Grant Jackson vs. Joe Kostal — Career Comparison

Looking at the career totals, Grant Jackson and Joe Kostal are fairly close on the surface numbers. Joe Kostal posted stronger numbers in ERA (0 vs 3.46) and home runs allowed (0 per nine innings vs 0.72). Grant Jackson had the advantage in WHIP (1.365 vs 2.000). By the career numbers, Joe Kostal 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.