[EdZ]

Ed . . . why do you think there is more accuracy inherent in the TSP? Not sure I'm ready to buy in . . . interested to hear your rationale.

The steeper the plane, the less potential sidespin (within the limits of the clubs designed lie angle).

In an ideal application for accuracy (not a human, but a mechanical machine), the plane would be verticle, with exactly the right alignments (ball at proper low point etc).

Of course that assumes a club designed differently (a 90 degree lie angle).

In an ideal application for power, the plane would be horizontal, with exactly the right alignments for ball position. (for those being picky, I suppose you would have to account for gravity's downward pull)

If you hold a club out in front of you, arms straight out in front of the chest and make a baseball swing, you have a more rotational motion, more potential power, but less potential accuracy (less margin for error in ball position and clubface alignment). Lots of #3, very little #2.

If you do the same thing, but swing up/down like an axe, you'd have great potential for accuracy, but power variation might be more difficult (less margin for error in angle of attack/spin). Lots of #2, but little #3.

Mechanically speaking, the best plane angle would be 45 degrees for all shots - to give the most margin for error in power and accuracy.

Of course all of the above must consider the human machine, and the club's design.