Hayden Birdsong vs. Juan Castillo — Career Comparison

On the career pitching numbers, Hayden Birdsong posted a stronger line than Juan Castillo. Hayden Birdsong posted stronger numbers in ERA (4.77 vs 6.94) and WHIP (1.438 vs 1.886). By the career numbers, Hayden Birdsong 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.