Atlanta Blocks Slower

(T&FN, March 1997)

If the '95 World Championships blocks had been used at the Olympics in Atlanta, times in the 100 would have been different, says Swedish statistician A. Lennart Julin.

"If you look at the reaction times recorded in Atlanta they were clearly on the slow side," he claims.

Julin continues, "A comparison with the '95 World Championships confirms the impression: all five male and four female 100 runners who reached the finals in both meets reacted systematically slower in Atlanta than in Goteborg. Taking their average reaction times for the four rounds in each meet they were between 0.012 and 0.041 slower (average 0.025).

"This apparent deterioration in reaction ability among the very best sprinters in the world might seem very strange, but it is not that hard to find the very simple explanation. The nominal slowing-down was a mirage caused by how the start procedure was carried out technically."

He is referring to the fact that in Göteborg a new starting system was used. Rather than the gun's report traveling through the air, the firearm itself made no sound. Instead, an artificial report came out of all the blocks at the instant the gun was fired.

Julin notes that the speed of sound in air is approximately 33Omps, which means that for each extra 3.3m (11ft) between the source of sound and the runner another 0.01 is added to both the reaction time and the finishing time of the runner. The further away the starter has positioned himself, the longer the extra delay. For the 100 in Atlanta the starter stood on the infield, some 15m up the track. The calculated disadvantage agrees well with the 2–4 hundredths actually shown by the top runners.

Apply these numbers to Linford Christie's 0.086 [which got him DQed] and you find that the actual time gap between when the "bang" reached him and he commenced the start motion was about 0.05. Says Julin, "That's a time for which absolutely nobody can seriously credit Christie's reaction ability. He was definitely not robbed."

Julin's conclusion? "The real robbery in the Atlanta sprints was that Donovan Bailey [a World Record 9.84] and all the other 100 runners had some three unnecessary 100ths added to their finishing times. An identical effort by Bailey with a non-delayed system would have resulted in a World Record of 9.81."