Over the last 40 seasons, only two Cleveland rookies have started at least 15 games while posting an ERA under 3.50: Cody Anderson in 2015 and T.J. House in 2014.
It’s odd that such a list would feature such irrelevant players, as neither had much hype as prospects or did much beyond their rookie years.
Here’s a few others who accomplished the feat, dating back to 1955 (it was slightly more common before then):
1975 – Dennis Eckersley
1972 – Dick Tidrow
1964 – Luis Tiant
1958 – Gary Bell
1955 – Herb Score