Is baseball more hazardous to athletes' health than football?

If the Grantland study had shown that, comparing “apples to apples,” football players die younger than baseball players, we would all have assumed that head injuries were a major reason why. But Barnwell’s numbers went in the opposite direction and left us with a perplexing question: Why might baseball, the gentleman’s game, be more deadly than football over the long term?

It could be that cumulative wear-and-tear is worse for your health than acute injuries. Football players get dinged multiple times per game, but their careers tend to be quite short—3.5 years, on average—and each season comprises just 16 to 20 games. Baseball players are less vulnerable to injuries on the field, but they’re asked to perform 10 times as often, and their careers tend to last 60 percent longer.

Or maybe the difference in mortality rates has more to do with nonathletic behaviors. Football players don’t shorten their lives with cigarettes, for example: A 2009 study in the Journal of the American Medical Association found that just 0.2 percent of NFL athletes smoke, compared with 30.5 percent of equivalent nonathletes. Meanwhile, a 2003 survey of Major League Baseball players found that about 36 percent are regular users of chewing tobacco or snuff.