I and others have been offering basically the same parental advice for years as bball123 has suggested above. For some reason there is always an argument, not even discussion, just arguements from the same.
I am not involved in the game as a professional and neither are most here, but if I was seeking some good advice for my young pitcher, it would be from someone who has coached higher successful profile players or those that are in college or involved in the professional game at some capacity. That could be but not limited to MLB scouts, agents, or someone like Jerry Ford who has probably seen almost every top young pro pitcher who pitched at some point.
Those that have experienced major surgeries TJ or shoulder add good advice as to what they did (or son did), and how they would change things, with keeping in mind that all bodies develop differently and that most pitchers do not reach their peak performance and physical maturity until they are in their 20's. Some of these folks have also had face to face advice and conversations with some of the best doctors in the field of sports medicine. When a high profile doctor tells you as a player that IHO that you began the game too early, what more proof do you need to understand that maybe it wasn't all that important at 8,9 and just maybe even if everything your folks thought they were doing was right now with that scar on your elbow or shoulder and months of rehab and lost time you may have started a bit too early.
I don't give a cr ap about the scientific proof.
I would not accept explanations on what works and what doesn't from those that proclaim themselves to be self appointed professionals. In other words their scope of experience doesn't go past being a parent of a player that has not reached any level after HS, not yet secured a college commitment or scholarship and actually pitched 3-4 years minimum past HS to actually understand that no matter what, injuries will at some point strike. FWIW, all baseball players have some type of injury along the way, it's inevitable. It just is a bit more devastating for pitchers to have to take 10-12 months off for surgery for elbow or shoulder because there is always someone to take your place, no matter how good you were before. The only time you get multiple chances to prove your worth is if you have a team that has invested millions.
Pitchers that are injured are released from college programs as well as the professional ranks, every year. In this day and age, with the competition being as it is, not too many get second chances.
We brought our pitcher up on common sense. You don't have to be a rocket scientist or read major scientific publications to figure it all out. No year round bb, FB and change up development and use before cb or sliders, good mechanics, limited time on mound as a youth (bring it on when it really counts in HS) and a good amount of time away from it as well by participating in other sports (as metnied above), etc.
Son played less BB (and all positions when not pitching) than many that post here, be aware he did sustain injury, it is inevitable. Nothing major, set him back a bit. Ironically he throws HARD yet he has had less issues than RHP collegues/friends of his that throw with less intensity. Pitchers that throw hard are more suseptible to injury because they are used more often as young adults.
Even mlb teams are now taking their high velo guys and placing them in the pen when they move them up to the big leagues first year or maybe two.
Remarkable, son is still in the game.
Parents of young pitchers, please, please, do your homework, let your parental instinct (protecting your child as you would for anything else) guide you to make the right decisions.