The first champions set the style of the game. In the 1850s the American Paul Morphy toured Europe and beat almost every top player he met. In 1858 he played the famous "Opera House" game against two opponents who were allies. William Steinitz was recognized as the first world chess champion, and he held the title until 1894. Steinitz had no equal at positional play, which means building up small advantages. Emanuel Lasker was world champion for 27 years, the longest reign of any chess champion. In 1921 the Cuban Jose Raul Capablanca beat Lasker to become the third world champion. Capablanca's endgame skill was considered the greatest the world had ever seen. Alexander Alekhine held the title from 1927 to 1935, then lost it to Max Euwe, and he is the only champion to die while holding the title; the 1948 world championship was the first one overseen by FIDE.

A 1925 short film, Chess Fever, helped spread chess in the Soviet Union. In 1972 the American Bobby Fischer beat Boris Spassky, 12.5 to 8.5, in a world championship match that many people followed. Karpov was known for a solid positional style that has been compared to a boa constrictor. Garry Kasparov was world champion for 15 years, the second longest unbroken reign after Lasker's 27. Karpov and Kasparov played 144 games against each other in their matches: 104 draws, 21 wins for Kasparov and 19 for Karpov. In May 1997 the computer Deep Blue beat Kasparov in a six-game match in New York, 3.5 to 2.5; a year earlier, in Philadelphia, Kasparov had won the match 4 to 2. By about 2005 chess engines had become consistently unbeatable by the best human players. In 2017 AlphaZero, a program that was given only the rules of chess, played 100 games against the engine Stockfish 8 and won or drew all of them.

Ratings put numbers on all this; the Elo rating system was made by Arpad Elo, a physics professor and chess master, and FIDE adopted it in 1970; a player rated 100 points higher than an opponent is expected to win about 64 percent of their games. Garry Kasparov was the first player to cross the 2800 mark on the official FIDE rating list. As of November 2026 the highest official FIDE classical rating ever is 2882, reached by Magnus Carlsen in 2014, and no human player has officially reached 2900. The title of grandmaster is awarded by FIDE to a player with a 2500 FIDE classical rating who also earns norms; the first grandmaster titles were awarded to 27 players in 1950. As of May 2020 there were 1,770 active grandmasters; the Shannon number, about 10^120, is a rough estimate of how many move sequences are possible in chess, assuming about 30 legal moves in a typical position; it is an order-of-magnitude estimate, not an exact count.

Other ideas show how deep chess runs. A passed pawn grows stronger as fewer pieces are left on the board. Zugzwang is a German word that means "a compulsion to move": a position in which any move a player makes leaves them worse off. The Knight's Tour puzzle, visiting every square with a knight, was studied in Arabic and Indian sources before the Swiss mathematician Leonhard Euler studied it. Chess960 is a variant that Bobby Fischer advocated, in which the pieces start in one of 960 possible setups. In the endgame the king often steps into the center or forward to support a passed pawn; a player who is ahead in material usually wants to trade pieces, and a player who is behind tries to avoid trades.

Words to know

• positional: plans and space
• zugzwang: forced bad move
• grandmaster: top title
• engine: chess program
• variant: changed version