I'm kind of obsessed with Jeff Demps' 84-yard touchdown run against Kentucky. It's one of the more aesthetically beautiful plays I can remember a Gator making. It's the perfect demonstration of Demps' one-cut, straight-line speed-fueled greatness. And it's a lot of fun to add "WHOOSH" and "VROOM" sound effects to it as Demps leaves defenders in the dust, too.
This video shows it better than last night's did, but Demps gets the ball at the right hash mark on the Florida 11 at 10:36 on the game clock and crosses the goal line about two yards from the left sideline, after pulling up, at 10:26 on the game clock. Covering 89 yards in 10 seconds is obviously evidence that Demps is very fast, but it's roughly the same as running the 100 meters in 12.3 seconds, which doesn't sound so impressive when you consider that Demps once ran 100 meters in 9.96 seconds. That's okay, there's more math to do.
It's better to recognize that Demps actually travels 93.23 yards — actually, probably more, but I used the Pythagorean theorem (267 feet from the 11-yard line to the goal line squared plus 83.25 feet from the right hash to where Demps crosses the goal line squared equals 279.67 feet squared; that's 93.225 yards) to find the hypotenuse of a right triangle and I can't really correct for Demps not running neatly along it — in that 10 seconds. That's the equivalent of a 11.74-second 100 meters.
And Demps does it in pads, while avoiding a defender with a hurdle, and without running full speed at the end. His average speed for that stretch, given those numbers? 19.15 miles per hour; an ESPN graphic shown during a 2 a.m. SportsCenter suggested his top speed was closer to 24 miles per hour.
I welcome attempts to improve on my method, refine those numbers, and produce comparisons, but I'm pretty well convinced of this: Demps' run was the fastest I have ever seen a human run on a football field, and the benchmark by which I will measure all other runs.