But as with all great swings, we still strive to make it better. The big key for Luke, and he'll tell you the same thing, is that he needs to work harder on stabilizing his lower body on the downswing. It starts with having too much knee flex at address, although he looks good in these photos. We constantly check for that. But also on the way down, he sometimes drives too hard with his lower body. When he does that, the club shallows out, the face gets closed and the ball flight is left to left. It's a tendency he's had since he was a kid, and we all know that your swing tendencies, good and bad, never really go away.
What I'd like to see from Luke is a taller posture at address. I'd also like to see him rotate the clubface open as he takes it to the top of the backswing. Finally, he needs to do a better job of keeping his lower body quiet as he swings down. If he manages all three, he hits a nice, high shot and is as accurate as anyone in the game.
What I really like about Luke's swing, and this is something I try to get amateurs to copy, is that he makes a downward strike with his arms into the ball. You can see in this swing sequence that he really compresses the ball at impact. The feeling I'm trying to teach, that Luke does so well, is that the body should feel like it's swinging on an upslope, but the arms should feel like they're swinging down a slope. To help teach this, I built a mat where players hit balls with their feet on an upslope and the ball on a downslope.
Pat Goss, the men's golf coach at Northwestern University, has been Donald's swing coach since Donald came to the U.S. from England in 1997. He evaluates Donald's swing: