Paul Castner vs. Michael Kopech — Career Comparison

Michael Kopech built a career as a starting pitcher and Paul Castner as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Michael Kopech posted stronger surface numbers — ERA 4.14 and WHIP 1.333 compared to 6.3 and 1.900 for Paul Castner. By the career numbers, Michael Kopech had the better of this cross-role comparison — though era context would sharpen the verdict.