Fischer, eligible as US Champion, decided against his participation in the 1964 Amsterdam Interzonal, taking himself out of the 1966 World Championship cycle, even after FIDE changed the format of the eight-player Candidates Tournament from a round-robin to a series of knockout matches, which eliminated the possibility of collusion. Instead, Fischer embarked on a tour of the United States and Canada from February through May, playing a simultaneous exhibition, and giving a lecture in each of more than 40 cities. He had a 94% winning percentage over more than 2,000 games. Fischer declined an invitation to play for the US in the 1964 Olympiad in Tel Aviv.