40-yard dash

In terms of judging a person's speed, the best method of timing is through lasers which start and stop the times when passed through. A laser start (from a stationary position) is more accurate for measuring pure speed as it does not register a runner's reaction time, however, this method of timing a 40-yard dash can affect the accuracy by as much as 0.5 seconds with the manual stopwatch method. The National Football League (NFL) did not begin using partial electronic timing (i.e. started by hand, stopped electronically) at the NFL Scouting Combine until 1999. For purposes of measurement at the Combine, the run is made along the sideline from the front of the end zone to the 40-yard line, and for electronically timed 40-yard dashes, the runner is allowed to start when they wish, and a timer hand-starts the clock. In contrast, track and field races have the runner react to a starting gun. Elite male sprinters typically take 0.15 to 0.2 seconds (based on FAT timing) to react; further to this, IAAF rules state any runner with a reaction time of less than 0.1 second is subject to disqualification. This aspect means that comparisons with track times are essentially impossible given that a reaction time is not factored in, and the use of hand-timing in the 40-yard dash can considerably alter a runner's time: the methods are not comparable to the rigorous electronic timing used in track and field. Though not a current event, the 40-yard dash was briefly contested at the USA Indoor Track and Field Championships for women in 1927, 1928, 1929, 1930, 1931, and 1932. It was never staged as a men's event. The fastest winning time, including reaction, was 5.2 (originally recorded as 5) seconds, first set by Rosa Grosse and later tied by Mary Carew twice. ==Records==

In most settings, the 40-yard dash is conducted without fully automatic timing, where lasers are used at both the beginning and end of the race. Instead, the 40-yard dash is most often hand-timed, leading to considerable measurement error. Many (in particular older) reports of times below 4.2 or 4.3 are considered suspect, such as Baylor's Gerald McNeil's 4.19-second 40-yard dash in the 1980s before being signed to the United States Football League (USFL), or Deion Sanders's 4.27-second 40-yard dash in 1989. More recent examples include rugby union's Carlin Isles time of 4.22 at a Detroit Lions facility during a 2013 workout, and Texas Tech's Jakeem Grant being hand-timed by a New Orleans Saints scout at 4.1 in 2016. Also unofficially, Bo Jackson, who was invited to the 1986 combine and declined, ran the 40 to show off for scouts at Auburn. Electronically, with a laser, he has said it measured 4.12, and by hand it was 4.16. "I got down there, and I took off and ran completely through. I just kept going right out the door and didn’t come back." he was quoted after. In 2017, Olympic sprinter Christian Coleman ran a time of 4.12 seconds on turf in response to claims that NFL players are as fast as Usain Bolt. In 2024, University of Iowa sprinter Kalen Walker ran a 4.15 on turf during the halftime of a Hawkeyes football game. A year and a half after he retired from active competition, Usain Bolt ran a 4.22 in flat-soled shoes and a tracksuit at a promotional event for the Super Bowl in Atlanta, Georgia on February 2, 2019. NFL Scouting Combine This is a list of the official 40-yard dash results of under 4.31 seconds recorded at the NFL Scouting combine since 1999, the first year electronic timing was implemented at the NFL Scouting Combine. ==Average time by position==

According to a five-year NFL combine report, wide receivers and cornerbacks had the fastest average times at 4.48, followed by running backs at 4.49. The following average times were measured between 2000 and 2012 at the NFL combine for players who played at least 5 games. ==References==