Josh Hader vs. Isaac Mattson — Career Comparison

Looking at the career totals, Josh Hader and Isaac Mattson are fairly close on the surface numbers. Josh Hader posted stronger numbers in ERA (2.64 vs 2.98) and WHIP (0.949 vs 1.256). Isaac Mattson had the advantage in home runs allowed (0.63 per nine innings vs 1.14). By the career numbers, Josh Hader 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.