Devon Allen's disqualification at World Championships has reignited track's 'major problem' figuring out false starts

• Devon Allen was disqualified from a World Championships race for a false start that was .001 seconds too quick.
• Racers cannot leave the starting block until 100 milliseconds after the gun, but there has been great debate over whether that number is appropriate.

American sprinter Devon Allen was disqualified from the men's 110 meter hurdles at world championships for a false start.

Allen appeared to literally jump the gun a fraction of a second too soon. Racers are allowed to leave their blocks .1 seconds after the gun. Sensors in the blocks showed Allen left the block at .099 seconds — .001 too soon.

Allen was in disbelief of the disqualification and perhaps for good reason — some say that the .1 second threshold is arbitrary.

World Athletics' rule suggests that it takes .1 seconds for athletes to hear the gun, process the noise, then begin running — anything sooner than that is a false start.

However, Drew Harrison, Associate Professor in Sports Biomechanics at the University of Limerick and a coach for the Irish national track and field team, told Insider that different studies over the years have found different reaction times from athletes. World Athletics ultimately set the reaction time at 100 milliseconds, a nice round number that gives leeway to different times found in these studies.

One problem, according to Harrison, is that the technology used to measure reaction times isn't exactly standardized, and it is then up to the starter at the race to make a judgment call.

"It's a deeply complex problem," Harrison said. "Reaction time is something that you will detect with technology. Now, World Athletics have accepted various systems that will allow the starter to be assisted by the technology. But the problem is they're all different technologies. So there's no real regulation on exactly what the technology is, whether it's a force sensor or an accelerometer."

Furthermore, Harrison said, these technologies measure force (which determines if a runner jumps too soon) with different algorithms. And the companies that create the technology are secretive about their algorithms.

"World Athletics doesn't want to have a monopoly on technology taking over the sprint start," Harrison said. "So what it does is it says it will give approval of various different systems, but they all use 100 millisecond in rule.

"But we know that some systems will detect a different reaction time from others. And some algorithms in different systems will detect the reaction time later than others.

"So the technology and the algorithms to detect it are not standardized. And that's one of the huge problems."

Harrison said some studies have shown athlete response times to be under 80 milliseconds. But reaction times vary depending on what part of the body is being measured. He told Insider that he and his team have studied over 8,000 start times and found the average response of feet on block sensors is actually around 115 milliseconds.

Hands, on the other hand, are often the first body part that reacts, Harrison says.

"The thing we know is, if you look at the block response and you look at the hand response, the time between them, it varies between athletes," Harrison said.

He added: "If you measure the reaction time in the blocks, we have a real problem for World Athletics because they're measuring the wrong thing. If you want to genuinely find out what the reaction time is and stop an athlete from anticipating, you have to measure the first response. And our research has shown that the first response is probably 99% of the time is from the hands."

Though Harrison said he didn't want to criticize World Athletics, he said he believes the organization needs to determine the best way to measure reaction time and stick with it, rather than rely on different technology.

Others in the athletics world have proposed rule changes.

One 2009 study, which was backed by the IAAF suggested lowering the start time to 80 milliseconds and determining false starts by the first body part to move.

On Monday, Ross Tucker, a renowned sports scientist, suggested something simpler in a Twitter thread: Obvious false starts, happening well before the 100-millisecond threshold, would result in disqualifications. Less-obvious movements, occurring so close to the 100-millisecond threshold that they are imperceptible, even on review, would result in a do-over, and a second false start would result in a disqualification.

"It's a major problem," Harrison said. "And I have to say, I have some sympathy for World Athletics as well, because it's difficult for them to solve a difficult problem. And they're relying on the technology to actually help them. But in actual fact there are serious problems that need to be ironed out."