Michelle Dube explains the 'Pump Drill' or sometimes referred to as the '6/100th drill' (the position where most pros are 6/100th's of a second before impact.
Note, that I believe in 'D Plane' and that Dube's assertion that the path causes the initial ball flight is wrong. Instead, the *clubface angle* causes the initial ball flight direction (or about 70-90% of the cause) and the path causes the 'curve' of the ball. I was talking about this with a friend of mine and we started discussing 'D Plane' and other sports.
I initially brought up tennis and when tennis players hit the second top hand serve that 'hooks' and gets overspin. I believe the curvature is due to the 'path' of the tennis racket, not a 'closed' angle of the racket. My friend brought up bowling, with the bowler swiveling his wrist. And then I brought up baseball and the batter who gets the top hand turning over too much and starts hitting 'low hooks.'
The problem with golf is that we're always learning and often times we found out what we used to think was wrong. It appears that way with 'D Plane', but whose to say that we won't have some new person come along and figure out that 'D Plane' isn't exactly true either?
So for now I have confidence in 'D Plane', but I'm keeping my eye out for any new information in regards to the subject.
Lastly, I think this is a better drill for 'swingers' than 'hitters', but both can give it a whirl.