Correspondence chessCorrespondence chess is chess played by various forms of long-distance correspondence, traditionally through the postal system. Today it is usually played through a correspondence chess server, a public internet chess forum, or email. Less common methods that have been employed include fax, homing pigeon and phone. It is in contrast to (OTB) chess, where the players sit at a chessboard at the same time, or play each other in real time via the internet.
Internet chess serverAn Internet chess server (ICS) is an external server that provides the facility to play, discuss, and view the board game of chess over the Internet. The term specifically refers to facilities for connecting players through a variety of graphical chess clients located on each user's computer. In the 1970s, one could play correspondence chess in a PLATO System program called 'chess3'. Several users used chess3 regularly; often a particular user would make several moves per day, sometimes with several games simultaneously in progress.
Stockfish (chess)Stockfish is a free and open-source chess engine, available for various desktop and mobile platforms. It can be used in chess software through the Universal Chess Interface. Stockfish has consistently ranked first or near the top of most chess-engine rating lists and, as of April 2023, is the strongest CPU chess engine in the world. Its estimated Elo rating is around 3550 (CCRL 40/15). It has won the Top Chess Engine Championship 14 times and the Chess.com Computer Chess Championship 19 times.
ChessBaseChessBase is a German company that develops and sells chess software, maintains a chess news site, and operates an internet chess server for online chess. Founded in 1986, it maintains and sells large-scale databases containing the moves of recorded chess games. The databases contain data from prior games and provide engine analyses of games, while endgame tablebases offer optimal play in some endgames. ChessBase's Indian YouTube channel ChessBase India has amassed more than a million YouTube subscribers and more than 671 million total views as of November 2022.
Chess engineIn computer chess, a chess engine is a computer program that analyzes chess or chess variant positions, and generates a move or list of moves that it regards as strongest. A chess engine is usually a back end with a command-line interface with no graphics or windowing. Engines are usually used with a front end, a windowed graphical user interface such as Chessbase or WinBoard that the user can interact with via a keyboard, mouse or touchscreen.
AlphaZeroAlphaZero is a computer program developed by artificial intelligence research company DeepMind to master the games of chess, shogi and go. This algorithm uses an approach similar to AlphaGo Zero. On December 5, 2017, the DeepMind team released a preprint paper introducing AlphaZero, which within 24 hours of training achieved a superhuman level of play in these three games by defeating world-champion programs Stockfish, Elmo, and the three-day version of AlphaGo Zero.
Chess variantA chess variant is a game related to, derived from, or inspired by chess. Such variants can differ from chess in many different ways. "International" or "Western" chess itself is one of a family of games which have related origins and could be considered variants of each other. Chess developed from chaturanga, from which other members of this family, such as ouk chatrang, shatranj, Tamerlane chess, shogi, and xiangqi also evolved. Many chess variants are designed to be played with the equipment of regular chess.
Elo rating systemThe Elo rating system is a method for calculating the relative skill levels of players in zero-sum games such as chess. It is named after its creator Arpad Elo, a Hungarian-American physics professor. The Elo system was invented as an improved chess-rating system over the previously used Harkness system, but is also used as a rating system in association football, American football, baseball, basketball, pool, table tennis, various board games and esports, and more recently large language models.
World Chess ChampionshipThe World Chess Championship is played to determine the world champion in chess. The current world champion is Ding Liren, who defeated his opponent Ian Nepomniachtchi in the 2023 World Chess Championship. Magnus Carlsen, the previous world champion, declined to defend his title. The first event recognized as a world championship was the 1886 match between the two leading players in the world, Wilhelm Steinitz and Johannes Zukertort. Steinitz won, becoming the first world champion.
Computer chessComputer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysis, entertainment and training. Computer chess applications that play at the level of a chess master or higher are available on hardware from supercomputers to smart phones. Standalone chess-playing machines are also available.