i think there is a limit, but i dont no how u could tell....but there is one kid in my city who is like 5'6 and grade 8 and he can touch the rim from a standing jump....his standing vertical was atleast 30 inches cuz his standing reach is about 5 inches shorter than mine ( so his would be 7'1) and the rims we were playing on were about 9'8 , no less...so 7'1 and 9'8, thats 31 inches for a 8th grader, but his running vert is like barely better than his standing, there was only maybe a 2 or 3 inch difference than his standing, but still i was amazed when i saw it....but i dont think you'll ever see some1 15 or younger with a standing 40" vert...no way. maybe some could get close to it around 37-38 but thats probly cuz they have crazy genes and are the next aut or vince.

but alot of ppl can get 40 inch verts with vjb or sumthin b4 they reach 15 or 16 years...just imagine lebron starting vjb or tvp when he was a freshman in hs....

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Whaaaa?