Keury Mella vs. Sean O'Sullivan — Career Comparison

Sean O'Sullivan built a career as a starting pitcher and Keury Mella 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 7.22 and 2.128 for Keury Mella. By the career numbers, Sean O'Sullivan had the better of this cross-role comparison — though era context would sharpen the verdict.