Canada had long been at a disadvantage in international ice hockey tournaments as its best players were professionals in the NHL and therefore ineligible to play at the ostensibly amateur World Championship and Olympic Games. The Soviets masked the status of their best players by having them serve in the military or hold other jobs affiliated with the teams, so they retained amateur status, even though playing hockey was their only occupational responsibility. The International Ice Hockey Federation (IIHF) promised to allow Canada to use a limited number of professional players at the 1970 tournament but later reneged, causing the nation to withdraw from all international competition. Officials in Canada and the Soviet Union subsequently negotiated an arrangement that would see the top players of each nation – amateur or professional – play in an eight-game "Summit Series" in September 1972 between the world's two greatest hockey nations. Canadian fans and media approached the series with confidence; many predicted that the Canadian professionals would win all eight games.