Question about contact points?

CaptainJR

CaptainJR

Shiver me timbers.
Silver Member
We have done a lot of researching, experimenting and discussing aiming here. I'd like to take a little time to discuss the most common methods of aiming. Contact points or ghost ball are the most commonly used aiming technique. I would consider them almost one in the same. Maybe not quite but for the one question I'll be asking, I think will apply to both.

98 percent of the time I use feel (or familiarity) to pocket balls. However, all to often in crucial situations I stand over a shot, make my decisions and when I bend down to line up and shoot I'm just not certain I'm lined up perfectly. The majority of times it turns out that I am, but it is the pressure of the situation that brings that doubt across my mind. Having that doubt can be disastrous. Doubt can make you subconsciously make incorrect adjustments. It can lead to a tentative stroke. No good can come from doubt. This is when I need something to reassure myself that I'm lined up correctly.

So I'll check the contact point on the object ball, visualize the contact point on the cue ball and rethink my adjustments (if any). Hopefully make a true stroke and pocket the ball.

What is the problem with all this? With any aiming system adjustment are adjustments and if your going to use english you have to make them. What I'm talking about is that other word in that sentence that is an estimation. The word 'visualize'. You can't see the contact point on the cue ball because it is on the back side of it.

So, I'm wondering if there is a way to exclude this from the equation and just use the contact point on the object ball. I have noticed something and it seems to look right, but I'd sure like some confirmation so I don't have to wonder if it is my imagination LOL. So here goes. Maybe this is a common aiming system and I don't know it. That would be fine. I'm not trying to say I invented it. I just want to know if it is correct. I'm not going to bother with drawings. I think I'll be able to describe it well enough that someone that uses it will know what I'm talking about. If someone confirms it and someone else says 'what the heck are you talking about?' Then I'll do some drawings.

Once I've found the contact point on the object ball. (Using a cut to the right for this example) Looking from the shooting perspective, if you double the distance from the left edge of the object ball to the contact point and put the right edge of the cue ball on that line. Does that put the cue ball in the position of the ghost ball at contact? Whew, I know I said above that I thought I could explain it well enough for someone to recognize it, but reading this again I'm not to sure about that. I think somewhere along the way I've heard something about 'doubling the distance'. Is this what they are talking about?
 
CaptainJR, still trying to understand your description...

CaptainJR said:
...if you double the distance from the left edge of the object ball to the contact point...
Click to expand...
Double the distance in what direction? Are you simplying mirroring the contact point of the object ball about its left edge...such as this new point is to the left of the OB?

CaptainJR said:
...and put the right edge of the cue ball on that line. Does that put the cue ball in the position of the ghost ball at contact?
Click to expand...
If what I said above was correct, the you would completely miss the OB, since the right edge of the CB would be lined up to point not that doesn't touch the OB. I must be misunderstanding.

CaptainJR said:
I think somewhere along the way I've heard something about 'doubling the distance'. Is this what they are talking about?
Click to expand...
I've heard of "doubling the distance" when it talks about the center of the OB, not the contact point. If you draw a line that goes from the pocket through the center of the OB, and you double the distance of the OB's center to its edge that's opposite the pocket through that same line, then this resulting point is the center of the ghost ball. You then just aim the CB right at that new point. Maybe that's what you're trying to get at?
 
CaptainJR said:
Once I've found the contact point on the object ball. (Using a cut to the right for this example) Looking from the shooting perspective, if you double the distance from the left edge of the object ball to the contact point and put the right edge of the cue ball on that line. Does that put the cue ball in the position of the ghost ball at contact?
Click to expand...
Okay, I was rethinking what you said, and I think I know exactly what you're looking for.

For a cut shot to the right, you don't double the distance from the left edge of the OB to the contact point, but the right edge to the contact point. Then, you would line up not the right edge of the CB, but the left edge to this new point.

Let me put it another way. From the shooting perspective (again, from a cut shot to the right), you mirror the right edge of the OB about its contact point, such as this new point falls to the left of the OB (if it's a straight in shot, this new point will fall directly on the left edge of the OB). You then line up the left edge of the CB with this new point, and if you connect the dots, the CB will fall exactly where the idealized ghost ball should be.

If you draw up a diagram that shows the ghost ball in contact with the OB (top down view), a line that goes through the right edge of the OB and a parallel line that goes through the left edge of the CB, you'd notice that the contact point bisects (divides in two) these two parallel lines...thus proving the aiming system. Pretty cool CaptainJR...thanks.

EDIT: Actually, your description above CaptainJR is precisely correct if you meant a cut shot to the left, which is what I think you meant. ;)
 
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jsp said:
CaptainJR, still trying to understand your description...


Double the distance in what direction? Are you simplying mirroring the contact point of the object ball about its left edge...such as this new point is to the left of the OB?


If what I said above was correct, the you would completely miss the OB, since the right edge of the CB would be lined up to point not that doesn't touch the OB. I must be misunderstanding.


I've heard of "doubling the distance" when it talks about the center of the OB, not the contact point. If you draw a line that goes from the pocket through the center of the OB, and you double the distance of the OB's center to its edge that's opposite the pocket through that same line, then this resulting point is the center of the ghost ball. You then just aim the CB right at that new point. Maybe that's what you're trying to get at?
Click to expand...


I tried to make drawings, didn't do very good. In reference to your first quote of me.

A. ...if you double the distance from the left edge of the object ball to the contact point...
You ask 'in what direction. On a cut to the right the direction would be from left to right. From the left edge of the object ball to the contact point then continue right to double that distance. making a new point to the right of the contact point which is twice the distance from the left edge of the object ball as the contact point is.

Since you misunderstood because of my lousy explanation. Your second sentence doesn't apply.
 
hey- i get the same grief on crucial shots or tougher cuts-readjust because im not sure of myself....whether it be reaiming at time of stoke or what i call 'steering' the object ball in by moving my damn arm subconsciously while i'm stroking.. i use the ghost ball method of aiming.... so i trick myself on these shots by doing the following:
i walk up to the object ball and imagine where the ghost ball is supposed to beand at the center point of the ghost ball <where you should be aiming the center of your cueball> i put my finger on the table (no chalk or anything on my fingers so i'm not cheating) and when i decide that's the spot i want to hit i look at the cloth-there's always a ding, chalk mark, discoloration or something right within mm's of my imaginary aiming point. So i keep my eye on it, walk to the cue keeping my eye on the 'spot' --aim, review my stroke and stance then shoot for that spot.... i catch myself doubting that it's the right spot, but i just was there and that's the spot i know will sink the object ball. When i override doubts in my mind and control my stroke and aim for that spot where my finger was with good followthrough, i usually sink the ball... so that';s my little 'trick' it gives me a definitive target to push my cue through at...
An x bigtime player was watching me the other day and started talking about 1/2 ball aiming shots... i kinda get it and still am working at it.. when you know the cueball needs to contact 1/2 the object ball to sink it, he says look at the tip of your cue and aim that at the edge of the object ball... i've been trying it and it works some of the times-more for acute angle shots...
 
jsp said:
Okay, I was rethinking what you said, and I think I know exactly what you're looking for.

For a cut shot to the right, you don't double the distance from the left edge of the OB to the contact point, but the right edge to the contact point. Then, you would line up not the right edge of the CB, but the left edge to this new point.

Let me put it another way. From the shooting perspective (again, from a cut shot to the right), you mirror the right edge of the OB about its contact point, such as this new point falls to the left of the OB (if it's a straight in shot, this new point will fall directly on the left edge of the OB). You then line up the left edge of the CB with this new point, and if you connect the dots, the CB will fall exactly where the idealized ghost ball should be.

If you draw up a diagram that shows the ghost ball in contact with the OB (top down view), a line that goes through the right edge of the OB and a parallel line that goes through the left edge of the CB, you'd notice that the contact point bisects (divides in two) these two parallel lines...thus proving the aiming system. Pretty cool CaptainJR...thanks.

EDIT: Actually, your description above CaptainJR is precisely correct if you meant a cut shot to the left, which is what I think you meant. ;)
Click to expand...

No, on a cut to the right, the right edge of the object ball would have nothing to do with it.
 
jsp said:
Okay, I was rethinking what you said, and I think I know exactly what you're looking for.

For a cut shot to the right, you don't double the distance from the left edge of the OB to the contact point, but the right edge to the contact point. Then, you would line up not the right edge of the CB, but the left edge to this new point.

Let me put it another way. From the shooting perspective (again, from a cut shot to the right), you mirror the right edge of the OB about its contact point, such as this new point falls to the left of the OB (if it's a straight in shot, this new point will fall directly on the left edge of the OB). You then line up the left edge of the CB with this new point, and if you connect the dots, the CB will fall exactly where the idealized ghost ball should be.

If you draw up a diagram that shows the ghost ball in contact with the OB (top down view), a line that goes through the right edge of the OB and a parallel line that goes through the left edge of the CB, you'd notice that the contact point bisects (divides in two) these two parallel lines...thus proving the aiming system. Pretty cool CaptainJR...thanks.

EDIT: Actually, your description above CaptainJR is precisely correct if you meant a cut shot to the left, which is what I think you meant. ;)
Click to expand...


OK, I'll try this. Now the drawing isn't accurate but maybe it will clear it up. Black line is left edge of object ball. Red line points to contact point. Green line points to spot double the distance of the contact point from the left edge of object ball.

START(
%AH2I9%Hr5O7%PQ8L2%WI3K1%XO1S2%YJ4J0%ZX3H5%]G2J5%^Z8N5

)END
 
CaptainJR said:
A. ...if you double the distance from the left edge of the object ball to the contact point...
You ask 'in what direction. On a cut to the right the direction would be from left to right. From the left edge of the object ball to the contact point then continue right to double that distance. making a new point to the right of the contact point which is twice the distance from the left edge of the object ball as the contact point is.
Click to expand...
Yes, you're correct! I went the wrong way. You would also get the ghost ball with this method, but you'd also get the ghost ball with the method i described above, but with the other edge of the CB.

It's cool, cuz we listed 4 different ways to get at the ghost ball, and each lines up a different part of the CB. You can either line up the contact point, center, outside edge, or inside edge using the methodologies we described. You can just pick and choose what method works best for you. :)
 
jsp said:
Yes, you're correct! I went the wrong way. You would also get the ghost ball with this method, but you'd also get the ghost ball with the method i described above, but with the other edge of the CB.

It's cool, cuz we listed 4 different ways to get at the ghost ball, and each lines up a different part of the CB. You can either line up the contact point, center, outside edge, or inside edge using the methodologies we described. You can just pick and choose what method works best for you. :)
Click to expand...



WE GOT THERE YYEEAAAAAAAA! LOL
 
jsp said:
Yes, you're correct! I went the wrong way. You would also get the ghost ball with this method, but you'd also get the ghost ball with the method i described above, but with the other edge of the CB.

It's cool, cuz we listed 4 different ways to get at the ghost ball, and each lines up a different part of the CB. You can either line up the contact point, center, outside edge, or inside edge using the methodologies we described. You can just pick and choose what method works best for you. :)
Click to expand...


Hmmm, I'm thinking........ I see two ways. I'm missing two. Double the distance from the right edge to the contact point, and double the distance from the left edge to the contact point. I don't see the other two ways.


In any case, it sure is simple and works on any shot.
 
CaptainJR said:
... Once I've found the contact point on the object ball. (Using a cut to the right for this example) Looking from the shooting perspective, if you double the distance from the left edge of the object ball to the contact point and put the right edge of the cue ball on that line. ...
Click to expand...
This system has been described several times in print, including

http://www.sfbilliards.com/articles/1999-11.pdf

http://www.sfbilliards.com/articles/2004-06.pdf

It was also in Robert Byrne's December 1989 column in Billiards Digest, which is reprinted in his "Wonderful World of Billiards." In that column, he credits Paul Hahn with its invention.
 
jsp said:
Okay, I was rethinking what you said, and I think I know exactly what you're looking for.

For a cut shot to the right, you don't double the distance from the left edge of the OB to the contact point, but the right edge to the contact point. Then, you would line up not the right edge of the CB, but the left edge to this new point.
Click to expand...


Let's see.. For a cut shot, if you use the left edge, and double the distance (going to the right) from the left edge to the contact point, the right edge of the CB should align with that new point.

It's both. The contact point to either left or right edge should have an equal distance wrt to the cueball (if you could properly overlap the two).

And yes, CaptainJR, this is what they're talking about when they say "Double the Distance."

Also, check out Joe Tucker's aiming system. You'll see that it takes care of the whole "I can't see the contact point of the cueball" issue.


Fred <~~~ or you could try ball-to-ball relation aiming, or edge aiming
 
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Good thread if i ain't using the aim and pivot then i aim with familiarity, nyce way to say it CaptainJR.
 
CaptainJR said:
Hmmm, I'm thinking........ I see two ways. I'm missing two. Double the distance from the right edge to the contact point, and double the distance from the left edge to the contact point. I don't see the other two ways.
Click to expand...
Both ways are identical, geometrically speaking, if the cueball and object balls are the same size, but not so if they aren't. One method introduces much more error into the object balls direction than the other, when the error is due to differences in the ball's diameters. Where I play you can't take this for granted.

With either method you're essentially centering the contact point between the appropriate edges. For the cut shot to the right, centering the contact point between the left edge of the object ball and the right edge of the cueball is much better than centering it between the right edge of the object ball and the left edge of the cueball. In other words, centering it between the edges closest to it produces less error than centering it between the edges farthest from it.

The contact point is also equidistant between the centers of the balls. For mild cut angles, using the centers of the balls is more accurate than using the edges, as far as ball size differences go, but with the obvious caveat that the centers are hardly as well defined as the edges. This may well negate its advantage and depends on how well a player can visualize them.

For large cut angles, centering it between the closest edges is better than centering it between the ball's centers. I think the dividing line is, not too surprisingly, a 30 degree or half-ball hit.

It was pretty astute of you to figure out the double the distance formula without, apparently, any recourse to compass and protractor.

Jim
 
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