Advanced Defensive Stats: Pass Rush

| June 28th, 2021

Over the next few days, I want to look at advanced defensive statistics from Pro Football Reference to better examine some of Chicago’s individual defenders as we prepare for the 2021 season. Today will focus on pass rush, while upcoming articles will examine missed tackles and pass coverage.

On the surface, Chicago’s pass rush was not terribly impressive last year. The Bears finished with 35 sacks (17th in the NFL) and 137 pressures (23rd). They pressured QBs on only 22.4% of dropbacks, which ranked 21st of 32 NFL teams. I’ll note here that pressures can be a somewhat subjective stat, and thus they differ a bit from source to source. Pro Football Focus, for instance, had the Bears as the 4th best pass rush in the NFL.

I don’t have access to PFF’s data, however, so I’m going forward with Pro Football Reference numbers. I specifically want to hone in on pressures today, because those tend to be a more reliable measure of pass rush effectiveness than sacks. Last offseason, I found that, on average, NFL players get about 3.8 pressures per sack. This allows you to get a feel for expected sacks (pressures/3.8), which you can then compare to the actual sacks to see which players got lucky (more sacks than expected) or unlucky (less sacks than expected). I found there is no carryover from one season to the next in this stat, so it gives us an idea of what players we might expect to bounce back the upcoming season.

When looking at league-wide data for 2020, I noticed that total sacks seemed lower. The pressure numbers were about the same (105 players had 15+ pressures in 2020 compared to 107/year in 2018-19, 36 players had 30+ pressures compared to 32 per year in 2018-19) but I found there were 4.3 pressures per sack in 2020. My hypothesis is that the NFL calling fewer holding penalties led to more pressures where the pass rusher couldn’t finish the play. Either way, I used the 4.3 pressures/sack number to get the expected sacks for Bears players in 2020, and you can see how they did compared to their actual sacks below. Players in green outperformed their expected sack total by at least 1 sack, while those in red underperformed by at least 1 sack.

A few thoughts:

  • Overall, the Bears performed about as expected when looking at the relationship of pressures and sacks (I’ll note this was only for full-time pass rushers, so off-ball LB like Roquan Smith were excluded). This was a stark change from 2019, when they underperformed expectation by almost 10 sacks. Like I said last year, sacks relative to expectation has no year-to-year carryover.
  • Of course, the Bears also saw their overall pressure drop significantly in 2020. The 2019 defense had 167 pressures from their pass rushers, compared to only 120 here. And remember, 2020 saw more pressures relative to sacks, so the expected sacks dropped from 36.5 in 2019 to 28.5 in 2020.
  • That’s particularly disappointing considering the biggest contract Chicago handed out last offseason was to pass rusher Robert Quinn, who was supposed to provide an upgrade to Leonard Floyd. That obviously did not happen. Quinn averaged 32 pressures/year in 2018-19, but got only half of that amount in 2020. He really needs to bounce back in 2021 for the Bears’ defense to avoid falling off due to downgrades at CB. Again, though, different sources count pressures differently; Next Gen Stats had Quinn as the 10th most effective pass rusher in terms of pressure rate in the NFL last year.
  • One of the big reasons for Chicago’s decrease in pass rush effectiveness was Khalil Mack. He definitely saw a dip in production in 2020, though it was masked by overperforming his expected sacks. Mack had 45+ pressures in both 2018 and 2019, but that dropped to 31 in 2020. In a given year, 45+ pressures puts you among the top 5-10 rushers in the NFL, while 31 makes you a low-end #1 rusher (teams average about 1 player with 30+ pressures each year). Mack was still a really good overall player, but he’s getting paid $23.5M a year to bother the quarterback, and he didn’t do that enough last year.
  • It appears Akiem Hicks’ decrease in sacks last year, on the other hand, was nothing to worry about. He had 29 pressures in 2018, was on pace for 29 before getting hurt in 2019, and had 29 again in 2020. He just had bad sack luck, and should hopefully see those numbers rebound this year if he can stay healthy.
  • The Bears re-signed Mario Edwards this offseason, but it appears his 4 sack number was a bit inflated last year. He’s a pass-rush specialist who teams don’t trust against the run, which really limits his snaps (he played <25% of Chicago’s defensive snaps last year), and thus his impact. Edwards has never hit 10 pressures in a season, and I don’t expect him to be a significant factor going forward.
  • The bottom two names on the table are players Chicago brought in this offseason to replace the departing Brent Urban, Roy Robertson-Harris, and Barkevious Mingo. Attaochu in particular appears to be a significant upgrade over Mingo as the 3rd edge rusher. He provides Chicago with a solid fallback option if Robert Quinn continues to struggle.

Overall, the Bears’ pass rush was about as mediocre as expected last year, which does not reflect the substantial investment they have made in pass rushers Akiem Hicks, Khalil Mack, and Robert Quinn. Chicago needs to have one of the best pass rushes in the NFL to justify those contracts, but last year only Akiem Hicks did enough as a pass rusher to justify his contract. It’s hard to expect massive improvement in 2021 considering all 3 players are 30 or older, but they need to be significantly better if the Bears are going to be good.

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