Lichess

File:Thibault Duplessis.jpg

Lichess was founded in 2010 by French programmer Thibault Duplessis.{{cite web|url =https://www.liberation.fr/sports/2017/12/15/carnet-d-echecs_1616978|title =Carnet d'échecs|first =Pierre|last =Gravagna|website =Libération|date =15 December 2017|language =fr}}{{Cite web|title=About lichess.org • lichess.org|url=https://lichess.org/about|access-date=2020-07-23|website=lichess.org}} The software running Lichess and the design are mostly open source under the AGPL license{{cite web|last1=Duplessis|first1=Thibault|title=LICENSE|url=https://github.com/ornicar/lila/blob/master/LICENSE|website=GitHub|access-date=25 October 2016}} and other free and non-free licenses.[https://github.com/ornicar/lila/blob/master/COPYING.md lila/COPYING.md at master · ornicar/lila · GitHub] The name Lichess is a "combination of live/light/libre and chess".{{cite web |title=Why is Lichess called Lichess? |url=https://lichess.org/faq#name |website=Lichess.org |access-date=5 March 2023}}

On February 11, 2015, an official Lichess mobile app was released for Android devices.{{cite web|title=Android apps in Google Play|url=https://play.google.com/store/apps/details?id=org.lichess.mobileapp|access-date=21 February 2016}} An app for mobile devices running iOS was released on March 4, 2015.{{cite web|title=lichess – Free Online Chess in the App Store| website=iTunes |url=https://apps.apple.com/us/app/lichess-online-chess/id968371784|access-date=21 February 2016}}

In April 2021, the United States Chess Federation announced its official endorsement of Lichess's fair play methodology that automatically detects cheaters based on engine move matching analysis.{{Cite web|last=Lucas|first=Daniel|date=2021-04-01|title=US Chess Endorses LiChess Fair Play Methodology|url=https://new.uschess.org/news/us-chess-endorses-lichess-fair-play-methodology|access-date=2021-05-06|website=US Chess.org|language=en}}

As of April 28, 2022, lichess.org had a global rank of 683 at Alexa, with most of its visitors coming from the United States, India, and China.{{cite web|title=lichess.org Site Overview|url=http://www.alexa.com/siteinfo/lichess.org|access-date=28 April 2022|publisher=Alexa Internet|archive-date=25 May 2019|archive-url=https://web.archive.org/web/20190525165532/https://www.alexa.com/siteinfo/lichess.org|url-status=dead}} According to its Alexa rank, Lichess is ranked second only to Chess.com as one of the most popular internet chess servers in the world.{{cite web|url=http://chess-links.org/|title=Chess Links and Websites|access-date=7 October 2018|archive-date=4 January 2021|archive-url=https://web.archive.org/web/20210104225729/http://chess-links.org/|url-status=dead}}{{update needed|date=December 2024}}

File:Lichess Titled Arena March 2021.png

In December 2017 Lichess began hosting a monthly Lichess Titled Arena with cash prizes for titled players, featuring some of the best players in the world playing bullet chess.{{Cite web|url=https://lichess.org/blog/WgtAgSgAABRkEU_x/titled-prize-tournament|title=Titled Prize Tournament!|access-date=2020-09-14|website=lichess.org|date=22 November 2017 |language=en-US}} Magnus Carlsen won the first titled arena, and has regularly competed and won events since then.{{Cite web|title=Magnus Carlsen wins the first Lichess Titled Arena|url=https://lichess.org/blog/WjRTPScAAJXo7r5s/magnus-carlsen-wins-the-first-lichess-titled-arena|access-date=2020-06-25|website=lichess.org|date=15 December 2017 |language=en-US}}{{Cite web|title=Online Chess Taking Advantage Of Opportunity To Grow, Entertain During Coronavirus Pandemic|url=https://www.forbes.com/sites/michaellore/2020/05/26/online-chess-taking-advantage-of-opportunity-to-grow-entertain-during-coronavirus-pandemic/#f0923c9b9745|website=Forbes.com|language=en-US}}{{Cite web|title=DrDrunkenstein's Reign of Terror|url=https://slate.com/culture/2020/02/magnus-carlsen-speed-chess-drdrunkenstein-pseudonyms-twitch-youtube.html|access-date=2020-09-14|website=Slate.com|date=21 February 2020|language=en-US}}{{Cite news|url=https://www.spiegel.de/sport/magnus-carlsen-und-online-schach-drnykterstein-plant-die-revolution-a-6d3cdb5d-c0d2-4c9f-ae5c-aedc664bf9e0|title=DrNykterstein plant die Revolution|language=de-DE|access-date=2020-09-14|website=Der Spiegel|date=19 April 2020|last1=Pütz|first1=Florian}} Later editions have featured blitz chess as well, and some events were played as Chess 960 events with randomized starting positions for each game.

As of February 2022, Carlsen has a record 17 victories in titled arenas, followed by Alireza Firouzja with 13 victories.{{Cite web|title=Alireza wins a 13th Titled Arena.|url=https://lichess.org/blog/YDLy4hMAACMAEiKs/alireza-wins-a-13th-titled-arena.|access-date=2021-03-07|website=lichess.org|date=23 February 2021 |language=en-US}} Other participants in past editions include Fabiano Caruana, Maxime Vachier-Lagrave, Vladimir Fedoseev, Vladislav Artemiev, Alexander Grischuk, and Anish Giri.

The Saint Louis Chess Club (SLCC) regularly hosted events on Lichess with large prize funds, attracting the world's best players to compete until Lichess terminated the relationship in 2023.

In May 2020, the SLCC hosted the Clutch Chess: USA on Lichess, a four-player knock-out event with $100,000 in prizes.{{Cite web|title=Clutch Chess: USA|url=https://www.uschesschamps.com/2020-clutch-chess/overview|website=U.S. Chess Champs|language=en-US}} The participants were Fabiano Caruana, Wesley So, Leinier Domínguez, and Hikaru Nakamura. The event was won by So, beating Caruana on tiebreaks in the final (more wins in clutch games) after a final score of 9–9.{{Cite web|title=Wesley So wins Clutch Chess Champions Showdown|url=https://en.chessbase.com/post/clutch-chess-2020-final-2|website=ChessBase|date=30 May 2020|language=en-US}}

In June 2020, the SLCC hosted the Clutch Chess: International on Lichess, an eight-player invitational knock-out tournament with a prize fund of $265,000, which at the time was the largest prize fund ever offered for an online chess event.{{Cite web|title=Clutch Chess: International|url=https://www.uschesschamps.com/2020-clutch-chess-international/overview|website=U.S. Chess Champs|language=en-US}} The participants were Magnus Carlsen, Maxime Vachier-Lagrave, Leinier Domínguez, Alexander Grischuk, Levon Aronian, Fabiano Caruana, Wesley So, and Jeffery Xiong. Carlsen won the event, beating Caruana 9.5–8.5 in the finals.{{Cite web|title=Magnus Carlsen wins Clutch Chess International|url=https://www.fide.com/news/579|website=FIDE|language=en-US}}{{Cite web|title=Last Gasp victory for Magnus Carlsen in the Clutch Chess International 2020|url=https://theweekinchess.com/chessnews/events/clutch-chess-champions-showdown-international-2020/last-gasp-victory-for-magnus-carlsen-in-the-clutch-chess-international-2020|website=The Week in Chess|language=en-US}}

In September 2020, the SLCC hosted the 2020 Champions Showdown: Chess 9LX on Lichess, a Chess 960 invitational rapid tournament with a prize fund of $150,000.{{Cite web|title=2020 Champions Showdown: Chess 9LX|url=https://www.uschesschamps.com/2020-champions-showdown-chess-9lx/overview|website=U.S. Chess Champs|language=en-US|access-date=2020-09-14}} The participants of this event were Magnus Carlsen, Garry Kasparov, Fabiano Caruana, Hikaru Nakamura, Wesley So, Levon Aronian, Maxime Vachier-Lagrave, Alireza Firouzja, Leinier Domínguez and Peter Svidler. The event was jointly won by Carlsen and Nakamura, both scoring 6/9.{{Cite web|title=Champions Showdown Chess 9LX: Carlsen and Nakamura share first place|url=https://en.chessbase.com/post/champions-showdown-chess-9lx-carlsen-and-nakamura-share-first-place|website=ChessBase|date=14 September 2020|language=en-US|access-date=2020-09-14}}

Later in September 2020, the SLCC hosted the 2020 Saint Louis Rapid and Blitz on Lichess, a combined rapid and blitz event with a prize fund of $250,000.{{Cite web|url=https://www.uschesschamps.com/2020-saint-louis-rapid-blitz/overview|title=2020 Saint Louis Rapid & Blitz|website=Saint Louis Chess Club|language=en-US|access-date=2020-09-21}}{{Cite web|url=https://theweekinchess.com/chessnews/events/saint-louis-rapid-blitz-2020|title=Saint Louis Rapid & Blitz 2020|website=The Week in Chess|language=en-US|access-date=2020-09-21}} The ten invited participants included Carlsen, Nakamura and So. Carlsen and So were the joint overall winners with 24 points, with So winning the three-day rapid phase with 13 points, while Carlsen and Nakamura shared first in the two-day blitz phase with 12 points each.{{Cite web|url=https://www.uschesschamps.com/2020-saint-louis-rapid-blitz/final-standings|title=Final standings|website=Saint Louis Chess Club|language=en-US|access-date=2020-09-21}}{{Cite web|url=https://en.chessbase.com/post/st-louis-rapid-and-blitz-2020-day-5|title=So and Carlsen co-champions of the Saint Louis Rapid & Blitz tournament|language=en-US|website=ChessBase|date=20 September 2020|access-date=2020-09-21}}

{{Anchor|SLCC article}}In August 2023, an article was published on the Lichess website, stating "Lichess will no longer cooperate with the US Chess Federation and the Saint Louis Chess Club". The article included previously unpublished details of sexual misconduct allegations against two US grandmasters, and criticized the handling of it by both organizations.{{Cite web|url=https://lichess.org/blog/ZNTniBEAACEAJZTn/breaking-the-silence|title=Breaking the Silence|date=2023-08-10|website=lichess.org|language=en|access-date=2023-08-15}}

In April 2020, Magnus Carlsen and Alireza Firouzja played a bullet match on Lichess, with the winner of the overall match being the first player to reach 100 wins. After 194 games Firouzja won the match 103.5–90.5 (100 wins, 7 draws and 87 losses).{{Cite web|title=Chess: Magnus Carlsen prepares for meeting with prodigy Alireza Firouzja|url=https://www.theguardian.com/sport/2020/apr/09/chess-magnus-carlsen-prepares-for-meeting-with-prodigy-alireza-firouja|website=The Guardian|date=9 April 2020|language=en-US|access-date=2020-09-14}}{{Cite web|title=Firouzja and Carlsen battle it out in bullet marathon|url=https://en.chessbase.com/post/firouzja-and-carlsen-battle-it-out-in-bullet-marathon|website=ChessBase|date=10 April 2020|language=en-US|access-date=2020-09-14}}

In May 2020, Lichess hosted the Play for Russia charity event, to raise money for hospitals and health workers fighting the COVID-19 pandemic.{{Cite web|title=Chess Federation of Russia|url=https://ruchess.ru/en/championship/detail/2020/charity_tournament_/|access-date=2020-09-14|website=ruchess.ru|language=en-US}}{{Cite web|title=Super-GM Charity Tournament to be held on lichess.org: 12–14 May|url=https://lichess.org/blog/XqxUIxIAACEAxMBl/super-gm-charity-tournament-to-be-held-on-lichess.org-12---14-may|access-date=2020-09-14|website=lichess.org|language=en-US}}{{Cite web|title=Play for Russia 2020 |url=https://theweekinchess.com/chessnews/events/play-for-russia-2020|website=The Week in Chess|language=en-US|access-date=2020-09-14}} The event raised 24,670,000 roubles ($335,000) and was won by Alexander Grischuk, beating Evgeny Tomashevsky in the finals.{{Cite web|title=Grischuk topples Kramnik to win Play for Russia Charity Tournament|url=https://lichess.org/blog/Xr2GWBIAACYAl1jz/grischuk-topples-kramnik-to-win-play-for-russia-charity-tournament|website=lichess.org|date=14 May 2020 |language=en-US|access-date=2020-09-14}} Other participants included Vladimir Kramnik, Ian Nepomniachtchi, Sergey Karjakin, and Peter Svidler.

In the same month, several chess players (including Sebastien Feller) hosted a charity event on Lichess to raise money for the Mercy hospital in Metz, France, in the fight against COVID-19.{{Cite web|title=Marathon d'Echecs: Tous ensemble pour Mercy|url=https://www.leetchi.com/c/marathon-tous-ensemble-pour-mercy|access-date=2020-09-14|website=leetchi.com|language=fr-FR}}

In August 2020, the Qatar Chess Federation hosted the Katara International Bullet Tournament on Lichess, with a prize fund of $10,000.{{Cite web|title=Announcing the Katara International Bullet Tournament with World Champion Magnus Carlsen|url=https://lichess.org/blog/Xz7dXRAAACIAIWVd/announcing-the-katara-international-bullet-tournament-with-world-champion-magnus-carlsen|website=lichess.org|date=21 August 2020 |language=en-US}} The event was won by Magnus Carlsen, beating Daniel Naroditsky in the finals.{{Cite web|title=Magnus Carlsen wins the Katara International Bullet Tournament 2020 |url=https://theweekinchess.com/chessnews/events/magnus-carlsen-wins-the-katara-international-bullet-tournament-2020|website=The Week in Chess|language=en-US|access-date=2020-09-14}} The 2021 edition with a prize fund of $12,800 was won by Vladislav Artemiev; in the finals, he beat Andrew Tang, who had knocked out Magnus Carlsen in the semifinals.{{Cite web|title=Vladislav Artemiev wins Katara 2021|url=https://lichess.org/blog/YNS5nhIAACMAnt9L/vladislav-artemiev-wins-katara-2021|website=lichess.org|date=25 June 2021 |language=en-US}}

The 4545 Lichess League is an online chess competition established in 2015 in collaboration with Lichess. Running for 42 seasons, the league focuses on classical time control play and features team-based tournaments, including the Lonewolf League, which is designed for individual players. The 4545 Lichess League aims to promote competitive play and community engagement among chess enthusiasts worldwide.{{Cite web|title=4545 Lichess League|url=https://www.lichess4545.com/|publisher=4545 Lichess League|access-date=2024-04-27}}{{Cite web|title=League History|url=https://www.lichess4545.com/team4545/season/41/document/league-history/|publisher=4545 Lichess League|access-date=2024-04-27}}

File:Lichess Horde game.png

The website allows users to play games of live and correspondence chess against other players at different time controls. It has training features, including chess basics, tactics training, chess coordinates, a chess video library, an opening explorer, studies, and an analysis board.{{cite web|last1=Wilde|first1=Tyler|title=The best chess games on PC|url=http://www.pcgamer.com/best-chess-games/|website=PC Gamer|access-date=20 November 2017|date=2017}}{{cite news|title=Play chess for free|url=https://www.highbeam.com/doc/1G1-244006414.html|archive-url=https://web.archive.org/web/20171201080952/https://www.highbeam.com/doc/1G1-244006414.html|url-status=dead|archive-date=December 1, 2017|access-date=20 November 2017|work=Liverpool Daily Post|date=December 11, 2010|location=Liverpool, UK}} It also has a section where chess coaches can advertise their services to users.{{cite web|title=Certified Coaches|url=https://lichess.org/coach|website=Lichess.org|access-date=7 October 2018}} Users can create "arena" or "swiss"-style tournaments in any time control and variant, including custom starting positions (for example, a thematic blitz tournament from the starting position of the King's Gambit). Users can also create simultaneous exhibitions in which they play against multiple other users at the same time.

File:Lichess Racing Kings.png

In addition to enabling blindfold chess,{{cite web|title = Lichess embraces blind players with new chess site features|url=http://www.slashgear.com/lichess-embraces-blind-players-with-new-chess-site-features-23334731/|website = slashgear.com|date=23 June 2014|access-date=7 August 2016}} the website supports the following chess variants:{{Cite web|url=https://lichess.org/variant|title=Lichess variants • lichess.org|website=Lichess.org|language=en|access-date=2017-05-31}}

• Antichess
• Atomic chess{{Cite web|url=https://lichess.org/blog/VLPYGCkAACkAnY7D/atomic-chess-and-more|title=Atomic Chess! And more|website=lichess.org|date=12 January 2015 |language=en|access-date=2019-06-14}}
• Chess960 (Fischer Random Chess)
• Crazyhouse{{Cite web|title = OMG Crazyhouse!|url = http://lichess.org/blog/Vp3sMSEAAB4AHiwT/omg-crazyhouse|website = lichess.org| date=20 January 2016 |access-date = 2016-01-25}}
• Horde (a variant of Dunsany's chess)
• King of the Hill
• Racing Kings
• Three-check chess

It also has a mode that enables one to play from a set position, whether entered manually or from another game.[https://lichess.org/editor]

Lichess was the first chess-site to have features to help visually impaired people play chess on a website.{{Cite web|url=https://lichess.org/blog/U5AX_DcAADkAz-L5/accessibility-for-blind-players|title=Accessibility for blind players|website=lichess.org|date=11 June 2014 |language=en|access-date=2019-06-14}}{{cite web|last1=Torres|first1=JC|title=Lichess embraces blind players with new chess site features|url=http://www.slashgear.com/lichess-embraces-blind-players-with-new-chess-site-features-23334731/|website=Slashgear.com|date=23 June 2014|access-date=14 August 2015}} It also has a chess puzzle-based CAPTCHA system.{{cite web|last1=Leyden|first1=John|title=We shall CRUSH you, puny ROBOT... with CHESS|url=https://www.theregister.co.uk/2013/03/14/chess_based_captcha/|publisher=The Register|date=14 March 2013|access-date=20 August 2015}}{{cite web|last1=Araújo|first1=Santi|title=Captcha de ajedrez: la mejor jugada contra los bots|url=https://www.genbeta.com/seguridad/captcha-de-ajedrez-la-mejor-jugada-contra-los-bots|website=Genbeta.com|access-date=20 November 2017|language=es|date=2017}}

For registered players, Lichess employs a Glicko-2{{cite web |title=Rating Distribution |url=https://lichess.org/stat/rating/distribution/blitz |website=lichess |access-date=8 July 2020}} rating system, and grants the ability to compete in tournaments, post in the forums, and request a server-side full game analysis for any finalized game. The ratings for standard chess are categorized into Ultrabullet, Bullet, Blitz, Rapid, Classical, or Correspondence depending on the game's total time or estimated total time (if using Fischer time control which increments time after each move).

A Lichess mobile app is available for iOS and Android.{{Cite web |url=https://lichess.org/mobile |title=Mobile • lichess.org|access-date=5 June 2017}}

File:Lichess Puzzle Storm.pngGames are stored in a database and are available to download which has served as the basis for multiple academic papers.{{Cite thesis |last=Zelek |first=Jakub |date=2022-07-07 |title=Topological Data Analysis in chess |url=https://ruj.uj.edu.pl/xmlui/handle/item/295689}}{{Cite book |last=Tom |first=Schwarzschild, Avi Borgnia, Eitan Gupta, Arjun Bansal, Arpit Emam, Zeyad Huang, Furong Goldblum, Micah Goldstein |url=http://worldcat.org/oclc/1269570261 |title=Datasets for Studying Generalization from Easy to Hard Examples |date=2021-08-12 |oclc=1269570261}}{{Cite book |last1=Rosemarin |first1=Hanan |last2=Rosenfeld |first2=Ariel |title=Proceedings of the 7th International Conference on Human-Agent Interaction |chapter=Playing Chess at a Human Desired Level and Style |date=2019-09-25 |chapter-url=https://dl.acm.org/doi/10.1145/3349537.3351904 |language=en |location=Kyoto Japan |publisher=ACM |pages=76–80 |doi=10.1145/3349537.3351904 |isbn=978-1-4503-6922-0|s2cid=203620985 }}

Users can play games against the Stockfish chess engine at a number of difficulty levels.{{cite web |date=2014 |title=Сайт дня: Lichess.org – чёрное и белое онлайн |url=https://www.ferra.ru/ru/techlife/news/2014/07/21/Lichess-sitesoftheday/ |url-status=dead |archive-url=https://web.archive.org/web/20180615032119/https://www.ferra.ru/ru/techlife/news/2014/07/21/Lichess-sitesoftheday/ |archive-date=15 June 2018 |access-date=20 November 2017 |website=Ferra.ru |language=ru}} They may analyze specific positions from standard chess or any of the supported chess variants. The website implements a version of the Stockfish engine that runs on the user's local machine within the user's web browser for limited or infinite analysis,{{cite web |title=Recent Improvements |url=https://lichess.org/blog/WJEdvicAACYAYrIS/recent-improvements |access-date=Feb 2, 2017 |website=Lichess.org|date=2 February 2017 }} which will calculate best lines of play or major opponent threats. An opening book based on games played on the site or a database of two million games played by FIDE titled players is available.{{cite web |title=Opening Explorer |url=https://lichess.org/blog/Vs0xMTAAAD4We4Ey/opening-explorer |access-date=Feb 26, 2016 |website=Lichess.org|date=26 February 2016 }} In the Antichess analysis board, users can utilize Mark Watkins's antichess solution database.{{cite web |last1=Watkins |first1=Mark |title=Losing Chess: 1. e3 wins for White |url=http://magma.maths.usyd.edu.au/~watkins/LOSING_CHESS/ICGA2016.pdf |access-date=17 January 2017}}

On March 19, 2021, Lichess announced a new feature – Puzzle Racer, a mix of Puzzle Storm, released in January of the same year. Like Puzzle Storm, a timed puzzle feature, it prompts the user to solve chess puzzles with increasing difficulty as quickly as possible, but with the goal to outperform opponents in both the time and accuracy sense and hence be the first to finish the race. Each correct move, not puzzle, gives a user one point and fills the combo bar by one. When a bar is filled a point bonus is given as shown below.

• 5 moves: +1 point
• 12 moves: +2 points
• 20 moves: +3 points
• 30 moves: +4 points
• Then +4 points every 10 other moves.

As with puzzle storm, an official leaderboard is not yet implemented, however, players can see their daily high scores. There are no bots participating but unregistered players can also join and are given their user names randomly.{{Cite web |title=Puzzlers on the Storm |url=https://lichess.org/blog/YBCoVBUAANCqHhLv/puzzlers-on-the-storm |access-date=2021-03-20 |website=lichess.org |date=27 January 2021 |language=en-US}}{{Cite web |title=New feature: Puzzle Racer |url=https://lichess.org/blog/YFOLzhMAACIAarsp/new-feature-puzzle-racer |access-date=2021-03-20 |website=lichess.org |date=19 March 2021 |language=en-US}}{{Cite web |title=Puzzle Racer • lichess.org |url=https://lichess.org/page/racer |access-date=2021-03-20 |website=lichess.org}}

File:Lichess example profile.png|Example profile

File:Lichess.org bullet game.png|A bullet chess game in progress

File:Lichess puzzles correct theme.png|A chess puzzle

File:Lichess Puzzle Streak.png|Puzzle Streak, where players solve increasingly difficult chess puzzles until a mistake is made

File:Lichess analysis board.png|Post-game analysis with Stockfish

File:Lichess study.png|A study for the Sicilian Defence

• Glossary of chess
• List of internet chess platforms
• Outline of chess

{{Notelist}}

{{Reflist|30em}}

• {{Official website}}
• [https://database.lichess.org/ Open database] of rated games played on lichess.org
• [https://github.com/lichess-org/papers Official repository of "papers"] – features publications {{quote inline|... that study Lichess, use Lichess data, or otherwise use or mention Lichess in a meaningful way}}

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