When I started to use english, decades ago, I used rote to effect the amount that I desired using fractions of the ferrule away from the center of the CB. Small fractions to whole and more offsets for more english.
I was, even then, a double distance (DD) aim shooter that started the aim at the center of the CB to the double distance location/spot. Then, I would shift the ferrule to the desired fractions using front hand english (FHE). Using a stiff heavy house cue, small offset fractions were often negated by squirt and the CB would hit the OB in the wrong place - not the double distance location desired to send the OB to the target.
Using FHE The angle of the cue was no longer parallel to the line from the center of the CB to the DD, but had created an angle away with the axis at my stroking hand. This compensated for the squirt to some small degree when the CB and OB were a couple of feet away from each other.
When the CB and OB were, say, 4 feet apart or more, I noticed that swirve would take the CB further to the outside of the OB and closer to the desired DD location.
Later I observed that using back hand english (BHE), I coulld increase the attack angle because the axis of the shift was now at my bridge hand. I would adjust my stance to accomodate BHE. Using the same ferrule fraction offsets and increased angle I could compensate for squirt where the CB separation to the OB was, say, a couple of feet apart - before swerve would occur to help to hit the DD location.
After awhile, I could walk into the shot with the ferrule offsets in place with my bridge as long as I started with the DD aim stance.
If my DD stance was correctly positioned, I could even move my bridge had slightly to effect english or even swipe the CB or swoop my stroke hand closer or farther away from my hip during the stroke before impact to swipe the CB to effect english.
With practice (many hours), I incorported these tools into my skill sets for recall - by rote - both tips of english and stroke.
It's all good.:wink::thumbup:
Also having an understanding of the geometry of the angles (path of the CB to the OB) required in cutting OB to the target is the begining of aiming - be it ghost ball (GB) or DD. From that fundamental knowledge, one can apply outside english to reduce/negate the effects cut induced throw (CIT) to achieve the true geometric cut angle - rather than undercutting the shot with center CB hit (no english).
Well now the Cabernet has been kicking in and I will kill this rant.:thumbup:
Thanks for the thread and all of the informative posts within.