The front elbow.
What does -- and doesn't -- it do during a high-level swing?
That's a question I touched on in my Rotational Hitting 101 DVD, particularly when I talked about the Running Start.
However, I didn't spend that much time talking about it because, in my experience, most hitters move pretty well, naturally.
Then my younger son naturally developed an inefficiency.
Then, and more importantly, I started talking to the hitters at HSSU and came to realize how much -- and how badly -- they had been taught about the front elbow.
As a result, I've put together this piece that draws upon an understanding I first started to develop during some conversations with Josh Donaldson that resulted from my working with Mark Trumbo and my efforts to help him.