How can we compare Packers pass rushers and defensive linemen?
It can be hard to contextualize NFL analytics for one simple reason: there’s a sample size problem.
Relative to baseball, basketball, and hockey, there are incredibly few NFL games by which we can generate stats. And since there are so few games, it’s pretty easy for a few players to eat up most of the snaps, meaning there will always be relatively few players that we can confidently assess.
There are a couple of solutions to this problem. If you want to contextualize a certain player’s performance, you can compare him to the league as a whole or you can stack him up against other players in a given team’s history. Comparing to the league as a whole creates its own problems, most of them having to do with scale. Parsing stats for the whole league to look at a couple of players is not impossible, but it’s a lot of work. Sorting through the history books is also a lot of work, but it gives us some really accessible comparison points since fans should be fairly familiar with previous players we’re using as context.
That’s a long way of saying I’m introducing a new way for us to look at the Packers’ defensive linemen and edge rushers.
Pro Football Focus has two useful metrics for assessing defensive players: pressure rate and stops. Both, I think, are pretty easy to understand. Pressure rate is the rate at which a pass rusher pressures the quarterback, either through a hurry, hit, or sack.
Stops, meanwhile, are plays where the defender stops (get it?) the offensive from having a successful play, as defined here by PFF. If you take a player’s stops and divide them by the number of run defense snaps a player plays, you can create a new stat called “stop rate.” It’s not perfect, since some stops could come on passing plays, but it generally indicates someone who’s active in the run game, so it’s good enough for our purposes.
Since we have two metrics, that means we can chart them against each other to visualize the most effective players (along with the least effective players, I suppose). PFF has data going back to 2006, so I’ve charted out the pressure rate and stop rate for every Packers defensive lineman and edge rusher dating back through that season. To avoid cluttering up the chart too much, I’ve restricted this to players who logged at least 100 pass rush snaps and 50 run defense snaps in a given year.
A few takeaways:
First, in terms of pure pass rushing excellence, nobody can match Rashan Gary’s abbreviated 2022 season. Through nine games, Gary posted a pressure rate of 18.63%, one of only two seasons since 2006 where a Packers player has cracked 18%. The other was Rashan Gary in 2021. Gary, in fact, is responsible for three of the four seasons since 2006 where a player has recorded a pressure rate above 15%, Za’Darius Smith in 2019 being the other. He’s good at rushing the passer, it turns out.
Second, there have been precious few “double-double” seasons; that is, seasons where a player has recorded a double-digit pressure rate and stop rate. There have been nine such seasons since 2006, and a whopping five of them came in 2015, when Clay Matthews, Datone Jones, Mike Daniels, Julius Peppers, and Mike Pennel all crossed 10% in both metrics. Nobody’s done it for the Packers since Nick Perry in 2016.
There are a couple of surprises when you look at the best double-double seasons. Three seasons stand above the rest: Aaron Kampman in 2008, Julius Peppers in 2014, and Kabeer Gbaja-Biamila in 2006. Kampman makes some intuitive sense, given that he was a hard-nosed maniac on the edge. But Peppers and Gbaja-Biamila both had a reputation as being liabilities in the run game, but the stats don’t necessarily bear that out. Neither logged heavy snaps in run defense those years (Just 345 for Peppers in 2014 and 283 for KGB in 2006), but both were effective when they were on the field.
Finally, if you’re just looking for an answer as to who’s the best, here’s one potential way to calculate that: add a player’s pressure rate to their stop rate and you can come up with something that should at least approximate someone’s impact. Doing that, an interesting top five emerges:
Kabeer Gbaja-Biamila (2007) - 31.83%
Ryan Pickett (2009) - 31.08%
Rashan Gary (2022) - 28.51%
Cullen Jenkins (2008) - 27.77%
Clay Matthews (2015) - 26.32%
That’s quite a range of players, from the lithe KGB to the rotund Pickett to the violently athletic Gary and beyond. Even if this isn’t a perfect metric, it shows that there are a lot of different ways to affect a football game, and all kinds of players can be useful additions to your team.