Sergio does this, and it seems to me that the only way to comensate is to rotate body hard through impact. The only success I have had is to get the player to feel very open with shoulders at impact(30 deg or more). That move is very hard to change in a player that is at the level that you are talking about.
Do the Right Forearm Angle of Approach dowel Drill, which I'm sure you know a lot about already. Set up at Fix with the dowels, then just bring the dowel straight up and down, making sure the dowel stays on the same plane throughout. This can only be achieved if the Right Wrist stays Level, its amount of Bend remains constant, and the Hands stay on the same plane. Get your players to feel the Right Forearm going towards that Angle of Approach with a straight line effort. A very simply motion: straight up and straight down.
I know the above produces a Zero Shift, which is not what you're looking for. But trust me, you must exaggerate what is correct to make changes.
Another drill:
Stick a dowel into the ground at the desired Elbow Plane Angle (or even Turned Shoulder Plane angle for the purpose of this drill). Get an impact bag and have your player going from Release to Impact using the plane angle you've just set. You have the option of setting it up so that if the player goes under plane, his club/dowel will hit the dowel beneth. If you're not around to coach, he can use a mirror. Make sure everthing is On Plane. Once the player has a describable sensation of the Elbow plane from Release to Impact, do the same drill but start from the Top rather than Release.
Hybrid Mode
