Interzonal
The fifth Interzonal was planned for the Netherlands in 1961, but the sponsors could not guarantee that visas could be obtained for all participants. Subsequently efforts were made to play in Moscow, and then Madrid, but these arrangements also fell through. Finally the Interzonal was played in Stockholm under the direct sponsorship of FIDE, from 26 January to 8 March 1962. The 23-player single round-robin tournament was won convincingly by 18 year old American Bobby Fischer with 17½ points out of 22 (13 wins, 9 draws, no losses), a margin of 2½ points. The next four places were taken by the Soviets Tigran Petrosian and Efim Geller with 15 points, and the Soviet Victor Korchnoi and Miroslav Filip of Czechoslovakia with 14 points.
For the sixth and final qualifying spot there was a three-way tie at 13½ points. Leonid Stein (USSR), Pal Benko (USA), and Svetozar Gligorić (Yugoslavia) played a double round-robin playoff tournament which was dominated by Stein and Benko. Although Stein won, a rule adopted in 1959 allowed no more than three players from a single Federation to qualify from the Interzonal. Stein could play in the Candidates only if one of the other qualifiers from the USSR (Geller, Petrosian, or Korchnoi) was unable to participate. With Stein excluded, Benko took the final place in the Candidates Tournament.
Read more about this topic: World Chess Championship 1963