You wrote-: "Look at this from this perspective: the lead forearm clockwise turn in the backswing makes the hosel cover the sweetspot and it remains this way until the anticlockwise forearm rotation happens in the downswing. If the clubhead rotates around the shaft/hosel it would mean that both the hosel as well as the sweetspot goes out of plane together with forearm rotation back."
You do not understand my viewpoint. I have never stated that the clubhead rotates around the hosel. I have repeatedly stated that there is no rotation around the Z axis (between PP#3 and the sweetspot) and therefore the clubhead sweetspot cannot rotate around the hosel (or vica versa). I have also repeatedly stated that that the clubface sweetspot and hosel have a fixed relationship with the back of the flat left wrist/hand and that they both rotate to exactly the same degree as the left hand. I have also previously stated that the sweetspot is on an extension from the end of the clubshaft (= clubhead) that is fixedly at roughly a 90 degree angle relative to the clubshaft. The fact that the extension is at roughly a right angle to the clubshaft means that it will change its position when the left hand rotates, and it will move from one plane to another plane even if the clubshaft remains on the same plane. During that movement from one plane to another plane, the sweetspot is not rotating around the clubshaft - because there is no rotation around the Z axis.
So, consider again this photo series of Yoda Luke' swing.
Image 1
At address, the clubshaft is on the elbow plane. The sweetspot in on sweetspot plane 2. The back of the left hand faces the target.
Image 2
Note what has happened to the left hand - it has rotated about 135 degrees from its address position (due to internal rotation of the left humerus and a small amount of left forearm pronation) and it it lies on the clubshaft plane at the end of an abbreviated backswing and the back of the flat left wrist/hand is parallel to the clubshaft plane, and also on the clubshaft plane. The clubshaft's hosel and clubface sweetspot have no choice - they also have to undergo that 135 degrees of rotation in unity with the back of the flat left wrist/hand. Because the hosel is in a straight line relationship with the clubshaft it doesn't shift planes during the backswing, so it remains on the elbow plane with the clubshaft. However, the sweetspot is on an extension that is a roughly at a 90 degree angle to the clubshaft. Therefore, the sweetspot rotates from sweetspot plane 2 (at address) to the clubshaft plane (by the end of the abbreviated backswing). When doing so, the sweetspot didn't rotate around the hosel - because there was no rotation around the Z axis. The sweetspot merely shifted positions from one plane to another plane because the flat left wrist/hand rotated about 135 degrees.
When the flat left wrist/hand is on the inclined plane (whatever the steepness of the inclined plane) at any time point between the top of the backswing and the third parallel, then the clubshaft and clubface must also be on that same plane. If the clubface sweetspot was on any other plane, then the clubshaft is off-plane.
From Yodas Luke's end-backswing position, the downswing should be a mirror image reversal of the backswing process. The biomechanical events causing the movement of the left hand from its end-backswing position to its impact position are the reverse of the backswing movement - they are external rotation of the left humerus and a small amount of left forearm supination. During this process the flat left wrist/hand undergoes a 135 degree rotation so that the back of the FLW/hand faces the target at impact. The clubshaft and clubface sweetspot must also undergo this rotation without there being any rotation about the Z axis. In this process, if the left hand is on the elbow plane at a point near the delivery position (because it was simply coming down the same inclined plane) and it is on the elbow plane at impact, then there was no plane shift when the clubshaft moved from the delivery position to impact. Therefore, the hosel will remain on that elbow plane during the release swivel phase. However, the clubface sweetspot has to rotate back to sweetspot plane 2 during its 135 degrees of rotation because the clubhead extension has a fixed near-right angle relationship to the end of the clubshaft. When the clubface sweetspot rotates from the elbow plane to sweetspot plane 2 during the release swivel phase of the downswing, it doesn't rotate around the hosel - because the sweetspot, hosel and left hand are all rotating at the same rpm.
You regard photo 2 as misleading because you thought that the hosel and sweetspot should be on the higher plane. Why did you think that it should happen if the flat left wrist/hand stayed on the lower plane? If the hosel and sweetspot were on the higher plane, then that would represent an off-plane motion of the clubshaft. Yodas Luke was not shifting planes during his backswing, so why should his clubshaft hosel and sweetspot shift planes?
Threaded Mode
