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an [[UCI]] compatible [[:Category:Open Source|open source]] chess engine developed by [[Tord Romstad]], [[Marco Costalba]], [[Joona Kiiski]] and [[Gary Linscott]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=58779 Stockfish 7] by [[Joona Kiiski]], [[CCC]], January 02, 2016</ref>, licensed under the [[Free Software Foundation#GPL|GPL v3.0]]. Marco forked the project from version 2.1 of Tord's engine [[Glaurung]], first announced by Marco in November 8, 2008 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=24675 Stockfish 1.0] by [[Marco Costalba]], [[CCC]], November 02, 2008</ref>, and in early 2009 Joona's [[Smaug]], a further Glaurung 2.2 derivative, was incorporated <ref>[http://www.talkchess.com/forum/viewtopic.php?t=26971&start=1 Re: Smaug: a new chess engine based on glaurung] by [[Marco Costalba]], [[CCC]], March 12, 2009</ref> . Starting out among the top twenty engines, Stockfish has quickly climbed in [[Playing Strength|strength]] to become the world strongest chess entity as of 2018 - at least concerning the [[AlphaZero]] hype <ref>[[David Silver]], [[Thomas Hubert]], [[Julian Schrittwieser]], [[Ioannis Antonoglou]], [[Matthew Lai]], [[Arthur Guez]], [[Marc Lanctot]], [[Laurent Sifre]], [[Dharshan Kumaran]], [[Thore Graepel]], [[Timothy Lillicrap]], [[Karen Simonyan]], [[Demis Hassabis]] ('''2017'''). ''Mastering Chess and Shogi by Self-Play with a General Reinforcement Learning Algorithm''. [https://arxiv.org/abs/1712.01815 arXiv:1712.01815]</ref>, public available chess entity. The name "Stockfish" reflects the ancestry of the engine. Tord is Norwegian and Marco Italian, and there is a long history of [https://en.wikipedia.org/wiki/Stockfish stockfish] trade from Norway to Italy (to Marco's home town of [https://en.wikipedia.org/wiki/Vicenza Vicenza], in fact). Stockfish also referred another famous "little fish", the then strongest chess engine [[Rybka]]. In 2011, Marco Costalba and Joona Kiiski stepped down as Stockfish maintainers <ref>[http://www.talkchess.com/forum/viewtopic.php?t=40610 Stockfish on github] by [[Marco Costalba]], [[CCC]], October 02, 2011</ref>. From that, the project is being developed and maintained by the [[:Category:Stockfish Contributor|Stockfish community]].

In 2011. Marco Costalba and Joona Kiiski stepped down as Stockfish maintainers <ref>[http://www.talkchess.com/forum/viewtopic.php?t=40610 Stockfish on github] by [[Marco Costalba]], [[CCC]], October 02, 2011</ref>. From that, the project is being developed and maintained by the [[:Category:Stockfish Contributor|Stockfish community]]. A synergy effect with the [[Shogi]] community led to the promising branch of [[Stockfish NNUE]], courtesy of [[Hisayori Noda|Nodchip]], who introduced [[NNUE]] to Stockfish in 2019 <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=2&t=74059 Stockfish NN release (NNUE)] by [[Henk Drost]], [[CCC]], May 31, 2020</ref>. On September 02, 2020, '''Stockfish 12''' was released with a huge jump in [[Playing Strength|playing strength]] due to NNUE and further [[Automated Tuning|tuning]] of the engine as a whole <ref>[https://blog.stockfishchess.org/postblog/6281728108529254402020/stockfish-12 / Stockfish 12], The Stockfish Team, [https://blog.stockfishchess.org/ Stockfish Blog], September 02, 2020</ref>. The release of '''Stockfish 13''' on February 19, 2021, has been triggered by the start of sales of the [[Fat Fritz#Fat Fritz 2|Fat Fritz 2]] engine by [[ChessBase]], based on a recent development version of Stockfish with minor modifications <ref>[https://stockfishchess.org/blog/2021/stockfish-13/ Stockfish 13], The Stockfish Team, February 19, 2021</ref>. '''Stockfish 14''', released on July 02, 2021, further improved due to efforts by [[Tomasz Sobczyk]] and [[Gary Linscott]] in designing a new [[Stockfish NNUE#HalfKA|NNUE architecture]] in conjunction with a [[GPU]] accelerated trainer written in [https://en.wikipedia.org/wiki/PyTorch PyTorch]. Further, the collaboration with the [[Leela Chess Zero]] team payed off, in providing billions of positions to train the new NNUE <ref>[https://stockfishchess.org/blog/2021/stockfish-14/ Stockfish 14], The Stockfish Team, July 02, 2021</ref>.

Since April 2017 the interactive '''Stockfish Evaluation Guide''' is available to explore Stockfish's [[Evaluation|evaluation]] with a [[JavaScript]] implementation running in a [https://en.wikipedia.org/wiki/Web_browser browser] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=64025&start=27 Re: How far away are we from deep learning Stockfish, Komodo] by [[Gary Linscott|Gary]], [[CCC]], May 21, 2017</ref> . One may enter a [[Forsyth-Edwards Notation|FEN]] string of a [[Chess Position|position]], to get the resulting [[Score|score]] of the main evaluation term considering the [[Game Phases|game phases]] within its [[Tapered Eval|tapered evaluation]], and may navigate through the tree of subterms and features with its particular characteristics for the given position <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/ Stockfish Evaluation Guide]</ref>, also supporting [[Stockfish NNUE]] nets <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/?p=nnue Stockfish Evaluation Guide - NNUE]</ref> .

On July 19, 2014, Stockfish 5 played a four game match versus [https://en.wikipedia.org/wiki/Daniel_Naroditsky Daniel Naroditsky] plus [[Rybka|Rybka 3]] (2008), 45 minutes plus 30-second increment. Stockfish won 3½ - ½ <ref>[http://www.chess.com/article/view/how-rybka-and-i-tried-to-beat-the-strongest-chess-computer-in-the-world Can a GM and Rybka beat Stockfish?] by GM [https://en.wikipedia.org/wiki/Daniel_Naroditsky Daniel Naroditsky], [https://en.wikipedia.org/wiki/Chess.com [Chess.com]], August 08, 2014</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=53228 GM and Rybka vs. Stockfish] by Robert Maddox, [[CCC]], August 09, 2014</ref> . A few weeks later the experiment continued with [https://en.wikipedia.org/wiki/Hikaru_Nakamura Hikaru Nakamura] in [https://en.wikipedia.org/wiki/Burlingame,_California Burlingame, California] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=53315 Nakamura vs Stockfish, public match 8/23] by Jesse L, [[CCC]], August 17, 2014</ref> . Supported two games by Rybka 3, Nakamura lost ½ - 1½, two games with pawn odds (Stockfish both Black without h- and b-pawn) ended ½ - 1½ in favour to Stockfish 5 as well. It played the latest development build compiled for [[Mac OS|OS X]] running on a 3 GHz 8-Core [[Macintosh|Mac Pro]] <ref>[http://www.chess.com/news/stockfish-outlasts-nakamura-3634 Stockfish Outlasts "Rybkamura"] by [http://www.chess.com/article/view/chesscom-player-profiles-fm-mikeklein FM Mike Klein], [https://en.wikipedia.org/wiki/Chess.com [Chess.com]], August 24, 2014</ref> .

: [[BMI2#PEXTBitboards|BMI2 - PEXT Bitboards]] (not recommend for [[AMD]] [https://en.wikipedia.org/wiki/Ryzen Ryzen] <ref>[https://www.reddit.com/r/Amd/comments/60i6er/ryzen_and_bmi2_strange_behavior_and_high_latencies/ Ryzen and BMI2: Strange behavior and high latencies] by DonnieTinyHands, [https://en.wikipedia.org/wiki/Reddit Reddit], March 20, 2017</ref>prior to [https://en.wikipedia.org/wiki/Zen_3 Zen 3])* [[Piece-Lists]] until Stockfish 12 <ref>[https://github.com/official-stockfish/Stockfish/blob/sf_12/src/position.h#L193 Stockfish/position.h at sf_12 · official-stockfish/Stockfish · GitHub]</ref> <ref>[https://github.com/official-stockfish/Stockfish/pull/3247 Remove piece lists by syzygy1 · Pull Request #3247 · official-stockfish/Stockfish · GitHub]</ref> <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=7&t=69364&start=12 Re: piece lists advantage with bit-boards?] by [[Ronald de Man]], [[CCC]], December 26, 2018</ref>

* [[NNUE]]** [[Stockfish NNUE#HalfKP|HalfKP]] (Strockfish 12)** [[Stockfish NNUE#HalfKA|HalfKAv2]] (Strockfish 14): ''See also'' [[Evaluation Philosophy]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=135133&t=15504 The Art of Evaluation] by [[Tord Romstad]], [[CCC]], August 2, 2007</ref> <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/ Stockfish Evaluation Guide]</ref> and [[NNUE]]

 =Videos= * [[Daylen Yang#Video|How do modern chess engines work? | VideoBill Jordan]], Talk by [[Daylen Yang]], ('''2020'''). ''Calculation versus Intuition: Stockfish versus Leela''. [httphttps://www.tngtechamazon.com/tngCalculation-versus-ueberIntuition-uns/bigtechday/bigStockfish-techdayLeela-8.html TNG | Big Techday 8], June 12, 2015* [[Tord Romstad#Video|Parallelism and Selectivity in Game Tree Search | Video]], Talk by [[Tord Romstad]], [http:ebook/dp/www.tngtech.com/tng-ueber-uns/bigtechdayB08LYBQDMB/big-techday-8.html TNG | Big Techday 8amazon], June 12, 2015* » [[Tord Romstad#Video|How Modern Chess Programs Work | VideoTCEC]] by , [[Tord RomstadLeela Chess Zero]], [http://2017.flatmap.no/talks/romstad/ flatMap(Oslo)], May 02, 2017

* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=74059 Stockfish NN release (NNUE)] by [[Henk Drost]], [[CCC]], May 31, 2020 » [[NNUE]], [[Stockfish NNUE]]* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=74339 Stockfish has included WDL stats in engine output] by Deberger, [[CCC]], July 02, 2020 » [[Pawn Advantage, Win Percentage, and Elo]]

==Chess engineEngine==

* [httphttps://nextchessmove.com/dev-builds NCM Stockfish Dev Builds]* [https://abrok.eu/stockfish/ Stockfish Development Versions] hosted by [[Roman Korba]]

* [http://www.chess.fortherapy.co.uk/ Arduino & Raspberry PI Chess Computer] running [[Stockfish]] on [[Raspberry Pi]], by [[Max Dobres]] » [[Arduino]], [[Sensory Board]]==Issues==* [http://tech.mit.edu/V133/N62/chess.html One chess champion per laptop] by [http://www.mit.edu/~roberto/ Roberto Perez-Franco], [[Massachusetts Institute of Technology|MIT's]] [https://en.wikipedia.org/wiki/The_Tech_%28newspaper%29 The Tech], January 15, 2014 » [[TCEC Season 5]]* [http://en.chessbasegithub.com/post/johnofficial-hartmann-and-then-there-were-two And then there were two] by [http:stockfish/Stockfish/en.chessbase.comissues Issues · official-stockfish/author/john-hartmann John Hartmann], [[ChessBase|ChessBase News]], June 09, 2015 » [[Komodo]], [[Stockfish]· GitHub]* [https://rjlipton.wordpressgithub.com/2015official-stockfish/10Stockfish/06issues/depth2823 NNUE merge · Issue #2823 · official-of-satisficingstockfish/ Depth of SatisficingStockfish · GitHub] by [[Kenneth W. Regan|Ken ReganJoost VandeVondele]], [https://rjlipton.wordpress.com/ Gödel's Lost Letter and P=NP], October 06July 25, 2015 » [[Depth]], [[Match Statistics]], [[Pawn Advantage, Win Percentage, and Elo]], [[Stockfish]], [[Komodo]] 2020 <ref>[http://www.talkchess.com/forumforum3/viewtopic.php?f=2&t=57890 Regan's latest: Depth of Satisficing74560 An info] by Carl LummaSylwy, [[CCC]], October 09July 25, 20152020</ref>* [https://rjlipton.wordpressgithub.com/2016official-stockfish/01Stockfish/21issues/a2915 NNUE ideas and discussion (post-chessmerge) Issue #2915 official-firewall-at-zerostockfish/ A Chess Firewall at Zero?Stockfish · GitHub] by [[Kenneth W. Regan|Ken ReganJoost VandeVondele]], August 06, 2020* [https://rjlipton.wordpressgithub.com/ Gödel's Lost Letter and P=NP], January 21, 2016* [http:official-stockfish/Stockfish/adamsccpages.blogspot.com/pissues/sf3021 NNUE eval rotate vs mirror · Issue #3021 · official-framework-history.html Adam's Computer Chess Pages: stockfish/Stockfish Progression· GitHub] by [[Adam Hair]] » [[Stockfish#Fishtest|FishtestTerje Kirstihagen]], August 18, 2020==BlogPull Requests==* [https://bloggithub.stockfishchess.orgcom/official-stockfish/ Stockfish Blog]* [https:/pulls Pull requests · official-stockfish/blog.stockfishchess.org/post/152699558142/stockfish-8 Stockfish 8· GitHub], November 01, 2016* [https://bloggithub.stockfishchess.orgcom/postofficial-stockfish/180690834147/stockfish-9 Stockfish 9], February 09, 2018* [https:/pull/blog3474 Update default net to nn-8a08400ed089.stockfishchess.orgnnue by Sopel97 · Pull Request #3474 · official-stockfish/post/180691011237/stockfish-10 Stockfish 10· GitHub], December 01, 2018* by [https://blog.stockfishchess.org/post/190398991302/stockfish-11 Stockfish 11], The Stockfish Team, January 15, 2020* [https://blog.stockfishchess.org/post/625828091343896577/introducing-nnue-evaluation Introducing NNUE EvaluationTomasz Sobczyk], August 07, 2020* [https://blog.stockfishchess.org/post/628172810852925440/stockfish-12 Stockfish 12], The Stockfish Team, September 02, 2020

* [httphttps://tests.stockfishchess.org/tests Stockfish Testing Framework] » [[Stockfish#Fishtest|Fishtest]]

* : [https://groupshxim.googlegithub.comio/forumStockfish-Evaluation-Guide/#!forum/fishcooking FishCooking - Google Groups] a discussion group for developers and testers of [[?p=nnue Stockfish]] chess engine* <span id="Support"></span>[http://support.stockfishchess.org/home Welcome Evaluation Guide - Stockfish SupportNNUE]

: [https://github.com/glinscott/fishtest/wiki/Creating-my-first-test Creating my first test· glinscott/fishtest Wiki · GitHub] by : [[Stephane Nicolet]https://github.com/glinscott/fishtest/wiki/Fishtest-mathematics Fishtest mathematics · glinscott/fishtest Wiki · GitHub]

* [http://www.chess.com/article/view/how-rybka-and-i-tried-to-beat-the-strongest-chess-computer-in-the-world Can a GM and Rybka beat Stockfish?] by GM [https://en.wikipedia.org/wiki/Daniel_Naroditsky Daniel Naroditsky], [https://en.wikipedia.org/wiki/Chess.com [Chess.com]], August 08, 2014 » [[Stockfish#Matches|GM+Rybka vs. Stockfish]]* [http://www.chess.com/news/stockfish-outlasts-nakamura-3634 Stockfish Outlasts "Rybkamura"] by [http://www.chess.com/article/view/chesscom-player-profiles-fm-mikeklein FM Mike Klein], [https://en.wikipedia.org/wiki/Chess.com [Chess.com]], August 24, 2014* [https://www.chess.com/news/view/alphazero-reactions-from-top-gms-stockfish-author AlphaZero: Reactions From Top GMs, Stockfish Author] by [http://www.chessvibes.com/?q=peterdoggers [Peter Doggers]], [https://en.wikipedia.org/wiki/Chess.com [Chess.com]], December 08, 2017 » [[AlphaZero#StockfishMatch|AlphaZero vs. Stockfish]]