12 Ways to AIM WITH A POOL CUE

dr_dave

Instructional Author
Gold Member
Silver Member
Thanks.

Measuring the gap between a ball and the rail with another ball is illegal. Wouldn't a cue with scales be a violation of the spirit of that rule?

I always wondered why cues never came with scales. I just figured it must be against the rules.


Jeff Livingston

I don't think the WPA "official rules of pool" prohibit use of the cue or the CB (in hand) as a gap-measuring ruler. CSI/BCAPL rules do prohibit this:

1-3.1g - You may only use your vision to judge whether the cue ball or an object ball would fit through a gap, or to judge what ball the cue ball would contact first. You may not use any ball, cue, rack, chalk cube, or any other equipment or other part of your body as a width-measuring device.

Neither WPA or CSI prohibit using the cue to help aim/visualize shots. Here's the pertinent CSI rule:

1-3.1f - You may use your cue, held in your hand or not, to help align a shot.
 

chefjeff

Nazis are back.
Silver Member
I don't think the WPA "official rules of pool" prohibit use of the cue or the CB (in hand) as a gap-measuring ruler. CSI/BCAPL rules do prohibit this:

1-3.1g - You may only use your vision to judge whether the cue ball or an object ball would fit through a gap, or to judge what ball the cue ball would contact first. You may not use any ball, cue, rack, chalk cube, or any other equipment or other part of your body as a width-measuring device.

Neither WPA or CSI prohibit using the cue to help aim/visualize shots. Here's the pertinent CSI rule:

1-3.1f - You may use your cue, held in your hand or not, to help align a shot.

I DO sometimes use my finger to find the center of the ghost ball. It's not the width of a gap but the spot I'm looking for, so I assume we can all do that and the things in the video without fouling. I play leagues, bcapl and others.

If the WPA is ok with it, why hasn't some cuemaker put out a line of "Cues that rule"?


Jeff Livingston
 

Patrick Johnson

Fish of the Day
Silver Member
I like it. Nice and simple. The advantage of using the cue or the shaft is: You can mark the cue with the ideal point instead of trying to estimate 1/4, which is itself an estimate. FYI, I did an analysis showing the error for the 1/4 (0.25) estimate, and I found the ideal length fraction, taking ball inelasticity and friction into account. Here it is:

TP B.24 - Estimating Rolling CB Carom Angle with 1/4 Cue Point

2/7 (0.286) is very close, but if you want it to be perfect, the ideal length fraction is 0.281. So if you are marking a standard 58" cue, the length is 16.3" (about 2" above the 1/4 point). And if you are marking a standard 29" shaft, the length is 8.2" (about 1" above the 1/4 point). And if you really want to be accurate, you still need to parallel-shift the carom line to account for tangent-line shift due to shot speed. Maybe I'll do a new video demonstrating all of this.

Catch you later,
Dave
So, a "fat quarter" plus a "speed shift".

Gotta put this to the test today...

pj
chgo
 

dr_dave

Instructional Author
Gold Member
Silver Member
I DO sometimes use my finger to find the center of the ghost ball. It's not the width of a gap but the spot I'm looking for, so I assume we can all do that and the things in the video without fouling. I play leagues, bcapl and others.

You can check for yourself. All rule sets can be found on the Pool Rule Differences Resource Page.

If the WPA is ok with it, why hasn't some cuemaker put out a line of "Cues that rule"?

I always thought every cue maker should mark the natural pivot length on every shaft. That way you could easily compare different shafts and immediately know how much to adjust for CB deflection.
 

chefjeff

Nazis are back.
Silver Member
Maybe you could make an aftermarket product that marks cues. Kinda like undercoating.

You'll be rich beyond your wildest dreams.


Jeff Livingston
 

dr_dave

Instructional Author
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Silver Member
Gotta dumb it down for myself or I'll never use it. :)

pj
chgo
Do you know what is even "dumber?" Put a small mark on your cue and just look down the line. No guesswork, estimating, or thinking required. Just point and shoot. :unsure:
 

Patrick Johnson

Fish of the Day
Silver Member
Do you know what is even "dumber?" Put a small mark on your cue and just look down the line. No guesswork, estimating, or thinking required. Just point and shoot. :unsure:
Sorry, Dave, I don't follow... how would this work?

Oh, wait... this is Bob's original method, right?

pj <- more dumber, please...
chgo
 
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Patrick Johnson

Fish of the Day
Silver Member
OK, one more whack at this horse's cadaver...

I tried this out today, both on a real table and on VP4 (shown below with my patented "point and shift" method of measuring).

The verdict: uncannily accurate, even more so on the real table.

Thanks, guys!

pj <- I know, I know... fingers!
chgo

carom.jpg
 

dr_dave

Instructional Author
Gold Member
Silver Member

dr_dave

Instructional Author
Gold Member
Silver Member
So, a "fat quarter" plus a "speed shift".

FYI, if you want to be a little more accurate with the "visual length factor approximation," the ideal factor 0.281 is between 1/4 (0.25) and 1/3 (0.33). So instead of a "fat quarter," you can use "between a quarter and a third."
 
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Patrick Johnson

Fish of the Day
Silver Member
FYI, if you want to be a little more accurate with the "visual length factor approximation," the ideal factor 0.281 is between 1/4 (0.25) and 1/3 (0.33). So instead of a "fat quarter," you can use "between a third and a half."
Will do. Thanks. (Assuming you mean "between 1/4 and 1/3".)

pj
chgo
 

Szymczak

New member
Another great post and video, thank you Dr. Dave!!!
#12=Visualizing 1 rail kicks raises a question I was about to start a thread on, maybe someone can answer here. In the number 12 example you use your cue to measure the distance from the cue ball to the diamonds, I was in that situation the other night and I used my cue to measure the distance from the center of the cue ball to the cushion for a 1 rail kick (I was not checking width to see if a ball would pass thru a gap) I was told that this was a foul and that you are not allowed to use your cue as a measuring device. According to BCAPL rules does anyone know if this is legal or not? I could only find info in the rules pertaining to measuring for a gap.
This is incorrect. . put your cue at the contact point of the object ball with the whole tip inside the diameter of the object then put your finger on the cue at the rail location and then slide it back till the cue tip meet the edge of the rail. Your figure on the cue back to the cue ball is your target. Use very little running if any to make this shot.
 

fastone371

Certifiable
Silver Member
This is incorrect. . put your cue at the contact point of the object ball with the whole tip inside the diameter of the object then put your finger on the cue at the rail location and then slide it back till the cue tip meet the edge of the rail. Your figure on the cue back to the cue ball is your target. Use very little running if any to make this shot.
What???? I guess I dont really understand what is incorrect here.

" I was in that situation the other night and I used my cue to measure the distance from the center of the cue object ball to the cushion for a 1 rail kick" Thats what I meant to say. I think thats what you are saying too.
 

dr_dave

Instructional Author
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Silver Member
... put your finger on the cue at the rail location and then slide it back till the cue tip meet the edge of the rail. Your figure on the cue back to the cue ball is your target.

The position of the reference line on the rail needs to change with shot speed (or you need to adjust the amount of sidespin, which is a risky proposition) if you want to be accurate over a wide range of shots. For more info, see the videos and other resources here:
 
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