On Monday, I posted in response to Bill Barnwell’s article on Grantland called “Mere Mortals” where he makes the claim that regular NFL players who played between 1959 and 1988 have a statistically significantly lower mortality rate than regular baseball players of the same era.  I suspect all that has been demonstrated is that older people die more often than younger people because the groups are not directly comparable, since age was not controlled for in the comparison.  What I believe we are dealing with here is correlation and not causation.  Baseball, almost surely, is not killing people faster than baseball players.  And even if it was, it has not been demonstrated.  Not even close.

So, I’ve been reading some other stuff by Barnwell (which I really enjoy) including his Twitter feed lately and two particular tweets interested me greatly.  The first one:

Appreciate the kind words about the study. For those who asked: Average age of MLB player at time of passing was 60.9; for NFL, it was 58.8.

And the second one:

Went back and looked at age for all players in my study by request; MLB players in sample were on average 24 months older than NFL players.

The first tweet should make someone pause and think about how this can be, while at the same time, baseball players have a higher mortality rate.  I suspected, originally, and still do, that it was because one group was simply older than the other group.  Which…..is exactly what was tweeted in the second tweet.  MLB players in the sample were TWO YEARS older than NFL players in the sample.  Can you name something that 62 year olds do more often than 60 year olds?  I can.  They die more often.

So, it seems to me like all that the study has actually demonstrated is that older people die more often.  So, maybe Barnwell will dial back his “stunning” claims?  Maybe not.  This is the tweet directly before tweet number 2:

ICYMI: Wrote about the stunning respective mortality rates of MLB and NFL players from 1959-88 on @grantland33. http://ow.ly/d1QGH

Cheers.