John Firth vs. Mauricio Robles — Career Comparison

Looking at the career totals, John Firth and Mauricio Robles are fairly close on the surface numbers. Mauricio Robles had the edge in ERA (1.93 vs 8). By the career numbers, Mauricio Robles 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.