Sean O'Sullivan vs. John Williams — Career Comparison

On the career pitching numbers, John Williams posted a stronger line than Sean O'Sullivan. John Williams posted stronger numbers in ERA (4.37 vs 6.01) and WHIP (1.436 vs 1.616). By the career numbers, John Williams 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.