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.
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.
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.
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.
ChessChess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to distinguish it from related games, such as xiangqi (Chinese chess) and shogi (Japanese chess). The recorded history of chess goes back at least to the emergence of a similar game, chaturanga, in seventh century India.