average fastball velocity
10 Years Old and Younger. The average fastball velocity for pitchers 10 years old and younger is between 40-50 mph. The average change up speed for this age group is about 10 mph slower, putting the velocity between 30-40 mph. 11 and 12 Year Olds. Pitchers in this age group are playing in the Majors division in Little League. The average fastball is between 50-60 mph. However, at this age the players may start to hit puberty, therefore it is not uncommon to see a pitcher throwing near 70 mph. The changeup velocity at this age is typically between 40-50 mph.