Mark Leiter vs. John Sullivan — Career Comparison

Looking at the career totals, Mark Leiter and John Sullivan are fairly close on the surface numbers. John Sullivan posted stronger numbers in ERA (4.2 vs 4.57) and home runs allowed (0 per nine innings vs 1.18). Mark Leiter had the advantage in WHIP (1.412 vs 2.133). By the career numbers, John 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.