My son threw hard, hit 98. He never had TJS. Not without minor injury but no TJS. There are many who throw hard who dont have TJ. IMO, I think the damage occurs for most in HS.
Fireballers move quickly through the system. Years ago all of these young guys fireballers would still be in milb.
I just read somewhere the average player in ml is 4 years. That is an old stat, probably due to TJS and shoulder surgery it would be higher.
JMO