[BerntR]

Busy week guys and may not be able to come back, but . .

Perfectly executed . . .

Both Vertical and Horizontal Action produce Backspin. This is what gets the ball in the air.

Neither produce a 'side spin'.

Yoda,

In the big scheme of things it's the loft of the club that gets the ball airborne and produces the back spin, not the hinge action. And it is basically the difference between plane line and club face orientation that creates the side spin. I was taking those major spin contributors out of the equation to amplify the differences between the two hinge actions. The hinge action creates a little spin too.

Perfect compression means that the center of contact point between the ball and the club face remains the same through the impact interval. Which means that the ball adopts how the clubface rotates.

With a horizontal hinge the club and the ball rotates horizontally. The closing without layback. This is easy to see in 2-c-1 #2a, #2B, #3, the "swingers hinging". With a vertical hinge the club and the ball rotates vertically. Layback without closing. And that is illustrated in 2-c-2.

The axis of the hinge rotation is imposed on the ball. You can't have perfect ball compression otherwise.

I know you know this so perhaps I wasn't clear enough in my post above.