"Defense wins championships." It's a saying as old as the hills, and it gets repeated as if it's an inviolable truth in the NFL.
But with the record-shattering offenses of the past few seasons, "defense wins championships" seems like it's just not true anymore.
When we think of the teams that have dominated recent seasons, we think of quarterbacks and passing offenses: Tom Brady and the New England Patriots, Aaron Rodgers and the Green Bay Packers, Drew Brees and the New Orleans Saints.
Are defenses losing their grip on the NFL? Let's take a statistical look.
Defense and Championships
The NFL ranks defenses by how many yards they allow. But defenses are judged by their ability to prevent the offense from scoring.
When we talk about "defense wins championships," we're talking about elite scoring defenses. Since 12 teams make the playoffs, we'd expect a number of the top 12 scoring defenses to make the postseason.
Let's break down how often good defenses make the playoffs, reach the second round, reach the conference championship game, make the Super Bowl and win the Super Bowl. This chart shows the last 10 seasons (including this incomplete one), and how many top 12 scoring defenses made it to each milestone:
Each bar represents one NFL season. The color bands on each bar represent a playoff round, and the the thickness of each band represents how many teams with top 12 scoring defenses made that round that season. The overall length of the bar, then, means more teams with top 12 defenses went deeper into the playoffs.
In both 2003 and 2004, six and four teams made the playoff field and second round. That's fewer than the annual averages over that period (7.50 and 5.11). But three of the four teams in the conference finals were top 12 defenses, as were both Super Bowl teams (and thus, the winner).
Since those seasons, with exceptions of 2006, 2007 and 2011 (we'll get there), more defenses have been making it deeper into the playoffs. In fact, for the nine seasons prior to 2012, the average number of teams appearing in each season's conference championship is 3.0!
That means that on the average, three out of four recent conference finalists have boasted top 12 scoring defenses.
With the same exceptions—2006, 2007 and 2011—every Super Bowl in this stretch has been won by a team with a top 12 scoring defense. Four of the nine Super Bowls have been played between two such teams.
This is a consistent phenomenon. Only 2006 and 2011 saw fewer than three top 12 defenses make the NFL's "Final Four," despite wild swings in the number of top 12 defenses that made the playoff field. We can infer that having a top 12 defense is a major advantage when it comes to winning playoff games.
Now, let's deal with the exceptions.
Exceptions...or Are They?
2006's champion was the Indianapolis Colts, a team with a 23rd-ranked scoring defense. When the well-respected research website Cold Hard Football Facts said "defense wins championships" is on its last legs, they held up this 2006 Colts squad as an example.
But over the course of their four-game postseason, the Colts allowed scores of eight, six, 34 and 17. This means they allowed an average of just 16.5 points per game, a full touchdown less than their season average of 22.5.
This can be attributed to the return of impact safety Bob Sanders. He was knocked out in the first week of the regular season, and the Colts defense was dramatically worse off for it.
2007's champion was the New York Giants, a team with a mediocre 17th-ranked defense. But wait, wasn't that the team whose mighty pass rush toppled the 18-0 New England Patriots?
Over their four-game playoff run, the 2007 Giants allowed an average of 16.25 points per game. If the Colts or Giants defense played anything like they did in the postseason during the regular season, the 2006 and 2007 bars would have matched right up with all the others.
Hockey fans may recognize this problem: The biggest factor in playoff success is great goaltending, but there's little or no correlation between a goalie's nominal/historical/regular-season performance and who stands on their head in any given playoffs.
2011: The Beginning of the End?
2011, however, was significantly different. Only five of the 12 playoff teams had top 12 defenses, below the 10-year average of 7.50. Only three advanced to the second round, below the average of 5.11.
Only two of the four conference finalists had top 12 regular-season scoring defenses; 2006 was the only other year there were fewer than three.
Finally, 2011 was the only season in the last decade where neither of the Super Bowl participants had top 12 defenses.
2011 was an outlier of a season in a lot of ways. It came on the heels of a lockout that killed the entire offseason. Offenses moved the ball through the air in historic numbers, all across the board.
Offenses passed the ball like crazy, especially through the first few weeks. There were three 5,000-yard passers in 2011, just as many as there had been throughout the history of the NFL to that point.
2012 wasn't quite so bonkers, but it still featured an awful lot of passing. Drew Brees again topped the 5,000-yard mark, and more quarterbacks broke the 4,000-yard barrier than ever before.
Perhaps this season's playoffs will continue the trend of 2011, and none of the seven top 12 scoring defenses that made the field will reach the Super Bowl. Or maybe defense will win the day and restore order after a one-year outlier.
But "defense wins championships" is, for the moment, as true as it's been for the last decade.