Robinson Leyer vs. Michael Petersen — Career Comparison

On the career pitching numbers, Michael Petersen posted a stronger line than Robinson Leyer. Michael Petersen posted stronger numbers in ERA (5.02 vs 21.21) and WHIP (1.593 vs 4.286). By the career numbers, Michael Petersen 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.