I just started playing golf last spring, and my swing has gone through some major changes. I started off duck hooking everything, then got to where I was hitting pretty well, and then got to the point where most of my iron shots were straight pushes - especially shorter irons - and my driver consistently had a wicked slice that started straight. My 4W goes straight as an arrow provided I hit it clean. I still average 3++ putts/hole, so that accounts for a lot of the (made-up) handicap!
So I was thinking and started looking into "D-Plane", and I might have found some solutions to my issues... if the swing is an inclined arc, and if the clubface stays square to the arc, then at the bottom of the arc the clubface is square to the target line, assuming you set up square. The bottom of the arc ought to fall somewhere just forward of center of your stance I reckon because of the lateral movement forward during the swing.
So assuming you set up completely square to the target (where the target line would be tangent to the bottom of the arc)...
You're supposed to hit the ball first with your irons (ball in middle of stance), so the club is on the way down, and should be traveling in to out along the arc, with the clubface slightly open at impact (but square to path). ...and so I hit a push. And with shorter clubs like wedges the arc is shorter and the push is more pronounced. Makes sense.
You sweep with the fairway woods, which to me means you put the ball at the bottom of the arc. Path and face are square; ball flies straight.
Driver was the toughest thing to figure out; you put the ball way forward in your stance, in front of the bottom of the arc and hit the ball on the way up, which means the club must be coming out to in. If you manage to hold the face square to the line, you still hit a slice. I don't know how you shift the arc so far forward that it's traveling square AND up into the ball without changing your stance.
So now I'm experimenting with different address positions and I'm having some success (two days in a row, so we'll see...). When driving, I'm setting up several degrees closed (not just moving my rear foot back, but rotating my stance as if I'm hitting an imaginary ball in the middle of my stance that's behind and inside the actual ball), so the target line is tangent to the impact point on the arc, as opposed to being tangent to the bottom of the arc. The drives immediately started going straight and far, one after the other. That's right... aiming right cured my slice (for now). Counterintuitive. Makes the finish position slightly awkward - got to work through that.
My iron shots were going straight, but were just pushed right. So I set up slightly open and they go where I want.
I post all this because it feels like a breakthrough, but I was curious to get others' input here. I don't want to mask swing faults, but I do want to find a swing that makes sense mechanically.
As an aside, this site has lots of info on it. I'm not sure if they ripped off a book(s) or what with the graphics, but I found it helpful. Still reading through it...