Sean O'Sullivan vs. George Zackert — Career Comparison

Sean O'Sullivan built a career as a starting pitcher and George Zackert as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Sean O'Sullivan posted stronger surface numbers — ERA 6.01 and WHIP 1.616 compared to 11.88 and 3.120 for George Zackert. By the career numbers, Sean O'Sullivan had the better of this cross-role comparison — though era context would sharpen the verdict.