Tuesday, September 30, 2008
Height and home run rates
Posted by David GasskoI got an e-mail from a reporter today inquiring about changes in home run rates among differently sized players. His question piqued my interest, and I decided to run a simple query, checking on whether players of different heights have seen their home run rates decline by different amounts since the peak of the home run boom.
I decided to split players up into three groups: Tall, which means 6'5" or greater, and includes about 10% of all baseball players; short, which means 5'10" or less, and also includes about 10% of all players; and medium, which includes all the rest. Here are the home run rates per 150 games (640 plate appearances) among the three groups at the peak of the offensive boom, in 2000:
Short: 12.5
Medium: 19.9
Tall: 28.2
And here are their averages in 2008:
Short: 8.9
Medium: 17.8
Tall: 20.2
The percentage changes from 2000 to 2008 are:
Short: -28.8%
Medium: -10.6%
Tall: -28.1%
There isn't much of a difference between short and tall players, but home run rates among "medium" players declined markedly less, and I have no idea why. The only theory I can come up with is that short and tall players have much greater incentive to use steroids: Short players because most of them are tweeners and for whom a little bit of power might mean the difference between starting in the major leagues and being a veteran minor leaguer, and tall players because they generally are not good fielders and therefore need to put up big offensive numbers to be worth keeping around. So maybe steroid testing affected the home run rates of those two groups a lot more than it did the rest of major league baseball.
That's just a theory, however, and I want to hear what other explanations my readers might have. Also keep in mind that this was a quick query, and perhaps there are things that would need to be controlled for in a rigorous study. Let me know what you think! You can e-mail me at .(JavaScript must be enabled to view this email address).
David Gassko is a former consultant to a major league team. He welcomes comments via e-mail.