Nolan Ryan. He was the first star pitcher in the 1970s noted for some bad records on bad teams. Despite leading the AL in stats like Ks, IP, CG, SHO, H9 (and no H9), Ryan lost 15 games a year for almost a decade. On the Angels, he was the Mike Trout of pitchers.
The Ryan season that should end this debate, however, was 1987 on a below-.500 Houston club. That's when he led the NL in ERA, Ks, FIP, H9, K9, ERA+, K/BB... but for some reason only finished 5th in Cy Young voting, with 0 1st place votes. Maybe it was his won-loss record: 8-16.