re: Actual football question, offensive line rotation.

Like somebody said, on a pass play a defensive lineman is basically in a sprint against 300+ lbs of resistance. Offensive lineman can't go downfield on passes, but defensive linemen are trying to get up the field then will chase after the pass, particularly against these dink and dunk pass attacks.

On run plays, they are often getting double teamed or if not for the full play for the initial part of the play (or trying to tie up more than one blocker) so trying to fight through 600+ lbs at that point.