Unknown Allison vs. Hayden Birdsong — Career Comparison

On the career pitching numbers, Unknown Allison posted a stronger line than Hayden Birdsong. Unknown Allison posted stronger numbers in ERA (3 vs 4.77) and home runs allowed (1 per nine innings vs 1.37). By the career numbers, Unknown Allison 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.