Age and Home Runs

Craig Edwards publishes the second part of the comparison of the steroid era with today’s game to see if PEDs are increasing home runs. Today he looks at age in 2002 versus age in 2017:

There are a lot more young players now than there were during the PED era. That +8.1% change for players 25 years old an under represents a 44% increase in playing time compared to 15 years ago. While the players likely to be in their prime, from age 26 through age 30, have seen slight decrease in playing time, it’s the league’s oldest players who’ve taken the biggest hit, accounting for 6% fewer plate appearances now.

There’s a pretty good reason for that drop in playing time: the younger players are a lot better than they used to be relative to the rest of the league.

That’s a pretty good indicator nothing is going on league wide. When Bill James studied the issue, his claim was that steroids keep you young. That isn’t happening right now.

I would like to point out, however, that Edwards is comparing two points in time. The post yesterday encouraged me to look at home runs by position more closely. This spreadsheet contains a graph that shows the percentage of home runs by position from 1998 to 2017, the 30 team era. It also covers the end of the PED era. The positions are stacked so the ones most important for defense are at the bottom. It turns out that 2002 was a fairly bad year for defensive positions hitting home runs. The overall story still works, but 2002 was the most extreme year he could have chosen.

It also shows this tendency toward more home runs from catcher, shortstop, and second basemen started around 2011. So it’s not a change in the ball or launch angle, but the continuation of a trend. We should look at age the same way, rather than just picking two points.

from baseballmusings.com http://ift.tt/2xBB76M