When you've been using a rotational swing with a big shoulder turn, some habits are hard to break. I suspected that was Art's problem when he said he was having problems getting rid of 'the consistent tendency to swing outside/in from the top of my backswing …' Here's my solution.
Art,
The #1 cause of swinging outside-in is too much shoulder turn in the backswing, where the arms and club are swung behind the toe line, into the “Sacred Burial Ground” (everything behind the toe line in the backswing and forward upswing), and the club is likely laid off. The issue here is that most golfers want to hit a relatively straight shot. To hit it straight, the physics of impact dictates 3 things have to happen. 1. the club has to approach the ball on the aiming line; 2. the club has to be on the aiming line and square (clubface perpendicular) to it at the moment of impact; 3. the club has to leave on the aiming line. This is what I call on-on-and-on.
This on-on-and-on issue means the club has to be on the aiming line for around 3 inches approaching impact and after impact. The problem is that, whether a golfer consciously knows the on-on-and-on physics or not, the body knows it from trial and error. The mind and body know that the only way to hit a straight shot is that the arms and club have to get pulled up and in front of the body to approach the ball, swinging toward the target.
The problem most golfers who make the big shoulder turn is that the arms and club get behind the torso and can't be swung straight down to the ball. The body is in the way. And, even if you could, the ball would be hit straight right, because your path from behind the body, straight down and through, is to the right.
So, the answer to trying to hit it straight from behind the body is that the arms and club are swung up and around the torso to get in front of the body and be able to approach the ball on the aiming line. Unfortunately, this usually requires the torso to turn to the left to help pull the arms and club up. Pulling to the left throws the arms and club up and out to the right, and the club is pulled down to the left, following the left side turning to the left. The result? An outside-in swing. (Note: most golfers will hit the push and slice, but if they release at impact, pulls and hooks can also be hit with the Out to in swing.)
The answer is the PPGS “70 degree Limited Turn Backswing.' You turn your shoulders only to where your left arm gets over the toe line. There is no more turning of the shoulders, just lifting the club up to a 3/4 length to finish the backswing. I describe the PPGS backswing as “a little bit of turn and a lot of lift.”
The second major cause of the outside-in path to impact is swinging to parallel or more. Usually this swing is directly connected and part of too much shoulder turn and getting the arms and club deep into the “Sacred Burial Ground.”. So, as I said above, the answer is to work on the PPGS 3/4 length/Limited Turn/Vertical Backswing, with the left arm over the toe line and the club straight up so it can then come straight down, approaching on the aiming line.
The Surge!