Chess.com

Chess.com is an internet chess server and social networking website. The site has a freemium model in which some features are available for free, and others are available for accounts with subscriptions. Live online chess can be played against other users in daily, rapid, blitz or bullet time controls, with a number of chess variants available. Chess versus a chess engine, computer analysis, chess puzzles and teaching resources are offered.

As one of the largest chess platforms in the world, Chess.com achieved the milestone of 100 million users on December 16, 2022 and has about 11 million daily active users as of April 2023. Chess.com has hosted online tournaments including Titled Tuesdays, the PRO Chess League, the Speed Chess Championships, PogChamps, Online Chess Olympiads and computer vs. computer events.

Founding
The domain Chess.com was originally set up in 1995 by Aficionado, a company based in Berkeley, California to sell Chess Mentor, a chess tutoring software program. In 2005, Internet entrepreneur Erik Allebest and partner Jarom "Jay" Severson, who met as undergraduate students at Brigham Young University, bought the domain name and assembled a team of software developers, redeveloping the site as a chess portal. The site was relaunched in 2007, having heavy campaigning and promotion on social media.

Two years later, Chess.com acquired a similar chess social networking site, chesspark.com. In October 2013, Chess.com acquired the Amsterdam-based chess news site chessvibes.com as well. This news site, founded and operated by Dutch chess journalist Peter Doggers, continued to cover chess tournaments in a digital setting.

Growth in the 2010s
The website reached a milestone in 2014, when it announced that over a billion live games had been played on the site, including 100 million correspondence games. In January 2016, Chess.com announced a two-year overhaul of its previous interface (titled 'v3'). The site introduced features including computer analysis of games, and the chess variants of crazyhouse, three-check chess, king of the hill, chess960, atomic and bughouse. Chess.com reached another milestone in June 2017, as the 2,147,483,647th (= 231-1) game was played, which caused the iOS app to stop working for those with 32-bit Apple devices. This occurred because of an integer overflow problem whereby the number was too large to be represented in the number of storage bits that were used.

In May 2018, Chess.com acquired the 3300+ Elo-rated commercial chess engine Komodo, which ranked third behind Stockfish and Houdini at the time of acquisition. In conjunction, the Komodo team announced the addition of the probabilistic method of Monte Carlo tree search machine learning, the same methods used by the recent chess projects AlphaZero and Leela Chess Zero.

In November 2020, Chess.com acquired the rights to broadcast the World Chess Championship 2021, which is broadcast on live-streaming platform Twitch.

Response to the Russian invasion of Ukraine
In response to the 2022 Russian invasion of Ukraine, Chess.com published two articles that were critical of the invasion and replaced Russian and Belarusian flags with grey flags that linked to these articles. In retaliation, Chess.com was blocked in Russia. The site blocked Sergey Karjakin, Russian (formerly Ukrainian) grandmaster, over his support for the invasion, and Karjakin in turn supported Russia's block of the website.

Chess cheating controversy
In September 2022, Chess.com was caught in the furor of a controversy regarding cheating in professional chess games. A controversy erupted with accusations by grandmaster Magnus Carlsen against Hans Niemann. Leaked emails revealed that some people cheated on the Chess.com platform in games involving prize money and that Chess.com removed some players' accounts, including grandmaster Maxim Dlugy, who had been found to be cheating. In August 2023, a US District Court judge dismissed the lawsuit filed by Niemann.

Chess.com Global Championship
In November 2022, The Chess.com Global Championship was inaugurated with a $1,000,000 prize pool. 8 players that advanced from the CGC Knockout competed for a $500,000 total prize fund and Global Champion title in the finals taking place in Toronto, Canada. Wesley So became the first Chess.com Global Champion, defeating Nihal Sarin in the finals with a match score of 4.5–1.5.

ChessKid.com
Chess.com runs the subsidiary site chesskid.com for chess players that are under the minimum age requirement for Chess.com.

ChessKid.com has run a yearly online championship called CONIC (the ChessKid Online National Invitational Championship), since 2012 which is recognized by the United States Chess Federation. According to David Petty, the event organizer in 2013, ChessKid has made agreements and partnerships with chess associations in schools. In 2014, for a trial period. They have a long-term partnership with the NTCA (North Texas Chess Academy) which gives children access to online instructors.

Play Magnus Group
In August 2022, the Play Magnus Group accepted an offer to be acquired by Chess.com at a value of 800 million kr (US$80 million). The Play Magnus Group owns brands and businesses including the chess server chess24, the mobile app Play Magnus, the Champions Chess Tour, and the chess improvement website Chessable. On December 16, 2022, the acquisition was officially closed. According to Dot Esports, the Play Magnus Group was unable to make a "sustainable profit" on anything but Chessable, and the merge left "no other realistic chess competitor" except the free, open-source Lichess.

Speed Chess Championship
Chess.com has held the Speed Chess Championship annually since 2016, involving a single-elimination tournament featuring some of the world's best players. Nakamura has won five championships, while Carlsen has won three.

Tournament formula
The most important elements of the tournament formula:
 * 16-player single-elimination bracket
 * Matches consist of three segments: 90 minutes of 5+1, 60 minutes of 3+1, and 30 minutes of 1+1.
 * The player with the most cumulative points at the end of the match wins.
 * Games that start before the time for a segment runs out count toward the final score.
 * Players can resign from the match within the last 10 minutes of the 1+1 segment, with the player's win percentage being capped at 35%.
 * In case of equal number of points - tiebreaks:
 * A four-game 1+1 match.
 * A single bidding armageddon game with a base time of 5 minutes.

Tournament formula
The tournament starts on January 1 and, depending on the number of participants, consists of 4 or 5 rounds. All players are divided into groups (up to 12 people ), and only the winners advance to the next round. Players play in each round a maximum of 22 games simultaneously (with each opponent as White and Black), with a maximum of one day allocated for each move. So it can be considered a form of correspondence chess. The winner of the Championship is the player who accumulates the most points in the final round.

Titled Tuesdays
Titled Tuesday is an 11-round Swiss-system 3+1 blitz chess tournament held every Tuesday. Grandmaster participants include Hikaru Nakamura, Magnus Carlsen, Maxime Vachier-Lagrave, Alexander Grischuk, Dmitry Andreikin, Alireza Firouzja, Daniel Naroditsky, Wesley So, and Fabiano Caruana. The first event was held on October 28, 2014, with a prize fund of $500 and was won by Baadur Jobava. The prize fund was gradually upgraded to $5000 per week. As of February 2024, GM Hikaru Nakamura has won a total of 64 tournament wins since October 2020, followed by GM Dmitry Andreikin with 16, Magnus Carlsen has won three of the events in which he has partaken as of 2017.

In June 2018, Chess.com held a special version of the tournament for which the winner would go on to participate in the Isle of Man International which had a prize fund of £144,000. Iranian GM Pouria Darini won the event.

Death Matches
Death Matches were introduced in January 2012. They feature titled players taking part in a series of blitz games over a non-stop 3-hour period (5-minute, 3-minute and 1-minute, all with a one-second increment). There have been 38 deathmatches, participants including the grandmasters Hikaru Nakamura, Dmitry Andreikin, Maxime Vachier-Lagrave, Lê Quang Liêm, Wesley So, Fabiano Caruana, Judit Polgár and Nigel Short.

Chess.com Computer Chess Championship
In November 2017, Chess.com held an open tournament, called the Chess.com Computer Chess Championship (CCCC, later CCC), with the ten strongest chess engines, with $2,500 in prize money. The top-two engines competed in a "Superfinal" tournament between the two finalists – Stockfish and Houdini. In the 20-game Superfinal, Stockfish won over Houdini with a score 10.5–9.5. Five games were decisive, with 15 ending in a draw. Of the decisive games, three games were won by Stockfish, and two by Houdini.

In August 2018, the site announced that the Chess.com Computer Chess Championship has returned, this time as a non-stop tournament for chess engines.

PogChamps
Chess.com has hosted PogChamps, an amateur online tournament featuring Twitch streamers, since 2020. The first PogChamps featured streamers including xQcOW, MoistCr1TiKaL, Ludwig Ahgren, and forsen. New participants from PogChamps 2 included itsHafu and Hafþór Júlíus Björnsson. PogChamps 3, beginning in February 2021, debuted with a wider range of Internet personalities and celebrities, with new competitors including MrBeast, Neekolul, Myth, Pokimane, actor Rainn Wilson, and rapper Logic.

Coaches
Chess.com provides an extensive feature for connecting with professional chess coaches. Users can search for coaches at Chess.com Coaches Club based on rating, language, and availability, and view detailed profiles that include teaching styles, experience, and rates. Coaches include top players like: José Eduardo Martínez Alcántara, Raunak Sadhwani , Benjamin Bok and many more.