Posted By:
JasonWell I think SABR has taken the approach that you compare players from the same generation of baseball and use stats like VORP and Winshares.
Using such stats allows you to see the most dominate players of a given era. Of course comparing the numbers of Keefe to Johnson to Gibson to Clemens is still debateable, but it gives you an idea of dominance in an era and helps you place them among the all time greats.