After an upside-down wild card round that produced four road winners, sanity was restored for the higher-seeded teams during divisional weekend. It wasn’t always easy — each game was decided by a touchdown or less — and some of the finishes were flat–out unbelievable. But after the dust settled, the Panthers, Broncos, Patriots and Cardinals all survived, making this the first time since 2004 that the No. 1 and 2 seeds in both the AFC and NFC advanced to their conferences’ championship games.
There are a few similarities among the remaining teams beyond their overall strength. Each has an accomplished quarterback, and three of the four dominated passing expected points in their wins (Denver being the lone exception). Together, Peyton Manning, Tom Brady, Carson Palmer and Cam Newton have 51 seasons of NFL experience, 31 combined Pro Bowl nods and 647 career points of Approximate Value. (That’s enough AV to stock a typical team’s entire roster for more than three seasons!) Collectively, they also soak up 8.8 percent of their teams’ salary cap, a big leap from the 6.7 percent cap share occupied by conference-title-game QBs over the previous two seasons. These are well-known, well-paid QBs that will by vying for a Super Bowl berth in a week’s time.
But despite their impressive pedigrees, the signal-callers probably ought to get less attention than the playmakers on the other side of the ball. That’s because, defensively, this might be the best quartet of teams in any conference championship round.
In terms of the average defensive quality of each conference’s finalists1, this season’s final four ranks fifth since the AFL-NFL merger. But even that probably undersells how impenetrable these defenses are. In no phase of the game — rushing or passing — were any of the remaining defenses below average during the regular season, and only the Patriots failed to finish better than a standard deviation above average in at least one phase. (The Cardinals and Broncos cleared average by that much in both phases of defense.)
To quantify the all-around defensive greatness of the conference championship participants in a given year, I took the harmonic mean (a specialized type of average intended to heavily penalize low outliers) of their defensive indices against the run and the pass, looking for seasons like this, where the final four defenses had no weak links to speak of. And by that standard, only one crop of finalists was (slightly) better: 2010, which featured Steelers and Jets teams that stopped the run at historic rates, a notably dominant Green Bay pass defense and a tough all-around Bears D thrown in for good measure.
Even that bunch had holes, though: As good as the Packers were at thwarting passers, for instance, they were below-average against the run. By contrast, the weakest aspect of this this year’s remaining defenses — the Patriots’ pass defense — was still a sixth of a standard deviation better than the average NFL team. For any group of conference finalists since the merger, that’s the strongest “weak link” on record, and it isn’t especially close. Simply put, it’s really hard to find something to exploit in these defenses.
That doesn’t mean Newton, Palmer, Brady and Manning won’t find a way. But we shouldn’t let the combined star power of the QBs overshadow the fact that, statistically, this could be the best group of defenses to ever collide on the brink of the Super Bowl.