Grant Jackson vs. Dan O'Brien — Career Comparison

Looking at the career totals, Grant Jackson and Dan O'Brien are fairly close on the surface numbers. Grant Jackson posted stronger numbers in ERA (3.46 vs 5.9) and WHIP (1.365 vs 1.931). Dan O'Brien had the advantage in home runs allowed (0.31 per nine innings vs 0.72). By the career numbers, Grant Jackson 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.