Mark Mercer vs. John Thornton — Career Comparison

On the career pitching numbers, John Thornton posted a stronger line than Mark Mercer. John Thornton posted stronger numbers in ERA (4.1 vs 4.7) and WHIP (1.486 vs 1.826). By the career numbers, John Thornton 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.