After his first 6 yrs, Koufax was untouchable...Ryan never had an era over 4 until he was 46 yrs old---he led the league in 1987 with an era of 2.76 and his record was 8-16...can you spell frustration....
check out 1981---era of 1.69 and he was 11-5--gave up 2 hr's and 28 runs in 21 games started...
Nolan suffered from two things, one was with all the k's, the fielders tended to fall asleep behind him. Lots of errors didn't help him, and he played for a lot of mediocre teams.