John Costello vs. Joe Ostrowski — Career Comparison

Looking at the career totals, John Costello and Joe Ostrowski are fairly close on the surface numbers. John Costello had the edge in ERA (2.97 vs 4.54). By the career numbers, John Costello had the better of this comparison — though ERA and WHIP alone don't account for era, park factors, or the defenses each pitcher worked behind.