After reading this article I'm more hopeful that something can be salvaged from the Arrieta, Matusz, Hunter trainwreck. These are all talented pitchers but the league has chewed them up the last 2 months. The salvage of Tillman by Peterson is pretty amazing (granted, we've seen one start). Let's hope that Peterson can do the same stuff with these guys.
The pitching motion appears to be like a golf swing. You have to master doing things in an unnatural way to get better. Don't try to kill the ball, develop some trust for the mechanics instead of your instincts. Instead of thinking of hitting the ball, think about swinging through the ball. Or in the case of pitching, throwing through the release point.
Arrieta and Hunter look like the best candidates for this type of training. They both have velocity but have control issues. Arrieta in particular seems to have lost confidence in his fast ball. I think that Arrieta has the highest ceiling if he can get things under control and gain the confidence back.
One thing I've noticed (or should I say my father noticed) is that Matusz has been trying to over throw on his pitches to squeeze out a few more mph's. I'm not sure what input is driving him to over throw but he needs to go back and look at what kind of a pitcher he really is. He's a junk ball pitcher. He's never going to have the velocity that is the hallmark today. He needs to work on an array of pitches that can break over the corners or drop. I'm not sure how much the bio-mechanical stuff is going to help him. He needs to accept his identity. He may just be a bullpen guy unless he can develop some sort of Greg Maddox type of mastery over his pitches.
Regardless, cheers to Peterson for his good work.