Sunfish

**[[Home]] * [[Engines]] * Sunfish**
|| [[image:Elassoma_sp.jpg link="http://en.wikipedia.org/wiki/File:Elassoma_sp.jpg"]] ||~   || **Sunfish**,
a simple [[Open Source Engines|open source chess engine]] under the [[Free Software Foundation#GPL|GPL]] written by [[Thomas Dybdahl Ahle]] in [[Python]] for didactic purposes, inspired by [[Harm Geert Muller|Harm Geert Muller's]] [[Micro-Max]] <ref>[[http://www.reddit.com/r/programming/comments/1xmj1a/sunfish_a_111_line_chess_engine_in_python/|Sunfish – A 111 line Chess Engine in Python]] by [[Thomas Dybdahl Ahle]], [[http://en.wikipedia.org/wiki/Reddit|reddit]], February 16, 2014</ref> . Without the code lines of the [[Piece-Square Tables|piece-square tables]] and its simple [[CLI|command line interface]], it takes up just 111 lines of code. ||
|| [[http://en.wikipedia.org/wiki/Pygmy_sunfish|Pygmy sunfish]] <ref>Pygmy sunfish (Elassoma sp.). [[http://digitalmedia.fws.gov/cdm/singleitem/collection/natdiglib/id/4499/rec/1|Drawing]] by [[http://www.ncwas.com/raver.html|Duane Raver]] for the [[http://en.wikipedia.org/wiki/United_States_Fish_and_Wildlife_Service|United States Fish and Wildlife Service]], [[http://en.wikipedia.org/wiki/Pygmy_sunfish|Pygmy sunfish from Wikipedia]]</ref> ||~   ||^   ||
[[toc]]
=Description= 
Sunfish applies MTD-bi, the binary search version of [[MTD(f)]] <ref>[[Aske Plaat]], [[Jonathan Schaeffer]], [[Wim Pijls]], [[Arie de Bruin]] (**1995**). //A New Paradigm for Minimax Search//. Technical Report EUR-CS-95-03. [[http://publishing.eur.nl/ir/repub/asset/1440/eur-few-cs-95-03.pdf|pdf]]</ref> , also known as [[NegaC*]] as proposed by [[Jean-Christophe Weill]] in 1990 <ref>[[Jean-Christophe Weill]] (**1991**). //Experiments With the NegaC* Search - An Alternative for Othello Endgame Search.// [[2nd Computer Olympiad#Workshop|Heuristic Programming in AI 2]]</ref> <ref>[[Jean-Christophe Weill]] (**1992**). //The NegaC* Search.// [[ICGA Journal#15_1|ICCA Journal, Vol. 15, No. 1]]</ref> , which is based on [[NegaC*|C*]], introduced by [[Kevin Coplan]] in 1981 at [[Advances in Computer Chess 3]] <ref>[[Kevin Coplan]] (**1982**). //A special-purpose machine for an improved search algorithm for deep chess combinations.// [[Advances in Computer Chess 3]]</ref> . MTD-bi is embedded inside an [[Iterative Deepening|iterative deepening]] framework. Its [[Fail-Soft|fail-soft]] [[Scout|scout]] originally lacked the [[Quiescence Search|quiescence search]], which made it blunder pretty badly in some positions <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=51430&start=7|Re: SUNFISH - a new chess engine written in Python !]] by [[Thomas Dybdahl Ahle]], [[CCC]], February 28, 2014</ref> , but a version of this was later added <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=51430&start=20|Re: SUNFISH - a new chess engine written in Python !]] by [[Thomas Dybdahl Ahle]], [[CCC]], February 28, 2014</ref>. The rudimentary [[Evaluation|evaluation]] considers [[Point Value|point values]] and [[Piece-Square Tables|piece-square tables]] - an aggregated [[Score|score]] is [[Incremental Updates|incremental updated]] during [[Make Move|make move]].

=Etymology= 
Sunfish is named after the [[http://en.wikipedia.org/wiki/Pygmy_sunfish|Pygmy Sunfish]], which is amoung the very few fish to start with the letters 'Py', and refers other famous [[Various Classifications#Fish|fish engines]] such as [[Stockfish]] and [[Rybka]] <ref>[[https://github.com/thomasahle/sunfish|thomasahle/sunfish · GitHub]]</ref> .

=See also= 
* [[Various Classifications#Fish|Fish]]
* [[Various Classifications#Geography|Geography]]
* [[PyChess]]

=Postings= 
* [[http://www.reddit.com/r/programming/comments/1xmj1a/sunfish_a_111_line_chess_engine_in_python/|Sunfish – A 111 line Chess Engine in Python]] by [[Thomas Dybdahl Ahle]], [[http://en.wikipedia.org/wiki/Reddit|reddit]], February 16, 2014
* [[http://www.talkchess.com/forum/viewtopic.php?t=51430|SUNFISH - a new chess engine written in Python !]] by [[http://www.talkchess.com/forum/profile.php?mode=viewprofile&u=881|Ruxy Sylwyka]], [[CCC]], February 27, 2014
* [[http://www.talkchess.com/forum/viewtopic.php?t=61182|New version of Sunfish]] by [[Thomas Dybdahl Ahle]], [[CCC]], August 20, 2016
* [[http://www.talkchess.com/forum/viewtopic.php?t=66216|Sunfish (Python Engine)]] by [[Norbert Raimund Leisner]], [[CCC]], January 02, 2018

=External Links= 
==Chess Engine== 
* [[https://github.com/thomasahle/sunfish|thomasahle/sunfish · GitHub]]
==Misc== 
* [[http://en.wikipedia.org/wiki/Sunfish|Sunfish from Wikipedia]]
* [[http://en.wikipedia.org/wiki/Sunfish_Lake_%28Ontario%29|Sunfish Lake (Ontario) from Wikipedia]]
* [[http://en.wikipedia.org/wiki/Basking_shark|Basking shark from Wikipedia]]
* [[http://en.wikipedia.org/wiki/Pygmy_sunfish|Pygmy sunfish from Wikipedia]]

=References= 
<references />
=What links here?= 
[[include page="Sunfish" component="backlinks" limit="30"]]
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