Older Version Newer Version

GerdIsenberg GerdIsenberg Mar 12, 2018

**[[Home]] * [[Engines]] * Zurichess**
|| [[image:Zürich_German_monophthongs_chart.svg.png width="224" height="163" link="https://commons.wikimedia.org/wiki/File:Z%C3%BCrich_German_monophthongs_chart.svg"]] ||~   || **Zurichess**,
an [[UCI]] compliant [[Open Source Engines|open source chess engine]] and chess library by [[Alexandru Mosoi|Alexandru Moșoi]], written in the [[Go (Programming Language)|Go]] programming language <ref>[[https://bitbucket.org/brtzsnr/zurichess/|brtzsnr / zurichess — Bitbucket]]</ref> , first released in January 2015. The name Zurichess is in dependence on [[https://en.wikipedia.org/wiki/Zurich_German|Züritüütsch]], the [[https://en.wikipedia.org/wiki/High_Alemannic_German|High Alemannic dialect]] spoken in the [[https://en.wikipedia.org/wiki/Canton_of_Z%C3%BCrich|Canton of Zurich]], [[https://en.wikipedia.org/wiki/Switzerland|Switzerland]] <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=54990&start=17|Re: Mr.Ruxy versus Zurichess]] by [[Alexandru Mosoi]], [[CCC]], January 17, 2015</ref>. Versions are named after [[https://en.wikipedia.org/wiki/Cantons_of_Switzerland|Swiss Cantons]] in alphabetical order <ref>[[https://bitbucket.org/zurichess/zurichess/src/d80fadb47a1ecac6692cd582554d806b8e95ed62/CHANGELOG.md?at=master&fileviewer=file-view-default|zurichess / zurichess / source / CHANGELOG.md — Bitbucket]]</ref>. ||
|| [[https://en.wikipedia.org/wiki/Zurich_German|Zurich German]] [[https://en.wikipedia.org/wiki/Monophthong|monophthongs]] <ref>[[http://www.uni-marburg.de/fb09/igs/mitarbeiter/fleischer/index_html|Jürg Fleischer]], [[https://www.philosophie.hu-berlin.de/institut/lehrbereiche/theorie/mitarbeiter/schmid|Stephan Schmid]] (**2006**). // [[http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=591416&fileId=S0025100306002441|Illustrations of the IPA: Zurich German]]//. [[https://en.wikipedia.org/wiki/Journal_of_the_International_Phonetic_Association|Journal of the International Phonetic Association]], Vol. 36, No. 2, page 256; doi:10.1017/S0025100306002441, [[https://en.wikipedia.org/wiki/Wikimedia_Commons|Wikimedia Commons]], [[https://en.wikipedia.org/wiki/Zurich_German|Zurich German from Wikipedia]]</ref> ||~   ||^   ||
[[toc]]
=Description=
==A-B== 
Zurichess uses [[Bitboards|bitboards]] with [[BitScan#DeBruijnMultiplation|De Bruijn bitscan]] for [[Bitboard Serialization|serialization]], and [[Magic Bitboards#Fancy|fancy magic bitboards]] to determine [[Sliding Piece Attacks|sliding piece attacks]]. The [[Search|search]]  applies [[Fail-Soft|fail soft]] [[Negamax|negamax]] [[Alpha-Beta|alpha-beta]] plus [[Transposition Table|transposition table]] inside the [[Iterative Deepening|iterative deepening]] loop with [[Aspiration Windows|aspiration windows]] <ref>[[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=499768&t=46624|Re: Aspiration window - effect? Issue with hashtables?! LONG POST]] by [[Matthew R. Brades]], [[CCC]], December 29, 2012</ref>. [[Move Ordering|Move ordering]] is improved by the [[Killer Heuristic|killer heuristic]] and considers [[MVV-LVA|MVV/LVA]] for [[Captures|captures]]. [[Evaluation]] relies on the [[Simplified evaluation function|simplified evaluation function]] using a [[Tapered Eval|tapered eval]] interpolating between [[Opening|opening]] and [[Endgame|endgame]] [[Score|scores]] of [[Material|material]] and [[Piece-Square Tables|piece-square tables]]. While the first  public release **Aargau** lacked all kinds of [[Pruning|forward pruning]], [[Reductions|reductions]] and [[Extensions|extensions]], subsequent versions, **Appenzeller** and **Basel** improved on various search and evaluation topics, now addressing [[Null Move Pruning|null move pruning]] and [[Mobility|mobility]] beside a lot of other things and optimizations, not to mention fixing bugs <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=56136|zurichess basel released]] by [[Alexandru Mosoi]], [[CCC]], April 27, 2015</ref>. **Bern** release in June 2015 is about 130 Elo stronger than Basel <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=56617|zurichess bern released]] by [[Alexandru Mosoi]], [[CCC]], June 07, 2015</ref>.  
[[#Fribourg]]
==Fribourg==
Zurichess **Fribourg**, released on August 30, 2015, now has [[Passed Pawn|passed pawn]] evaluation, considering [[Connected Passed Pawns|connected]] and [[Isolated Pawn|isolated]] pawns. [[Automated Tuning|Tuning]] was done using [[Texel's Tuning Method|Texel's tuning method]] implemented by **txt** <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=55696|txt: automated chess engine tuning]] by [[Alexandru Mosoi]], [[CCC]], March 18, 2015</ref> <ref>[[https://bitbucket.org/zurichess/txt|zurichess / txt — Bitbucket]]</ref>. [[Late Move Reductions|LMR]] was added, as well as [[Static Exchange Evaluation|static exchange evaluation]] (SEE) to sort [[Captures|captures]], to [[Pruning|prune]] bad captures (SEE < 0) in [[Quiescence Search|quiescence search]] and to aggressively [[Reductions|reduce]] bad [[Quiet Moves|quiet moves]] (SEE < 0) at higher depths. Further, [[Move Generation#Staged|staged move generation]] and [[Pondering|pondering]] were added, and [[Repetitions|two-fold repetitions]] at non-root nodes pruned. Zurichess Fribourg is about 200 Elo stronger than Bern <ref> [[http://www.talkchess.com/forum/viewtopic.php?t=57440|zurichess fribourg released]] by [[Alexandru Mosoi]], [[CCC]], August 30, 2015</ref> .
[[#Geneva]]
==Geneva==
Zurichess **Geneva**, released on November 29, 2015, and now aware of the [[Fifty-move Rule|fifty-move draw rule]], has added basic [[Futility Pruning|futility pruning]] and relaxed [[Null Move Pruning|null move conditions]] allowing [[Double Null Move|double null moves]]. In eval, [[Automated Tuning|tuning]] switched from **txt** to [[https://en.wikipedia.org/wiki/TensorFlow|TensorFlow]] <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=58211|tensorflow]] by [[Alexandru Mosoi]], [[CCC]], November 10, 2015</ref> - a two layers [[Neural Networks|neural network]] is used, where the second layer is responsible for a [[Tapered Eval|tapered eval]] to phase [[Endgame|endgame]] and [[Middlegame|middlegame]] [[Score|scores]] <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=60883&start=1|Re: Deep Learning Chess Engine ?]] by [[Alexandru Mosoi]], [[CCC]], July 21, 2016</ref>. Rooks were evaluated on [[Rook on Open File|open and half-open files]], and [[Mobility|mobility]] calculation was improved. Zurichess Geneva is about 100 Elo stronger than Fribourg <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=58415|zurichess geneva released]] by [[Alexandru Mosoi]], [[CCC]], November 29, 2015</ref>.
[[#Glarus]]
==Glarus==
Announced and released on April 17, 2016, Zurichess **Glarus** has improved [[Futility Pruning|futility conditions]] and added [[History Leaf Pruning|history leaf pruning]], further improving [[Pawn Hash Table|pawn hash table]] utilization by caching [[King Safety#PawnShield|pawn shelter]], [[King Safety|king safety]] by considering number of simultaneous attackers, and [[Time Management|time control]]. Glarus is about 80 Elo stronger than Geneva in self-play <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=59885|zurichess glarus released]] by [[Alexandru Mosoi]], [[CCC]], April 17, 2016</ref>. 
[[#Graubuenden]]
==Graubuenden==
Zurichess **Graubuenden** was released on August 16, 2016 with various tweaks, search and evaluation improvements such as [[Transposition Table|hashing]] in [[Quiescence Search|quiescence search]], and new features like skill levels and [[Principal Variation#MultiPV|multi-PV]]. Further, a new version of the Go compiler yields in increased search speed. In self-play Graubuenden is about 110 Elo stronger than Glarus <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=61141|zurichess graubuenden released]] by [[Alexandru Mosoi]], [[CCC]], August 16, 2016</ref>.
[[#Jura]]
==Jura==
Zurichess **Jura** appeared on February 18, 2017 with improved [[Selectivity|selectivity]], [[Move Ordering|move ordering]] and evaluation, introducing [[Razoring|razoring]], [[Countermove Heuristic|countermove heuristic]], [[King Safety#KingTropism|king-queen tropism]] and [[Piece-Square Tables|rook-square tables]] plus various tweaks and re-tuning. In self play at fast time controls Jura is about 85 Elo stronger than Graubuenden <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=63202|zurichess jura released]] by [[Alexandru Mosoi]], [[CCC]], February 18, 2017</ref>. 
[[#Luzern]]
==Luzern==
Zurichess **Luzern**, released on May 08, 2017, further enhanced its search and evaluation, in particular a 16% faster search and considering defended minors, [[Pawn Attacks (Bitboards)|pawn attacks]] an potential pawn attacks. In self play Luzern is about 64 Elo stronger than Jura <ref> [[http://www.talkchess.com/forum/viewtopic.php?t=63931|zurichess - new version release]] by [[Alexandru Mosoi]], [[CCC]], May 08, 2017</ref>.
[[#Neuchatel]]
==Neuchâtel==
Zurichess **Neuchâtel** became a stable release in September 2017 <ref>[[https://bitbucket.org/zurichess/zurichess/commits/f5f1b02de17478f3166c06d138d95178ea0c7941|zurichess / zurichess / commit / f5f1b02de174 — Bitbucket]]</ref> with an expected gain of 50 Elo <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=65033|zurichess neuchatel - preview release]] by [[Alexandru Mosoi]], [[CCC]], August 29, 2017</ref>.

=See also=
* [[ETH Zurich]]
* [[Various Classifications#Geography|Geography]]

=Forum Posts= 
==2015==
* [[http://www.talkchess.com/forum/viewtopic.php?t=54990|zurichess - new chess engine]] by [[Alexandru Mosoi]], [[CCC]], January 16, 2015
* [[http://www.talkchess.com/forum/viewtopic.php?t=55404|zurichess appenzeller - new version]] by [[Alexandru Mosoi]], [[CCC]], February 21, 2015
* [[http://www.talkchess.com/forum/viewtopic.php?t=55696&start=81|Re: txt: automated chess engine tuning]] by [[Alexandru Mosoi]], [[CCC]], April 11, 2015 » [[Automated Tuning]]
* [[http://www.talkchess.com/forum/viewtopic.php?t=56136|zurichess basel released]] by [[Alexandru Mosoi]], [[CCC]], April 27, 2015
* [[http://www.talkchess.com/forum/viewtopic.php?t=56617|zurichess bern released]] by [[Alexandru Mosoi]], [[CCC]], June 07, 2015
* [[http://www.talkchess.com/forum/viewtopic.php?t=57440|zurichess fribourg released]] by [[Alexandru Mosoi]], [[CCC]], August 30, 2015
* [[http://www.talkchess.com/forum/viewtopic.php?t=58415|zurichess geneva released]] by [[Alexandru Mosoi]], [[CCC]], November 29, 2015
==2016==
* [[http://www.talkchess.com/forum/viewtopic.php?t=58826|hacking on zurichess]] by [[Alexandru Mosoi]], [[CCC]], January 06, 2016
* [[http://www.talkchess.com/forum/viewtopic.php?t=59600|trivia: ELO boost from a better compiler]] by [[Alexandru Mosoi]], [[CCC]], March 22, 2016 » [[Go (Programming Language)]]
* [[http://www.talkchess.com/forum/viewtopic.php?t=59647|king safety: hard positions for zurichess]] by [[Alexandru Mosoi]], [[CCC]], March 27, 2016 » [[King Safety]], [[Test-Positions]]
* [[http://www.talkchess.com/forum/viewtopic.php?t=59885|zurichess glarus released]] by [[Alexandru Mosoi]], [[CCC]], April 17, 2016
* [[http://www.talkchess.com/forum/viewtopic.php?t=60883&start=1|Re: Deep Learning Chess Engine ?]] by [[Alexandru Mosoi]], [[CCC]], July 21, 2016
> [[http://www.talkchess.com/forum/viewtopic.php?t=60883&start=4|Re: Deep Learning Chess Engine ?]] by [[Alexandru Mosoi]], [[CCC]], July 21, 2016
* [[http://www.talkchess.com/forum/viewtopic.php?t=61141|zurichess graubuenden released]] by [[Alexandru Mosoi]], [[CCC]], August 16, 2016
==2017==
* [[http://www.talkchess.com/forum/viewtopic.php?t=62875|zurichess jura - preview release]] by [[Alexandru Mosoi]], [[CCC]], January 19, 2017
* [[http://www.talkchess.com/forum/viewtopic.php?t=63202|zurichess jura released]] by [[Alexandru Mosoi]], [[CCC]], February 18, 2017
* [[http://www.talkchess.com/forum/viewtopic.php?t=63408|improved evaluation function]] by [[Alexandru Mosoi]], [[CCC]], March 11, 2017 » [[Texel's Tuning Method]]
* [[http://www.talkchess.com/forum/viewtopic.php?t=63502|speed up or avoiding move sorting]] by [[Alexandru Mosoi]], [[CCC]], March 19, 2017 » [[Move Ordering]]
* [[http://www.talkchess.com/forum/viewtopic.php?t=63931|zurichess - new version release]] by [[Alexandru Mosoi]], [[CCC]], May 08, 2017
* [[http://www.talkchess.com/forum/viewtopic.php?t=65033|zurichess neuchatel - preview release]] by [[Alexandru Mosoi]], [[CCC]], August 29, 2017
* [[http://www.talkchess.com/forum/viewtopic.php?t=65886|need some help assessing the evaluation]] by [[Alexandru Mosoi]], [[CCC]], December 02, 2017

=External Links= 
==Chess Engine==
* [[https://bitbucket.org/brtzsnr/zurichess/|brtzsnr / zurichess — Bitbucket]]
* [[https://bitbucket.org/zurichess/zurichess|zurichess / zurichess — Bitbucket]]
* [[http://www.computerchess.org.uk/ccrl/4040/cgi/compare_engines.cgi?family=Zurichess&print=Rating+list&print=Results+table&print=LOS+table&print=Ponder+hit+table&print=Eval+difference+table&print=Comopp+gamenum+table&print=Overlap+table&print=Score+with+common+opponents|Zurichess]] in [[CCRL|CCRL 40/40]]
==Misc==
===Aargau===
* [[https://en.wikipedia.org/wiki/Aargau|Aargau from Wikipedia]]
===Appenzell===
* [[https://en.wikipedia.org/wiki/Appenzell_%28disambiguation%29|Appenzell (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Appenzell_%28town%29|Appenzell (town) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Appenzeller_cheese|Appenzeller cheese from Wikipedia]]
===Basel===
* [[https://en.wikipedia.org/wiki/Basel_%28disambiguation%29|Basel (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Basel|Basel from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Basel|Canton of Basel from Wikipedia]]
===Bern===
* [[http://en.wikipedia.org/wiki/Bern_%28disambiguation%29|Bern (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Bern|Bern from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Bern|Canton of Bern from Wikipedia]]
===Fribourg===
* [[https://en.wikipedia.org/wiki/Freiburg_%28disambiguation%29|Fribourg (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Fribourg|Fribourg from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Fribourg|Canton of Fribourg from Wikipedia]]
===Geneva===
* [[https://en.wikipedia.org/wiki/Geneva_%28disambiguation%29|Geneva (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Geneva|Geneva from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Geneva|Canton of Geneva from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Geneva_Conventions|Geneva Conventions from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Geneva_Protocol|Geneva Protocol from Wikipedia]]
===Glarus===
* [[https://en.wikipedia.org/wiki/Glarus|Glarus from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Glarus|Canton of Glarus from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Glarus_Alps|Glarus Alps from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Glarus_thrust|Glarus thrust from Wikipedia]]
===Graubünden===
* [[https://en.wikipedia.org/wiki/Grisons|Graubünden (Grisons) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Three_Leagues|Three Leagues from Wikipedia]]
===Jura===
* [[https://en.wikipedia.org/wiki/Canton_of_Jura|Canton of Jura from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Jura_Mountains|Jura Mountains from Wikipedia]]
===Luzern===
* [[https://en.wikipedia.org/wiki/Lucerne|Lucerne from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Lucerne|Canton of Lucerne from Wikipedia]]
===Neuchâtel===
* [[https://en.wikipedia.org/wiki/Neuch%C3%A2tel_(disambiguation)|Neuchâtel (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Neuch%C3%A2tel|Neuchâtel from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Neuch%C3%A2tel|Canton of Neuchâtel from Wikipedia]]
===Zurich===
* [[https://en.wikipedia.org/wiki/Zurich_%28disambiguation%29|Zurich (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Z%C3%BCrich|Zürich from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Canton_of_Z%C3%BCrich|Canton of Zürich from Wikipedia]]

=References= 
<references />
=What links here?= 
[[include page="Zurichess" component="backlinks" limit="40"]]
**[[Engines|Up one Level]]**