[Yoda]

I can not disagree with anything above that you have mentioned. Excellently stated and quite clear as I sift through my book (which is already coming apart).

My concern is, why should the impact plane line be a chord of the circle and not tangent to the circle and any chord that connects impact and low point is not parallel to a tangent of the circle from the same low point. This is true by definition of what a chord is.

I define low point plane line as the line tangent to the point where low point occurs. I would also define the impact plane line using the same definition (a line tangent to the point where impact occurs).

Why would one plane line have a different definition than the other?

Clearly you can see that at no point is any chord parallel to the low point plane line. When (P) and (Q) are the same point then it becomes a tagent.

Can I move point (P) and make a parallel chord? Sure.

But why would I?

What would be the reason to justify that?

Because, except during a Low Point Impact, the Ball does not leave the Circle on an Impact Tangent (a line perpendicular to the radius and necessarily to the right of Target when the Ball is Up Plane from Low Point). Instead, because of the Golf Club's design (Hooked Face) it leaves the Circle on an Impact Chord (Impact Plane Line pointing toward the Target).