William Brennan vs. Bobby Castillo — Career Comparison

William Brennan built a career as a starting pitcher and Bobby Castillo as a reliever — different jobs with different demands — but on the metrics that apply to both, a comparison is still worth making. Bobby Castillo posted stronger surface numbers — ERA 3.94 and WHIP 1.431 compared to 5.18 and 1.849 for William Brennan. By the career numbers, Bobby Castillo had the better of this cross-role comparison — though era context would sharpen the verdict.