Jeff Passan's in depth look at the history of pitching, Tommy John surgery, the way youth sports is destroying kid's elbows now, and also a lot of insight into how major league times are trying to keep arms healthy, along with a very in depth look into the Cubs-Lester negotiations. I have no idea how or why but it's for sale right now on Amazon for $1.99 (for the kindle edition at least). I have no idea why it's on such an insane deal but buy it. It's really good.