David Aardsma vs. William Matthews — Career Comparison

Looking at the career totals, David Aardsma and William Matthews are fairly close on the surface numbers. William Matthews posted stronger numbers in ERA (3.24 vs 4.27) and home runs allowed (0.54 per nine innings vs 1.09). David Aardsma had the advantage in WHIP (1.487 vs 1.560). By the career numbers, William Matthews 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.