Thank you tongzilla and Peter Croker for your valueable answer.
I really want to hear the answer from Mathew , ChrstNZ , 12 piece bucket and others too.
I think if you want to go any deeper than the 3 Imperatives . . . then 1-L is where you want to look.
This sums it up for me in a nutshell . . .
1-L #10 THE LEVER ASSEMBLY MUST BE DRIVEN THROUGH IMPACT BY AN ON PLANE FORCE (MOVING TOWARD THE PLANE LINE).
To me that is the ultimate rule that the "uncompensated" stroke would need to comply with . . . which of course leaves many options as I think Mr. K would like.