NFL Penalty Trends

Background

If you’re a fan of the National Football League, so far this season you’ve heard an uninterrupted string of commentary surrounding penalties, rule changes, and the role of violence in the game. This is a fascinating topic because a number of greater trends have coincided to cause this moment - particularly the NFL’s desire to protect quarterbacks, rule changes that have reduced the amount of practice time teams have during the offseason and between games, and game-calling decisions designed to encourage passing and free up downfield receivers. Put together, these factors have led to a slow inflation in the number of penalties called per NFL game, which is now reaching a tipping point.

While I don’t have a particularly strong stance on these issues (though leaning towards support of the NFL’s QB-friendly/offense-first perspective), I did want to dig into the numbers and understand the scale of the NFL’s penalty problem and the biggest contributing factors. To do so, I grabbed the latest penalty information from Pro Football Reference, extrapolated the first five weeks of the season out, and retrieved data from 2008-2017 to compare against.

Aggregated Penalty Data

Total Penalty Trends

This chart shows a sustained increase over the past decade, with a noticeable spike between the 2013-2015 seasons. It’s interesting to note that the 2011 Collective Bargaining Agreement (CBA) included a reduction in the number of offseason practices, ban on “two-a-days”, and restriction on the number of practices in pads during the season. Others have hypthothesized that these changes made players more unprepared at the start of the season, creating an increase in penalties - while it’s still unclear the impact those changes made, the trends definitely do align.

Also of note here is the “Replacement Refs” saga of 2012, which potentially depressed the number of penalties called through the beginning of the 2012 season. Most notable amongst these incidents was the Packers-Seahawks “Fail Mary”, where officials declined to call pass interference on a heavily-contacted contested catch situation.

Top Penalty Trends

This chart breaks down the most frequently called penalties across the league for the past decade - led by False Start/Offensive Holding, which have recently switched positions.

Examining Specific Penalties

Defensive Penalty Trends

The NFL’s embrace of a more wide-open passing game can be seen directly in the rise in coverage penalties over the past decade - penalties called more closely that favor receivers in downfield passing situations. While despised by the likes of Richard Sherman, it’s clear that the NFL has placed more emphasis on calling these plays as penalties.

Roughing the Passer Trends

I’ll just leave this here…. Clay Matthews may have a point.

Offensive Holding Trends

Finally, the biggest single factor for the rise in penalties - Offensive Holding. The bane of every head coach’s existence, Holding is alive and well, ready to bring back touchdowns and ruin drives. While it is unclear whether the spike has been due to a change in true incidence rate or merely the rate at which it is called (one could argue some amount of holding occurs on every play), increased Offensive Holding calls are the largest contributor to the NFL’s penalty surge. While Roughing the Passer may get the headlines, the incidence rate at which Offensive Holding is called (2.8 penalties/game vs 0.7 penalties/game) makes it a much more obvious detractor to the quality of play in the modern NFL game.