Jim Peterson vs. George Zettlein — Career Comparison

George Zettlein built a career as a starting pitcher and Jim Peterson as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. George Zettlein posted stronger surface numbers — ERA 2.55 and WHIP 1.297 compared to 5.27 and 1.665 for Jim Peterson. By the career numbers, George Zettlein had the better of this cross-role comparison — though era context would sharpen the verdict.