Keith Atherton vs. Riley O'Brien — Career Comparison

Looking at the career totals, Keith Atherton and Riley O'Brien are fairly close on the surface numbers. Riley O'Brien posted stronger numbers in ERA (3.55 vs 3.99) and home runs allowed (0.93 per nine innings vs 1.19). Keith Atherton had the advantage in WHIP (1.407 vs 1.457). By the career numbers, Riley O'Brien 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.