Revisiting Pass Rusher Momentum with Pass Rush Moves
Which players generated the most power last season? Who generates the most power on bullrushes?
A year ago I looked into creating a metric to measure a pass rusher’s raw power by calculating their momentum (kg m/s) around an estimated point of contact between the rusher and the blocker.
The key takeaways of the research were -
Alignment matters for creating momentum
EDGEs have more space to create momentum than their interior teammates
Ex. Aaron Donald by Alignment - EDGE Mo: 534 kg m/s | IDL Mo: 413 kg m/s
Weak relationship between pressure and momentum (more on this in a minute)
Momentum is moderately sticky Week to Week
EDGE Leaders (kg m/s): Rashan Gary (581 ), Joey Bosa (574), Myles Garrett (566)
IDL Leaders (kg m/s): Poona Ford (446), Vita Vea (445), Arik Armstead (440)
My proposition before the study was that a player’s average momentum generated would have a decent impact on his pressure rate. But the results showed the relationship regarding momentum and pressure was weak no matter how you sliced it — all pass rusher alignments, EDGE only, IDL only, X/Y vector components, etc. The correlation coefficient for players aligning at EDGE in Weeks 1-8 of 2021 was 0.24.
When I retested on new data the correlation coefficient increased to 0.40, indicating a moderately positive relationship.
There are a few explanations why this number increased. For one — the pressure data I have for 2023 differs from how it’s collected from 2021. There is overlap, but pass rush wins are included in the 2023 pressure data — so the pressure data is not apples to apples. For that reason I won’t be making any broad statements that power is now the most coveted trait for EDGEs compared to speed/acceleration measures or leverage.
Other explanations include randomness, the data being from a different season, and increased sample size with the data being over the course of a full season rather than a half season.
2023 EDGE Pass Rush Momentum Leaders
player_name EDGE_momentum weight_lbs
1 R.Gary 558 277
2 B.Chubb 548 275
3 T.Walker 544 275
4 J.Phillips 544 266
5 M.Hoecht 541 267
6 M.Garrett 539 272
7 C.Thomas 537 270
8 T.Hendrickson 536 270
9 T.Tuipulotu 535 290
10 D.Fowler 534 255
> Were top 10 in EDGE Momentum in Weeks 1-8, 2021Pass Rush Move Momentum — Bullrushes
I noted in my original piece about momentum that pass rush moves need to be accounted for as the collision of a bullrush is different than that of a speed rush. They both create momentum, but the use of that momentum is clearly different. A bullrush will explode linearly through the blocker — while a speed rush will attempt to run around and turn the corner on the tackle. There is still impact being made on outside rushes, but it’s usually a half-man relationship and not through the body. The speed and space element allows outside moves to generate higher momentums than bullrushes (and inside moves).
pass_rush_move EDGE_momentum
Outside 525
Bullrush 506
Inside 452To further illustrate — momentum is calculated by multiplying Mass * Velocity — meaning how fast a pass rusher is moving directly impacts the momentum generated. A speed rush may build more momentum than a bullrush on average but that is only because the bullrush is normally met by the blocker more directly. The blocker absorbs the momentum created and takes on some of that momentum himself.
Seems obvious, but let’s assume of the measures available to us, speed is the key to a successful outside move (a speed move) and power is the key to bullrushes — as a result of a pass rusher’s mass and velocity.
In terms of causing pressure — EDGE momentum explains 5% of the variability in pressure rate on bullrushes across the entire sample of pass rushers (r = 0.23). I’m not exactly sure what to conclude of this yet. The sample is diluted by pass rushers who aren’t utilizing bullrushes often which might be a signal they’re less skilled using the move. Compared to when I narrow down the same to EDGE rushers who have used bullrushes 50+ times (given the parameters) I get a much stronger correlation coefficient (r = 0.51).
The latter could be a result of a limited pool of players that frequently use bullrushes or it could be due to pass rushers who are more specialized utilizing bullrushes, leading to a stronger relationship. I would need more seasons of data to have more bullrushes in the dataset and determine which is the case.
2023 EDGE Pass Rush Momentum Leaders — Bullrushes
player_name pass_rush_move EDGE_momentum 95th_%ile_momentum
1 R.Gary Bullrush 573 651
2 J.Phillips Bullrush 570 641
3 M.Hoecht Bullrush 563 613
4 C.Jordan Bullrush 561 637
5 B.Chubb Bullrush 560 662
6 T.Walker Bullrush 558 632
7 J.Bosa Bullrush 556 649
8 T.Tuipulotu Bullrush 554 647
9 A.Nelson Bullrush 549 618
10 B.Dupree Bullrush 548 619Player Revisits
Rashan Gary — Green Bay Packers
Gary finished first in EDGE Pass Rush Momentum when I created this metric last season and he finishes first again in overall and bullrush momentum created. Gary utilized the bullrush on 30.6% of pass rushes (w/ parameters) last season causing pressure 30.2% of the time.
Micah Parsons — Dallas Cowboys
Parsons is not as reliant on the bullrush opting to use it just 14% of the time, but he’s shown an increase in his max raw power output since his rookie season from 630 kg m/s to 701 kg m/s. This is all purely velocity related his listed weight remains at 245 pounds.
Michael Hoecht — Los Angeles Rams
Hoecht popped in terms of his raw power outputs regardless (finishing 5th among EDGE), but originally I was calculating his momentum using his draft weight of 310 pounds. This greatly impacted his Mass variable used to calculate momentum. Hoecht switched from defensive tackle to outside linebacker out of necessity in midseason of 2022. In 2023 he moved to EDGE full-time and slimmed down to 267 pounds — the weight I manually inputted.
Tomorrow I’ll be profiling a group of players and offer up potential ideas on how they can develop into stronger pass rushers via their pass rush mix strategy.