Making Reasonable Comparisons
The Rookies of the Year will be announced about the time this post goes up, or shortly thereafter. I do not know who will win, but there are a number of good candidates. Among those candidates should be a pair of 21 year-old first basemen: Kansas City’s Eric Hosmer and Atlanta’s Freddie Freeman. Controversial defensive metrics aside, their 2011 hitting performances (114 wRC+ for Hosmer, 118 wRC+ for Freeman) have rightly earned them recognition. Apart the passing glory of the Rookie of the Year award, what is most exciting for fans of both players is how such performances at such a young age bode for their respective futures in the game. While those numbers are unspectacular for first basemen, to have done so at an age when most of their peers were in college or the minors is most promising. This leads to columns like this, which compares Hosmer’s 2011 performance with that of other 21-year olds who hit as well or better. It is an impressive list, of course, and the general point is sound. But by only comparing Hosmer with players who hit as well or better at 21 it also skews the perception of Hosmer’s season. It makes Hosmer’s 2011 seem closer to Frank Robinson‘s age 21 performance (139 wRC+ in 1957) while leaving out that it is much closer to Jim Fregosi’s 1963 (111 wRC+). That should not be taken to demean Hosmer or Freeman. However, looking at more reasonable comparisons can leave optimistic impressions without being unrealistic.

