if the pivot point matches the bridge length on normal shafts and squirt and swerve are self correcting then why need an LD shaft at all?
Squirt (not swerve) is only self-correcting if you pivot right at the shaft's "natural" pivot point. Pivot anywhere else and the correction is either too much or too little.
again i am suggesting if you hit the cue ball off vertical axis ie you are putting unintentional english on the object ball
Sure, but the
aiming problem is that you're under- or over-correcting for squirt (unless your bridge is right on the shaft's pivot point).
am i thinking this thru incorrectly??
I think maybe we both did - we haven't taken into account a couple of less obvious factors:
1. The squirt angle changes more per inch of pivot length difference for higher squirt shafts.
This weighs in favor of your answer (higher squirt shafts are less forgiving).
2. Swerve (present on most shots) reduces the effect of squirt, making the "effective" pivot point of any shaft longer.
This weighs in favor of my answer (lower squirt shafts are less forgiving).
Given these I'm not sure how the analysis comes out on balance. The difference is at least smaller than I thought.
pj
chgo