physically. Instead of relying on scheme and execution -- especially the QB making the read AND the accurate throw -- ND can literally physically impose their will on 8 to 9 teams they play per year.
It is college, not NFL. Not all teams are equal physically in college. ND can just run right down the throats of 8 or 9 teams per year simply because we have more gifted and bigger players than they do. Over the course of a game they just can't hang with us.
We do not use that at all because we don't run the ball enough nor do we practice it to the point where our OL learns how to pound on players versus chip at them when we run.
We don't play to our recruiting strengths at all. We can always load up on great OL and RBs and we can usually get several good skill players mixed in over a four year period -- but we have gaps usually. We can't consistently get great defensive players because for whatever reason that seems to be the academically more challenged side of the ball in this sport.
If we ran more and had a passing game to compliment that, then we'd have options every game to score points one way or the other, we can go after elite teams where they are weakest (pass or run), we can survive a bad QB accuracy day, survive a day where they load the box to stop the run or the opposite to stop the pass, and most importantly we would find that 9 or so games per year we don't need anything fancy to win. Just beat the living shit out of the other team and they will collpase during the 2nd half and we will start rolling up points sans anything clever.
Your defense also doesn't have to be 2012 level to do ok because we are winning TOP most games by a wide margin and better yet we can protect a 10 point lead in the 4th quarter by simply running the clock out even if we don't score. We win by 3 instead of losing by 4 and in some instances that physical beat the shit out of them thing means you add to the lead in the process.