David Aardsma vs. Tom Knowlson — Career Comparison

Tom Knowlson built a career as a starting pitcher and David Aardsma as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Tom Knowlson posted stronger surface numbers — ERA 3.49 and WHIP 1.579 compared to 4.27 and 1.487 for David Aardsma. By the career numbers, Tom Knowlson had the better of this cross-role comparison — though era context would sharpen the verdict.