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.
Portable Game NotationPortable Game Notation (PGN) is a standard plain text format for recording chess games (both the moves and related data), which can be read by humans and is also supported by most chess software. PGN was devised around 1993, by Steven J. Edwards, and was first popularized and specified via the Usenet newsgroup rec.games.chess. PGN is structured "for easy reading and writing by human users and for easy parsing and generation by computer programs." The chess moves themselves are given in algebraic chess notation using English initials for the pieces.
Endgame tablebaseAn endgame tablebase is a computerized database that contains precalculated exhaustive analysis of chess endgame positions. It is typically used by a computer chess engine during play, or by a human or computer that is retrospectively analysing a game that has already been played. The tablebase contains the game-theoretical value (win, loss, or draw) in each possible position, and how many moves it would take to achieve that result with perfect play. Thus, the tablebase acts as an oracle, always providing the optimal moves.
BitboardA bitboard is a specialized bit array data structure commonly used in computer systems that play board games, where each bit corresponds to a game board space or piece. This allows parallel bitwise operations to set or query the game state, or determine moves or plays in the game. Bits in the same bitboard relate to each other by the rules of the game, often forming a game position when taken together. Other bitboards are commonly used as masks to transform or answer queries about positions.
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.comChess.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 also available. Chess versus a chess engine, computer analysis, chess puzzles and teaching resources are also offered.
CheckmateCheckmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game. In chess, the king is never actually captured—the player loses as soon as the player's king is checkmated. In formal games, it is usually considered good etiquette to resign an inevitably lost game before being checkmated. If a player is not in check but has no legal moves, then it is stalemate, and the game immediately ends in a draw.
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.
Glossary of chessThis glossary of chess explains commonly used terms in chess, in alphabetical order. Some of these terms have their own pages, like fork and pin. For a list of unorthodox chess pieces, see Fairy chess piece; for a list of terms specific to chess problems, see Glossary of chess problems; for a list of named opening lines, see List of chess openings; for a list of chess-related games, see List of chess variants; for a list of terms general to board games, see Glossary of board games.
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.