Once again the 40 yard dash is the most overhyped stat in the world. Yes it can be nice knowing some kid has speed but when during a game does that player strip down to his spandex put on their track shoes and run 40 yards? Pro agility times and 10 yardtimes are way more bigger inclinations of what kind of player you are getting. Change of direction and quick bursts, now you never see those aspects on Saturdays do you?
A great 40 time is still important because it is still the best overall measure of pure speed.
However, your casual dismissal of a player's 40 time is foolish to say the least. Your argument is that in the game of football players wear pads and not spandex and track shoes which is of course true. Once the pads go on they affect players the same. So that RB that runs a 4.51 at the combine is now probably a 4.61. The DB running a 4.34 is now a 4.44. How is this important?
Let's put this discussion into football terms: When a RB breaks into the open field and is being chased by the backside safety the difference between a DB that can run a 4.34 versus a 4.48 could be the difference between making a tackle which prevents a touchdown or the RB scoring. You can apply this to other positional groups: LB's covering TE's, CB's covering WR's, etc.
Now, has the 40 time been somewhat over-hyped? Sure. But it ain't meaningless either.
