champ -- this post from Spidey may help as well: http://forums.azbilliards.com/showpost.php?p=2833281&postcount=200
Proofs of the EXACTNESS of Pivot Systems
- Thread starter jsp
- Start date
LAMas, not sure why you want them, but here are sample values.What are the cut angles +/- X degrees achieved by the secondary aim points A, B, or C and 1/8 with pivot in and pivot out?
The first number is the CB-OB separation, which is followed by the pivot distance behind a plane perpendicular to the cue and passing through the center of the cueball. For the 18" separation, I assumed a pivot length of 7.5" from the tip, for the 36" and 72" separations, 8.5". Add to these 1.125" for ball radius, and another arbitrary 1/4" gap to avoid the cueball foul after pivoting, to get 8.875" and 9.875".
E-A stands for edge to A, E-C for edge to center, and 8-8 for 1/8 ball to 1/8 ball (per Stan's meaning). OP stands for outside offset (1/4"), and IP for inside offset (1/4"). The two cut angles generated by them follow, respectively. "---" means a whiff of the object ball, while a negative value indicates a cut in the opposite direction (right cut instead of left).
I assumed the cue's pre-pivot direction is parallel to the secondary alignment line (edge to A, for instance). This may not be in accord with the Pro One prescription:
18" - 8.875" E-A OP/IP: 1.4/28.4
18" - 8.875" E-C OP/IP: 16.0/46.4
18" - 8.875" 8-8 OP/IP: 31.7/76.9
36" - 9.875" E-A OP/IP: -8.9/40.9
36" - 9.875" E-C OP/IP: 5.5/64.8
36" - 9.875" 8-8 OP/IP: 20.2/---
72" - 9.875" E-A OP/IP:-34.0/---
72" - 9.875" E-C OP/IP:-18.0/---
72" - 9.875" 8-8 OP/IP: -3.4/---
Jim
Last edited:
Hi,
I like Champ2107 sunburst diagram and find it a usefull tool. I see cut angles and can recall where to aim - like a look up table in a processor. This relation exists for those that can visualize this way.
I reverse engineered starting with the line from the GB to the center of the CB, then shifted the cue 1/2 tip (.25") to the side (not both for now), and studied what happens when one shifts from the edge of the CB to point 1/8 OB, to the left to 1/4 (C) and 1/2 (B).
I was using my left eye to aim the edge of the CB at these points. As I moved from point to point, my eyes, head and body was moving to the right in small increments. I am not at the development where I can see to converging aim lines; rather, my right eye was being taken away from the original CTE line.
When I was at each locations above, I brought the cue up and placed my bridge and cue offset by 1/2 tip to the side of the center of the CB with the cue between my eyes and under the center of my chin.
The cue is shown with the wide line in the 1/2 tip offset pre-pivot.
I shoot the 30 degree cut angle using the initial CTE line without offsetting the cue or pivoting. I didn't show the straight in shot either.
I like Champ2107 sunburst diagram and find it a usefull tool. I see cut angles and can recall where to aim - like a look up table in a processor. This relation exists for those that can visualize this way.
I reverse engineered starting with the line from the GB to the center of the CB, then shifted the cue 1/2 tip (.25") to the side (not both for now), and studied what happens when one shifts from the edge of the CB to point 1/8 OB, to the left to 1/4 (C) and 1/2 (B).
I was using my left eye to aim the edge of the CB at these points. As I moved from point to point, my eyes, head and body was moving to the right in small increments. I am not at the development where I can see to converging aim lines; rather, my right eye was being taken away from the original CTE line.
When I was at each locations above, I brought the cue up and placed my bridge and cue offset by 1/2 tip to the side of the center of the CB with the cue between my eyes and under the center of my chin.
The cue is shown with the wide line in the 1/2 tip offset pre-pivot.
I shoot the 30 degree cut angle using the initial CTE line without offsetting the cue or pivoting. I didn't show the straight in shot either.
Last edited:
If I am reading this correctly.......This shows why it seems pointless to me why anyone would even try and show "exactness" of CTE.
How on earth is a player going to consistently measure out 9.875....assuming that is actually the correct pivot point....are players marking thier cue????
Then we throw in the "air pivot" on top of that.
It just seems pointless to try and break down the preciseness......
There are so many ackronyms and terms being made up over this it seems to me like it is getting to be over complicated.
What happened to the simple method of Point here pivot and fire???
Jim,
Thanks for the calculations. It's interesting that the bridge distance behind the CB is within an inch of each other.
The pivot right and pivot left from the same edge of CB to aim point on the OB results in very unrelated cut angles...this is hard for me to digest...I can't get the whiff.
At the table, I was finding that for me some of the pivoting resulted in the same cut angle achieved by another aim point and pivot...negating it's utility for me.
At 18", the cut angles are 1.4, 16.0 28.4, 31.7 and 76.9. The 28.4 and 31.7 are very close to each other and the 76.9 leaves a large gap between it and the 31.7.
Thanks..:thumbup:
So you put the stick beside the line from the center of your chin to the center of the CB? Seems like that line (and therefore your stick) should be parallel to the edge-to-aimpoint line, but it doesn't look like that in your drawings.
Do the drawings show what actually happened at the table?
pj
chgo
:thumbup:
What I wrote:
"When I was at each locations above, I brought the cue up and placed my bridge and cue offset by 1/2 tip to the side of the center of the CB with the cue between my eyes and under the center of my chin."
After I pivoted, I was more in line/parallel with the edge of the CB to the aimpoint line. I have been thinking that I should try to forget about the 1/2 tip offset and just get down parallel to the edge-to-aimpoint line with the cue at the center of the CB without pivot...would that be the "air pivot"?
Thanks.:thumbup:
What I wrote:
"When I was at each locations above, I brought the cue up and placed my bridge and cue offset by 1/2 tip to the side of the center of the CB with the cue between my eyes and under the center of my chin."
After I pivoted, I was more in line/parallel with the edge of the CB to the aimpoint line. I have been thinking that I should try to forget about the 1/2 tip offset and just get down parallel to the edge-to-aimpoint line with the cue at the center of the CB without pivot...would that be the "air pivot"?
Thanks.:thumbup:
You're welcome, LAMas. The bridge distances were chosen to be about what Stan recommends, although I probably should have used 9" instead of 8.5" for the 72" separation. In other words, they were imposed, not calculated as in the earlier graph.
Yes, it doesn't provide any useful information as far as I can see. The figures show that the difference in cut angle in going from outside pivot to inside pivot grows with distance, but we could have predicted that without them.The pivot right and pivot left from the same edge of CB to aim point on the OB results in very unrelated cut angles...this is hard for me to digest...I can't get the whiff.
The problem could be worked in reverse, generating a table of CB-OB separations that produce a uniform gradation of cut angles. But I can't see that being very helpful.
Jim
Sounds to me like it would simply be a 3/4-ball aim (using A or C) or a half-ball aim (using B).
I concur.
I am a double distance aim shooter and would double the distance from the contact/impact point to the center of the OB to the outside of the OB and shoot...except when the CB and OB are very close together.....but you knew that.
:thumbup:You are on top of this AtLarge.:thumbup:
This process seems to accomplish the same result as the one I put forward. It's probably provable using the same theorem. This has three steps and mine has two.
I think we are all closing in on, or have learned about principles we can include in our arsenals in order to carry out consistent shot making. I think the larger part of the pool community is motivated to think about these things because we do not have the unique gifts for the game that the top players have. I like to think I'm having fun and enjoying the game. The precision and related difficulties seem to fuel my fascination ...
Last edited:
:thumbup:
What I wrote:
"When I was at each locations above, I brought the cue up and placed my bridge and cue offset by 1/2 tip to the side of the center of the CB with the cue between my eyes and under the center of my chin."
After I pivoted, I was more in line/parallel with the edge of the CB to the aimpoint line. I have been thinking that I should try to forget about the 1/2 tip offset and just get down parallel to the edge-to-aimpoint line with the cue at the center of the CB without pivot...would that be the "air pivot"?
Thanks.:thumbup:
LAMas,
Yes, it can be. If you pivot to where the eyes have moved to the right or left of the cte line. The vertical plane created by the two cue ball edge points, perpendicular to to your physical alignment will be your starting reference. With practice and familiarity of the correct pivot direction, this pivot will consistently set up the desired position for your bridge hand placement.
Initially it took me about a week to get the Pro One move. After a couple of months I videoed myself and I couldn't even tell it's there except for a consistent pre shot routine.
Best,
Mike
I not sure what im missing here? is it a 1/8 inside to outside pivot position?
You are not aiming into space because your cte and your aim line is 1/8 cue ball to 1/8 ob. It may seem to you that your off in space after the pivot but your not.
The 6 lines of aim are clearly defined here:
The first two depend on CB-OB distance (see the "*" note).
I hope that helps,
Dave
You could say the same thing about aiming the CB's right edge at "A" or its left edge at "C". But Stan seems to think those should be avoided for some reason.
(By the way, the CTE line can't be 1/8 to 1/8.)
pj
chgo
I now totally understand how stan goes from the 2 visuals right to the pre pivot without using either line to guide him to right or left pivot position. I figured it out last night and it makes it so easy to go right into pro1 naturally and had I had to stop myself from automatically going into pro1 until i mastered the visuals and understood them .
Pivots:
I hope you are going to share the info with us Champ.
I hope you are going to share the info with us Champ.
So all the shots are 15*,30*,45*,60*,75* cuts i notice on your site. So how do i make the 60* shot using stans system, it seems to fall in between ccb-robe-b-lp and the ccb-robe-1/8-lp or am i missing the 15*? am i having a brain cramp?
Ok, i think you are saying the 60* shot is made by ccb/robe - L1/8 cb to L1/8 ob but with a right pivot, was that on the dvd, lol?
Last edited:
ctel and the other line is 1/8 to 1/8. Using an A or C will be a bad miss, maybe 15 degrees when you have a very thin cut.
Last edited: