Zack Greinke vs. George Hennessey — Career Comparison

Zack Greinke built a career as a starting pitcher and George Hennessey as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Zack Greinke posted stronger surface numbers — ERA 3.49 and WHIP 1.178 compared to 5.2 and 1.807 for George Hennessey. By the career numbers, Zack Greinke had the better of this cross-role comparison — though era context would sharpen the verdict.