Because the Packers' run defense was pretty weak all season in 2019, and then got really exposed against the 49ers in the playoffs, it has been a pretty common topic of discussion.
That got me thinking about the value of run defense, generally speaking, in today's NFL. So as is my inclination, I did some digging and aggregated some data. What I found out was pretty interesting.
For a sample size, I looked at all of the teams to make the playoffs in the past three seasons. I assessed their run defense based on two measures: yards per carry allowed, and run defense DVOA.
Here's what I found.
2019
YPC Allowed:
- TEN; 4.0 (7th)
- PHI; 4.1 (9th)
- NE; 4.2 (13th)
- NO; 4.2 (14th)
- BUF; 4.3 (18th)
- MIN; 4.3 (19th)
- BAL; 4.4 (20th)
- SF; 4.5 (22nd)
- GB; 4.7 (24th)
- HOU; 4.8 (27th)
- KC; 4.9 (28th)
- SEA; 4.9 (29th)
Four of twelve playoff teams were in the top half of the league in YPC allowed, and eight were in the bottom half. The two Super Bowl teams were 22nd and 28th, and the eventual winner was actually one of the teams worse than the Packers in this regard.
Additionally, those 4 teams in the top half of the league in YPC allowed combined for 2 wins in the playoffs, for a win rate of .5 per team. The 8 teams in the bottom half of the league in YPC allowed combined for 9 wins in the playoffs, for a win rate of 1.1 per team.
DVOA:
- PHI: -18.5 (4th)
- NO: -14.3 (5th)
- NE: -14.0 (6th)
- MIN: -13.1 (8th)
- TEN: -12.6 (9th)
- SF: -12.0 (11th)
- BUF: -8.9 (18th)
- BAL: -7.0 (20th)
- HOU: -5.0 (22nd)
- GB: -0.8 (23rd)
- SEA: 1.0 (26th)
- KC: 4.2 (29th)
DVOA paints a little bit more balanced picture-- 6 teams in the top half, and 6 in the bottom. The top half teams accounted for 5 wins, for a win rate of .83, and the bottom half teams accounted for 6 wins, for a win rate of 1.0.
2018
YPC Allowed:
- HOU: 3.4 (1st)
- NO: 3.6 (2nd)
- BAL: 3.7 (3rd)
- DAL: 3.8 (4th)
- CHI: 3.8 (5th)
- IND: 3.9 (6th)
- LAC: 4.3 (13th)
- PHI: 4.7 (25th)
- SEA: 4.9 (29th)
- NE: 4.9 (30th)
- KC: 5.0 (31st)
- LAR: 5.1 (32nd)
Very interesting results, as the elite teams and the terrible teams in this metric all made the tournament, and nothing in between (other than the Chargers, and really they hardly count, since no one gives a **** about them). Once again, the two Super Bowl teams, the Rams and Patriots, were poor in this metric-- 30th and 32nd. Overall, 7 PO teams were top half of the league, and 5 were bottom half.
Those 7 top half combined for 4 PO wins, for a win rate of .57. The 5 bottom half teams combined for 7 wins, for a win rate of 1.4.
DVOA:
- HOU: -30.1 (1st)
- CHI: -27.3 (2nd)
- NO: -24.9 (3rd)
- IND: -18.8 (4th)
- DAL: -17.3 (5th)
- BAL: -16.9 (6th)
- PHI: -12.9 (9th)
- LAC: -12 (10th)
- SEA: -7.6 (17th)
- NE: -7.0 (19th)
- LAR: 1.1 (27th)
- KC: 9.8 (32nd)
Similar story, with just a little shift in the direction of plus run defense. By this measure, 8 of the PO team were top half, and 4 were bottom half. Those 8 teams accounted for 5 wins, for a .63 win rate. The 4 bottom half teams accounted for 6 wins, for a 1.5 win rate.
2017
YPC Allowed:
- TEN: 3.6 (4th)
- MIN: 3.7 (5th)
- PHI: 3.8 (7th)
- CAR: 4.0 (14th)
- ATL: 4.1 (18th)
- BUF: 4.3 (24th)
- KC: 4.3 (25th)
- JAC: 4.3 (26th)
- NO: 4.4 (27th)
- PIT: 4.4 (28th)
- LAR: 4.7 (30th)
- NE: 4.7 (31st)
For the first team in the data, a plus run defense team was in the Super Bowl, though the other one (NE) was poor in this metric. 4 top half teams made the PO's, and 8 bottom half teams. Those four teams accounted for 5 wins, for a rate of 1.25. The bottom half teams accounted for 6 wins, for a rate of .75.
DVOA:
- PHI: -21.6 (2nd)
- CAR: -16.9 (5th)
- MIN: -16.9 (6th)
- TEN: -15.6 (7th)
- PIT: -5.6 (18th)
- ATL: -4.3 (20th)
- LAR: -4.1 (21st)
- NO: -3.7 (23rd)
- JAC: -2.8 (27th)
- BUF: 2.7 (30th)
- NE: 2.8 (31st)
- KC: 3.0 (32nd)
Very similar outcomes when you look at it from this angle. Four top half teams that account for 5 wins, for a win rate of 1.25. Eight bottom half teams that account for 6 wins, for a win rate of .75.
General Takeaways:
- While at times this data seems to be saying that it's actually a good thing to have a bad run defense, we can obviously dismiss that. Correlation is not causation. All else being equal, having a better run D is better than having a worse run D, and I'm not saying any different.
- This deep dive is of the quick and dirty variety. Using top half vs. bottom half is an imperfect (albeit easy) way to look at the data. A more careful analysis might shift things a bit, but not enough to dramatically change the broad conclusions.
- *Assuming that this three year sample is reliable* having a good or bad run defense does not seem to have a significant impact on your ability to make the playoffs.
- *Assuming that this three year sample is reliable* having a good or bad run defense does not seem to have a significant impact on your ability to win games once you're in the playoffs.
- *Assuming that this three year sample is reliable* having a good or bad run defense does not seem to make much of a difference in a team's ability to make the Super Bowl, or win the Super Bowl.
Conclusion: The Packers should make adjustments to improve the run defense. It's really hard to win a game when you perform as badly as they did in the NFCCG. However, the general importance of run defense overall is minimal. It doesn't make a big difference to a team's chances of having a successful season. It would seem that fans tend to overstate the importance of this particular facet of the game.