Joe Kostal vs. Martin Perez — Career Comparison

Martin Perez built a career as a starting pitcher and Joe Kostal as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Joe Kostal posted stronger surface numbers — ERA 0 and WHIP 2.000 compared to 4.41 and 1.441 for Martin Perez. By the career numbers, Joe Kostal had the better of this cross-role comparison — though era context would sharpen the verdict.