[OC] Penalties called in the 2019 NFL Regular Season

The scaling on this chart seems off unless I’m misinterpreting

Source: https://www.pro-football-reference.com/, https://www.nflpenalties.com/

Tools: Python - Beautiful Soup, Selenium, Matplotlib

Summary: Apologies if something like this has been posted recently. I was curious how consistently refs ended up calling games over the course of the regular season (i.e. letter-of-the-law or let-them-play). I used pro-football-reference to collect the head referees for each regular season game in 2019 and then used nflpenalties to collect all the penalties called for each game (for some reason PFR play-by-play doesn’t report all penalties when more than 1 occurred on a play). I then totaled up all penalties each ref crew called. It’s very possible that certain crews just happened to call games where more penalties occurred. I did not care about this subtlety here however and simply wanted to summarize the calls that have been made. This point could probably be estimated to some degree by assuming that procedural penalties for all crews might be about equal but I won’t speculate more than this. I grouped all 51 penalty types called this year into different categories according to what I generally see them associated with:

OFFENSIVE HOLDING: Offensive Holding

DEFENSIVE HOLDING: Defensive Holding

BLOCKING: Illegal Block Above the Waist, Illegal Use of Hands, Illegal Blindside Block, Illegal Double-Team Block, Chop Block, Illegal Crackback, Clipping, Low Block

OFFENSIVE PASS INTERFERENCE: Offensive Pass Interference

DEFENSIVE PASS INTERFERENCE: Defensive Pass Interference, Illegal Contact

TACKLING: Face Mask (15 Yards), Lowering the Head to Initiate Contact, Horse Collar Tackle

CONDUCT: Unsportsmanlike Conduct, Disqualification, Taunting

UNNECESSARY ROUGHNESS: Unnecessary Roughness

ROUGH PASSER: Roughing the Passer

ROUGH KICKER: Running Into the Kicker, Roughing the Kicker

TRIPPING (this rarely called penalty didn’t really belong anywhere): Tripping

PROCEDURAL (I took some liberties here, but assumed these would more or less be called consistently): False Start, Defensive Offside, Neutral Zone Infraction, Delay of Game, Illegal Formation, Illegal Shift, Defensive Too Many Men on Field, Encroachment, Offensive Too Many Men on Field, Illegal Motion, Illegal Forward Pass, Offside on Free Kick, Illegal Substitution, Player Out of Bounds on Kick, Ineligible Downfield Kick, Kickoff Out of Bounds, Invalid Fair Catch Signal, Defensive Delay of Game, Delay of Kickoff, Intentional Grounding, Ineligible Downfield Pass, Leverage, Illegal Touch Pass, Illegal Bat, Illegal Touch Kick

If you don’t know, NFL ref crews remain approximately constant throughout the year. There are swing referees who can fill in if there are injuries or schedule conflicts however (http://www.footballzebras.com/2019/06/officiating-crews-for-the-2019-season/). Note that all ref crews called 15 games except for Walt Anderson’s crew, which called 16 games.

In addition to the plot, here is a table of summary statistics for the total numbers of each penalty category called over 15 games (Walt Anderson’s crew penalties were normalized to 15 games). This should help assign concrete numbers to the above chart. The standard deviation is the population standard deviation. Please remember that comparing absolute counts isn’t ideal though because of the different number of plays each crew called. Offensive holding is easily the most called penalty.

Here is the same table but now per 100 plays (to approximately reflect an actual game):

Here, we can see that if the Offensive Holding penalty can somehow be reworked, it would save an average of 2 penalties per 100 plays, which I think we can all agree would be nice. Unfortunately I have no idea how to do this. Finally, note that we cannot simply sum the range column to compare a crew calling few penalties with a crew calling many because these ranges can come from different crews. Instead, here is summary table for each ref crew:

Disclaimer: I checked the data I scraped and got penalty totals that agreed with the online totals. It is always possible I did something stupid that could change these numbers though.

Feedback: Please let me know if you have constructive criticisms on ways of representing this data better! I tend to default to using bar and scatter plots the most but am always open to learning new techniques.

This is fantastic information and something Ive always wished I had when deciding how good/bad a ref is when he and his crew get assigned to us. Saving this for sure.

I would say that I really hate this type of graph, as visually it doesn't allow yourself to easily compare different categories of penalty across crews. I think visually a better way to do this was just have an album of bar graphs per penalty type, and then one more for total penalties per play.

Regardless, great stuff!

Taking what OP said at face value and analyzing how I feel about Walt Anderson as our ref for the Vikings game.

• 1st in procedural penalties seems fine, probably the crew least likely to miss a blatant procedural penalty, I would want all of those called.

• Being the median rank for offensive holding and for blocking is also nice. Hopefully that'll be the happy medium between how can you call that a hold/bad block vs how do you miss that hold/bad block.

• Being more likely to call roughing the passer than average is a little disconcerting. Might help us with how long Jimmy G holds onto the ball until getting it out at the last second I guess, but I dont like ticky tacky rough the passer calls, and our pass rush is physical.

• Being one of the lowest on unnecessary roughness I think is good. I feel like maybe it's just our team, but it gets called too much on not actual unnecessary roughness, should be blatant for a 15 yard penalty.

• He calls like 0 conduct penalties which I also like. Let the players play and have fun. Fuck penalties for taunting bs.

• Being high on tackling penalties is worrying a little. I feel like tackling penalties are usually clear cut, but are sometimes called wrong on the initial look and can't be reviewed like PI. I'm definitely worried avout some incorrectly called tackle penalties because it looked bad.

• Calls both DPI and OPI at one of the highest rates... that's going to be really annoying with our physical secondary. I do like that it's matched up with calling OPI, so we don't get a push off no call situation hopefully, but thats the biggest thing Im not a fan of, and they're the biggest penalties.

• He's high on defensive holding, but I feel like usually that should be an obvious hold, hopefully nothing ticky tacky.

Overall, kind of feel in the middle, I think the areas of worry are DPI, roughing the passer, and tackling penalties.

I'm going to keep putting interesting tidbits here I find from these graphs because I really like them.

Alex Kemp has the highest rate of OPI called with the 4th lowest rate of DPI called. As someone who doesn't like that the rules are so favored to offense that ticky tacky DPIs are called while OPI is given more leeway, that's the kind of ref I like. It's worth noting that even with that largest discrepancy, he still calls DPI at a higher rate than OPI, which is as expected.

Craig Worlstad is the opposite type of ref I don't like. Noticeably highest rate of calling DPI, while the 5th lowest rate of calling OPI. It appears he calls DPI ~6 times as often as OPI, which is just absurd.

Seems to confirm my long-standing belief that Boger uses any excuse to hop on the mic and call "ho-ding".

Number 72 holding. Kill me now