The NFL play-by-play reports when players are injured on each play, or at least when the injury stops play so trainers can attend to the injured player. These are far from 100% all injuries suffered in the course of play, but they are the ones that tend to be significant or severe--ACLs, broken bones, separated shoulders, concussions--the kind of things that really worry players, teams, and the league.
With that information in hand, we can see the injury rates for each type of play, including kickoffs.
Injuries are increasing for all types of plays over the last decade. Last season, the injury rate was 1.6% on runs, 1.5% on passes, 1.3% on punts, and 2.0% on kickoffs. The graph illustrates there is something systemic at work increasing injuries at predictably steady rate, or at least increasing the reporting of injuries. Because of the very real concern around the NFL, I'd assume most of the increase is real.
(If I had to guess, the simultaneous near-doubling of injuries on all play types between 2004 and 2005 could be due to an increased effort to report injuries in the play-by-play. But even accounting for that jump, injuries are still steadily on the rise. I also suspect the drop in injuries in 2010 for passes and runs may not be just statistical noise and could be due to enforcement of helmet-to-helmet hits.)
Increasing the number of touchbacks will certainly reduce the number of kickoff injury rates simply by reducing the number of return plays. Needless to say, the fewer the kick returns there are, the fewer the injuries there will be. The question becomes: How much of a reduction can the NFL expect?
It's hard to estimate how many more touchbacks there will be under the new rules. Kickers may kick higher but shorter, or returners may decide to return the ball from deeper in the endzone than in previous years due to the shorter run-up allowed to the coverage team. But there is preseason data to work with. Because of weather factors (temperature is far more important to kick distances than most think) and other considerations, we'll compare the 2010 preseason to the 2011 preseason.
In 2010 the preseason touchback rate was 19.5%, and in 2011 it doubled to 39.4%. That equates to a 24.8% reduction in returnable kicks (60.6% / 80.5% = 75.2%). The NFL can expect a proportional reduction in injuries on kickoffs, reducing the rate from 2.0% to 1.5%. (We'll plan to revisit the actual numbers later this season.)
But what does this mean in real terms? How many injuries will this prevent?
In 2010, there were about 9.5 kickoffs per game, which is consistent with the previous 10 years. So reducing the injury rate by half a percent won't add up to much. Instead of the 51 kickoff injuries in 2010, we might expect about 38 in 2011. Thirteen fewer injuries over 32 teams and 267 games from week one through the Super Bowl. That's a reduction of 0.024 injuries per team per game--imperceptibly small and meaningless in practical terms.
Again, not all injuries are reported in the play-by-play. But even if we stipulate that this estimate is an entire order of magnitude too small, that's still only 0.2 fewer injuries per team per game!
Further, looking back at the graph above, it appears that over the past few years, injury rates on kickoffs are in line with those on run and pass plays. In fact, in 2008 and 2009 the kickoff injury rates were lower than for typical scrimmage plays. Getting rid of the two-minute warning in the first half, a gimmick that only allows extra commercials, would have a similar injury-reducing effect just by reducing the number of pass and run plays.
In my mind, this miniscule reduction in injuries does not justify ruining one of the more exciting plays in the game. The trade off just isn't wise--there are better ways to address injury reduction. Even if the kickoff injuries are significantly reduced this season, whatever factors have been causing injuries in general to increase remain unaddressed. Those are the things the league needs to fix, or else injury rates will be back on the climb.
As it stands today, the entire NFL post-score kabuki dance is unwatchable. First there's an automatic review that could take up to several minutes featuring two beer and two car commercials. Then there's the virtually automatic extra point, the NFL's version of...well, I can't think of anything else in the universe so pointless. Now throw in the touchback, followed by Dennis Leary hocking Ford F150s and a positively terrifying ad for some horror/sado-torture movie that gives every kid under 13 nightmares for the next week, plus one for Cialis and one for whatever lame hour-long drama featuring a tough-cookie hot single mom NYPD detective is going to be cancelled on CBS later this fall. Then it's back to some moron sideline reporter who tells us something we either already knew or could just as easily be relayed through the booth announcers. Then, finally, it's back to the game.
Pssst, NFL. Your problem isn't not enough touchbacks.