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'''[[Main Page|Home]] * [[Engines]] * AI Chess'''
'''AI Chess''', (A.I. Chess)<br/>
a chess program by [[Marty Hirsch]] and predecessor of [[MChess]]. AI Chess was written in [[8086]] [[Assembly|assembly language]] to ran on an [[IBM PC]] under [[MS-DOS|DOS]] <ref>[[Monroe Newborn|Monty Newborn]], [[Danny Kopec]] ('''1989'''). ''Results of The Nineteenth ACM North American Computer Chess Championship''. [[ACM#Communications|Communications of the ACM]], Vol. 32, No. 10, [http://www.sci.brooklyn.cuny.edu/%7Ekopec/Publications/Publications/O_23_C.pdf pdf]</ref>. It played the [[ACM 1988]] in [https://en.wikipedia.org/wiki/Orlando%2C_Florida Orlando], the [[WCCC 1989]] in [https://en.wikipedia.org/wiki/Edmonton Edmonton] and the [[WMCCC 1989]] in [https://en.wikipedia.org/wiki/Portoro%C5%BE Portorož] <ref>[https://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|quiescence 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 quiescence 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.
=See also=
* [[MChess]]
=External Links=
* [https://www.game-ai-forum.org/icga-tournaments/program.php?id=352 AI Chess' ICGA Tournaments]
=References=
<references />
'''[[Engines|Up one level]]'''
[[Category:DosEngine]]
'''AI Chess''', (A.I. Chess)<br/>
a chess program by [[Marty Hirsch]] and predecessor of [[MChess]]. AI Chess was written in [[8086]] [[Assembly|assembly language]] to ran on an [[IBM PC]] under [[MS-DOS|DOS]] <ref>[[Monroe Newborn|Monty Newborn]], [[Danny Kopec]] ('''1989'''). ''Results of The Nineteenth ACM North American Computer Chess Championship''. [[ACM#Communications|Communications of the ACM]], Vol. 32, No. 10, [http://www.sci.brooklyn.cuny.edu/%7Ekopec/Publications/Publications/O_23_C.pdf pdf]</ref>. It played the [[ACM 1988]] in [https://en.wikipedia.org/wiki/Orlando%2C_Florida Orlando], the [[WCCC 1989]] in [https://en.wikipedia.org/wiki/Edmonton Edmonton] and the [[WMCCC 1989]] in [https://en.wikipedia.org/wiki/Portoro%C5%BE Portorož] <ref>[https://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|quiescence 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 quiescence 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.
=See also=
* [[MChess]]
=External Links=
* [https://www.game-ai-forum.org/icga-tournaments/program.php?id=352 AI Chess' ICGA Tournaments]
=References=
<references />
'''[[Engines|Up one level]]'''
[[Category:DosEngine]]
