Notre Dame lost Manti Te'o, a consensus All-American linebacker and the ballast of their team, to the NFL this offseason, but its defense might come back even stronger in 2013.
Make no mistake: The loss of Te'o will hurt. This isn't some application of the Ewing Theory or an instance of addition by subtraction. Notre Dame's defense will be better not because Te'o was hurting them somehow, but rather because its current leaders are another year older.
Stephon Tuitt and Louis Nix, 66 percent of the Irish's starting defensive line, should both be in contention for All-American honors this season. Three linebackers return around Te'o's replacement, Jarrett Grace, and three members of an overachieving secondary are back as well.
Brian Kelly and Bob Diaco have coached this unit into a perpetual powerhouse, a self-generating unit that should feed off the backlash from Te'o's loss and be among the best in the nation. Which begs an obvious question:
Will Notre Dame's defense be good enough to make another BCS title game?
The answer is complicated, especially given the departure of last year's starting quarterback, Everett Golson. In his place comes Tommy Rees, a junior with starting experience at Notre Dame, albeit in underwhelming seasons. But will he be good enough to compensate for Golson's loss?
Some would answer an emphatic "yes," especially given the talent around him. Notre Dame will be fine not because Rees is particularly good, but because there's a faulty perception that Notre Dame's offense, the one Golson ran, was also pretty bad last season. So long as the defense remains in tact, Rees can play conservative football and lead Notre Dame back to glory.
But the stats suggest otherwise. According to Football Outsiders FEI, an opponent-adjusted metric that measures a team's efficiency, Notre Dame actually had the 12th best offense in college football last year. By comparison, their defense ranked just 16th, below the likes of Utah State and Cincinnati.
By that token, Notre Dame's defense didn't, as most people claim, lead it to a national championship berth last season. The Irish ran the table because of balance, because both of their predominant units were among the nation's top 20. The only other teams that could make that claim were Alabama, Oregon, Texas A&M, Georgia and Ohio State.
But that begs a whole different question, one of a more philosophical nature. Can any defense lead a team to the BCS National Championship, or does going that far require a certain amount of equipoise? Is there a threshold by which one unit stops being able to carry the other?
Here's a look at the last 10 teams to play in the title game (winners in bold):
|2012 Notre Dame||.470||12||-.476||16|
There are a couple obvious trends to make note of. First and foremost, each of the last 10 teams to reach the BCS National Title have finished top-20 in both defense and offense. It turns out balance is requisite to success; nobody can get this far without excelling on both sides of the ball.
You might also notice 2012 Notre Dame is the only team listed that didn't finish top-10 in either one. Ninety-percent of the time, it seems, you need to have at least one signature unit to hang your hat on, and Notre Dame was the exception.
That initially gives credence to those who call Notre Dame an undeserving title game participant, but the fact that they finished top-20 in both categories rebukes that argument with ease.
Look closer, though, and you'll see something else. Each of the past five champions has finished top five in at least one category. Alabama's three title teams have all featured a top-five defense, Auburn had the number one offense and Florida finished top-three in both in 2008.
If Tommy Rees proves capable under center, that actually bodes well for Notre Dame. It means their defense, if as dominant as Brian Kelly & Co. seem to think it can be, might be able to carry this team past making the BCS National Championship and into the realm of actual champions.
They need to finish top-five, though, which is easier said than done; 50 percent of the top-five defenses in 2011 and 2012 came from the SEC.
Still, through statistical analysis, we arrive at a mixed answer to our titular question. Yes, Notre Dame's defense can carry them to back to the BCS National Championship game. If they finish top-10 that means they, as a unit, have done their collective job.
But they can't do it all by themselves. Notre Dame's defense can do the heavy lifting, but unless its offense finishes top-20 in FEI, history suggests the team can't repeat last year's success. Doing so would be a statistical anomaly.
Even if Notre Dame's offense isn't top-20, though, its performance will dictate what kind of bowl the Irish make in 2013. Again, a defense can only do so much. Here are the teams that finished top-10 in defense but not top-20 in offense last season. Notice what happens as offensive FEI decreases:
|Team||Rec.||Bowl||OFEI (Rk)||DFEI (Rk)|
|Kansas State||10-2||Fiesta||.337 (21)||-.563 (10)|
|South Carolina||10-2||Outback||.244 (28)||-.629 (5)|
|Stanford||12-2||Rose||.190 (34)||-.670 (3)|
|Florida State||10-2||Orange||.163 (41)||-.571 (9)|
|Florida||10-2||Sugar||.144 (43)||-.795 (1)|
|LSU||9-3||Chick-fil-a||.125 (46)||-.605 (6)|
|Michigan State||7-6||Buffalo Wild Wings||-.056 (66)||-.683 (2)|
|Rutgers||8-4||Russell Athletic||-.156 (80)||-.591 (7)|
Even if Notre Dame's defense finishes top-10 next season, Tommy Rees and the offense hold the key to its future. Even if they don't finish top-20 in offensive FEI—which they probably won't—the amount by which they fall short could be the difference between a BCS bowl and the Russell Athletic, between being Florida State or Rutgers.
So don't get too gung-ho, Irish fans, on the heights your defense might reach. Stephon Tuitt and Louis Nix can take you far, but there's a pronounced ceiling on that distance.
The other side of the ball is the one you should be watching.