# Couple of interesting things about side spin

#### Patrick Johnson

##### Fish of the Day
Silver Member
The scale drawing below shows an overhead view of three cues hitting three cue balls at different offsets - cue moved 1/4", 1/2" and 3/4" to the left. Just for fun, it also compares where nickel and dime shaped tips contact the CB at those offsets, assuming the cue's centerline is offset the same amount.

I notice two interesting things:

1. These three very common tip offsets - often called 1, 2 & 3 (or 1/2, 1 and 1 1/2) "tips" - produce almost exactly 1/3, 2/3 and 3/3 of maximum sidespin (the red lines on the CB), which correspond to 1, 2 and 3 diamonds of cross-table angle change. I just find this correspondence remarkably convenient.

2. The difference in contact points for nickel and dime shaped tips (shown by the circles at the cues' tips and the lines connecting their centers with the CB's center) is almost nonexistent: 1/128" at 1/3 max sidespin, 1/64" at 2/3 max sidespin and less than 1/32" at maximum sidespin (true for nickel and dime tips of any width). So how true is it really that a dime shaped tip can produce noticeably more spin for the same tip offset?

Doing my part to use up these damned pixels...

pj
chgo

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#### slide13

##### AzB Silver Member
Silver Member
Interesting, never realized a dime and nickel radius were so close to each other when it comes to contact point. Good to know, thanks for sharing.

#### Neil

##### AzB Silver Member
Silver Member
Pat, your diagram would reference a tip with no compression. I believe that in actuality, the difference is even less due to compression of the tip.

#### Patrick Johnson

##### Fish of the Day
Silver Member
Pat, your diagram would reference a tip with no compression. I believe that in actuality, the difference is even less due to compression of the tip.
That could be, Neil - interesting point.

pj
chgo

#### 336Robin

##### Multiverse Operative
Silver Member
I agree with Neil

Pat, your diagram would reference a tip with no compression. I believe that in actuality, the difference is even less due to compression of the tip.

I have at times played banks with a heavier shaft and a skinnier shaft. I always preferred the heavier shaft because it felt as if I had more control in that particular game. Im not sure why that is but perhaps its because there is less shaft bend and because of you feel as if you are just a little more in charge of things but I have made some great bank shots with a skinny shaft although it seems as if I have to pay very close attention to what I am doing.

I think this factor might be the confidence factor as it pertains to shaft vibration and control of the physics of the shaft.

I'm not sure how one would measure that but it could be argued that even these slight differences in contact point could be viewed as differences that one could say they could feel although that is unlikely.

There is something different between playing banks with those two different types of shafts I prefer a less skinny one at least somewhere around 12.75 but that is my preference.

#### Patrick Johnson

##### Fish of the Day
Silver Member
Interesting, never realized a dime and nickel radius were so close to each other when it comes to contact point. Good to know, thanks for sharing.
I was a little surprised too, but it made sense once I understood the geometry.

I realized that when spheres (or circles) touch, their contact points are offset from their respective centers in the same ratio as their sizes. So, for instance, when the spheres are the same size the contact point is midway between their centers (the principle we're familiar with in "double overlap" aiming). But when the spheres/circles are different sizes (like balls and rounded tips), then the contact point is closer to the smaller one's center, but still in ratio with their sizes.

A pool ball (2.25" dia) is about 3 times the size of a dime or nickel (~11/16" & 13/16" dia), so their shared contact point is ~3 times as far from the ball's center as it is from the tip's center (~3/4 of the way from ball center to tip center). But the difference between the two coin sizes is much smaller, so the difference in their ratios with the much bigger ball is even less - only about 6% difference.

pj <- had to get that off my chest
chgo

#### Patrick Johnson

##### Fish of the Day
Silver Member
I have at times played banks with a heavier shaft and a skinnier shaft. I always preferred the heavier shaft because it felt as if I had more control in that particular game. Im not sure why that is but perhaps its because there is less shaft bend and because of you feel as if you are just a little more in charge of things but I have made some great bank shots with a skinny shaft although it seems as if I have to pay very close attention to what I am doing.

I think this factor might be the confidence factor as it pertains to shaft vibration and control of the physics of the shaft.

I'm not sure how one would measure that but it could be argued that even these slight differences in contact point could be viewed as differences that one could say they could feel although that is unlikely.

There is something different between playing banks with those two different types of shafts I prefer a less skinny one at least somewhere around 12.75 but that is my preference.
Shaft size doesn't make any difference in contact point location - only tip curvature (the "size" of the curve) matters. Notice the shafts in my drawing are the same.

So you're "feeling" something else.

pj
chgo

#### ENGLISH!

##### Banned
Silver Member
Small differences can be HUGE in a game of millimeters.

It's not just about the small differences at the contact on the cue ball.

It's about the differences that they yield in the results.

As a tip compresses it also wraps around & it's about how the ball is 'released' out of contact.

Hard tip...less compression & less wrapping than a medium tip.

Soft tip... more compression & more wrapping than a medium tip.

Different releases & then throw in a different size & radius tip.

Too often parameters are too isolated in 'discussions'. The big picture should be kept in mind.

Just food for thought. Not interested in any arguments.

Each individual player can & will have to do their own thinking to make their own determinations, perhaps after doing some experimenting own their own.

Best 2 ALL.

PS If anyone thinks that differences do not yield differences, they certainly have the right to think that way & any other way that they choose to think. Each individual should be responsible for their own game.

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#### ENGLISH!

##### Banned
Silver Member
I have at times played banks with a heavier shaft and a skinnier shaft. I always preferred the heavier shaft because it felt as if I had more control in that particular game. Im not sure why that is but perhaps its because there is less shaft bend and because of you feel as if you are just a little more in charge of things but I have made some great bank shots with a skinny shaft although it seems as if I have to pay very close attention to what I am doing.

I think this factor might be the confidence factor as it pertains to shaft vibration and control of the physics of the shaft.

I'm not sure how one would measure that but it could be argued that even these slight differences in contact point could be viewed as differences that one could say they could feel although that is unlikely.

There is something different between playing banks with those two different types of shafts I prefer a less skinny one at least somewhere around 12.75 but that is my preference.

Robin,

Some can feel differences & some can not. Some can feel the tip on the ball & some can not.

Like I said, If anyone thinks that differences do not yield differences they are certainly entitled to think that way & any other way that they choose or wish to think.

Best to YOU & All.

PS I have 2 - 11.75 mm conical taper OB Pro Shafts & I have a Predator 314 CAT that has been juiced, sanded down, to 12 mm with a very long pro taper that is even a bit more narrow about 15" from the tip. The Cat shaft squirts less & spins the ball more. Yes the tips are not exactly the same & other parameters are not exactly the same, BUT the results are very different. I prefer the more stiff OB shafts then the flexible juiced Predator for overall play BUT I like that Predator in close quarters like just 1/2 the table. I can easily see the game evolving to where players will one day be using different cues for different shots just as golfers use different clubs for different shots, as long as the shot clock does not become prohibitive of that.

#### Patrick Johnson

##### Fish of the Day
Silver Member
...The difference in contact points for nickel and dime shaped tips (shown by the circles at the cues' tips and the lines connecting their centers with the CB's center) is almost nonexistent: 1/128" at 1/3 max sidespin, 1/64" at 2/3 max sidespin and less than 1/32" at maximum sidespin (true for nickel and dime tips of any width). So how true is it really that a dime shaped tip can produce noticeably more spin for the same tip offset?
One last point: these small differences are smaller than any player's cueing accuracy, even pros. In other words, if you see differences in the amount of spin you get from tip to tip, it's more likely because of the inaccuracy of your stroke than the shape of your tip.

pj
chgo

#### JB Cases

##### www.jbcases.com
Silver Member
Interesting, never realized a dime and nickel radius were so close to each other when it comes to contact point. Good to know, thanks for sharing.
Known that for a while. I did several similar drawings when developing the Cuesight training ball.

It is why I made one side of the ball have little circles that represent the contact patch so that players can more easily visualize the amount of tip that will contact the ball.

Sent from my SAMSUNG-SM-N900A using Tapatalk

#### Patrick Johnson

##### Fish of the Day
Silver Member
I made one side of the ball have little circles that represent the contact patch so that players can more easily visualize the amount of tip that will contact the ball.
Maybe I misunderstand your point, but I don't think the size of the contact patch has anything to do with the difference in contact points.

pj
chgo

#### ENGLISH!

##### Banned
Silver Member

As the tip goes more offset & the 'curve' of the cue ball comes more into play since the tangent angle on the ball changes those small differences can become more apparent, as the tip is making contact more 'around' the ball.

Some individuals stay close to center while others venture farther out when 'needed' or desired.

Some can feel, note, or see the different results while others seem incapable of discerning the differences.

One's stroke accuracy is not the deciding factor regarding the differences.

The same stroke with differences in equipment will yield different results.

Again just food for thought.

Best 2 All.

PS Again, if anyone chooses to think or believe that differences do not yield differences that is certainly their right to think or believe as they choose.

#### JB Cases

##### www.jbcases.com
Silver Member
Maybe I misunderstand your point, but I don't think the size of the contact patch has anything to do with the difference in contact points.

pj
chgo
My point was that the contact point difference is miniscule between radius sizes and that it's better imo to think of spin offset as a larger and actual 'patch' of tip rather than a point to a point.

Having studied slow motion video it is clear that the tip compresses to about a 3mm section that actually moves the cue ball. This is why I made the circles 3mm apart. Each one simulates approximately a 1/2 tip offset from the shooter's perspective.

Sent from my SAMSUNG-SM-N900A using Tapatalk

#### Patrick Johnson

##### Fish of the Day
Silver Member
My point was that the contact point difference is miniscule between radius sizes and that it's better imo to think of spin offset as a larger and actual 'patch' of tip rather than a point to a point.
Maybe I still don't understand, but the amount of offset isn't determined by the size of the contact patch; it's where the center of the patch is located on the ball (regardless of the patch's size).

Having studied slow motion video it is clear that the tip compresses to about a 3mm section that actually moves the cue ball. This is why I made the circles 3mm apart. Each one simulates approximately a 1/2 tip offset from the shooter's perspective.
To each his own, but I think a "1/2 tip" is most commonly considered to be related to the size of the actual cue's tip.

My 1st point above is that when the tip is moved sideways 1/2 the tip's width (assuming a common tip width of 12.75mm), then 1) it's visually easy to measure, and 2) it moves the contact point almost exactly 1/3 of maximum offset (a convenient fraction for estimating spin effect).

Of course you can move the tip any amount no matter how you visualize it; this "1/2 physical width = 1/3 of maximum spin" is just a conveniently memorable way to gauge it.

pj
chgo

#### 336Robin

##### Multiverse Operative
Silver Member
Correct as I stated

Shaft size doesn't make any difference in contact point location - only tip curvature (the "size" of the curve) matters. Notice the shafts in my drawing are the same.

So you're "feeling" something else.

pj
chgo

Exactly as I stated, I guess I related tip curvature to shaft diameter so that is my bad. I haven't noticed and real differences banking with different tip curvature.

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#### ronscuba

##### AzB Silver Member
Silver Member
One last point: these small differences are smaller than any player's cueing accuracy, even pros. In other words, if you see differences in the amount of spin you get from tip to tip, it's more likely because of the inaccuracy of your stroke than the shape of your tip.

pj
chgo

Can't argue with the geometry and science you list.

But there are repeatable results in reference to different tip shapes and tip sizes.

In the hands of a human being, a thinner shaft with a smaller tip will tend to spin more. Exactly why is up for debate, but it's hard to argue with the results.

Take 10 average league players. Let them shoot with a 13mm shaft nickel shaped tip vs an 11mm shaft dime shaped tip. What do you think the results would be ?

Is it possible the thinner shaft and smaller tip exposes stroke inaccuracies ?

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#### Patrick Johnson

##### Fish of the Day
Silver Member
In the hands of a human being, a thinner shaft with a smaller tip will tend to spin more. Exactly why is up for debate, but it's hard to argue with the results.
What results? What actual evidence is there aside from what some players think happens?

pj
chgo

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#### dr_dave

##### Instructional Author
Gold Member
Silver Member
Nice post, Pat.

FYI, for future reference, I've added a quote and link to the "tips" of english, and percentage english resource page, where much more additional and related info is also available.

Regards,
Dave

The scale drawing below shows an overhead view of three cues hitting three cue balls at different offsets - cue moved 1/4", 1/2" and 3/4" to the left. Just for fun, it also compares where nickel and dime shaped tips contact the CB at those offsets, assuming the cue's centerline is offset the same amount.

I notice two interesting things:

1. These three very common tip offsets - often called 1, 2 & 3 (or 1/2, 1 and 1 1/2) "tips" - produce almost exactly 1/3, 2/3 and 3/3 of maximum sidespin (the red lines on the CB), which correspond to 1, 2 and 3 diamonds of cross-table angle change. I just find this correspondence remarkably convenient.

2. The difference in contact points for nickel and dime shaped tips (shown by the circles at the cues' tips and the lines connecting their centers with the CB's center) is almost nonexistent: 1/128" at 1/3 max sidespin, 1/64" at 2/3 max sidespin and less than 1/32" at maximum sidespin (true for nickel and dime tips of any width). So how true is it really that a dime shaped tip can produce noticeably more spin for the same tip offset?

Doing my part to use up these damned pixels...

pj
chgo

View attachment 53737

#### dr_dave

##### Instructional Author
Gold Member
Silver Member
Shaft size doesn't make any difference in contact point location
... unless somebody uses a literal interpretation of "tips of english." Half a large-diameter tip is larger than half a small-diameter tip. Also, a smaller-diameter shaft will typically have less endmass and produce slightly less squirt (CB deflection). That can also have a small effect on how much sidespin is applied for a given tip offset.

For those interested, more info and illustrations related to these topics can be found here:

"tips" of english

tip size and shape effects

getting more spin with an LD shaft

Enjoy,
Dave