[Daryl]

I realise he's tracking the sweet spot. But there's a discrepancy between the sweet spot lines and the contact point with the ball on the bottom drawing. At least for the most angled clubs.

How high on the ball impact happens is a direct function of effective loft at impact. If the drawing was correct, a driver and a 64 degree wedge would have almost the same launch angle with ball back in the stance.

This is something I need to study. Thankyou for the insight.

My instincts say that the Angle of Attack is much different between the Driver and 64 degree wedge. And, more importantly, the downward degree of the Line of Compression is determined by that, which determines rebound direction and rebound force. So, although the contact points are the same, the trajectory is much different. As far as spin is concerned, although the "Ball, rolling up the face of the inclined striker doesn't account for all of the spin production" it may account for a fair amount of it when the ball is located that far back in your stance.