Adam Scott is a master at keeping his head steady and his body centered, which in turn gives him the ability to maintain his spine angle during his swing. This is what instructors call "staying in the shot," and Adam does it as well as anyone in the history of the game.
He's certainly better at it than most amateurs, who tend to slide to both sides and bob up and down throughout the swing. This excess movement negates any chance of rotating around a stable spine, which is how you get max speed. Try the drill at right to create Scott-like stability and effortless power. I learned it many years ago from Tom Watson. He called it, "The Secret to the Golf Swing." -- Lou Guzzi, Golf Magazine Top 100 Teacher