On the Changing Size of MLB Players

From SABR member Bill Petti at Beyond the Box Score on April 19:

Last week, when I was putting together my post on the greatest short player of all time, I became curious as to how the size of players has changed over time. Generally speaking, adult males in the US have become bigger over time. But the question that came to mind was whether MLB players have grown at a greater, lesser, or similar rate than the general population.

Unfortunately, I don’t have access to full data on the average height and weight of US males back to the 1870’s, but I did find some data going back to 1960 that I’ve used to create the comparative graphic above*.

The average height of a major league player has increased almost 7% since the 1870’s, from 68.9 inches to 73.7 inches. In terms of weight, the average ballplayer is almost 14% heavier than the average player in the 1870’s, increasing from 167.3 lbs to 190.6 lbs. There was a pretty steep acceleration of player weight from the 1870s to 1900’s, then a decline through the 1920’s, and then a steady increase since 1930. Oddly enough, we don’t see big jumps in weight during the advent of weight training.

Comparatively speaking, major league players have maintained a 5-6% height advantage over other US males every decade since 1960. What’s interesting is that the gap between the average major league and US male weight-wise has shrunk dramatically since 1960, all the way from a 12% difference to just a tad over 2%.

Read the full article here: http://www.beyondtheboxscore.com/2011/4/19/2114631/the-changing-size-of-mlb-players-1870-2010

Originally published: April 24, 2011. Last Updated: April 24, 2011.