For instance, in the World Chess Championship 1963 cycle, nine different Zonals were played. Each qualified between one and four players for the Interzonal, depending on the strength of the region, with 23 players qualifying for the Interzonal. The Interzonal was played in January to March 1962, with the top six players qualifying for the Candidates. They were joined by Mikhail Tal (loser of the 1961 match for the championship with Mikhail Botvinnik), and Paul Keres, who had finished second at the 1959 Candidates tournament. Those eight played a quadruple round-robin in the Candidates tournament in May and June 1962. The winner was Tigran Petrosian, who then played Botvinnik in a match for the championship in 1963.