Abstract
The differences in velocity of fastballs thrown by 14 college pitchers with and without known presence of a “scout” (the experimenter) with speedgun was investigated. Each pitcher threw 40 fastballs in a game situation. The first 20 were measured with the pitchers seeing the experimenter measuring their velocity with a speed gun. The next 20 were measured without the pitchers seeing the speedgun or the experimenter. Analysis shows that with known presence of scout and speedgun, the average fastball among the 14 pitchers was clocked at 75.6 mph. Without known presence, the speed for the same 14 pitchers was measured at 79 mph. This finding questions the validity of a scout's or coach's measurements of a pitcher's true throwing velocity.