John Halama vs. Williams Perez — Career Comparison

Looking at the career totals, John Halama and Williams Perez are fairly close on the surface numbers. John Halama had the edge in ERA (4.65 vs 5.18). By the career numbers, John Halama 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.