I spent the summer with our high school coach's radar gun to some pretty high powered events. One observation is most people give the TOP speed a kid throws when answering the question of "how hard do they throw." It really varies. I've seen many times a kid hits 90 a few times in his first inning of work, and then never hits it again. Or... he goes into the stretch and drops 4 mph - and that is pretty common. What I would look at is what speed does he hit most often. In our neck of the woods, cold damp weather, mid-80's on a consistant basis is pretty dang hard. When it gets warmer, the numbers tend up some. We are at a large high school and lefties who hit 80 consistently are a rare bird. The two on our staff last year, and they did very well threw 74-76. Stud hitters can't hit 59 mph curve balls coming from a lefty either.