If you look at photographs of good players at impact, you’ll notice their upper bodies are tilted behind the ball. This is especially true when they’re hitting TaylorMade SLDR Driver. They’re using their body weight to put more power into the shot. This notion of staying behind the ball is an important one, but you have to do it correctly.
Many amateurs misinterpret it. Instead of shifting their weight to their front foot as they start down, they favor their back foot in an effort to stay behind the ball. Their weight moves in the wrong direction. You want your spine to stay back, but your lower body should move toward the target.
As you start the downswing, shift your hips to the left. You’ll feel your weight transfer to your front foot. Then rotate your upper body around your front leg as if it were a post. This is the proper way to stay behind the ball. Do it right, and you’ll add some nice pop to your tee shots.
If you’re struggling to hit the TaylorMade R11S Driver solid, shorten things up for a while. Make half swings where your left arm gets no higher than parallel to the ground on the backswing and your right arm gets no higher than parallel on the follow-through (right). When you start consistently making center-face contact, you can go back to the full motion.
Source from: http://www.onlineaustraliagolf.com/article-44-Stay-behind-the-ball-but-do-it-the-right-way.html