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Vision center, and what not to do about it
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Vision center, and what not to do about it - 05-28-2019, 06:03 AM

Most people I know, at one point in their lifelong pursuit to become a better player, get obsessed with "vision center" or the "dominating eye".

So did I. But after experimenting and thinking about it, I realized that most information found on the subject are trial and error suggestions, re-told myths.
The quote below from the "stroking straight question", thread, especially the part in bold, has motivated me to write those thoughts down, in hope that this may help someone.

Quote:
Originally Posted by Unknown
Just because you feel comfortable in a certain position, doesn't mean you can stroke the cue in a straight line from there. You just have to experiment with it and if part of the solution is moving your vision one way or the other, you'll get used to it soon enough.
.
I do believe there is a vision center and most likely a dominant eye, but the conclusions drawn in the hope of improving one's game are often wrong. Especially, experimentation in the classical sense is not the correct way to go about it. What you see is what you get. If you need to get used to something looking wrong, chances are likely that it is wrong in the first place.
Here's my theory (and it's just that, a theory):

It starts with someone having tendencies to
a) over cut shots to one side, and under cut shots to the other side, and/or
b) unwanted side spin, predominantly towards one side of the cue ball

With only this information, the source of the problem can be stroke and/or alignment related.

Then, someone suggests that it might be because their vision center is not on the line of the shot. That might still very well be true. They are then advised to do one of those dominant eye tests.

Let's do one too, shall we. Cut a small hole through a sheet of A4 paper. Hold it at arms length. Look at a small distant object through that hole with both eyes open. Close one eye at a time. If you see the object, according to the test, this eye is your dominant eye.

If you do this test yourself, you are likely to find that one particular eye usually gets the glance at the object, while the other's view is blocked by the paper. At least for me, there's a clear tendency to catch the object with my left eye. But to draw the conclusion that one must have the cue under that eye, or at least slightly towards that eye, in order to be aligned, is nothing but guesswork. The reason why one eye wins over the other is at least as much related to the way the paper is moved (hand-eye coordination).

To understand why, now do the test differently. Move the paper from left to right, somewhat slowly, until you see the distant object. It will always be your left eye that can physically see the object first, while it is still hidden by the paper from your right eye. Then, move the paper from right to left until you see the object. You will see it with your right eye. Seeing the object with either eye doesn't pose any problems for your brain.

Once one eye has made visual contact on the object through the hole, try turning your head left- or rightwards while keeping the distant object in sight. However you rotate your head, and which ever eye you use, your brain automatically puts your "handicapped vision center" on the line between hole-in-the-paper and the distant object. It doesn't look "wrong" or "off", even with your not-so-dominating eye. It wouldn't make sense to move the "dominant" eye closer to that line. You would just not see the object anymore.

Of couse, this test cannot be done without the paper, but the conclusion I draw from this is: don't move your head purposely towards what you think is your dominant eye, especially not if you what you then see looks "off" or like you need to "get used to" it before any positive effects may kick in.

Instead, without paying any attention to where your eyes are in relation to the cue, move your head so that
a) the cue looks perfectly centered
b) looks perfectly vertical and not at an angle to the left or the right.

Like so:
----------||----------
----------||----------
----------||----------
Fig. 1. Vision center on the line of the cue.

and not like
------||--------------
------||--------------
------||--------------
Fig.2. Vision center to the right of, but parallel to the cue.

or
----------//----------
---------//-----------
--------//------------
Fig.3. Cue angled

Pay great attention to how the cue is aligned in your vision, try to notice even small deviations. If you see the cue as in Fig.1, your own, individual, personal, unique, whatever, ... "vision center" is hovering on top of the shot line, or on the plane of the shot. Without you having to consciously hold your head in any particular fashion. That's what you want, and that's all you can ask for w.r.t. alignment with your cue. As before, you can try turning your head. For any head orientation, there will also be a position of your head where the cue looks like Fig.1.

Now introduce a cue ball and an object ball. No need for a pocket, just aim for a full hit on the object ball, with the cue tip in the vertical center of the cue ball tip (i.e. no side spin). While you get down on the shot, focus mainly on cue ball and object ball, i.e. the line of the shot. Make sure to stay on the line, so that the line between the centers of the balls is not angled and centered in your vision, just as the cue was in the previous test. Then pay attention to the cue as before. You may have to adjust both your head and your cue to get everything on line.

----------0----------
----------------------
----------------------
----------0-----------
----------------------
----------||----------
----------||----------
----------||----------
Fig. 4. Balls, cue and vision center in perfect alignment.

If a full hit (a.k.a. straight in) shot doesn't look like Fig.4, then your alignment is off. Only subconscious last second swoops and quirks can make you strike along the line of the shot. If it looks like Fig.4., as far as alignment goes, you're good to go. In practice, of course, it is hard to spot small deviations from Fig.4, so small inaccuracies will still happen. But the more you focus on the alignment, the more accurate you will get, and the more you can trust (or work on) your stroke.

The bottom line is: it doesn't matter whether the cue is perfectly centered between your eyes, slightly towards or straight under one eye. Whether you stare straight at the line of the shot, or whether your head is turned. All that matter is that the output of your brain's stereo vision algorithm (i.e. what you perceive and see) is aligned and centered on the line of the shot, and that you put your cue on that line as accurately as you can. See Fig. 4.

Stephen Hendry (7 times snooker world champion) started his career playing with the cue centered on his chin, and with time the cue moved towards one eye. Asked about it, he said it just happened. While only he knows whether that's true, or whether he tinkered with it as countless others have before, letting it happen naturally is the correct way to align.

So don't randomly move your head towards one eye or the other, hoping that this will fix your problems once your brain has adapted. Instead, make sure what you see is in accordance with what you want to achieve.


And then, unfortunately for most of us, comes the much harder problem: controlling your muscles to keep the cue on that line throughout the stroke.

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05-28-2019, 08:31 AM

Have you seen this?

Dr. Dave's resource page on Pool Vision Center

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05-28-2019, 12:03 PM

Here's the thing about a physically dominant eye: It will always grab the information sooner than the recessive eye. Not once in awhile. Always, because the nerves that lead from the eye to the brain are configured that way.

Unless there's a pathological eye issue, a player normally will favor the dominant eye, which is why cues often wind up under that eye, even without any coaxing.

It's true, that what that eye sees, may not be optimal or accurate. But it may be. But if it isn't, then the player is faced with two choices:

One: Consciously change the placement of the cue away from the dominant eye until positive results are obtained.

or Two: Leave the cue under the dominant eye and adjust your aim accordingly.

To many, the obvious answer would be to change the placement of the cue. I disagree with this choice because in my experience in teaching and for myself as a player over the years, I have found that the cue will naturally start to drift back under the dominant eye --- and especially those with a severely dominant eye.

This is where all the theories about cue placement start to fall apart. You can choose to try to fight the physically dominant eye, but you will have to consciously check yourself all the time.

All of that physical in-fighting with yourself is unnecessary if you just figure out how to adjust your aim with the cue in it's most comfortable place under your dominant eye, because you will be pretty much assured of a consistent cue placement.

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05-29-2019, 12:56 AM

Quote:
Originally Posted by Patrick Johnson View Post
Yes, I have. And while I'm a huge fan of Dave's work*, a small section on this particular page is one example of the contradicting information circulating on vision center.

Quote:
Originally Posted by https://billiards.colostate.edu/faq/eyes/vision-center/
A useful technique to find your “vision center” is to set up a straight-in shot (e.g., with the CB and OB along the diagonal of the table, with the OB close to a corner pocket and the CB close to the middle of the table) with a cue shaft carefully laid down on the table centered in front of the CB and perfectly aligned with the straight line of the shot. Then position your head over the shaft close to the place and orientation your head would be while down in your stance. Then move your head left and right, without tilting or turning, until the tip position looks centered and the shaft and shot alignment look perfectly straight. This head position is your “vision center.”
Quote 1
Nothing to argue about here. You know cue and balls are setup in a straight line. Just put your head in such a way that you can see this perfect alignment. Then you know your head is in the right spot, your "vision center" is on the line of the shot. This is how it must look if you come across a straight in shot in a game. This may require more focus for some players to consciously see minor deviations from the perfect alignment. But it certainly doesn't require knowing where exactly your eyes are. It either looks right or it doesn't.

But then:
Quote:
Originally Posted by https://billiards.colostate.edu/faq/eyes/vision-center/
Another good drill to help you find and test your vision center, ..., is to set up a long straight-in shot into a corner pocket, marking the CB and OB positions with self-adhesive hole reinforcements (AKA, a “little white donuts”). Then hit stop shots. If the CB has no sidespin after hitting the OB, and if the OB goes into the center of the pocket consistently, then you have your vision center properly aligned (and you have a good stroke). If not, then shifting your head will probably help.
Quote 2
I don't agree with that. You should just do the same visual verification as in Quote 1. The only difference (and added difficulty) is that you also need to place the cue on that line and verify its alignment. But once you have verified that everything looks just like in the setup described in Quote 1, why on earth would you move your head. You will move your head away from the line of the shot, away from perfectly aligned cue and balls. If moving the head fixes the problem with this particular shot, it means you're compensating a stroke related flaw with a visual flaw. Likely not going to work for varying cue ball - object ball distances.


If you have relatively healthy eyes, there is no logical explanation for why anyone would see both balls and the cue in perfect alignment for a straight-in shot, when they actually aren't. You would have to see straight lines as curves for this to make sense.

Quote:
Originally Posted by https://billiards.colostate.edu/faq/eyes/vision-center/
If the CB consistently goes to the right of target, causing the OB to go left of the pocket, your left eye is probably dominating the perception of the line of the cue. This causes you to position the cue a little to the left of center and to pivot the cue a little to the right of the desired line of aim. With your eye alignment to the left of center, you perceive the shifted and pivoted cue position as centered and straight, but it is not. If this is the case, try shifting your head to the right a little, and then try another set of stop shots.
Quote 3
What's missing here are the balls. If you start from the perfect alignment as in Quote 1, and then move your head, of course the cue will look pivoted and its tip no longer in the center of the cue ball. So you pivot it to re-center it in your vision. But then, if you follow the line of the cue through the cue ball, you will see that the cue ball won't be sent to the center of the object ball any longer. And even without paying any attention to the cue, you would see that the balls aren't lined up correctly. You just moved your vision center away from the line of the shot.

Don't move your head so that the cue looks right. Leave your head/vision center stationary on the line of the shot and put the cue on the right line. If the cue doesn't line up with the desired shot line, adjust bridge and backhand slightly while still keeping the head/vision center stationary on the line of the shot, or get back up and start again.

I really think it all starts with not paying enough attention while getting down and when down. At least it did for me, and it obeys the principles of optics (which I have a degree in).
If everything looks sort of alright and sort of lined up, you might not have aligned yourself and the cue as best as you could have. Is your head/vision center really on the line of the shot, or ever so slightly off to one side? Is your tip really in the center of the cue ball, or is it maybe a quarter of a mm to one side? Is your cue angled just a fraction of a degree when it should be straight? These small deviations lead to unwanted side spin and/or not hitting a straight shot perfectly straight. That is, of course, if you had a perfectly straight stroke. But as far as alignment goes, if you don't strive for the most accurate setup, you must live with the consequences.

* Hey Dave, if you read this. There's one more thing to criticize. Why can't I order a "Got English?" T-Shirt to Germany? I don't mind paying higher shipping costs, if that's the reason.
Otherwise, big thumbs up! You are a living encyclopedia of everything pool related.

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05-29-2019, 01:06 AM

Quote:
Originally Posted by FranCrimi View Post
Here's the thing about a physically dominant eye: It will always grab the information sooner than the recessive eye. Not once in awhile. Always, because the nerves that lead from the eye to the brain are configured that way.

Unless there's a pathological eye issue, a player normally will favor the dominant eye, which is why cues often wind up under that eye, even without any coaxing.
In total agreement here. I just mean to stress that this "favoring" of one eye is, or should be, completely intuitive.

Quote:
Originally Posted by FranCrimi View Post
It's true, that what that eye sees, may not be optimal or accurate. But it may be.
This leaves me puzzled. Take this image as an example:


The cue ball is in the horizontal center of one's field of view. The cue is perfectly vertical, and the tip aimed exactly at the center of the cue ball. The extended line of the cue through the cue ball center leads exactly to where the cue ball needs to go to pocket the 1 at that speed. In what way can your eyes deceive you here? How can a shot look perfectly aligned like that, but you end up over or under cutting the ball (assuming perfectly straight stroke as in Virtual Pool)?

If it were possible to take a screenshot of a players vision (not the raw pictures of each eye, but the picture the brain makes from those) (or two, one while focused on the cue ball, one on the object ball), and affirm that everything is lined up as in the Virtual Pool screenshot, how could that player be aligned incorrectly?


Quote:
Originally Posted by FranCrimi View Post
...
or Two: Leave the cue under the dominant eye and adjust your aim accordingly.
...
All of that physical in-fighting with yourself is unnecessary if you just figure out how to adjust your aim with the cue in it's most comfortable place under your dominant eye, because you will be pretty much assured of a consistent cue placement.
What exactly do you mean by adjusting one's aim? Can you maybe give an example?

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05-29-2019, 05:03 AM

Quote:
Originally Posted by deraltefritz View Post
Most people I know, at one point in their lifelong pursuit to become a better player, get obsessed with "vision center" or the "dominating eye".

So did I. But after experimenting and thinking about it, I realized that most information found on the subject are trial and error suggestions, re-told myths.
The quote below from the "stroking straight question", thread, especially the part in bold, has motivated me to write those thoughts down, in hope that this may help someone.



I do believe there is a vision center and most likely a dominant eye, but the conclusions drawn in the hope of improving one's game are often wrong. Especially, experimentation in the classical sense is not the correct way to go about it. What you see is what you get. If you need to get used to something looking wrong, chances are likely that it is wrong in the first place.
Here's my theory (and it's just that, a theory):

It starts with someone having tendencies to
a) over cut shots to one side, and under cut shots to the other side, and/or
b) unwanted side spin, predominantly towards one side of the cue ball

With only this information, the source of the problem can be stroke and/or alignment related.

Then, someone suggests that it might be because their vision center is not on the line of the shot. That might still very well be true. They are then advised to do one of those dominant eye tests.

Let's do one too, shall we. Cut a small hole through a sheet of A4 paper. Hold it at arms length. Look at a small distant object through that hole with both eyes open. Close one eye at a time. If you see the object, according to the test, this eye is your dominant eye.

If you do this test yourself, you are likely to find that one particular eye usually gets the glance at the object, while the other's view is blocked by the paper. At least for me, there's a clear tendency to catch the object with my left eye. But to draw the conclusion that one must have the cue under that eye, or at least slightly towards that eye, in order to be aligned, is nothing but guesswork. The reason why one eye wins over the other is at least as much related to the way the paper is moved (hand-eye coordination).

To understand why, now do the test differently. Move the paper from left to right, somewhat slowly, until you see the distant object. It will always be your left eye that can physically see the object first, while it is still hidden by the paper from your right eye. Then, move the paper from right to left until you see the object. You will see it with your right eye. Seeing the object with either eye doesn't pose any problems for your brain.

Once one eye has made visual contact on the object through the hole, try turning your head left- or rightwards while keeping the distant object in sight. However you rotate your head, and which ever eye you use, your brain automatically puts your "handicapped vision center" on the line between hole-in-the-paper and the distant object. It doesn't look "wrong" or "off", even with your not-so-dominating eye. It wouldn't make sense to move the "dominant" eye closer to that line. You would just not see the object anymore.

Of couse, this test cannot be done without the paper, but the conclusion I draw from this is: don't move your head purposely towards what you think is your dominant eye, especially not if you what you then see looks "off" or like you need to "get used to" it before any positive effects may kick in.

Instead, without paying any attention to where your eyes are in relation to the cue, move your head so that
a) the cue looks perfectly centered
b) looks perfectly vertical and not at an angle to the left or the right.

Like so:
----------||----------
----------||----------
----------||----------
Fig. 1. Vision center on the line of the cue.

and not like
------||--------------
------||--------------
------||--------------
Fig.2. Vision center to the right of, but parallel to the cue.

or
----------//----------
---------//-----------
--------//------------
Fig.3. Cue angled

Pay great attention to how the cue is aligned in your vision, try to notice even small deviations. If you see the cue as in Fig.1, your own, individual, personal, unique, whatever, ... "vision center" is hovering on top of the shot line, or on the plane of the shot. Without you having to consciously hold your head in any particular fashion. That's what you want, and that's all you can ask for w.r.t. alignment with your cue. As before, you can try turning your head. For any head orientation, there will also be a position of your head where the cue looks like Fig.1.

Now introduce a cue ball and an object ball. No need for a pocket, just aim for a full hit on the object ball, with the cue tip in the vertical center of the cue ball tip (i.e. no side spin). While you get down on the shot, focus mainly on cue ball and object ball, i.e. the line of the shot. Make sure to stay on the line, so that the line between the centers of the balls is not angled and centered in your vision, just as the cue was in the previous test. Then pay attention to the cue as before. You may have to adjust both your head and your cue to get everything on line.

----------0----------
----------------------
----------------------
----------0-----------
----------------------
----------||----------
----------||----------
----------||----------
Fig. 4. Balls, cue and vision center in perfect alignment.

If a full hit (a.k.a. straight in) shot doesn't look like Fig.4, then your alignment is off. Only subconscious last second swoops and quirks can make you strike along the line of the shot. If it looks like Fig.4., as far as alignment goes, you're good to go. In practice, of course, it is hard to spot small deviations from Fig.4, so small inaccuracies will still happen. But the more you focus on the alignment, the more accurate you will get, and the more you can trust (or work on) your stroke.

The bottom line is: it doesn't matter whether the cue is perfectly centered between your eyes, slightly towards or straight under one eye. Whether you stare straight at the line of the shot, or whether your head is turned. All that matter is that the output of your brain's stereo vision algorithm (i.e. what you perceive and see) is aligned and centered on the line of the shot, and that you put your cue on that line as accurately as you can. See Fig. 4.

Stephen Hendry (7 times snooker world champion) started his career playing with the cue centered on his chin, and with time the cue moved towards one eye. Asked about it, he said it just happened. While only he knows whether that's true, or whether he tinkered with it as countless others have before, letting it happen naturally is the correct way to align.

So don't randomly move your head towards one eye or the other, hoping that this will fix your problems once your brain has adapted. Instead, make sure what you see is in accordance with what you want to achieve.


And then, unfortunately for most of us, comes the much harder problem: controlling your muscles to keep the cue on that line throughout the stroke.

Why does it have to do with:

"...someone having tendencies to
a) over cut shots to one side, and under cut shots to the other side, and/or
b) unwanted side spin, predominantly towards one side of the cue ball"

Why can't it be a player puts their head in various positions, and needs to train to set into the correct position consistently? That's the reality I encounter out there...


-- Matt Sherman

Guide to Pool and Billiards, About.com
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05-29-2019, 05:13 AM

Quote:
Originally Posted by deraltefritz View Post
In total agreement here. I just mean to stress that this "favoring" of one eye is, or should be, completely intuitive.


This leaves me puzzled. Take this image as an example:


The cue ball is in the horizontal center of one's field of view. The cue is perfectly vertical, and the tip aimed exactly at the center of the cue ball. The extended line of the cue through the cue ball center leads exactly to where the cue ball needs to go to pocket the 1 at that speed. In what way can your eyes deceive you here? How can a shot look perfectly aligned like that, but you end up over or under cutting the ball (assuming perfectly straight stroke as in Virtual Pool)?

If it were possible to take a screenshot of a players vision (not the raw pictures of each eye, but the picture the brain makes from those) (or two, one while focused on the cue ball, one on the object ball), and affirm that everything is lined up as in the Virtual Pool screenshot, how could that player be aligned incorrectly?




What exactly do you mean by adjusting one's aim? Can you maybe give an example?
Sure. Here's an example of adjusting your aim. Let's say, for example, that with the cue under your most comfortable place under your dominant eye, an instructor watching you sees that you consistently line up a half tip to the left side of the cue ball, when you believe you are at the center of the cue ball. The aim adjustment would be an overall half tip adjustment to the right.

But, I do want to add that the adjustment is not always across the board. It can also be dependent on the particular type of shot. But if the player knows himself at the table, like Earl, for example, who has a severely dominant right eye and places his cue under the outer edge of that eye, they will know the adjustment to make when certain shots come up. Every player should know his tendencies at the table, regardless of his dominant eye issues.

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05-29-2019, 05:14 AM

Mister Sherman..........I concur with that reality.
Tough, sweat filled, training is hard for most people to digest in most endeavors.
It gets back to a basic work ethic, I think.
I recall my mother saying to me as a child when we were so poor......"The elevator to success is out of order, you better learn to take the stairs"

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05-29-2019, 06:01 AM

Quote:
Originally Posted by BilliardsAbout View Post
Why does it have to do with:

"...someone having tendencies to
a) over cut shots to one side, and under cut shots to the other side, and/or
b) unwanted side spin, predominantly towards one side of the cue ball"

Why can't it be a player puts their head in various positions, and needs to train to set into the correct position consistently? That's the reality I encounter out there...
That's usually the issue people describe before someone brings up the possibility of the vision center not being where it should be. It was merely an introduction to my theory.

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05-29-2019, 06:45 AM

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Originally Posted by FranCrimi View Post
Sure. Here's an example of adjusting your aim. Let's say, for example, that with the cue under your most comfortable place under your dominant eye, an instructor watching you sees that you consistently line up a half tip to the left side of the cue ball, when you believe you are at the center of the cue ball. The aim adjustment would be an overall half tip adjustment to the right.
If lining up half a tip left of the cue ball looks like lining up at the center of the cue ball for someone, how do they see the relation between cue ball and object ball? Are they aligned well there, and their dominant eye only deceives them w.r.t. the cue in relation to the cue ball? This cannot happen optically. Maybe the brain can do some weird stuff to one's perception, but it doesn't sound plausible.

Let's use a stop shot example again. Everything aligned perfectly, vision center on the line of the shot. Both from the shooter's point of view as well as from the instructor's. Where the shooter and the instructor want to end up, with a perfect setup.

Now to make it look like you describe from the instructor's point of view, the shooter would have to someway move the cue tip half a tip to the left.

It will now look wrong to the shooter of course. In order for them to perceive this situation as center ball without undoing the cue movement, the head must go to the left until the tip overlaps with or points directly at the center of the cue ball.

(Note that neither pivoting nor parallel shifts away from the initial perfect alignment will make the line of the cue ever point through the center of the cue ball. Only pivoting around the center of the cue ball can do that)

Now after moving the head, the cue ball and object ball can no longer be aligned as they were before.

I would assume, if the cue appeared to go towards the center of the cue ball for the shooter, but for an observer it appeared half a tip to the left, then they were aiming right of the intended target in the first place and just didn't realize it.


Sorry, I don't mean to annoy anyone, or question the authority and knowledge of instructors. Least of all you Fran.
But the dominant eye / vision center thing, and especially what to do about it, sounds a little unscientific to me. But maybe my "scientific" approach to it is flawed in a way I can't see. Please enlighten me, anyone.
  
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05-29-2019, 07:01 AM

Quote:
Originally Posted by deraltefritz View Post
Sorry, I don't mean to annoy anyone, or question the authority and knowledge of instructors. Least of all you Fran.
But the dominant eye / vision center thing, and especially what to do about it, sounds a little unscientific to me. But maybe my "scientific" approach to it is flawed in a way I can't see. Please enlighten me, anyone.
I think maybe you're not taking into full account the fact that your vision:

1. isn't a simple one-perspective picture like a camera lens - it's "compiled" by your visual cortex from two different pics, neither of which might be directly on-line, and

2. isn't positioned directly over the things it's trying to line up - they're all at various distances in front of you.

These conditions make your "shot picture" a more complex thing to understand and use correctly than it might seem "at first glance".

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05-29-2019, 08:21 AM

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Originally Posted by Patrick Johnson View Post
I think maybe you're not taking into full account the fact that your vision:

1. isn't a simple one-perspective picture like a camera lens - it's "compiled" by your visual cortex from two different pics, neither of which might be directly on-line, and
I have worked with numerous multi-camera setups and know my way around multiple lenses and "retinas" and how they are related. And I know how lenses and their distortion work.

But you're right, I don't know how exactly our brain compiles our perception. That's why I also experimented (intensively and for long periods of time) with moving my head slightly, trying to program my brain to see something differently in the hope of it fixing my apparent alignment problems. Like what is suggested in Quote 2 from Dave's website.
But in the end, I just couldn't convince myself - it would not produce any permanent improvements. Short term fixes for only particular cue ball - object ball distances, at best. And it didn't make sense from any geometrical and lens-projection models known to be true.

What caused almost instant and drastic improvements was to forget about where my eyes were, and really pay attention to where the balls and the cue were. I could not believe how sloppy I was aligned. How I was off the line the cue ball needed to go, when I was certain that I was on it. When I thought I cued up to the center of the cue ball, I was half a mm left of it. Minor corrections were and still are necessary on almost any shot that I want to shoot with precision. Like 1/4mm tip correction with the bridge hand (mostly to the right), and similar small movements of my back hand.
From stopping the cue ball perfectly dead on medium range stop shots, my average went up from 3.5/10 to a little less than 6/10. Almost instantly compared the number of hours I already spent on the table in my lifetime. And not by randomly moving my head, or cueing in a way that looked slightly wrong. No, simply by making sure that what I see looks as accurate as I am able to perceive. And that doesn't go against what I know about geometry, lens distortion, and so on. It also doesn't go against the majority of what Dave writes on his page on the subject. But it doesn't comply with moving your head slightly and wait/wish/observe any improvements.


Quote:
Originally Posted by Patrick Johnson View Post
2. isn't positioned directly over the things it's trying to line up - they're all at various distances in front of you.
That is true. But still, a straight line is a straight line, even if you can only focus on certain parts of it at any time.
Look at your cue laying on the table, or the edge of the rail. It looks straight from any point in the room (from any perspective), but only from viewpoints on a certain plane does it look like that if you extended the line to infinity on both sides, it will pass right underneath you, will split your brain "compiled" image in half, here, underneath you, at the end of the room, or the end of a flat earth. On this plane, your "compiled" viewpoint, a.k.a. your personal vision center, must be for you to be aligned on a center ball shot. Do we agree on this?

Quote:
Originally Posted by Patrick Johnson View Post
These conditions make your "shot picture" a more complex thing to understand and use correctly than it might seem "at first glance".
I hope my always too long posts don't make the impression than I'm chit-chatting about my "first glance" at the topic :-P

Can you explain the complexity then?

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05-29-2019, 08:32 AM

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Originally Posted by deraltefritz View Post
...not by randomly moving my head ... simply by making sure that what I see looks as accurate as I am able to perceive.
How do you "make sure" of that without moving your head or stick?

By the way, you wouldn't move your head "randomly".

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05-29-2019, 08:44 AM

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Originally Posted by Patrick Johnson View Post
How do you "make sure" of that without moving your head or stick?



By the way, you wouldn't move your head "randomly".



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A combination of moving my eyes between cue ball and object ball and in between, pretty much the standard procedure. Just with more focus on precision instead of assessing whether I'm in the ball park or not, I guess. And peripheral vision, in a vertical way.

And yeah I know, the direction isn't random. But by how much is random ("move your head a little to the left").

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05-29-2019, 10:02 AM

Quote:
Originally Posted by deraltefritz View Post
A combination of moving my eyes between cue ball and object ball and in between, pretty much the standard procedure. Just with more focus on precision instead of assessing whether I'm in the ball park or not, I guess. And peripheral vision, in a vertical way.
Sounds like you try to have CB/OB/stick/target "in view" all at once like I do.

Quote:
And yeah I know, the direction isn't random. But by how much is random ("move your head a little to the left").
You can judge by whether or not the shot picture improves ("move your head to the left until your alignment looks straight").

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