This story is for you if...
• You don't know how far back to swing your driver.\n• Your tee shots are often shorter than you desire.\n• You don't feel confident at the top of your swing.
Place a towel on the ground and kneel on it with your driver in hand. Choke down a few inches on the grip, sole the clubhead like you do in your normal address and swing back. When you can't go back anymore, hold this position. That's your natural backswing you shouldn't swing back any farther in your real swing.
Why It Works
When you swing from this position, your knees can't collapse (the move that allows you to take the club back farther than you should). Instead, your backswing is limited to how far you can turn your upper body against your hips the true barometer of swing length. If you take the club back too far, you won't be balanced at the top, which makes it impossible to make a powerful swing. Stick to your natural backswing length and you'll start hitting the ball longer (and straighter) immediately.