[Mathew]

During a swinger's backstroke left arm action, the left arm rotates clockwise so that an imaginary watchface on the left wrist would face the target at address, but eventually end up facing skywards at the top of the backstroke. I can imagine the left arm rotation i) occurring gradually throughout the backstroke, or ii) there can be a start-up swivel action that causes the imaginary watchface to face the ball-target line at the end of the takeaway (or be parallel to the inclined plane), followed by a more gradual left arm rotation during the remainder of the backstroke. Does it really matter which technique is used considering that the left arm must eventually have rotated to the same degree by the top of the backstroke?

Basically the hands turn to the plane on the backstroke so if there was a book between your hands, you would show the thin side of that book to someone watching you from a side on or down the line view. They always should turn to a pure backwards direction on the backstroke.

Now as to the 'rate' of loading. I would discourage you from turning the hand too quickly from startup aka Tomasello due to the fact that by turning the hands straight away as he teaches - 'anatomically' your left hand is turning then rolling and then turning again during the backstroke due to how the shoulder turn effect as transports and changes the relationship of the power package to the plane line. Whilst it can be done, ideally you want to have it happen a little later into your turn so that it becomes a pure 'anatomical' turning motion. This is why alot of players who turn to the plane very quickly oftentimes get off and underplane.