Jack O'Connor vs. Mark Prior — Career Comparison

Mark Prior built a career as a starting pitcher and Jack O'Connor as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Mark Prior led in strikeout rate (K%+ 170 vs 85), run prevention (ERA+ 133 vs 80), and skill-based run prevention (DICE+ 137 vs 86). Role difference aside, Mark Prior holds a clear edge on every meaningful shared measure.