How Are 40-Yard Dash Times Recorded?

It's the highlight of the NFL Scouting Combine every year and an event that has become known as the "dash for cash."

Every year college football's best and brightest gather in Indianapolis to take to the track and show off their speed in the 40-yard dash.

So far this year the title of the combine's fastest man "officially" belongs to Texas wide receiver Marquise Goodwin, who ran the 40 in 4.27 seconds, according to Dane Brugler of the Sports Xchange.

That was slightly slower that his unofficial time of 4.25 seconds, and quite a bit slower than the sub-4.2 time Mike Mayock of the NFL Network told Brugler scouts clocked Goodwin at.

In fact, Goodwin wasn't the only player that threatened Tennessee Titans running back Chris Johnson's combine "record" of 4.24 seconds in 2008.

As Will Brinson of CBS Sports reports, Auburn running back Onterio McCalebb ran an unofficial time of 4.21 seconds, and while that number was later adjusted to 4.34 seconds, McCalebb's run got Johnson's attention.

Why is there a disparity between unofficial and official times? Do the scouts have trouble telling time?

Not really.

Since 1999, the NFL has used partially electronic timing to determine 40-yard times at the combine. The start of the run is timed by hand, but the finish is recorded electronically using a laser "plane" that runs across the finish line.

That "unofficial" time is then adjusted (presumably to compensate for the reaction time of the hand-timed start), and the "official" combine time that the media and fans drool over is then determined.

Fastest "Official" Combine Times Since 1999

Those aren't the only times that the NFL releases to teams, however, and as Rob Rang of CBS Sports reported in 2012, how each team uses those times varies a great deal:

Here is what happens to get the 40 times at the Combine that are revealed:

--Those who participate in the 40 actually run twice, and on each run they are timed by two hand-held stopwatches and one electronic timer (that is actually initiated by hand on the player's first movement).

 --Combine data put together for NFL teams by National Scouting includes all six of those times for each player, but no single official time.

Team scouts and coaches have various approaches for reaching agreement on a 40 time they use from those six timings. Some use averages. Some throw out slowest and fastest and then average the rest. Some ignore the whole thing and use a time taken by their own scout.

Prior to 1999 the NFL used hand timing at the combine, and that resulted in some significantly faster times, including a blistering time of 4.12 seconds turned in by Auburn running back Bo Jackson back in 1986.

He isn't alone. Using hand timing, a handful of players broke the 4.2-second mark at the combine, including wide receiver Joey Galloway (4.18 seconds), running back Michael Bennett (4.13 seconds) and cornerback Darrell Green (4.15 seconds).

The most accurate method of timing the 40-yard dash would be Fully Automated Timing, where lasers are used at both the beginning and end of the race.

The NFL experimented with FAT at the 2012 combine. However, those results weren't released, as according to Rang's report there was a concern that those times, which were expected to be considerably slower, could rankle players:

According to coaches and scouts who discussed this with The Sports Xchange, the FAT times are expected to be .20 to .24 seconds slower than the relative times recorded using methods the Combine has gone with since 1990, and before.
  
"We were told it is just an experiment and we won't be told the results," said one team official. "People are worried about the reaction players may have if the 40 times change that much."

And therein lies the rub. Unless the NFL adopts FAT, the 40-yard dash will be what it has always been: a subjective exercise.

There's even some dispute as to the fastest time since 1999. The NFL recognizes Johnson's 4.24 seconds, but as Rang wrote, NFLDraftScout.com calls Trindon Holliday's time of 4.21 seconds in 2010 the top mark (the NFL adjusted Holliday's time all the way down to 4.34 seconds).

Thus, while the 40-yard dash times of players at the combine are fun to talk about, they aren't necessarily completely accurate.

Then there's the matter of what they really say about a player's ability on the football field, but that's a story for another day.