2004sp/ProjectArch/Chess/chessmain.html|AI Chess Project]] by [[Mikolaj Franaszczuk]], Fall 2003

=External Links=
* [[http://www.game-ai-forum.org/icga-tournaments/program.php?id=352|AI Chess' ICGA Tournaments]]

=References= 
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=What links here?= 
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