David Hernandez vs. Michael Petersen — Career Comparison

On the career pitching numbers, David Hernandez posted a stronger line than Michael Petersen. David Hernandez posted stronger numbers in ERA (4.12 vs 5.02) and WHIP (1.335 vs 1.593). By the career numbers, David Hernandez 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.