CB edge aiming with 2 pivots

Edge of the cue ball (CB) aiming with 2 pivots

If one can aim the edge (E) of the CB (3:00 or 9:00 O’clock) at the same edge on the OB and shoot the center of the CB parallel to the E2E line, he would make a straight in (0 degree) shot.

If one can aim the edge (E) of the CB (3:00 or 9:00 O’clock) at the opposite edge on the OB and shoot the center of the CB parallel to the E2E line, he would make a 90 degree cut shot. If one aims the edge at the center of the OB, he would make a 30 degree cut.

The other points can be calculated and diagramed later – it isn’t linear for the balls are round.

What that means is that aiming the edge of the CB at different points (P) on the equator of the OB, one can make all cut angles using points on the OB for all of the cut angles exist on the equator of the OB from 0 to 90 degrees when viewed from the CB edge.

The pivots (2) from the grip and then from the bridge

The rub is that establishing an accurate parallel stick/stroke line to the CB edge to OB point line is not easy. An easy way to do the first line (CB E2OB P) is to use the stick with the grip at the normal position at the side of the hip. Let’s say that the grip to the tip of the cue is 48”

If one moves the bridge hand from the CB E to the center (C) of the CB (front hand english), he creates a small angle if the stick is pivoted at the grip hand that is not parallel. This small angle (1.34 degrees) will cause the CB to travel to the outside of the intended shot line.

What if instead, one places the tip of the cue, say for example, 3/4 tip diameter (.375”) to the outside of the CCB and pivots the stick from the bridge using the grip hand outward (BHE) until the center of the tip is aimed at CCB. This might correct for the small angular error (1.34 degrees) above. Adjust the stance for the new grip position by moving the hip/legs to the grip.

Depending on how far back the bridge hand is normally placed, say 12”, behind the CB will determine if the 3/4 tip is correct. This tip offset can be adjusted and proven by shooting straight in shots and thin 90 degree cuts.

Assumptions:
- Balls are 2.25” diameter
- Tip is ½” diameter so 3/4 tip is .375”
- Bridge is 12” behind the CB
- The grip hand is 48” behind the CB so the bridge is 36” in front of the grip hand

It’s almost geometrically correct (for the assumptions) but not parsimonious.




Where to aim the edge of the CB to points on the OB of interest (0, 30 and 90 have been discussed already)





Have fun.

Renegade_56 said:

well in that theory yes, but what about the distance between balls?

Click to expand...

This system doesn't care about the distance between CB and OB for it accomplishes the parallel shift used also in other systems like contact point to contact point (CP2CP) etc.

AtLarge,
Hi again.
Your step 3 below is what I am focused on for the "bit past center CB" will vary depending on the cut angle. The CP2CP for a 90 degree cut will require a larger "bit" than a 15 degree cut. I can calculate the fraction of the tip diameter past center for various cut angles in multiples of 15 degrees (15, 30, 45, 60 and 75) when I get to it.

It is geometry but you knew that.

"(3) pivot the tip a bit past center CB using the back hand as the pivot point (i.e., by slightly deforming or moving the bridge sideways);"
AtLarge

Thanks and be well.

AtLarge said:

Hi, LAMas. Sounds like you're doing some parallel parking again. We talked about this sort of thing 4 years ago. Here's a list of steps for double pivoting with contact-point-to-contact point aiming.

(1) identify the OB and CB contact points;
(2) get down into shooting position with the stick on the line/plane that runs through those two points;
(3) pivot the tip a bit past center CB using the back hand as the pivot point (i.e., by slightly deforming or moving the bridge sideways);
(4) pivot the tip back to center CB using the front hand as the pivot point; and
(5) shoot

You might be surprised to find how well CP-to-CP aiming can work just doing steps 1, 2, and 5 above, i.e., keeping the cue in the plane of the contact points rather than shifting it over to center CB. One might think that squirt would play havoc with that approach, but it can work well on many shots (depending on things like shot speed, degree of cue elevation, and severity of cut -- but those things don't matter much, right? ) This, of course, produces inside english on all cut shots, although the tip can then be moved from the CP-to-CP plane to produce more or less inside or even outside.

[And, of course, one can simply visualize the line or vertical plane running through the two contact points and align the cue stick through CB center, parallel to that plane or line, without initially placing the stick in the cp-to-cp plane.]

Lots of things to play with, eh?

Click to expand...

I will hijack my own thread to agree with the steps 1, 2 and 5, like CP2CP.
With this - use stick aiming on the step 1 line while standing with the bridge and grip hand on the cue.
Hold the position an bend down (both hands will move the same distance to the side) on to the shot with the tip pointed at the center of the CB. This will give a very accurate parallel shift then shoot - adjust for english if desired.

Have fun