Julian Aguiar vs. Sean O'Sullivan — Career Comparison

Looking at the career totals, Julian Aguiar and Sean O'Sullivan are fairly close on the surface numbers. Sean O'Sullivan posted stronger numbers in ERA (6.01 vs 6.25) and home runs allowed (1.64 per nine innings vs 2.27). Julian Aguiar had the advantage in WHIP (1.358 vs 1.616). By the career numbers, Sean O'Sullivan 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.