Fred Mauer vs. Casey Janssen — Career Comparison

Looking at the career totals, Fred Mauer and Casey Janssen are fairly close on the surface numbers. Casey Janssen posted stronger numbers in ERA (3.63 vs 36) and WHIP (1.238 vs 5.500). Fred Mauer had the advantage in home runs allowed (0 per nine innings vs 0.88). By the career numbers, Casey Janssen 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.