re: "but i figure if your at college level already the most they can do is hurt. i do think there important though in little league"
-------It's not at all that simple, JJ. Pitchers don't learn their craft by the time they are finished with LL, and then stop learning. They don't develop a set of mechanics at 12 yo that is then set in stone.
Athletes refine their mechanics more and more carefully, and do quality reps more and more--not less--as they advance in their sport.
Elite pitchers who develop problems with their mechanics, either from injury or any other reason, study the checkpoints in their delivery when they were going good and they use elite coaches to help them regain the mechanical form that helped make them good.
Dedication to improvement, refinement of mechanics, and correction of flaws, are never-ending processes for any athlete who is continuing to advance--don't kid yourself about the value of checkpoints. Used well, checkpoints are a part of every good athletes life.
You are probably skeptical because you've seen a lot of misuse of checkpoints during the training of Little League kids. The idea is not to make an athlete robotic, with a jerky motion. The idea is to optimize mechanics by isolating and correcting flaws or inefficiencies.