NFL Playing Surfaces Data Analysis

Examining how synthetic and natural turf impact NFL players' movement and injury risk.

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Summary of Data Analysis

Dataset

Analysis of three datasets related to the effects that playing on synthetic turf versus natural turf can have on player movements and the factors that may contribute to lower extremity injuries.

The data provided for analysis are 250 complete player in-game histories from two subsequent NFL regular seasons. Three different files in .csv format are provided, documenting injuries, player plays, and player movement during plays:

• Injury Record: The injury record file in .csv format contains information on 105 lower-limb injuries that occurred during regular season games over the two seasons. Injuries can be linked to specific records in a player’s history using the PlayerKey, GameID, and PlayKey fields.

• Play List: The play list file contains the details for the 267,005 player-plays that make up the dataset. Each player is indexed by PlayerKey, GameID, and PlayKey fields. Details about the game and play include the player’s assigned roster position, stadium type, field type, weather, play type, position for the play, and position group.

• Player Track Data: player-level data that describes the location, orientation, speed, and direction of each player during a play recorded at 10 Hz (i.e. 10 observations recorded per second).

Tools

Python

Insights

Overall, Synthetic surfaces result in 13.89% more injuries than Natural surfaces

• Knee and Ankle injuries have the highest occurrences.

• The majority of injuries result in players missing between 1 day or more or 7 days or more.

  
  

Days Missed

Injuries on synthetic surfaces result in players missing more days than those on natural surfaces.

• Players have a relatively higher likelihood of suffering medium-duration injuries on Natural surfaces.

• Players have a relatively higher likelihood of suffering short, long and indefinite duration injuries on Synthetic surfaces.

  
  

Roster Position

• Natural surfaces result in more injuries for players in the Linebacker, Safety, Defensive Lineman and Offensive Lineman roster positions.

• Synthetic surfaces in more injuries for players in the Wide Receiver, Cornerback and Running Back roster positions

  
  

Note: The Roster Position refers to the official position assigned to the player but it may vary in the actual play itself. The Position refers to the player’s position during the actual play so this information must be verified with the Position data.

Position

Players in the Linebacker (LB) position group, who sustain the most injuries during a play, sustain more injuries on Natural surfaces than Synthetic ones.

• Players in 3 out of 7 position groups sustain more injuries on Synthetic Surfaces.

• Players in 3 out of 7 position groups sustain more injuries on Natural Surfaces.

• Players in 1 out of 7 position groups sustain about the same injuries on both surfaces.

  
  

Position Group

Players in the Linebacker (LB) position group, who sustain the most injuries during a play, sustain more injuries on Natural surfaces than Synthetic ones.

• Players in 3 out of 7 position groups sustain more injuries on Synthetic Surfaces.

• Players in 3 out of 7 position groups sustain more injuries on Natural Surfaces.

• Players in 1 out of 7 position groups sustain about the same injuries on both surfaces.

  
  

Stadium Type

• Injuries sustained in outdoor stadiums are primarily because of Natural Surfaces.

• Injuries sustained in indoor stadiums are primarily because of Synthetic Surfaces.

  
  

Identifying Potential Instances of Injury

We are assuming that the injury is sustained as a result of the impact, which would be reflected as a sudden change in the player's normal motion. We will assume any instance where the player’s movements are out of the ordinary across the variables in the Player Track Data indicates a high-risk instance where the injury could have occurred.

• The majority of plays seem to require some type of instantaneous change in the player’s direction of motion and orientation in the first 40 seconds of the game.

• The risk of injury is also the greatest during these first 40 seconds of the game.

• Generally, the variation in player speed is somewhat lower for most of these plays.

• There are 18.72% more instances of potential injury during plays on Synthetic surfaces as opposed to Natural surfaces.

• The average time for a potential instance of injury to occur is slightly lower on natural surfaces as opposed to Synthetic.