Sometimes, I wish the radar guns would be put away. To say a guy will go from 80 to 90 is incredible. A pitcher can add some speed by improving his pitching form, arm strength, etc...but 10 miles. Location, ball movement, change of speed, good breaking ball, change up can be very effective. A good fast ball for a high school pitcher is 85 (consistently). Remember, Greg Maddux very seldom hits 85 and he has been one of the best pitchers for yrs.