I have always wondered about measurable, especially 40 times. How many plays are run where the QB throws the ball more than 40 yards to a receiver on a straight fly route? Also, try mentally discerning the difference in 4. 4 seconds and 4.6 seconds, You cannot snap your fingers fast enough. A DB that runs a 4.6 can cover a WR who runs a 4.4. I believe all 40 test times should be run competitively, not individually. Line up 5 guys across a starting line and have them run 40 yards from a standing start and see how far apart they are at the end. Probably not more that arm’s length.