I just turned 15. I have not had any instruction or injury, except for a winter class last year that taught improper mechanics, and had me immediately throwing 120 feet; this lead to inflammation and I went to a couple weeks of PT, as a precaution. My height is 5 foot 10, and I am done growing. I am going of natural strength, and can throw low 70s with accuracy and movement. Here are my mechanics:
I am wiling to put in full effort, as long as I am not wasting time. I started working out once a little over a year ago, and had visible results (by others saying) within a couple weeks; less than a month. I ended up quitting, as I was busy and just never got back to it. I currently can regularly throw 150ish game pitches, and have my arm feel fine. As of family, my father played, and quit around my age, although was able to throw close to 90s being four inches shorter than me.