Clarence Blethen vs. Mason Thompson — Career Comparison

Looking at the career totals, Clarence Blethen and Mason Thompson are fairly close on the surface numbers. Mason Thompson posted stronger numbers in ERA (5.21 vs 7.32) and WHIP (1.667 vs 2.186). Clarence Blethen had the advantage in home runs allowed (0 per nine innings vs 0.87). By the career numbers, Mason Thompson 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.