Mark Mercer vs. Fernando Valenzuela — Career Comparison

Fernando Valenzuela built a career as a starting pitcher and Mark Mercer as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Fernando Valenzuela posted stronger surface numbers — ERA 3.54 and WHIP 1.343 compared to 4.7 and 1.826 for Mark Mercer. By the career numbers, Fernando Valenzuela had the better of this cross-role comparison — though era context would sharpen the verdict.