I don't know the cutoff date, but I know you can't sign until you're actually 16. There's been kind of a second signing period, where lots of guys sign in November. My guess is lots of these guys have later birthdays. And yeah, you can definitely gain velo at his age, my main concern, rightly or wrongly, is the height. Of course, he could still grow too, for all we know. Admittedly, I've fallen into the trap of only wanting taller pitchers, unless they throw serious heat. And I know I shouldn't look at it that way.