John Briggs. Had 3 really nice years in Milwaukee. It's very weird looking at his stats through the lens of today though. OPS was <.850, but OPS+ was in top 20 in BB. 21 HRs in 1971 was very good as only 34 guys hit 20+ in 1971 (130 in 2019!)
Started down the rabbit hole of 1971 and Hank Aaron at age 37 put up:
327/410/669/1079 slash line. 47 HRs. OPS+ of 194. Clearly, his best single season.