diagrams pertaining to pivot-based aiming systems

[dr_dave]

Several "cut-shot aiming systems" (e.g., CTE, 90/90, ETE, Pro-One, HH, etc?) are based on establishing an initial cue alignment and then pivoting the cue to the final required line of aim for the shot. There have been many reports that these systems are used successful by many people, at all levels of play; so obviously, the systems "work." In other threads on this topic in the past, the discussion "rarely stays on topic," to put it politely. I offered the info below in one of the "other" threads recently, but I think there was already too much "baggage" in the thread for anything good to come of it. Thus, I wanted to start a new thread, hoping a more civil discussion can continue. My point isn't to prove the systems don't work, because they obviously do. Instead, I am hoping we can better understand why they do work. If we can, the systems might become more useful for people who currently doubt them.

Here are the diagrams from my November '08 article that show what happens when you use a fixed pivot without changing your bridge length (see the article for detailed explanations of the diagrams):

Here's a diagram from my December '08 article that shows what happens when you vary your bridge length or effective pivot length (see the article for a detailed explanation of the diagram):

Obviously, to make pivot-based aiming systems work for a wide range of shots you need to vary either your bridge length or your effective pivot length (e.g., by shifting and/or adjusting the bridge hand pivot point, either when you form the bridge or when you "pivot"). A fixed bridge and/or fixed effective pivot length won't get the job done for a wide range of shots.

I look forward to civil and useful discussion, comments, and debate.

Thanks,
Dave

PS: If you want more background information, I have some basic descriptions and resources related to some of the systems here:

http://billiards.colostate.edu/threads/aiming.html​

 

[Cornerman]

. My point isn't to prove the systems don't work, because they obviously do. Instead, I am hoping we can better understand why they do work. If we can, the systems might become more useful for people who currently doubt them.

Here are the diagrams from my November '08 article that show what happens when you use a fixed pivot without changing your bridge length (see the article for detailed explanations of the diagrams):

My first statement is obviously going to reiterate that 2D drawings are inappropriate for explanation because of the obvious disconnect between what we see on 2D vs what we see in 3D. I encourage an on table, face-to-face in this regard because then and only then could we possibly understand each other. I've said it entirely too many times. I would hope by now those that know enough of me would realize how serious I am at this statement.

That being said, I have to ask what others who do CTE, SAM, or 90/90 do with these four shots? For my pivot system, there are three separate shots, so the same alignment and pivot don't and shouldn't work for my system. I can only guess that for SAM shooter, shot A, B, and C are Sam #1, #2, and #3 respectively (or something like that).

I think should just start at shot A and D on the left diagram (assuming you're using the same cueball in one fixed position for shot A & D). I think most if not all of these type of systems would treat these two shots the same. Someone please chime in if I'm incorrect in this assumption. Anyway, I'm not sure why you've drawn parallel lines for shot A and D. If you're an edge aimer with no pivot, for example, the actual angle of the object ball should be different, with respect to the table. That's a starting point.

Fred

 

[eyesjr]

How do you suggest compensating for speed? Pivoting further and using more english, or simply playing the bll fuller(outside) or thinner(inside). Just curious, I do not personally have many deflection, curveback troubles, because I learned with a traditional shaft....But I do have several guys I play with that cannot see the real action, or if they do, they have problems with compensating for various speeds...

My first statement is obviously going to reiterate that 2D drawings are inappropriate for explanation because of the obvious disconnect between what we see on 2D vs what we see in 3D. I encourage an on table, face-to-face in this regard because then and only then could we possibly understand each other. I've said it entirely too many times. I would hope by now those that know enough of me would realize how serious I am at this statement.

That being said, I have to ask what others who do CTE, SAM, or 90/90 do with these four shots? For my pivot system, there are three separate shots, so the same alignment and pivot don't and shouldn't work for my system. I can only guess that for SAM shooter, shot A, B, and C are Sam #1, #2, and #3 respectively (or something like that).

I think should just start at shot A and D on the left diagram (assuming you're using the same cueball in one fixed position for shot A & D). I think most if not all of these type of systems would treat these two shots the same. Someone please chime in if I'm incorrect in this assumption. Anyway, I'm not sure why you've drawn parallel lines for shot A and D. If you're an edge aimer with no pivot, for example, the actual angle of the object ball should be different, with respect to the table. That's a starting point.

Fred

 

[dr_dave]

My first statement is obviously going to reiterate that 2D drawings are inappropriate for explanation because of the obvious disconnect between what we see on 2D vs what we see in 3D. I encourage an on table, face-to-face in this regard because then and only then could we possibly understand each other. I've said it entirely too many times. I would hope by now those that know enough of me would realize how serious I am at this statement.

I hope we get to meet some day in person so you can show me in detail how you make the systems you use work for a wide range of shots.

I think should just start at shot A and D on the left diagram (assuming you're using the same cueball in one fixed position for shot A & D). I think most if not all of these type of systems would treat these two shots the same. Someone please chime in if I'm incorrect in this assumption. Anyway, I'm not sure why you've drawn parallel lines for shot A and D. If you're an edge aimer with no pivot, for example, the actual angle of the object ball should be different, with respect to the table. That's a starting point.

Agreed. To make all shots in the diagram (see below), and all shots in between all of the shots in the diagram, you need to use a different "aim" for each. The dashed parallel lines drawn show what would happen if the CB-OB relationship were the same for all shots (including shot "D") and if you used the same alignment and pivot for all shots. Obviously this doesn't work. So the question is: how do people change their aim for different shots when the CB-OB relationship is the same for those shots (i.e., the CB and OB are just being shifted slightly, and together, so only the required angle to the pocket is different)? I know that when the angle to the pocket changes a lot, you need to use a different alignment and/or pivot. However, I and others want to better understand what type of adjustments are made when you are using the same alignment and pivot for shots where only the angle to the pocket is slightly different.

I hope that is clear, but please let me know if is not.

Regards,
Dave

PS: Thank you for you well-thought-out and respectful response. Hopefully, that sets the tone for the remainder of the thread.

 

[dr_dave]

How do you suggest compensating for speed? Pivoting further and using more english, or simply playing the bll fuller(outside) or thinner(inside). Just curious, I do not personally have many deflection, curveback troubles, because I learned with a traditional shaft....But I do have several guys I play with that cannot see the real action, or if they do, they have problems with compensating for various speeds...

English (and the squirt, swerve, and throw that comes with it) is a whole separate matter. I would prefer to limit our discussion to just center-ball hits for now. I hope that's OK.

Thanks,
Dave

 

[Patrick Johnson]

2D drawings are inappropriate for explanation because of the obvious disconnect between what we see on 2D vs what we see in 3D

2D drawings are useful to show what can't be happening.

I encourage an on table, face-to-face in this regard because then and only then could we possibly understand each other.

Sounds like fun to me, but demonstrations at the table can probably only show that the systems can be made to work somehow. As Spiderdave demonstrated with his videos, you can't really tell what a shooter is doing in detail by watching.

I've said it entirely too many times.

Me too.

pj
chgo

 

[Tennesseejoe]

Dr. Dave, you always seem to have a refreshing, scientific, open minded approach without a political agenda. I hope the posters for this topic follow your example. The amount of time and thought you put into this forum is appreciated.

 

[dr_dave]

Dr. Dave, you always seem to have a refreshing, scientific, open minded approach without a political agenda. I hope the posters for this topic follow your example. The amount of time and thought you put into this forum is appreciated.

Thank you very much. I appreciate your appreciation.

I also hope we can finally get to the bottom of all of this stuff without the familiar personal attacks and useless rants.

Regards,
Dave

 

[eyesjr]

Yes sir!!

Yes, thats fine!! I am Glad to see someone as thorough as you here to help out and take the time to diagram, etc. I have viewed some of your previous posts, and I hope to see you on here some more. A google search took me to a post of yours, and ultimately got me signed up here. Thank you!!!

English (and the squirt, swerve, and throw that comes with it) is a whole separate matter. I would prefer to limit our discussion to just center-ball hits for now. I hope that's OK.

Thanks,
Dave

 

[mikepage]

My first statement is obviously going to reiterate that 2D drawings are inappropriate for explanation because of the obvious disconnect between what we see on 2D vs what we see in 3D. I encourage an on table, face-to-face in this regard because then and only then could we possibly understand each other. I've said it entirely too many times. I would hope by now those that know enough of me would realize how serious I am at this statement.

I know you pretty well Fred. I've been hearing you and I know how serious you are. And I agree with you on a lot of things. I just don't agree with you on this point.

 

[Cornerman]

2D drawings are useful to show what can't be happening.

This is probably at its simplest the very truth of it. That's why we don't use 2D drawings to describe what we're doing. I know what I'm doing in real space, I try to explain it, ... hell I even am more shocked than anyone when a ball goes in because it can't possibly work if it was drawn in 2D. In other words, what my perception of how I'm aiming is completely disconnected from 2D. If someone used laser pointers and measurement devices, I'm very open to the idea that I'm NOT pointing to where I think I am.

But.... the importance to that is that wherever I perceive to be aiming IS what I'm describing, and that system is getting me to whatever correct point has to happen. What I perceive and what actually happens doesn't have to be identical.

By correlation, I believe this has to happen to every player using ghost ball as well. That is, what they perceive as the ghost ball and the center of the ghost ball isn't quite right if they use laser pointers as proof. My handwaving proof is that people miss. And though you can point to the stroke as the culprit on many or most, the reality of this game is the visualizing the ghost ball point isn't easy, especially at distances and cuts. Yet people can make balls and they can miss balls with the same stroke. Those that play a lot have made the adjustments by instinct (funny how that's the same argument that the aiming system jury uses) either by naturally overcutting, undercutting, using a hair of outside, etc. No difference.

By your argument, a system based on geometrically correct aiming but with inherent human element errors is going to be better than a system based on non-geometrically correct aiming with the same inherent human element errors. On the surface and by instinct, this would seem like this has to be truth. But, if you base things from geometrically correct, then don't human errors take you away from geometrically correct? If you base things on non-geometrically correct, the human erros either take you farther away from the geometrically correct or towards geometrically correct. And farther than geometrically correct we can deal with because... we just click to the next shot reference.

Thoughts on that lunacy?

Fred

 

[Cornerman]

The dashed parallel lines drawn show what would happen if the CB-OB relationship were the same for all shots (including shot "D") and if you used the same alignment and pivot for all shots. Obviously this doesn't work. So the question is: how do people change their aim for different shots when the CB-OB relationship is the same for those shots (i.e., the CB and OB are just being shifted slightly, and together, so only the required angle to the pocket is different)? .

Again, I'm only talking about my system the same style of systems that I learned from Hal and what I know of SAM.

For my system or several Hal systems, there are more than one aim lines prior to pivot. The base system has two aim points on the cueball and two aim points on the object ball (center and edge). Each additional refererence point you decide to add on the the cueball therefore adds two lines of aim to your system. One goes to the center; the other goes to the edge.

So, if you have the cueball and object ball with the same relationship, you have to see where the pocket is in relationship to choose which aim line you want to use. There isn't just one aim line. You could just start adding additional aim points on the object ball, but when you're on the table, you'll find that if you have a total of 5 o 6 per side of the cueball, not only will you have trouble discerning between points (and remember, you're at the cueball which is right in front of you as opposed trying to break the object ball into sections which could be 8' away from you), but also, you'll find that you don't need to add more points.

I could say so much more, but look how wordy it gets.

Fred

 

[SpiderWebComm]

I know you pretty well Fred. I've been hearing you and I know how serious you are. And I agree with you on a lot of things. I just don't agree with you on this point.

Let me throw a thought at ya, Mike.

I keep mentioning perception to everyone, yet no one is really paying attention.

On a 2D diagram, the balls are all the same size.

In real life, well, they're the same size too (wouldn't ya know?)

The big "but" is.... your brain doesn't think so. The ball gets smaller to the eye in direct proportion to increased distance which makes you sight a line to the inside. I'll repeat......"perception, perception, perception."

Hal once told me the "geometric proof" isn't a 2D proof, and he's right. Although he doesn't visit the forum anymore because of his health, he used to giggle at everyone posting cuetable diagrams in order to show why it didn't work.

Let's all cook on that one for a while. The old man knows something we don't. Hmmm...the CB looks "big" because it's right in front of your face.

Regards,
Dave

P.S. Dr. Dave, can you simulate 3D in 2D space? Can each ball have two edges - the true edge and perceived edge (smaller) and recalculate? I think everyone would be surprised at how different the results look.

 

[Beware_of_Dawg]

As much as I've tried, I just can't internalize this information. I don't know if it's my learning style or what but these drawing and explanations, as much as I appreciate the effort... just can't sink into my hard head. very frustrating as I am generally a willing and motivated sponge when it comes to pools wisdom & instruction.

 

[SpiderWebComm]

Let me throw a thought at ya, Mike.

I keep mentioning perception to everyone, yet no one is really paying attention.

On a 2D diagram, the balls are all the same size.

In real life, well, they're the same size too (wouldn't ya know?)

The big "but" is.... your brain doesn't think so. The ball gets smaller to the eye in direct proportion to increased distance which makes you sight a line to the inside. I'll repeat......"perception, perception, perception."

Hal once told me the "geometric proof" isn't a 2D proof, and he's right. Although he doesn't visit the forum anymore because of his health, he used to giggle at everyone posting cuetable diagrams in order to show why it didn't work.

Let's all cook on that one for a while. The old man knows something we don't. Hmmm...the CB looks "big" because it's right in front of your face.

Regards,
Dave

P.S. Dr. Dave, can you simulate 3D in 2D space? Can each ball have two edges - the true edge and perceived edge (smaller) and recalculate? I think everyone would be surprised at how different the results look.

Where'd all the aiming people go? I cant wait to discuss.

 

[mikepage]

Where'd all the aiming people go? I cant wait to discuss.

I'll respond later. I'm off to teach a class about reducing a 36-dimensional problem to a 30-dimensional problem --and then what can be learned by looking at the key features in 3D and 2D..... no kidding.

 

[shinigami]

I'll respond later. I'm off to teach a class about reducing a 36-dimensional problem to a 30-dimensional problem --and then what can be learned by looking at the key features in 3D and 2D..... no kidding.

What's would be an example of a 36 dimensional problem?

 

[dr_dave]

Yes, thats fine!! I am Glad to see someone as thorough as you here to help out and take the time to diagram, etc. I have viewed some of your previous posts, and I hope to see you on here some more. A google search took me to a post of yours, and ultimately got me signed up here. Thank you!!!

you're very welcome. I hope you enjoy your AZB experience.

Regards,
Dave

 

[supergreenman]

Yawn...........

Another aiming thread whoopie.

:angry: :frown: :sorry:

 

[SpiderWebComm]

I'll respond later. I'm off to teach a class about reducing a 36-dimensional problem to a 30-dimensional problem --and then what can be learned by looking at the key features in 3D and 2D..... no kidding.

I like your voice inflection and style. I'm sure you're a fun teacher.

P.S. I thought the universe only had 11 dimensions???