Jonathan Aro vs. Oswaldo Mairena — Career Comparison

Looking at the career totals, Jonathan Aro and Oswaldo Mairena are fairly close on the surface numbers. Oswaldo Mairena posted stronger numbers in ERA (6.06 vs 6.55) and WHIP (1.654 vs 1.909). Jonathan Aro had the advantage in home runs allowed (1.64 per nine innings vs 2.02). By the career numbers, Oswaldo Mairena 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.