Jerry Koosman vs. Ramon Lopez — Career Comparison

Looking at the career totals, Jerry Koosman and Ramon Lopez are fairly close on the surface numbers. Jerry Koosman posted stronger numbers in ERA (3.36 vs 5.14) and home runs allowed (0.68 per nine innings vs 1.29). Ramon Lopez had the advantage in WHIP (1.143 vs 1.290). By the career numbers, Jerry Koosman 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.