Sean O'Sullivan vs. Kai-Wei Teng — Career Comparison

Looking at the career totals, Sean O'Sullivan and Kai-Wei Teng are fairly close on the surface numbers. Sean O'Sullivan posted stronger numbers in ERA (6.01 vs 7.3) and WHIP (1.616 vs 1.697). Kai-Wei Teng had the advantage in home runs allowed (0.89 per nine innings vs 1.64). 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.