Athletics at the 1964 Summer Olympics – Men's 100 metres
The men's 100 metres was the shortest of the men's track races in the Athletics at the 1964 Summer Olympics program in Tokyo, Japan. It was held at the Olympic Stadium on 14 and 15 October 1964. 76 athletes from 49 nations entered, with 3 not starting in the first round. Nations were limited to three athletes each, per rules in force since the 1930 Olympic Congress. The first two rounds were held on 14 October, with the semifinals and the final on the following day. In the  final, American Bob Hayes tied the world record of 10.0 seconds and won the gold medal. Enrique Figuerola of Cuba and Harry Jerome of Canada tied the old Olympic record time. It was Cuba's first medal in the event; Canada earned its first men's 100 metres medal since 1928. Background. This was the fifteenth time the event was held, having appeared at every Olympics since the first in 1896. Neither of the top two runners from 1960 returned, but Rome bronze medalist Brit Peter Radford and fourth-place finisher Cuban Enrique Figuerola did. Other notable entrants were American  Bob Hayes (the favorite who was unbeaten in the event, including the 100 yards variant, since 1962) and Canadian Harry Jerome (a 1960 semifinalist who held a share of the world record). A muscle strain prevented Venezuelan Horacio Esteves (another 1960 semifinalist with a share of the world record) from competing. Cameroon, the Republic of the Congo, the Dominican Republic, Iran, the Ivory Coast, Madagascar, Mali, Northern Rhodesia, Rhodesia, Senegal, and Vietnam were represented in the event for the first time. The new federation of Malaysia also competed for the first time, though both Malaya and Singapore had previously appeared . The United States was the only nation to have appeared at each of the first fifteen Olympic men's 100 metres events. Competition format. The event retained the same basic four round format from 1920–1960: heats, quarterfinals, semifinals, and a final. However, after an extremely static format from 1936 to 1956, the format was modified for a second time in 1964 after 1960's tweaks. The changes generally increased the number of athletes in each race; for the first time in Olympic men's 100 metres history, 8 runners competed at a time. Records. Prior to the competition, the existing  World and Olympic records were as follows. Bob Hayes had an official time of 10.0 seconds in the final, breaking the Olympic record by 0.2 seconds and matching the world record. His official time of 9.9 seconds in the semifinals did not count for records purposes because of wind assistance. Results. First round. The top three runners in each of the 10 heats advanced. The Official Report describes the weather for these heats as 'rainy'. The wind varied widely, between a 2.85 m/s headwind (in heat 3) and a 1.60 m/s tailwind (in heat 6). Heat 2. Wind , -2.51 m/s Quarterfinals. The top four runners in each of the four second round heats advanced to the semifinals. The weather was cloudy and winds were tailwinds throughout. Quarterfinal 1. Wind, +1.90 m/s Semifinals. The top four runners in each of the two semifinals advanced to the final. The weather was described as "fine," with lower humidity than the first two rounds and a temperature of 23.8 degrees Celsius. There was a strong tailwind for the first semifinal and a moderate headwind for the second. Semifinal 1. The tailwind speed of 5.28 m/s meant this semifinal was  ineligible for record purposes. Final. Until the Tokyo Olympics world records were measured by officials with stopwatches, measured to the nearest tenth of a second. Although fully automatic timing was used in Tokyo, the times were given the appearance of manual timing. This was done by subtracting 0.05 seconds from the automatic time and rounding to the nearest tenth of a second, making Hayes' time of 10.06 seconds convert to 10.0 seconds (a new Olympic record and matching the existing world record), despite the fact that the officials with stopwatches had measured Hayes' time to be 9.9 seconds, and the  average difference between manual and automatic times was typically 0.15 to 0.20 seconds. This unique method of determining the official time therefore denied Hayes the record of being the first to officially record 9.9 seconds for the 100 meters. The first official times of 9.9 seconds were recorded at the "Night of Speed" in 1968. The final was run in "fine" weather, with a tailwind of just over a metre per second. Hayes ran on lane one, which had been damaged by competitors in the men's 10,000 metres and the men's 20 km walk. Nevertheless, his "margin of  victory was described by "Track & Field News" as 'insulting to an Olympic final field.'"