For the world’s best 100m runners the race of a lifetime can be over in 10 seconds flat - or, heartbreakingly, in a mere fraction of a second.
That’s as a result of of World Athletics’ incredibly strict false start policies, which have memorably resulted in disqualifications for some of the world’s highest-profile athletes at its marquee events.
For the likes of Noah Lyles, Oblique Seville and Kishane Thompson going for glory in this Sunday’s blue-riband event at the Tokyo World Championships, even the most minute of false starts would send them straight out of contention and on the plane home.
What are the rules on false starts in World Athletics?
World Athletics operates a ‘one strike and you’re out’ policy on false starts, when a sprinter leaves the blocks before the gun fires.
Under the regulations, any reaction quicker than 0.10 seconds counts as a false start. That limit has been set as the science suggests the human body cannot react faster than that; any time quicker is deemed to be an athlete anticipating the gun, rather than reacting to it.
Electronic timing systems measure athletes’ reaction times, with pressure sensors in the blocks to detect them once the gun fires.
The rules were changed in 2010 to the current system of instant disqualification for any false start. Previously, any false start was charged to the field as a whole rather than the individual athlete responsible for it. Races up to 400m were allowed two false starts, but the athlete guilty of the second was disqualified, regardless of if they were responsible for the first.
Zharnel Hughes was infamously disqualified from the 100m final at the Tokyo 2021 Olympics for a false start, while Usain Bolt jumped the gun in the 100m final at the 2011 World Championships.
What is World Athletics’ card system?
Not all false starts are made equal, however. World Athletics operates a card system, whereby officials indicate whether someone is to be disqualified or not.
A green card - like that held during the first 100m semi-final on Sunday - indicates a faulty start where no athlete is at fault. In that instance, Sha’Carri Richardson twitched on ‘set’, setting off some of the other athletes, but it was deemed a green card rather than a false start for the American. In the case of a green card, the athletes are all allowed to run again and the race is restarted.
Athletes are given a yellow card for improper behaviour in the starting blocks, such as making noise once in the blocks to disturb other sprinters. If the same athlete gets another caution, they receive a red card and are disqualified.
