A stop watch is certainly one tool available when measuring the speed of NFL players, but like a lot of measuring tools that have been around for a while it is probably not the best. Simply gauging how long it takes a player to go from point A to point B in a straight line is a convenient way to compare a lot of people in a similar situation, but it’s not a thing that really happens on the football field much. A good example: Vikings rookie running back Dalvin Cook.