Yoda's Ground School Yellow Paper (Hit the DIRT!!!!)

[hcw]

We're talking about a Clubhead Orbit with a Radius (Left Arm and Club) of about five feet (and a Diameter of twice that). How much "down" is left in such a Stroke as the Clubhead bottoms out at Impact? If the Ball is located precisely at Low Point, the answer is 'none,' and the Impact and Low Point Plane Lines combine as one. And even if the Ball is positioned prior to Low Point, i.e., Up Plane, the answer is 'not much.' But, just as there is a tide in your morning coffee, it's there, and if you don't go all the way down, the Ball will tell you about it.

Regarding the Sweetspot Plane Line...

By definition in 2-F, both the Impact Plane Line and Low Point Plane Line are Sweetspot Plane Lines. It is the Sweetspot -- the Club's Longitudinal Center of Gravity -- that is orbiting On Plane (and hence 'On Line') through Impact and Low Point.

hmmm...maybe what i am thinking about is impact, separation, and lowpoint plane lines?

-hcw