It's been called the cruelest rule in Olympic sports, if not all sports: A runner is disqualified from a track event after just one false start. No warnings, no do-overs. You're done.
It happened to French sprinter Wilhem Belocian on Monday night in his 110-meter hurdles preliminary heat. Four years of Olympic training, gone a millisecond too soon.
Under the previous rule, the entire field was given a warning in the event of a false start; anyone in the same race who jumped the gun a second time would be disqualified, even if it wasn't the first offender.
But in 2010, the International Association of Athletics Federations changed the rule to its current draconian level because of two reasons: Under the old rule, slower runners would purposely jump the gun to throw off everyone else's timing and give themselves an edge, and the sheer number of false starts slowed down meets and caused television broadcasts to run over their time slots.
Hence the one-strike-and-you're-out policy, which was immediately called into question when Usain Bolt - i.e., the one sprinter who's considered appointment television and the fastest man alive - false-started in the 100-meter final at the 2011 world championships in South Korea, earning a disqualification.
Bolt, somewhat ironically, was an initial supporter of the rule change and refused to criticize it after his own disastrous false start in 2011. Others think it's awful.
"The sport suffers when Christine Ohuruogu and Usain Bolt get thrown out of worlds," four-time Olympic medalist and NBC track and field analyst Ato Boldon said in 2011, via Yahoo Sports. "They changed the rule saying they were trying to save time on television, but that did not work. That has not been the case. The reason the rule hasn't been changed back is you have an organization that's trying to save face."
Ohuruogu, who won 400-meter gold at the 2008 Beijing Olympics, also crashed out of the 2011 world championships, false-starting in a 400-meter preliminary heat.
Still others say that today's top-flight track and field athletes have grown up with the rule and are used to it by now, and that today's races are much better without all the gamesmanship.
The IAAF seems unwilling to change the rule, though in 2012 it adjusted the definition of a false start, ruling that a sprinter's hands had to leave the ground or their feet need to leave the blocks for it to be considered a false start (previously, a mere flinch in the blocks could earn you one). Still, the chance remains that a megastar like Bolt could see his Olympics end before the race even begins.