[EdZ]

I believe that Dr. Jorgensen's work would disagree that hinge action, whether horizontal, angled, or vertical, could have any effect on ballflight with regard to how the face is behaving during the "impact interval' (time the ball is in contact with the face of the club). I don't believe he would agree with the notion that the face is 3 degrees more open at impact than it is at seperation, either; impact doesn't last long enough and the face doesn't rotate fast enough for that to be possible. This is just from what I understand of his research.

Perhaps, but the idea isn't so much the directional influences of the impact interval face angle per se, but the efficient transfer of energy (and that transfers impact on ball flight) per chapter 2 force vectors discussion.

The line of compression being a straight line.