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Created page with "'''Home * Engines * Occam''' '''Occam''',<br/> a private chess program and later also Arimaa bot by Don Dailey <ref>[https://www.stmintz.com/ccc/ind..."
'''[[Main Page|Home]] * [[Engines]] * Occam'''
'''Occam''',<br/>
a private chess program and later also [[Arimaa]] bot by [[Don Dailey]] <ref>[https://www.stmintz.com/ccc/index.php?id=61157 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref> and [[Larry Kaufman]] <ref>[http://www6.chessclub.com/finger/occam Finger Occam] at [[Internet Chess Club]]</ref>, which evolved from [[Cilkchess]] as experimental development version of Don and Larry's later commercial programs. In it's early state, short after the [[WCCC 1999]], Don explicitly mentioned the [[Copy-Make]] approach in Occam <ref>[https://www.stmintz.com/ccc/index.php?id=61218 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref> which he later also preferred in [[Doch#Copy|Doch]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=291570&t=29770 Re: undo move vs. Position Cloning] by [[Don Dailey]], [[CCC]], September 16, 2009</ref> and presumably in [[Komodo]].
=Position=
Don gave following [[Board Representation|board representation]] and [[Chess Position|position]] structure <ref>[https://www.stmintz.com/ccc/index.php?id=61243 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 21, 1999</ref>:
<pre>
typedef struct ptag
{
SQUARES bd[65]; /* the board */
base_int king_loc[2]; /* location of kings */
u64 hashkey; /* position key for hash table */
int32 mat_sig; /* signature of material situation */
struct ptag *his[2]; /* pointer to last 2 positions */
ev_type inc_score; /* incremental component of score */
base_int ply_of_game; /* even = white to move */
base_int ply_of_search; /* start at 0 */
base_int pv[PV_LEN]; /* best move from position */
base_int last_move; /* move that got us here */
base_int null_count; /* how many recursive null moves? */
base_int in_check; /* is ctm king in check? */
} position;
</pre>
=Quotes=
==MTD==
Reply by [[Don Dailey]] to [[Bruce Moreland]], July 20, 1999 <ref>[https://www.stmintz.com/ccc/index.php?id=61151 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref>:
I have a primitive program called "Occam" playing on the chess server now. I don't have any kind of [[Aspiration Windows|aspiration search]] in it, just pure [[Alpha-Beta|alpha/beta]], no [[Principal Variation Search|PVS]], no [[MTD(f)|MTD]] or anything. I will implement PVS first so that I can do comparisions.
==Arimaa Bot==
Occam was further test-bed for an [[Arimaa]] bot which played the first computer-computer challenge in 2004 <ref>[http://arimaa.com/arimaa/challenge/2004/icgaNews2.html Arimaa Challenge 2004]</ref>. Quote by [[Omar Syed]] <ref>[[Omar Syed]] ('''2015'''). ''The Arimaa Challenge: From Inception to Completion''. [[ICGA Journal#38_1|ICGA Journal, Vol. 38, No. 1]]</ref>:
Soon after the challenge was announced, several members of the game AI-research community attempted to tackle the challenge. The late Don Dailey (developer of the [[Komodo]] chess engine) was the first to create an Arimaa engine. Within a couple months Don had a surprisingly strong program offering games in the Arimaa gameroom. In designing Arimaa, I had used the [[Zillions of Games|Zillions-of-Games]] [[General Game Playing|general game-playing]] engine, which allows specifying the rules of the game in a [[Lisp]] like language, and then immediately being able to play the game against the Zillions engine. Using only look ahead and no game-specific knowledge, this engine was able to play at a strong level in most games one could dream of. However, it was incredibly lousy at Arimaa due to the high branching factor. This helped build my confidence that Arimaa would be a difficult game for computers if only a [[Brute-Force|brute-force]] search was used. However, Don’s program, called OCCAM, surprised me in how well it played when the search engine was much faster and included some game knowledge. When Don realized that there was very little expert knowledge available for Arimaa, he felt that he could not make much progress on his program and went back to developing his chess engine which now has gone on to become the highest rated in the world.
=See also=
* [[Arimaa]]
* [[Cilkchess]]
* [[Doch]]
* [[Komodo]]
* [[Razoring]]
=Forum Posts=
* [https://www.stmintz.com/ccc/index.php?id=61058 MTD is a big win] by [[Don Dailey]], [[CCC]], July 19, 1999
: [https://www.stmintz.com/ccc/index.php?id=61151 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61157 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61218 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61243 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 21, 1999
=External Links=
==Chess Engine==
* [http://www6.chessclub.com/finger/occam Finger Occam] at [[Internet Chess Club]]
==Misc==
* [https://en.wikipedia.org/wiki/William_of_Ockham William of Ockham from Wikipedia]
* [https://en.wikipedia.org/wiki/Occam's_razor Occam's razor from Wikipedia]
* [https://en.wikipedia.org/wiki/Occam_%28programming_language%29 occam (programming language) from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Private]]
'''Occam''',<br/>
a private chess program and later also [[Arimaa]] bot by [[Don Dailey]] <ref>[https://www.stmintz.com/ccc/index.php?id=61157 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref> and [[Larry Kaufman]] <ref>[http://www6.chessclub.com/finger/occam Finger Occam] at [[Internet Chess Club]]</ref>, which evolved from [[Cilkchess]] as experimental development version of Don and Larry's later commercial programs. In it's early state, short after the [[WCCC 1999]], Don explicitly mentioned the [[Copy-Make]] approach in Occam <ref>[https://www.stmintz.com/ccc/index.php?id=61218 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref> which he later also preferred in [[Doch#Copy|Doch]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=291570&t=29770 Re: undo move vs. Position Cloning] by [[Don Dailey]], [[CCC]], September 16, 2009</ref> and presumably in [[Komodo]].
=Position=
Don gave following [[Board Representation|board representation]] and [[Chess Position|position]] structure <ref>[https://www.stmintz.com/ccc/index.php?id=61243 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 21, 1999</ref>:
<pre>
typedef struct ptag
{
SQUARES bd[65]; /* the board */
base_int king_loc[2]; /* location of kings */
u64 hashkey; /* position key for hash table */
int32 mat_sig; /* signature of material situation */
struct ptag *his[2]; /* pointer to last 2 positions */
ev_type inc_score; /* incremental component of score */
base_int ply_of_game; /* even = white to move */
base_int ply_of_search; /* start at 0 */
base_int pv[PV_LEN]; /* best move from position */
base_int last_move; /* move that got us here */
base_int null_count; /* how many recursive null moves? */
base_int in_check; /* is ctm king in check? */
} position;
</pre>
=Quotes=
==MTD==
Reply by [[Don Dailey]] to [[Bruce Moreland]], July 20, 1999 <ref>[https://www.stmintz.com/ccc/index.php?id=61151 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999</ref>:
I have a primitive program called "Occam" playing on the chess server now. I don't have any kind of [[Aspiration Windows|aspiration search]] in it, just pure [[Alpha-Beta|alpha/beta]], no [[Principal Variation Search|PVS]], no [[MTD(f)|MTD]] or anything. I will implement PVS first so that I can do comparisions.
==Arimaa Bot==
Occam was further test-bed for an [[Arimaa]] bot which played the first computer-computer challenge in 2004 <ref>[http://arimaa.com/arimaa/challenge/2004/icgaNews2.html Arimaa Challenge 2004]</ref>. Quote by [[Omar Syed]] <ref>[[Omar Syed]] ('''2015'''). ''The Arimaa Challenge: From Inception to Completion''. [[ICGA Journal#38_1|ICGA Journal, Vol. 38, No. 1]]</ref>:
Soon after the challenge was announced, several members of the game AI-research community attempted to tackle the challenge. The late Don Dailey (developer of the [[Komodo]] chess engine) was the first to create an Arimaa engine. Within a couple months Don had a surprisingly strong program offering games in the Arimaa gameroom. In designing Arimaa, I had used the [[Zillions of Games|Zillions-of-Games]] [[General Game Playing|general game-playing]] engine, which allows specifying the rules of the game in a [[Lisp]] like language, and then immediately being able to play the game against the Zillions engine. Using only look ahead and no game-specific knowledge, this engine was able to play at a strong level in most games one could dream of. However, it was incredibly lousy at Arimaa due to the high branching factor. This helped build my confidence that Arimaa would be a difficult game for computers if only a [[Brute-Force|brute-force]] search was used. However, Don’s program, called OCCAM, surprised me in how well it played when the search engine was much faster and included some game knowledge. When Don realized that there was very little expert knowledge available for Arimaa, he felt that he could not make much progress on his program and went back to developing his chess engine which now has gone on to become the highest rated in the world.
=See also=
* [[Arimaa]]
* [[Cilkchess]]
* [[Doch]]
* [[Komodo]]
* [[Razoring]]
=Forum Posts=
* [https://www.stmintz.com/ccc/index.php?id=61058 MTD is a big win] by [[Don Dailey]], [[CCC]], July 19, 1999
: [https://www.stmintz.com/ccc/index.php?id=61151 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61157 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61218 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 20, 1999
: [https://www.stmintz.com/ccc/index.php?id=61243 Re: MTD is a big win] by [[Don Dailey]], [[CCC]], July 21, 1999
=External Links=
==Chess Engine==
* [http://www6.chessclub.com/finger/occam Finger Occam] at [[Internet Chess Club]]
==Misc==
* [https://en.wikipedia.org/wiki/William_of_Ockham William of Ockham from Wikipedia]
* [https://en.wikipedia.org/wiki/Occam's_razor Occam's razor from Wikipedia]
* [https://en.wikipedia.org/wiki/Occam_%28programming_language%29 occam (programming language) from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Private]]
