Well, I don't agree with the concern about the grass, but...if a QB has practice throwing the ball to a receiver running 4.4, it's going to make a difference. That's a pretty good place for speed to matter. If a blocker needs to seal the edge for a 4.4 running back, he's going to have to hold that block a little longer, or the play design is off. Slowing everything down could mess with the timing. Everything is going to look a little sloppier.
Isn't that what one Michigan player blamed the Ap State loss on.