John Costello vs. Slim Harriss — Career Comparison

Slim Harriss built a career as a starting pitcher and John Costello as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. John Costello posted stronger surface numbers — ERA 2.97 and WHIP 1.395 compared to 4.25 and 1.481 for Slim Harriss. By the career numbers, John Costello had the better of this cross-role comparison — though era context would sharpen the verdict.