Friday, May 4, 2012

A Great Offense Is Not Enough

Having a top five defense in the NFL last year gave you roughly an 80% chance of making the playoffs. A bunch of us on Twitter continued the debate last night about whether a great defense was enough to make the Seahawks a playoff team, regardless of the offensive question marks at quarterback, offensive line and wide receiver. Softy made the assertion that the NFL is an offensively driven league, and a passing one at that. Most people would agree. I even agree that a team's chances of winning a Super Bowl without a good quarterback are minimal. That said, it is worth flipping the debate last night and seeing if a great offense gets teams any farther than a great defense. In other words, if you could only have a great offense or a great defense, which would be the more likely predictor of making the playoffs?

We start by looking at the inverse of the stats from last night. These rankings, collectively, should provide a solid view of the NFL's top offenses last season. Don't expect to see Seattle anywhere in these.

POINTS/GAME
1. GNB 35.0*
2. NO 34.2*
3. NWE 32.1*
4. DET 29.6*
5. CAR 25.4


YARDS/PLAY
1. NO 6.7*
2. GNB 6.6*
3. NWE 6.3*
T4. CAR 6.2
T4. PHI 6.2

PASSER RATING
1. GNB 122.6*
2. NO 110.5*
3. NWE 105.7*
4. DAL 100.1
5. DET 97.2*

YARDS/CARRY
1. CAR 5.4
2. MIN 5.2
3. PHI 5.1
T4. BUF 4.9
T4. NO 4.9*

GIVEAWAYS/GAME
1. SFO 0.7*
2. GNB 1.1*
T3. CLE 1.2
T3. NWE 1.2
T3. ATL 1.2*

*Made playoffs

A good offense is a strong predictor of playoff potential, as expected. It does not, however, correlate as well as a good defense did last season. Four out of the top five teams in scoring defense, opponent yards/play, and opponent passer rating made the playoffs. Five of the top five teams in takeaways made the playoffs. Flipping that over to offense, four out of the top five teams scoring and passer rating made the playoffs, but only three out of five in yards/play and giveaways did. Interestingly, having a good run defense or a good run offense was the least predictive, but even there, run defense was more important than run offense.

Math purists will argue about sample size and various other flaws in this reasoning. The simple truth is that a top five defense mattered more than a top five offense last season, and the Seahawks are right on the doorstep of a top five defense.

1 comment :

David said...

This got me thinking about the question, which is more important for having a winning football team: a good offense or a good defense. Obviously the conventional wisdom says the NFL is an offensive league, but the conventional wisdom is as often wrong as it is right. So I grabbed the Football Outsiders DVOA table for 2011 and put it into Excel. I then plotted offensive rank against wins, and defensive rank against wins. It's actually pretty striking. When you look at the offensive chart, you can clearly see a that a better offense leads to more wins. That's not really surprising, of course. What is, is that when you look at the defensive chart, it just looks like random dots thrown on a page. There's no clear correlation between having a better defense and having more wins. When I expanded it to other seasons, and then to looking at combined seasons 2007 to 2011, it becomes a little more clear that defense matters. 2011 may have been exceptional in that we had New England, Green Bay and New Orleans all having bad D's but having 13, 15 and 13 wins each. But even when I look at all 5 seasons combined it's still clear that having a better offense is more important than having a better defense, at least as far as regular season wins are concerned.