NFL Injuries Part III: Variation by Position and Age
by Zach Binney
If you haven't read part I and part II of this series, I highly recommend it. Part I lays out what we're trying to do in this four-part series (describe NFL injuries) and gives some important caveats. Part II looks at how injury trends typically change throughout the season, and how they have changed over the years.
Today we have a whole post investigating the complexity of how injuries vary by age. Is a veteran really more likely to miss games as he ages? If so, how much?
Injury Risk by Age
The data in this section (except where indicated) excludes quarterbacks, kickers, punters, and other special teams players. I have done this because these players have lower baseline injury risks and make up a large proportion of players in older age groups (together they become a majority of players 37 and older). Including them would artificially deflate the injury risk for the oldest players.
The denominator for the chart and table below is player-seasons where the player played in at least one regular season game or was on IR the whole year. So all of these injury risks are only applicable for players who were still good enough to play if they weren't injured. A banged-up or washed-up 31-year-old linebacker doesn't make this chart unless there's a good chance he makes somebody's roster. He has to pass a smell test of "would he play if he were healthy?" before the injury risks below apply to him. Everything in the chart is conditional on passing that smell test.
|Table 1. Number of Player-Seasons by Age|