The Dangers of Playing in the NFL

The NFL’s concussion crisis, explained

Video from Vox

What is CTE? 

CTE, or Chronic Traumatic Encephalopathy, is a progressive degenerative disease resulting from repeated traumatic impacts to the head. The brain of someone suffering from CTE will gradually deteriorate, leading to a loss in mass.

According to, symptoms of CTE, which is only diagnosable through post-mortem examination of the brain, include:

loss of memory, difficulty controlling impulsive or erratic behavior, impaired judgment, behavioral disturbances including aggression and depression, difficult with balance, and a gradual onset of dementia.

In a study conducted post-mortem by Dr. Ann McKee on the brains of 111 former NFL players, 110 were found to have CTE. The brains analyzed came from every position on the field, and from players of all different ages at the time of their death.

Using data collected from the journal article, Concussion Incidence in Professional Football, we created the chart below, which shows the number of concussions per 1000 plays for each position.

Number of Concussions per 1000 Plays by Position


NFL Acknowledgment and Implementation of New Rules

The NFL finally acknowledged the connection between football and CTE in March of 2016, and they have begun to implement new rules designed to limit the amount of concussions suffered during gameplay.

According to, the new rules implemented by the NFL will:

  • Prohibit the “leaper” block attempt on field goal and extra point plays.
  • Extend the rule changing the spot of the next snap after a touchback resulting from a free kick to the 25-yard line for another year.
  • Give a receiver running a pass route defenseless player protection.
  • Prohibit crackback blocks by a backfield player who is in motion, even if he is not more than two yards outside the tackle when the ball is snapped.

Using the information in the following two charts we were able to determine the percent chance of one player (of said position) getting injured within 1000 plays. The data highlights the fact that while skilled positions (quarterback, running back, wide receiver, tight end) are at higher risk of injury, there are more injuries suffered by players in non-skilled position (offensive line, defensive line, linebacker, secondary)

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The following graphs show the number of head injuries suffered by offensive and defensive over a six season span (2002-2007). These numbers were taken before the NFL implemented the new rules explained above.

Offensive Injuries by Position (2002-2007)


Defensive Injuries by Position (2002-2007)


Using the data on head injuries from 2002-2007, we created a theoretical data set to show the effect of the new rules on head injuries. Due to the recent implementation of the new rules, there is no data currently available on their effectiveness.

We arrived at the theoretical data by:

  • Cutting quarterback injuries by 50%
  • Cutting wide receiver injuries by 50%
  • Cutting secondary line injuries by 25%

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While the NFL has implemented new rules in an attempt to decrease head injuries, the rules themselves cannot cure a sport that predisposes player to head injuries. The dangers of playing football are made even more clear when the injury rate is compared to that of soccer. The overall injury rate in NCAA men’s soccer is 7.7 per 1,000 exposures, with only 5.5% of injuries being concussions. Coupled with the danger of playing in the NFL is the fact that newly adopted rule changes will not bring any substantial change, as demonstrated by our theoretical calculations. These rules are designed to protect the league’s star players, a group of individuals who make up only a small portion of total players.

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