The 1951 World Chess Championship (Botvinnik vs Bronstein)

The 1951 World Chess Championship was played between Mikhail Botvinnik and David Bronstein in Moscow from March 15 to May 11, 1951. It was the first match played under the supervision of FIDE; and the first to use a qualifying system of an Interzonal and Candidates Tournament to choose a challenger - a system which stayed in place until 1993.

Botvinnik was the defending champion: he was 39 years old, had been a world leading player in the 1930s and World Champion since 1948. The challenger, David Bronstein, was 27 years old and relatively new to top level competition.

The match ended in a 12-12 tie (5 wins each, and 14 draws), meaning Botvinnik retained the title of World Champion. Writing in 1973, Israel Horowitz described the match as "perhaps the most interesting match ever played for the world championship".

Game 5

Bronstein took the early lead in Game 5. Black (Bronstein) played 39...Nce3+, and Botvinnik resigned because it is mate next move.

Game 6

In Game 6, Bronstein (white) made one of the worst ever blunders in world championship play. He played 57 Kc2??, apparently expecting 57...Kf3 58 Ne6 e2 59 Nd4+ (however this line also leads to a win for black with correct play), but resigned when Botvinnik (black) played 57...Kg3, after which 59 Nd4 is not check. 57 Ne6+ was a simple draw. The blunder so upset Bronstein that he played weakly, and lost, in Game 7.