John Callahan vs. Erik Swanson — Career Comparison

On the career pitching numbers, Erik Swanson posted a stronger line than John Callahan. Erik Swanson posted stronger numbers in ERA (4.2 vs 16.2) and WHIP (1.154 vs 3.000). By the career numbers, Erik Swanson 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.