Chris Ash was in his "let's use the tOSU defense" mode, where he would only rush 4 down linemen, and let the rest play soft coverage.
That defense worked great for tOSU, because they had 4 monstrous defensive linemen, all of whom ended up playing on Sundays. Those guys generated so much pressure, that there was no need to blitz, or even to play aggressive man to man coverage.
That didn't work well for us, since our linemen weren't nearly that caliber, and losing Leonard Moore for a bit really hurt.