Starting January 1, 1977, the IAAF required fully automatic timing to the hundredth of a second for events 400 metres and under when submitted for record consideration.[2]
Jim Hines' October 1968 Olympic gold medal run was the fastest recorded fully electronic 100 metre race to that time, at 9.95.[3]Track and Field News has compiled an unofficial list of automatically timed records starting with the 1964 Olympics and Bob Hayes' gold medal performance there. Those marks are included in the progression.
The IAAF considers marks set at high altitude as acceptable for record consideration. However, some observers have noted that altitude can significantly assist sprint performances. One estimate suggests times in the 200 m dash can be assisted by .09 s to .14 s with the maximum allowable tailing wind (2.0 m/s), and gain .3 s at altitudes over 2000 m.[2] For this reason, separate low-altitude lists have been compiled, though the IAAF doesn't officially recognize separate records. Once the IAAF started to recognize only electronic times, marks set at high altitude were not equalled or surpassed by low-altitude performances until 1987. The following progression of low-altitude marks starts with the "record" when the IAAF started to recognize only electronic timing and continues to the first mark that equaled the world record in 1987. (Ben Johnson's 9.95 run in 1986 and 9.83 run in 1987 are omitted.)
^ "A" stands for records set more than 1,000 metres above sea level, "OR" stands for Olympic records
^ Carl Lewis's two performances at 9.93 were deemed by the IAAF to have equaled the world record after Johnson's 9.83 time was rescinded but were never world records; Lewis's 9.92 was recognized as the world record from January 1, 1990.
^Ben Johnson's time of 9.79 on September 24, 1988 was disallowed and never ratified as a record as he tested positive for stanozolol after the race. Johnson subsequently admitted to steroidstanozolol use between 1981 and 1988, including during the 1988 Olympics. His world record of 9.83 set on August 30, 1987 was rescinded by the IAAF Council in September 1989.
^Tim Montgomery's time of 9.78 from September 14, 2002 was annulled following disqualification for banned drug use. Ruling in 2005 on his involvement with BALCO scandal rescinded all records and medals from 2001 onwards. By that time, however, it had been surpassed by Asafa Powell.
^Justin Gatlin was briefly credited with a new world record time of 9.76, but the IAAF announced five days later that the official timers, Tissot Timing, had discovered that that time was incorrect. Gatlin's time, recorded to the thousandth of a second, was 9.766 and had erroneously been rounded down to the nearest hundredth instead of rounded up. This time instead made Gatlin co-world record holder with Asafa Powell. However, in 2007 this record was annulled following Gatlin's failed doping test.
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