A Deeper Understanding of Quarterback Pressure in Football

Karl Pazdernik, Jacques Kvam

Deep Football, LLC

August 2, 2019 I Within 2 yards? I Listed twice in the NFL 2019 Rulebook (not in deﬁnitions)

Deﬁnition of pressure: I Affecting quarterback play by decreasing the pocket area, causing expedited decision making or a sub-optimal outcome

Quarterback Pressure

Affecting quarterback play is both critical and achievable. Impact plays: I Sack I Knockdown I Hits I Hurry? I Pressure?

Quarterback Pressure Karl Pazdernik August 2, 2019 2 / 23 Deﬁnition of pressure: I Affecting quarterback play by decreasing the pocket area, causing expedited decision making or a sub-optimal outcome

Quarterback Pressure

Affecting quarterback play is both critical and achievable. Impact plays: I Sack I Knockdown I Hits I Hurry? I Pressure? I Within 2 yards? I Listed twice in the NFL 2019 Rulebook (not in deﬁnitions)

Quarterback Pressure Karl Pazdernik August 2, 2019 2 / 23 Quarterback Pressure

Deﬁnition of pressure: I Affecting quarterback play by decreasing the pocket area, causing expedited decision making or a sub-optimal outcome

Quarterback Pressure Karl Pazdernik August 2, 2019 2 / 23 Pocket Pressure

Issues with current methods: I Binary outcomes I Cannot differentiate based on quality of opponent I Quarterback may not optimally use that space

Pocket Pressure: I Expected pocket region I Area of the expected pocket attributed to each player I Quarterback contribution to pressure based on actual location relative to optimal location

Quarterback Pressure Karl Pazdernik August 2, 2019 3 / 23 Not all “Pressure” is created equal

38 ● Offense 38 ● Offense 38 ● Offense Defense Defense Defense 37 37 37

● ● 36 ● 36 36

35 35 35 ●

QB QB QB 34 ● 34 ● 34 ● 33 33 33 32 32 32

22 23 24 25 26 27 28 22 23 24 25 26 27 28 22 23 24 25 26 27 28

Quarterback Pressure Karl Pazdernik August 2, 2019 4 / 23 Issue: I What is the “expected” pocket?

Voronoi Tesselations

Real estate around the quarterback (the “pocket”) deﬁnes the success of the offensive line. I Voronoi tesselations = area for each player/team 30 30 28 28 26 26 24 24 22 22 20 20 20 25 30 35 40 45

Quarterback Pressure Karl Pazdernik August 2, 2019 5 / 23 Voronoi Tesselations

Issue: I What is the “expected” pocket?

Quarterback Pressure Karl Pazdernik August 2, 2019 5 / 23 Expected Pocket

Ideal pocket location is relative to the quarterback location and the play-call. I Does it matter if the quarterback is under center or in shotgun? I What is the quarterback depth and how quickly is it obtained? I What about motion and roll-outs?

Use quarterback clusters to subset the plays used for expected pocket calculation.

Quarterback Pressure Karl Pazdernik August 2, 2019 6 / 23 QB Path 20 20 18 18 16 16 14 14 12 12 10 10

24 26 28 30

Quarterback Pressure Karl Pazdernik August 2, 2019 7 / 23 QB Path

● Under Center 20 ● Shotgun 20 18 18 16 16 14 14 12 12 10 10

24 26 28 30

Quarterback Pressure Karl Pazdernik August 2, 2019 8 / 23 K-means Clustering

Under Center Shotgun 1.0 1.0

● ● ● ● ● ● ● ● ● ● ● 0.8 ● 0.8 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●

0.6 ● 0.6 ●

● ●

● 0.4 0.4 Variation Explained (%) Variation Explained (%) Variation ● 0.2 0.2

● ● 0.0 0.0

5 10 15 20 5 10 15 20

Number of clusters Number of clusters

Quarterback Pressure Karl Pazdernik August 2, 2019 9 / 23 QB Path Clusters

Under Center Shotgun

● Cluster 1 ● Cluster 1 20 20 20 20 ● Cluster 2 ● Cluster 2 ● Cluster 3 ● Cluster 3 ● Cluster 4 ● Cluster 4 ● Cluster 5 ● Cluster 5 18 18 18 18 16 16 16 16 14 14 14 14 12 12 12 12 10 10 10 10

22 24 26 28 30 32 22 24 26 28 30 32

Quarterback Pressure Karl Pazdernik August 2, 2019 10 / 23 Shotgun - Cluster 5

Quarterback Pressure Karl Pazdernik August 2, 2019 11 / 23 Under Center - Cluster 1

Quarterback Pressure Karl Pazdernik August 2, 2019 12 / 23 Expected Pockets - Under Center

Quarterback Pressure Karl Pazdernik August 2, 2019 13 / 23 Expected Pockets - Shotgun

Quarterback Pressure Karl Pazdernik August 2, 2019 14 / 23 Pole-of-inaccessibility

Pole-of-inaccessibility: I Location that is the most difﬁcult to reach based on a set of criteria I Optimization: maximize distance between a point and a polygon Challenge: I Doesn’t account for temporal dependence in QB location Image courtesy of blob.mapbox.com

Quarterback Pressure Karl Pazdernik August 2, 2019 15 / 23 Stratiﬁed Pole-of-inaccessibility

Modiﬁed algorithm: I Construct an extended pocket polygon (extend to OTs and beyond the QB) I Generate uniformly distributed points that cover the offensive real estate I Run K-Means and collect cluster centers (candidate sequences) I For each center, compute the distance to the nearest edge of the polygon I Use Viterbi algorithm to simultaneously maximize QB distance from defenders and minimize sequential movement

Objective Function: P I t (distance to edge of pocket)t - α * (distance from previous point)t I α is a tuning parameter

Quarterback Pressure Karl Pazdernik August 2, 2019 16 / 23 NE vs. KC

Quarterback Pressure Karl Pazdernik August 2, 2019 17 / 23 AZ vs. TB

Quarterback Pressure Karl Pazdernik August 2, 2019 18 / 23 Pocket Pressure - DT

Single Team Double Team

4.5

4.0

player

Aaron Donald player Damon Harrison Aaron Donald

3 DeForest Buckner 3.5 Bennie Logan Gene Atkins Cameron Heyward Gerald McCoy Corey Liuget Jurrell Casey DeForest Buckner Leonard Williams Kawann Short QB distance (yards) QB distance (yards) Other 3.0 Other Tom Johnson 2

2.5

1 2 3 4 1 2 3 4 seconds seconds

Quarterback Pressure Karl Pazdernik August 2, 2019 19 / 23 Pocket Pressure - EDGE

Single Team Double Team 5

4 4

player

Donald Ford player Melvin Ingram Calais Campbell 3 Myles Garrett Chandler Jones Other Derek Wake Robert Quinn Ezekiel Ansah Sha'Quille Thompson 3 Jonathan Allen Timothy Williams Other QB distance (yards) Victor Beasley QB distance (yards) Robert Ayers 2 Von Miller Whitney Mercilus

2 1

1 2 3 4 1 2 3 4 seconds seconds

Quarterback Pressure Karl Pazdernik August 2, 2019 20 / 23 Pocket Presence

Pocket Presence

1.00

0.75 player

Aaron Rodgers Andrew Dalton DeShone Kizer Drew Brees Jameis Winston 0.50 Kirk Cousins Marcus Mariota

Proportion of distance Other Tom Brady Tyrod Taylor

0.25

0.00

0 1 2 3 4 seconds

Quarterback Pressure Karl Pazdernik August 2, 2019 21 / 23 Conclusion & Future Work

Conclusion: I Our methodology allows us to I Provide a continuous, non-stationary measure of pressure I Scale according to the average competitor I Adjust for quarterback pocket presence I Create pressure region proﬁles (not shown)

Future Work I Propagate error in expected pocket I Scramble ability metric

Quarterback Pressure Karl Pazdernik August 2, 2019 22 / 23 Deep Football

For more information, visit DeepFootball.com

Thank you!

Quarterback Pressure Karl Pazdernik August 2, 2019 23 / 23