Sean O'Sullivan vs. Pop Williams — Career Comparison

Sean O'Sullivan built a career as a starting pitcher and Pop Williams as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Pop Williams posted stronger surface numbers — ERA 3.17 and WHIP 1.395 compared to 6.01 and 1.616 for Sean O'Sullivan. By the career numbers, Pop Williams had the better of this cross-role comparison — though era context would sharpen the verdict.