While a good 40-yard dash time is potentially worth millions and millions of dollars to potential NFL draft picks, there's good reason to doubt the scientific validity of the entire process.

In a fascinating 2005 article from the San Diego Union-Tribune, h/t @MattRHinton, Mark Ziegler talks to a bunch of people within the world of track, who point out that the way NFL scouts time football players is pretty suspect, from using their thumb (which has a slower reaction time) instead of their index finger to not having a starter's gun, automatic timing device or a wind gauge.

But, as Ziegler points out, the real red flag is the fastest recorded 40 in track history, the first 40 yards of Ben Johnson's gold-medal winning 100 meter dash in the 1988 Olympics:

He was running in spikes . . . on a warm afternoon perfectly suited for sprinting . . . with a slight tailwind . . . with years of training from arguably track's top coach, Charlie Francis . . . with Carl Lewis and six others of the fastest men on the planet chasing him . . . with 69,000 people roaring at Seoul's Olympic Stadium . . . with hundreds of millions of people watching on TV . . . with the ultimate prize in sports, an Olympic gold medal, at stake.

And, as we learned later, with muscles built with the assistance of the anabolic steroid stanazolol.

Four-point-three-eight seconds.

Then again, maybe Ben Johnson isn't the fastest 40-yard man in the world.

Maybe half the NFL is faster.

While a lot of these errors may even out when it comes to comparing 40 times between NFL prospects, it's something worth keeping in mind as Combine workouts dominate draft coverage.