Answered January 12th, 2020

Since 1947, Bob Gibson has the lowest ERA- with 250.0+ innings pitched in a season, with an ERA- of 38 in 1968.

best era- by a pitcher with 250 ip in a season since 1947
Interpreted as:
best era- by a pitcher with 250 or more ip in a season since 1947

See Trending MLB Searches