What is missing here was supplied by Dr. Dave (see snip below from TP-B26):
If you have a cue with a pivot length that does not match bridge length, you still pivot the cue around it's pivot point, but must use a combination of FHE and BHE. So for an LD shaft with the pivot at 15", the pivoting is still at the 15" point, but requires combination of FHE and BHE.
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With the bridge length at the natural pivot length of the shaft (B=N), the percentage of
BHE is 100% (P=1), with no FHE pivot.
With a bridge length shorter than the natural pivot length (B<N), the percentage of BHE
is less than 100% (P<1), and the FHE percentage completes the total pivot to 100%.
With a bridge length longer than the natural pivot length (B>N), and the percentage of
BHE is greater than 100% (P>1), with the FHE percentage being the negative of the
excess beyond 100%.
****
If you have a cue with a pivot length that does not match bridge length, you still pivot the cue around it's pivot point, but must use a combination of FHE and BHE. So for an LD shaft with the pivot at 15", the pivoting is still at the 15" point, but requires combination of FHE and BHE.
****
With the bridge length at the natural pivot length of the shaft (B=N), the percentage of
BHE is 100% (P=1), with no FHE pivot.
With a bridge length shorter than the natural pivot length (B<N), the percentage of BHE
is less than 100% (P<1), and the FHE percentage completes the total pivot to 100%.
With a bridge length longer than the natural pivot length (B>N), and the percentage of
BHE is greater than 100% (P>1), with the FHE percentage being the negative of the
excess beyond 100%.
****