While [...] the average age of ballplayers is on a steady decline since 2004 or so, I was curious how Baseball-Reference’s WAR might view the changing of the tide.

I grouped position players into four (admittedly) generic age groups, 21-25, 26-30, 31-35, and 36-40 from each season since 1900 and added up all the WAR earned by each age group. (In earlier versions of this chart I did leave in the “20 and younger” group as well as the “40 and older” group, but as it turns out neither has been ...