John Costello vs. Daniel Schlereth — Career Comparison

On the career pitching numbers, John Costello posted a stronger line than Daniel Schlereth. John Costello posted stronger numbers in ERA (2.97 vs 4.35) and WHIP (1.395 vs 1.667). 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.