Chess is a board game played between two players. It is played on a chessboard, which is a square-checkered board with 64 squares arranged in an eight-by-eight grid. At the start, each player controls sixteen pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. The object of the game is to checkmate the opponent's king, whereby the king is under immediate attack (in "check") and there is no way to remove or defend it from attack on the next move.
The current form of the game emerged in Europe during the second half of the 15th century after evolving from a much older game of Indian origin. Aspects of art are found in chess composition. Theoreticians have developed extensive chess strategies and tactics since the game's inception. One of the goals of early computer scientists was to create a chess-playing machine. Chess is now deeply influenced by the abilities of chess programs and the opportunity for online play. In 1997 Deep Blue became the first computer to beat the reigning World Champion in a match when it defeated Garry Kasparov.
The tradition of organized competitive chess started in the 16th century. The first official World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; the current World Champion is Viswanathan Anand. Chess is a recognized sport of the International Olympic Committee. Today, chess is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.