A good pitching drill that I have our pitchers do is called the wall drill. We have our kids line up about a foot or so from a wall with their body perpendicular and their throwing arm closest to the wall. We make them deliver the ball to a catcher 40 or so feet away. The intent of the drill is to make sure that the pitcher isn’t getting long in the back. If he is, then he will hit the wall with his throwing arm. Some coaches think that the use of this drill makes the kid short arm the ball, but our kids have full extension towards the ground, not straight back.