How much is rushing defense correlated with winning?
A lot of folks would probably ask why we even bother to do studies like this. That sentiment makes perfect sense and these articles certainly aren’t everyone’s cup of tea. However, if you do them long enough you begin to see the science behind why teams do what they do. You also begin to see if what they do makes sense. After all, there has to be a reason why certain teams seem to win regularly and others seem to lose regularly.
For instance, the Texans completely revamped their secondary this offseason. They also brought in a bevy of pass rushers on the defensive line. What they didn’t do was focus much on the run defense. Is there good reason for this? We won’t answer all of those questions in this piece, but we will begin to see some answers today and then some more next time.
We talk about correlations because football is a situational sport. Great teams blowout their opponents. When they blow them out the opposing team has to abandon the running game. That can tend to inflate passing numbers and deflate running numbers. So, simply looking at total yards rushing or even yards per carry can’t tell the whole story. What we can do is look at how strong the correlation is with winning. We don’t even know what direction the correlation goes. Does a strong run defense lead to winning or does winning tend to lead to good run defense numbers? Well, let’s find out.
Number One Run Defense
As we did with the offensive numbers and total defense numbers, we will look at the number one run defense each season between 2000 and 2021 to see where they ended up at the end of the season. Unlike running backs or wide receivers, there is no individual defender that is directly linked to just run defense, so we will stick with the overall defensive numbers for now.
Number One Rush Defense: 4 Super Bowls, 3 conference losers, 4 divisional losers, 3 wild card losers
This is unusual in that it seems to break down evenly across the board. Out of 22 teams, we saw 14 make the playoffs. That seems to have been the average in every single category on offense and defense. Those four Super Bowl participants saw three go to the winning side. Again, we aren’t sure what the direction that correlation goes. However, the test is how strongly rushing defense compares with overall defense. In other words, is it the driver of that train or is passing defense the driver?
The Final Four
We can’t help but compare this with the overall defense numbers we saw in the last article. I will add the composite rank in parenthesis as a gentle reminder. Ultimately, that’s the real takeaway here. We want to know whether a team is better building towards run defense first or whether defending the pass should be the higher priority.
Super Bowl Champs: 3 #1, 8 top five, 14 top ten, 16 top half (Composite 10.4) (Overall 10.8)
Super Bowl Loser: 1 #1, 9 top five, 12 top ten, 15 top half (Composite 11.1) (Overall 12.3)
Conference Loser: 3 #1, 16 top five, 24 top ten, 31 top half (Composite 11.1) (Overall 11.2)
This obviously cuts both ways and that is why we can’t attribute causation to anything we see. If we take these numbers at face value we would argue that run defense is more important than overall defense. That statement makes no sense. So, we would conclude instead that losing teams don’t run the ball as much as winning teams. So winning teams will tend to give up fewer rushing yards because their opponents will have fewer rushing attempts. It also means that the passing yards metric will likely have a weaker correlation as well.
The Texans were 31st in rushing yards allowed and 28th in rushing yards per attempt. Clearly, their run defense wasn’t very good. Yet, they added five defensive backs between free agency and the draft and added several defensive ends that seem more geared to rush the passer than defend the run. So, why exactly are they doing this?
They were 23rd in passing yards allowed and 30th in net yards per attempt. Either they saw the passing defense as a more immediate concern or they saw more opportunities between the draft prospects and free agency choices. Clearly, we will see if building the defense through defending the pass makes sense. Pundits certainly harp on the passing game as the new wave in the NFL. Unfortunately, the numbers above would seem to discredit that, but maybe they know something we don’t.