In the Wednesday Horse Tracks an interesting discussion started about how injuries relate to winning. Some took the side of "Next man up" while others felt injuries always hurt a team, no matter depth. I personally believed prior to this that injuries obviously made a huge difference in how a team's season plays out while others pointed out how the Packers won the Super Bowl with a host of injuries. There was a lot of good discussion but in the end, we felt that it would be interesting to delve more deeply into this.
To do this we'll cover a few different angles and I hope I do this topic justice since there are so many different sides to this topic, it's hard to cover every side and factor.
Since injury data is incredible hard to find, I went back as far as I could, but that was only six seasons. That still provides us with 192 samples which is a solid sample size. I gathered four pieces of data from each team:
- Injured Reserve players
- Pro Bowl players placed on Injured Reserve (these are players who made the Pro Bowl in the past 2 years)
- Starters games missed (based on adjusted games missed created by Football Outsiders)
- Key players missing 3+ games (key positions are QB, LT, MLB, S)
Now I understand these don't cover all the bases, especially about the key players missing games, but I feel that between these four categories we can get a decent picture and try and see a trend. Now for each category I broke them down into these areas:
- League average
- Teams with losing records
- Teams with an even record
- Teams with a winning record
- Teams with 11 or more wins
- Playoff teams
Now I wanted to include Super Bowl teams, but the size of the group is just too small, though I will talk about it later, so don't fret. Let's take a look at the data:
Now remember these are per season numbers.
|League Average||Losing Record||Even Record||Winning Record||11 or More Wins||Playoffs|
|Injured Reserve Players||9.5||11.4||9.1||8.1||7.5||9.2|
|Pro Bowler's Lost||0.51||0.73||0.48||0.30||0.36||.23|
|Starters Game Lost||53.9||60.2||46.9||47.9||45.1||47.8|
Now just from a general standpoint, it's pretty clear that teams with fewer injuries win more games, whether you gauge those injuries by IR, starter games lost or by whether you lost Pro Bowlers. Now it is interesting to note that playoff teams seem to have slightly higher IR and SGL lost numbers, whether that has to do with a smaller sample size or if it's just that way, it's hard to note. When it comes to starter games lost, it should be noticed that playoff teams tend to sit starters for a game at the end of the season, the Patriots often site 4-5 starters so that adds a few to the end of each season that might off-set the number. But that's just one thought since it's hard to really gauge.
A few fun facts:
- The team with the most players on Injured Reserve was the 2009 Detroit Lions with 24 players, they went 2-14.
- The team with the fewest players on Injured Reserve was the 2009 Minnesota Vikings with only 1, they went 12-4.
- The team who had the most starter games lost was the 2011 Carolina Panthers with 109, they went 6-10.
- The team who had the fewest starter games lost was the 2010 Kansas City Chiefs, they went 10-6.
- The worst year in terms of Injured Reserve was in 2009 when the league average was 12.5.
- The best year in terms of Injured Reserve was in 2011 when the league average was 6.8.
- The Super Bowl team with the most players on Injured Reserve was the 2009 New Orleans Saints with 16.
- The Super Bowl team with the fewest players on Injured Reserve was the 2007 New England Patriots with 6.
- For the statistics guys out there, the correlation between wins and players on Injured Reserve is -0.32045.
- The correlation between wins and starter games lost is -0.2237.
- So really there is actually a negative correlation between winning and injuries, at least that's what this shows.
and for comparison, here's the Broncos numbers for some recent seasons:
- 2011: 8 Injured Reserve players, 0 Pro Bowlers
- 2010: 9 Injured Reserve players, 1 Pro Bowler
- 2009: 14 Injured Reserve players, 0 Pro Bowlers
- 2008: 14 Injured Reserve players, 0 Pro Bowlers
- 2007: 9 Injured Reserve players, 0 Pro Bowlers
This was a bit trickier, and I really don't like it much since it is hard to really capture the essence of key players. I used quarterback, left tackle, middle linebacker and safety, but once again, it's pretty weak. Take the Ravens for example, losing Ray Rice, a running back, is much more damaging than losing their quarterback Joe Flacco. The same goes for a team that doesn't use their MLB as the defensive leader, like the Broncos for instance. D.J. Williams is more important in terms of on the field leadership than Joe Mays.
In the end, I really couldn't find a good way to organize and classify it. In the end I just looked a few different topics and points, mostly about quarterbacks:
- No team has won the Super Bowl with a backup since Trent Dilfer came in for Tony Banks and the 2000 Ravens. It's hard to call Dilfer a backup since he started nearly half the regular season.
- Since 2000, no backup QB has made the Super Bowl since Dilfer, either as a winner or loser.
- Since 1990, only two backup QB's have started in a Super Bowl, Trent Dilfer and Frank Reich for the Bills in 1992.
In the end, the biggest loss is the quarterback, unless your team is just awesome anyways (2008 Patriots) the chance of winning 10 or more games is very small with a backup QB.
Hope this answered the questions that had been raised and if you have any suggestions on how I can expand this study, please let me know. In the end, it seems injuries do have an effect on how effective a team is. That's not to say injuries doom a team, but rather it's easier to win with fewer injuries. I know it sounds overly simplistic but it's true. There are teams that win a lot of games, including the Super Bowl, with injuries, but those are rare, a team with more injuries is less likely to do well. But that's not to say it's impossible, the Packers and Saints proved that wrong in 2009 and 2010.
Thanks for all the great suggestions Mile High Report and keep them coming, we'll do our best to answer any questions brought up.