It's not really possible to give an accurate measurement of the average fastball during the years when Babe Ruth was playing baseball, which was from 1914 to 1935. read more
I have no idea what the average speed of a fastball was during the Babe Ruth era. The only thing I know is anecdotal information like the following. Bob Feller, who came up in 1936, was measured with a speed gun in 1946 at 98.6 mph. read more