Neil,
This a helpful explanation.
Perspective needs two eyes. Using both eyes, one can establish a centered line to an edge. If one can toggle between both eyes to make one and the other dominant, then the edge of the OB seems to move depending on which eye is made dominant forcing one to move his stance a bit to the left or right. Close one eye end then the other to experience this - I do.
This can create 3 positions center, a bit to the left or a bit to the right and result in 3 cut angles with "the same visual". I can do that though I am right eye dominant.
This may not be what you are proffering, but it works for me.
Thanks
The big thing is ones initial perspective. Which comes from visual intelligence. That means if I put the ob one diamond from the left rail and one diamond from the side pocket, then put the cb in line with it one diamond from the end rail, I need some visual intelligence to know approximately where to stand to cut the ball in the far corner.
I can't be standing off by the right side rail and expect to make it, nor can I expect to stand near the right corner pocket and expect to be able to see the angle to make it. Nor can I stand even a little to the right of the cb and see it properly. There is one obvious place, one objective place to stand to have a reasonable chance of making the ball. Everyone can find that spot rather easily.
From that objective perspective, one then applies the visuals. From that rough spot, there is only one place to see the visuals correctly.
Now, if I want to bank the ball, there is another perspective for that. In this case, it happens to be fairly near to the place for cutting the ball in the corner, but clearly is a different perspective of the shot. From that place, one can also find the visuals for banking the ball.
So, if one is missing by diamonds, either they have no visual intelligence towards pool, or their initial perspective of the shot is scewed to start with. With a fairly decent stroke, one should at least be coming very close to making the shot if their perspective of it was correct to start with and they found the visuals and made the correct sweep or pivot.
For each of the three shots, one has to have a different perspective for each of them. Just like they would when aiming by feel. Again, your perspective is where you are initially lined up to sight in the shot. For the three shots, if one looks closely, you will find that you are actually angled a little more to the shots farthest from the rail.
When attaining the proper perspective of the shot, the pocket general area is important. You have to have a general idea of what direction you want the ob to go to. Once you have your perspective, the pocket is out of the equation, and once you have your visuals and a locked cb and determine which direction to pivot, the ob is out of the equation.
edit: Again, your perspective is your rough line that you need the cue to be on to make the shot. CTE then fine tunes that line to line you up to center pocket with no english.