Grant Jackson vs. John Koronka — Career Comparison

John Koronka built a career as a starting pitcher and Grant Jackson as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Grant Jackson posted stronger surface numbers — ERA 3.46 and WHIP 1.365 compared to 6.25 and 1.642 for John Koronka. By the career numbers, Grant Jackson had the better of this cross-role comparison — though era context would sharpen the verdict.