Object ball "Skid" - real or just a BS excuse?

[TheOne]

Dude, you don't get it. You might be right, you might be wrong, I don't care, but saying "scientifically proven"? People do some little experiment and draw their own conclusions and say things are proven, and they don't have the slightest idea of what a null hypothesis is or the rigors of scientific study.

Like I said before, the experiment you described is only at best proving that chalk on the balls is NOT THE ONLY cause of skids. It didn't prove chalk doesn't or can't cause skids, and it doesn't prove that chalk does.

"Scientifically proven" requires a scientific design with no motive going into it, replication, statistical scrutiny, etc.

Does smoking cause lung cancer? I know someone who died of lung cancer, and they never smoked, so therefore it is proven that smoking does not cause lung cancer. That is the same argument you are making by stating the Mike Davis experiment proves chalk marks don't cause skids.

You can make arguments as to why you have your opinion and give examples of experiments that you think might give some credence to your opinion, but the scientifically proven talk is down right laughable.
Kelly

Not as laughable as your smoking analogy but we'll have to agree to disagree. They once tested babies who live in smoke free homes and they found trace's of nicotine in their lungs, everybody knows we all smoke whether we like it or not.

A unniveristy professor did a controlled experiment and easily recreated massive kicks with ZERO chalk present. I have seen similar experiments like the one willie mentions where both balls where completely covered in chalk and hundreds of shots where played without a single kick. For me this is enough eveidence to suggest that chalk is not the cause of kicks/skids.

Now if they had played a thousand shots with ZERO chalk on both balls and where unable to recreate a kick then I would consider the chalk theory to have more weight, fact is it was simple to recreate a kick with ZERO chalk.

 

[Colin Colenso]

Its like the blind leading the blind lol!

Zero chalk on cue ball or tip = massive kick!

The less said about using IE or OE to avoid kicks the better!

PS
The POMS have more innovations and inventions to their name than any other nation hehe!

I'd like to see how they conducted that experiment. It is possible that after they cleaned the balls, they induced a static charge on the surface, attracting dust particles from the air and cloth as the ball rolled.

The players are still asking for the CB to be cleaned regularly for chalk marks I see, so seems like they're not sold on this experiment's conclusions.

Anyway, would need to know more about this experiment to draw any useful conclusion. For now I'll just assume you're MAD

Colin

 

[Williebetmore]

I have seen similar experiments like the one willie mentions where both balls where completely covered in chalk and hundreds of shots where played without a single kick.

fact is it was simple to recreate a kick with ZERO chalk.

TheSmallestSingleInteger,
Actually the way Jerry set it up, it skid every single time, with every single shooter (we all used center or inside English).

It's hard to believe that someone played hundreds of shots without skid if the contact points were covered with chalk and if center ball or inside English was used. You'll find a lot of people who will wager they can make it skid with chalk - it's easy.

I will certainly agree that there may be many other causes. Any minor surface imperfection in a ball can do it - minor polish blemishes, or surface blemishes. Take a microscopic look at the surface of any pool ball and you will see tremendous irregularities. Even new, out-of-the-box sets of balls may be out of round and may not match each other at all when measured with a micrometer (Koehler actually found that the cheaper ball sets were better matched than the expensive ones - ouch!!).

 

[Purdman]

My .02

The one thing that will always cause skid is a fart with a lump in it, commonly known as a SURPRISE!
Purdman
Glad I could finally put this to rest.

 

[TheOne]

WillieEverLearn,
Interesting results, wish I had seen them. But assuming what we are both saying are true then we have the following:

• Kicks occur when there are zero chalk present
• Kicks occur frequently when there is a lot of chalk present
• kicks occur when a ball is cleaned
• kicks don't occur more frequently when both balls are covered in chalk

I now beleive it is clear that chalk is not the major contributor to kicks/skids.

I hope somebody can find the true cause soon

 

[Williebetmore]

[*]kicks don't occur more frequently when both balls are covered in chalk
[/LIST]

I now beleive it is clear that chalk is not the major contributor to kicks/skids.

I hope somebody can find the true cause soon

TheSmallDigit,
I'm going to have to disagree with this particular point; I do not believe it is true (and please quit calling them kicks, because my head is starting to hurt).

Anyway, find a way to get to the DCC this year and we can do some experiments in the AZB room - maybe even consume a few beverages. We may not make any scientific breakthroughs, but we can at least support the always-beleaguered beer industry.

 

[TheOne]

TheSmallDigit,
I'm going to have to disagree with this particular point; I do not believe it is true (and please quit calling them kicks, because my head is starting to hurt).

Anyway, find a way to get to the DCC this year and we can do some experiments in the AZB room - maybe even consume a few beverages. We may not make any scientific breakthroughs, but we can at least support the always-beleaguered beer industry.

I sure hope so willie, DCC is one of the few big comps I dream to play in. Besides you sure find some decent doubles partners!

PS
I'm not sure if its for UK viewers only but I just found the video on the BBC site, let me know if its blocked or not?

BBC Kick Video

Hope you can see it then you can make up your own mind? (Note they use the word kick alot

 

[jsp]

WillieEverLearn,
Interesting results, wish I had seen them. But assuming what we are both saying are true then we have the following:

• Kicks occur when there are zero chalk present
• Kicks occur frequently when there is a lot of chalk present
• kicks occur when a ball is cleaned
• kicks don't occur more frequently when both balls are covered in chalk

I now beleive it is clear that chalk is not the major contributor to kicks/skids.

I hope somebody can find the true cause soon

Let's be a bit logical here.

Friction causes skids.

The presence of chalk increases the likelihood of skids, because it increases friction.

If there is enough friction on the surface of the CB/OB interface (dirty or scuffed balls), skids can occur without the presence of chalk.

If you have two completely idealized spherical balls with absolutely no friction between them, physics says it's impossible for skids to occur.

Are you saying something other than CB/OB friction is the "major contributor" to skids...like the precise phase of the moon.

 

[Williebetmore]

PS
I'm not sure if its for UK viewers only but I just found the video on the BBC site, let me know if its blocked or not?

BBC Kick Video

Hope you can see it then you can make up your own mind? (Note they use the word kick alot

TheVerySmallNumber,
The site was blocked - only for the eyes of UK residents. What is this, some sort of UK conspiracy???

And while we're at it, those things driving down the freeway are trucks (I don't know what the f*&k a lorry is).

P.S. - I agree with jsp (he's got that physics background).

 

[Cornerman]

Is this real or just a BS excuse for missing the shot? If skid is a real freak of physics, is it due to dirty balls or table cloth condition or phase of the moon??

It is absolutely real. But, I see people use it as an excuse as well. IMO, there is no question when skid happens. Anyone who knows what it is can recognize it immediately.

It's not a freak of physics.. it's just plain physics. When the cueball and object ball contact each other, and there are remnants of chalk on the cueball exactly at that contact point, then skid is probable.

On some cloth and cueballs, the chalk marks left after striking the cueball aren't wiped off as easily. So, skid can happen more often during these situations.

Fred

 

[Cornerman]

As mentioned earlier, a touch of OE can reduce some of the effects of skids. Another method is to play firm stun-through position rather than slow roll through, but this takes a lot of practice to refine.

I think this is true only to a certain degree. If the chalk mark coincides with the contact point, then overthrow (reverse skid?) can happen.

Fred

 

[TheOne]

Let's be a bit logical here.

Friction causes skids.

The presence of chalk increases the likelihood of skids, because it increases friction.

If there is enough friction on the surface of the CB/OB interface (dirty or scuffed balls), skids can occur without the presence of chalk.

If you have two completely idealized spherical balls with absolutely no friction between them, physics says it's impossible for skids to occur.

Are you saying something other than CB/OB friction is the "major contributor" to skids...like the precise phase of the moon.

I watched the video again, its quite amusing reading some of these comments afterwards, oh well.

Two SUPER CLEAN balls, ZERO CHALK on the cloth, on the object ball, on the cue ball, or on the tip, zero, none. Cue ball surface almost perfect or atleast more spherical than normal and....Two MASSIVE skids/kicks in a row. They cleaned the balls not only with ethonol but also with another substance, ethonol actually makes the surface of the cb more spherical by removing imperfections.

Must have been that new invisible chalk theyre selling on seyberts!

www.seyberts.com/invisiblechalk/

Willie,
It's not what I'm saying, it's what the proffessor was saying and I'm betting he knows more about physics than anyone on here I'm still trying to figure out how you could ever have zero friction between two balls no matter how perfect?

 

[Bob Jewett]

... This phenomenon is usually referred to as "throw".

No, it's not. Throw refers to the usual effects of normal friction between the balls. Skid/Cling/Kick is very different.

 

[prolecat]

Got a perfect visual of the Skidddd

http://www.youtube.com/watch?v=kSHJoGAwWw4

Play this video... fast forward to about 4:10 and youll see the 5 ball skid..

 

[Bob Jewett]

... Steve Davis lined up a shot on a brand new cloth, using balls cleaned with ethanol, and a tip with zero chalk on it - he got a massive skid/kick! Case closed on the chalk theory.
...

Of course this proves nothing about whether chalk causes skids. I'm startled that anyone would claim that it did. What it does show is that you shouldn't use ethanol to clean the balls or they will become sticky.

Case open again.

 

[Colin Colenso]

I watched the video again, its quite amusing reading some of these comments afterwards, oh well.

Two SUPER CLEAN balls, ZERO CHALK on the cloth, on the object ball, on the cue ball, or on the tip, zero, none. Cue ball surface almost perfect or atleast more spherical than normal and....Two MASSIVE skids/kicks in a row. They cleaned the balls not only with ethonol but also with another substance, ethonol actually makes the surface of the cb more spherical by removing imperfections.

Must have been that new invisible chalk theyre selling on seyberts!

www.seyberts.com/invisiblechalk/

Willie,
It's not what I'm saying, it's what the proffessor was saying and I'm betting he knows more about physics than anyone on here I'm still trying to figure out how you could ever have zero friction between two balls no matter how perfect?

That 2 huge kicks occured straight away leads me to a couple of possibilities.

The cleaning, esp, using ethanol, seems to have increased the friction coeficient at the ball's surface by either:
1. Making it totally dry.
2. Making it statically charged which would draw in fine dust particles from the air and cloth.
3. Perhaps removing existing oils that tend to lubricate the surface slightly.
4. Ethanol chemically reacting to the balls to make them grip more.

Note: It's still significant that many of us have applied chalk to the contact points and had much higher than normal skid percentages.

Anyway, hope someone can youtube that video so we all can watch it.

Colin

 

[TheOne]

Of course this proves nothing about whether chalk causes skids. I'm startled that anyone would claim that it did. What it does show is that you shouldn't use ethanol to clean the balls or they will become sticky.

Case open again.

Hmm the plot thickens, so its not chalk that causes skids its Ethanol! I'm assuming given the nature of the video and the amount of research they had put into it sticky wouldnt have been an issue. Ethanol was used to reduce friction and any chalk. Damn the BBC and its international block lol

The other intesreting experiment they did was load a cushion up with chalk. They then rolled a ball down a roller onto the cushion and measured how far it travelled after it hit the cushion. The cue ball travelled MUCH further when hitting a cushion loaded with chalk compared to a cushion that had zero chalk.

 

[pete lafond]

On theones behalf the oils in the fabric, just like humidity and polishers, can cause chalk and dirt to stack the OB/CB and hold tight to the fabric. The chalk on the OB/CB do not have top be at contact points to skid, rather they can be at the bottom of the ball when contact is made, raising one ball higher than the other. This is another skid that can occur. Also chalk or a particle in front or behind a ball can cause the same.

One other point is that I have witnessed balls skidding more often with high English used. In fact when there is a chalk particle on the table (not the ball) it raises the ball add to this high English, the CB climbs up OB a very small amount.

The room I play in is 1/2 in the basement due to the sloping landscape, so it's a bit more humid. Anytime it rains, skids are quite frequent so it is very easy to become observant. Given the test at DCC with sprinkling chalk, my guess is that it is the chalk on the cloth and not the ball that also created the many skids.

I am also saying that the chalk at contact points skid too, but in our room they keep the equipment very clean. One last point is that I have noticed a change in the chalk. More than ever there is considerably more residue than ever before. My hands never got as chalk covered as it has over the past year.

 

[Bob Jewett]

Have you heard of SKID before?

...

It's also called kick (in the UK) and cling. It happens when the coefficient of friction between the cue ball and the object ball is, for one reason or another, greatly increased.

Here is how you can demonstrate skid: Apply chalk to the object ball. A little dampness will help to make the chalk adhere. Condensation from your breath will probably be sufficient. Put the object ball on the foot spot with the chalk spot towards the foot rail. Chalk the cue ball similarly. Spot it frozen to the object ball with their chalked spots touching. Aim the cue ball towards one of the head corner pockets with a little inside english (on the equator). Note where the object ball goes.

Is this a perfect test? No. It's just a lot better than what the British seem to have come up with.

I was the referee in a tournament (1980 World Championship 14.1) in which a lot of skids occurred. In several cases I was able to look at the balls afterwards and find chalk adhering along with a scuff mark.

Skid not only causes cut angle changes. When playing a straight-on follow shot, the cue ball, instead of following through smoothly, will jump into the air with a sharp sound and not follow forward nearly as much as you would expect. In one 2-hour match last week, I had two such skids. One problem with these follow-skids is that the cue ball has no (or little) chance to have the chalk rubbed off if you are playing with a rolling cue ball and the shot is short.

Skids are real. In major tournaments the players often have the referee clean the cue ball.

 

[TheOne]

That 2 huge kicks occured straight away leads me to a couple of possibilities.

The cleaning, esp, using ethanol, seems to have increased the friction coeficient at the ball's surface by either:
1. Making it totally dry.
2. Making it statically charged which would draw in fine dust particles from the air and cloth.
3. Perhaps removing existing oils that tend to lubricate the surface slightly.
4. Ethanol chemically reacting to the balls to make them grip more.

Note: It's still significant that many of us have applied chalk to the contact points and had much higher than normal skid percentages.

Anyway, hope someone can youtube that video so we all can watch it.

Colin

Colin just watched the bloody thing again lol, I think they also used acetone to remove static. I hope your not clutching at straws mate, maybe the ethonal sucked chalk from a random peice of chalk which was left on a table across the room?

I'm suprised you never saw the video a few years ago where they covered a cue ball in chalk and played many many shots without a kick. If you get time why dont you cover the cue ball in chalk and play 100 shots centre ball slow pace and then do the same thing with a cleaned cue ball? If chalk is truly the cause I would expect a massive difference in kicks?