David Aardsma vs. Unknown Nelson — Career Comparison

Looking at the career totals, David Aardsma and Unknown Nelson are fairly close on the surface numbers. David Aardsma posted stronger numbers in ERA (4.27 vs 9) and WHIP (1.487 vs 2.000). Unknown Nelson had the advantage in home runs allowed (0 per nine innings vs 1.09). By the career numbers, David Aardsma 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.