BOF,
Got a job for you when you are ready!
Listen folks, dont get offended, but measuring velocity of young pitchers really doesnt mean all that much, yet. As your pitcher grows his arm and strength will as well.
Then all of a sudden it stops.
Next time you are watching a college game or a ML game take a look at the pitchers lower body, thats where the power comes from. It takes years before the mechanics and the conditioning come together. Some players, like bacdor's son are blessed with what is called, pitchers frames. He is doing what we did, let the body grow and develop before the real work begins. He is projectible. He will be at his peak development probably at 23, 24. Thats like 8 years from now.
So creating a " reference point" before HS is useless, all bodies are different, its all in the genes, puberty, years of hard work, the perfect mechanics.
JMO