Fractional Aiming "Coverage" vs. Distance to Pocket

[Patrick Johnson]

FYI, here's a diagram that shows the relative amount of "coverage" for fractional cuts into a 4.5" corner pocket, taking into account "pocket slop", CB/OB distance and "effective" pocket size (angle of approach).

In these three examples:
- less than 1/2 of all possible cuts can be made from 17.5" (left pic)
- less than 1/4 of all possible cuts can be made from 35" (middle pic)
- less than 1/4 of all possible cuts can be made from 14.5" close to the rail (right pic).

pj
chgo

View attachment 63729

 

[Neil]

Pat, I don't want to say your diagram is wrong per se, but, I would be more inclined to say that it is closer to fractional aiming 101 when there are advanced versions of fractional aiming.

Your diagrams get one in the ball park of starting to use that aiming method, but it is not complete.

Try this with your diagrams and see how small the area of non-compliance actually is....
Set up a striped ball as the ob, for now, just put it on the head spot. Take the 8 ball and set it up as a ghost ball to make the ob. (the dark 8 makes a nice contrast to the white or light color of a striped ball, 9 ball works good for the ob)

Then place the cb along the rail (I did this on a bar table, but still gives decent distance between the two) and line up the stripe on the ob so it is centered vertically with the cb.

Once the cb is behind the head string, you obviously cannot use the center of the cb to align with the ob. So, use the edge of the cb to align. Look at the edge of the cb, and see where it aligns with the edge of the 8 ball on the striped object ball. Now, each time you move the cb, also re-align the stripe of the ob to be centered with the cb.

What you are looking for at each position of the cb is either the edge or the center of the cb aligning to a part of the ob. Once familiar with that, you can also use 1/8 and 1/4, ect. cb to align to parts of the ob. (the more advanced version of the system) Once doing this, you will not the correlation to the equal/opposite contact aiming system. They are actually close cousins.

Now, fractional aiming is not perfect. There are gaps in it. However, not as big of gaps as you think there are. Where fractional aiming can really help, is as a double check. Much more often than not, when going a little brain dead or vision impaired due to pressure, tiredness, whatever, you still will have the ability to at least aim the ob close to the pocket. Once that is done, use fractional aiming as a double check method. Are you aligned to a fraction of the ball when you think you are close to the proper position of aiming? If not, go ahead and make the minute adjustment to a fraction, and shoot. Far more often than not, you will make the ball that way.

 

[Patrick Johnson]

Pat, I don't want to say your diagram is wrong per se, but, I would be more inclined to say that it is closer to fractional aiming 101 when there are advanced versions of fractional aiming.

Your diagrams get one in the ball park of starting to use that aiming method, but it is not complete.

Try this with your diagrams and see how small the area of non-compliance actually is....
Set up a striped ball as the ob, for now, just put it on the head spot. Take the 8 ball and set it up as a ghost ball to make the ob. (the dark 8 makes a nice contrast to the white or light color of a striped ball, 9 ball works good for the ob)

Then place the cb along the rail (I did this on a bar table, but still gives decent distance between the two) and line up the stripe on the ob so it is centered vertically with the cb.

Once the cb is behind the head string, you obviously cannot use the center of the cb to align with the ob. So, use the edge of the cb to align. Look at the edge of the cb, and see where it aligns with the edge of the 8 ball on the striped object ball. Now, each time you move the cb, also re-align the stripe of the ob to be centered with the cb.

What you are looking for at each position of the cb is either the edge or the center of the cb aligning to a part of the ob. Once familiar with that, you can also use 1/8 and 1/4, ect. cb to align to parts of the ob. (the more advanced version of the system) Once doing this, you will not the correlation to the equal/opposite contact aiming system. They are actually close cousins.

Now, fractional aiming is not perfect. There are gaps in it. However, not as big of gaps as you think there are. Where fractional aiming can really help, is as a double check. Much more often than not, when going a little brain dead or vision impaired due to pressure, tiredness, whatever, you still will have the ability to at least aim the ob close to the pocket. Once that is done, use fractional aiming as a double check method. Are you aligned to a fraction of the ball when you think you are close to the proper position of aiming? If not, go ahead and make the minute adjustment to a fraction, and shoot. Far more often than not, you will make the ball that way.

Sorry, Neil, but I don't follow you're description. Maybe we could start with this:

"What you are looking for at each position of the cb is either the edge or the center of the cb aligning to a part of the ob."

Aligning the edge of the CB with fractions of the OB creates the same fractional cut angles as aligning the center of the CB with fractions of the OB. Did you mean to suggest otherwise?

pj
chgo

 

[Neil]

Sorry, Neil, but I don't follow you're description. Maybe we could start with this:

"What you are looking for at each position of the cb is either the edge or the center of the cb aligning to a part of the ob."

Aligning the edge of the CB with fractions of the OB creates the same fractional cut angles as aligning the center of the CB with fractions of the OB. Did you mean to suggest otherwise?

pj
chgo

You can't always align the center of the cb with a fraction of the ob because the center of the cb will be aligned off the ob out in space. There's your start....

 

[iusedtoberich]

You can't always align the center of the cb with a fraction of the ob because the center of the cb will be aligned off the ob out in space. There's your start....

True. But the diagrams are not meant as an aid for your eyes (IMO, maybe I didn't understand Pat's intent). They are intended to geometrically show what shots are possible with the standard ball overlap fractions, where the gaps are, and how both change as the shot distance changes. Nothing more, nothing less, IMO.

 

[Neil]

True. But the diagrams are not meant as an aid for your eyes (IMO, maybe I didn't understand Pat's intent). They are intended to geometrically show what shots are possible with the standard ball overlap fractions, where the gaps are, and how both change as the shot distance changes. Nothing more, nothing less, IMO.

And I'm just showing that the gaps are not that large when the system is used properly.

 

[iusedtoberich]

And I'm just showing that the gaps are not that large when the system is used properly.

If we assume PJ's drawing is mathematically accurate (I have not personally investigated it, and do not plan on it), then what more is there in "real life pool"?

This is just saying if you hit the OB at 1/4, 1/2, etc. overlaps, and take into account the margin of error of the pocket opening, you have only the possibilities in his drawing.

I'll take it one step further than Patrick, I think the margin of error is way, way less than what is on his drawings. The reason is, for the ball to go in clean, you are really only trying to hit a tiny fraction of the available pocket. Maybe just a 1" width to truly make the ball properly. If Patrick were to redo his drawing with a margin of error only 1" wide inside the pockets, then the gaps would become even larger.

 

[Neil]

If we assume PJ's drawing is mathematically accurate (I have not personally investigated it, and do not plan on it), then what more is there in "real life pool"?

This is just saying if you hit the OB at 1/4, 1/2, etc. overlaps, and take into account the margin of error of the pocket opening, you have only the possibilities in his drawing.

I'll take it one step further than Patrick, I think the margin of error is way, way less than what is on his drawings. The reason is, for the ball to go in clean, you are really only trying to hit a tiny fraction of the available pocket. Maybe just a 1" width to truly make the ball properly. If Patrick were to redo his drawing with a margin of error only 1" wide inside the pockets, then the gaps would become even larger.

Well, take what I wrote and check it out yourself. I know for a fact that the margin of error properly using the fractional system is much less than he showed. Not going to argue it, just try it out. If it helps someone, fine, if not, then just dismiss it.

 

[Patrick Johnson]

You can't always align the center of the cb with a fraction of the ob because the center of the cb will be aligned off the ob out in space.

I don't know what you think this changes. Yes, for cuts thinner than 1/2 ball it's easier to align the CB's edge with the OB's fractions - but that produces the same fractions and cut angles shown in my diagram.

The only way to increase the coverage for fractional alignments is to introduce smaller fractions (7/8, 5/8, 3/8) - but then you're making the system too detailed to be a useful simplification of the aiming process.

pj
chgo

 

[Neil]

I don't know what you think this changes. Yes, for cuts thinner than 1/2 ball it's easier to align the CB's edge with the OB's fractions - but that produces the same fractions and cut angles shown in my diagram.

The only way to increase the coverage for fractional alignments is to introduce smaller fractions (7/8, 5/8, 3/8) - but then you're making the system too detailed to be a useful simplification of the aiming process.

pj
chgo

Yes, as I stated with 1/8, you use eighths also. I don't feel it makes it complicated at all, no harder to look at an eighth than it is to look at a quarter.

 

[Patrick Johnson]

Yes, as I stated with 1/8, you use eighths also. I don't feel it makes it complicated at all, no harder to look at an eighth than it is to look at a quarter.

Of course adding more fractions would be a refinement, but I have to disagree that 8ths are no harder to visualize than 4ths - by that logic are 16ths no harder than 8ths?

Fractional aiming is even commonly called "quarters". I included a 1/8 cut (not other 8ths) only because otherwise the system includes no cuts thinner than 48 degrees. CTE, the most well known fractional system around here, includes it (but not other 8ths) for the same reason. Hal Houle's "3 angles" fractional system, the original popularized one, didn't include a 1/8 alignment (hence the "3 angles" name).

Anyway, the diagram is accurate for what's commonly known as "fractional" aiming or "quarters" aiming (plus 1/8). Do you know of other refinements than adding more fractions?

pj
chgo

 

[Neil]

Of course adding more fractions would be a refinement, but I have to disagree that 8ths are no harder to visualize than 4ths - by that logic are 16ths no harder than 8ths?

Fractional aiming is even commonly called "quarters". I included a 1/8 cut (not other 8ths) only because otherwise the system includes no cuts thinner than 48 degrees. CTE, the most well known fractional system around here, includes it (but not other 8ths) for the same reason. Hal Houle's "3 angles" fractional system, the original popularized one, didn't include a 1/8 alignment (hence the "3 angles" name).

Anyway, the diagram is accurate for what's commonly known as "fractional" aiming or "quarters" aiming (plus 1/8). Do you know of other refinements than adding more fractions?

pj
chgo

Well, if you want to limit the fraction system to just 1/4's, then you are stuck at fractions 101. Very limited as you stated. Don't understand why one would want to do that though. That's like teaching to aim only using one eye, and later learning to use both eyes.

As to other refinements, some, not all, can also learn to use the edges of the ferrules for finding fractions. However, it is a very subjective method as it does not use straight edge sighting down the edges of the cue, but rather peripheral vision sighting down the edges. However, once one learns to use it, for that person, it can become very near objective as that person sees the same every time where for another may see it differently, but still the same every time for him.

 

[Patrick Johnson]

Well, if you want to limit the fraction system to just 1/4's, then you are stuck at fractions 101. Very limited as you stated. Don't understand why one would want to do that though. That's like teaching to aim only using one eye, and later learning to use both eyes.

I'm sure with your experience you can see 1/8s very well. As you say, my diagram shows fractional aiming in its basic form, as most describe it and begin using it - its only purpose is to illustrate the concept of "partial coverage" and "reference cuts". If I used it or taught it, I'd stick with 1/4s because I think 1/8s is beyond the point of diminishing returns (for most) for a "reference" system like this.

As to other refinements, some, not all, can also learn to use the edges of the ferrules for finding fractions. However, it is a very subjective method as it does not use straight edge sighting down the edges of the cue, but rather peripheral vision sighting down the edges. However, once one learns to use it, for that person, it can become very near objective as that person sees the same every time where for another may see it differently, but still the same every time for him.

The way I'd say the part in blue above is that with enough practice any aiming method comes to feel as if it's objective - and a "reference" system like fractional aiming, with its familiar fixed "landmarks", can make that happen faster and be more resilient. Although I don't use fractions, I do use the OB contact point in a similar way as a kind of reference, and it does feel "objective" in a sense.

Also, your mention of different players seeing things differently but consistently for themselves is very insightful. I agree that it doesn't matter so much whether you see the fractions (or any other reference) geometrically accurately, so long as you see them the same way every time - you'll learn to use them accurately regardless.

Enjoy your comments, as always,

pj
chgo

 

[Ralph Kramden]

FYI, here's a diagram that shows the relative amount of "coverage" for fractional cuts into a 4.5" corner pocket, taking into account "pocket slop". We probably all know that it changes with distance, but maybe we don't realize how much.

In these two examples, less than 1/2 of all possible cuts can be made from 17.5" (1 diamond intersection, shown on right), and less than 1/4 of all possible cuts can be made from 35" (2 diamonds intersection - aka the spot, shown on the left).

pj
chgo

View attachment 49150

Nice diagram pj.
If the object ball is anywhere other than 45 degrees (straight into the pocket center)
the error increases. One pocket side must be favored.. with a smaller contact point.

Just my observation.

 

[Patrick Johnson]

Nice diagram pj.
If the object ball is anywhere other than 45 degrees (straight into the pocket center)
the error increases. One pocket side must be favored.. with a smaller contact point.

Just my observation.

Yes, that's true of course - except when the OB gets close to a rail shooting into a corner pocket. Then the "mirror" effect of the rail increases the "effective" pocket size (almost as big as the 45-degree pocket).

pj
chgo

P.S. You make a good point about fractional aiming too: the OB's angle to the pocket also changes fractional coverage - this 45-degree shot to the corner is the best case scenario.

 

[Ralph Kramden]

Yes, that's true of course - except when the OB gets close to a rail shooting into a corner pocket. Then the "mirror" effect of the rail increases the "effective" pocket size (almost as big as the 45-degree pocket).

pj
chgo

:yes: ... We must be playing on the same table...

.

 

[duckie]

In simple terms....as the distance from the pocket increases, the margin for error area on the OB decreases or in my terms, the impact area decreases. Impact area being the area of the OB that the CB can impact iand the OB goes in the pocket somewhere.

What's missing is showing how the OB angle into the pocket controls how much of the impact area can be used.

Really has nothing to do with any aiming method.....pure geometry which applies to all methods of aiming.

 

[Patrick Johnson]

What's missing is showing how the OB angle into the pocket controls how much of the impact area can be used.

Good point. As I said to Ralph Kramden above: "...the OB's angle to the pocket also changes fractional coverage - this 45-degree shot to the corner is the best case scenario."

pj
chgo

[EDIT] FYI, I've edited my original post to show the effect of pocket approach angle. Thanks!