Robbie Erlin vs. Billy Koch — Career Comparison

Robbie Erlin built a career as a starting pitcher and Billy Koch as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Billy Koch posted stronger surface numbers — ERA 3.89 and WHIP 1.466 compared to 4.87 and 1.297 for Robbie Erlin. By the career numbers, Billy Koch had the better of this cross-role comparison — though era context would sharpen the verdict.