"Aim Small" on the Cue Ball

There is something reported on Martin Goodwill's website (an English-billiards player) regarding some work he did on this with Ben Plummer (an engineer) here => http://www.englishbilliards.org/kicks

The conclusions they reached were that the worst type of kicks were caused by chalk (which explains why the phenomenon can readily be reproduced in the lab by the application of chalk); but that 'in the field' the type of kick that occurs much more frequently is not due to chalk. I have read that Martin was able to produce these less severe kicks 'at will' with very clean equipment.

However I have no details of the experiments actually done (including for example whether or not acetone was used to clean the balls - a concern previously raised by Bob Jewett). I am sure I can get Martin Goodwill's contact details if you want to follow this up.

Going back to anecdote :smile: it is widely believed by top players that kicks with snooker equipment are more of a problem with soft naturally rolling contacts (this belief is strong enough to sometimes sometimes influence shot selection). But even assuming that this is true, I don't know whether this would be to do with the frequency / severity of the kick or with the relative importance of a kick's outcome on that particular type of shot.


PJ wont like this one little bit
 
siz:
There is something reported on Martin Goodwill's website (an English-billiards player) regarding some work he did on this with Ben Plummer (an engineer) here => http://www.englishbilliards.org/kicks
sheffield6:
PJ wont like this one little bit
What's not to like? Their conclusions agree with everything I've said - kick is caused by excessive friction between the balls - chalk spots causing the worst kicks.

As for Thaig's jumping cue ball theory: "not really a kick".

Thanks for the link.

pj
chgo
 
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There is something reported on Martin Goodwill's website (an English-billiards player) regarding some work he did on this with Ben Plummer (an engineer) here => http://www.englishbilliards.org/kicks

The conclusions they reached were that the worst type of kicks were caused by chalk (which explains why the phenomenon can readily be reproduced in the lab by the application of chalk); but that 'in the field' the type of kick that occurs much more frequently is not due to chalk. I have read that Martin was able to produce these less severe kicks 'at will' with very clean equipment.

However I have no details of the experiments actually done (including for example whether or not acetone was used to clean the balls - a concern previously raised by Bob Jewett). I am sure I can get Martin Goodwill's contact details if you want to follow this up.

Going back to anecdote :smile: it is widely believed by top players that kicks with snooker equipment are more of a problem with soft naturally rolling contacts (this belief is strong enough to sometimes sometimes influence shot selection). But even assuming that this is true, I don't know whether this would be to do with the frequency / severity of the kick or with the relative importance of a kick's outcome on that particular type of shot.

Thanx for the link, Siz....it is great.

I've thought for years that static electricity is one reason for a skid/kick.
A pair of nylon gloves were exchanged for cotton and GREATLY reduced
kick occurrence in a Jimmy White match in the late 80's.

...and thick cloth is a common reason, I feel, for kicks.
Anyone who has played on 40 oz. cloth must be familiar with bad contacts.
I think it is resistance to impact because the object ball is sitting down
in the cloth...the contact is slightly delayed and the cue-ball is hydro-planing.
 
If I may take a whack at it.

Does any of this reflect your experience?

And, I'm not sure what the half-a-table length from the pocket has to do with anything? :)

Jim

Mr. Jal,

Thanks for your input. I'm not sure exactly what you mean by your question regarding my experience. I've been playing very well for 46 years. If you meant have I experienced the parameters outlined. Perhap & I believe so.

When playing on not the cleanest of equipment, mostly bar room tables, the ball has seemed to skid, skip, bounce, etc, namely react oddly when using inside english on the top end side more noticable on the slower speed shots As Dr. Dave has suggested sometimes it may be excess throw but at times it is in the opposite direction which belays the throw reason. The ball seems to bonce a hair or skid in the 'unpredictable' direction. I think it may be due to the CB's downward spin hit on the OB resulting it more frictio between the OB & the cloth. But my eyes are not a high speed camera so I am not sure. The distance from the pocket was probably just me making it a misable shot if such abnormal activity did occur.

I was asking his opinion as it certainly is not consistant, but that could be a spin to speed ratio thing.

Again thanks for your input.
Regards,
 
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I have never played snooker or seen what I would describe as a 'kick' in the many (frustrating) hours I have spent playing 3c. Is it true that the smaller the ball, the more susceptible it is to the cling/ kick?
 
One of the most important (and most overlooked) ways to improve your game is also one of the simplest to understand and do: hit the cue ball more precisely.

Most of us tend to hit the cue ball with "high right" or "a little left" or "lots of draw" without paying really close attention to exactly where our tip is making contact on the ball. After all, "a little left" isn't really that much different from a little more or less, is it? Yes, it is - in spades.

The obvious reason is that small changes in where we contact the CB make significant differences in where the CB goes after making the shot. There are also less obvious, but maybe even more significant, impacts on the effectiveness of our stroke and even on shotmaking itself.

Ever notice that when you're "in stroke" it seems almost effortless to make the CB do things that you usually struggle more with? And that you can see and hit cut angles much more accurately, also with less effort? Hitting the CB precisely where we intend to is a big part of why this is so (I think the biggest part).

It isn't so much that things are really easier; it's that things are more often turning out just like we intended them to - because we're giving the cue ball precise "instructions", not just general "suggestions". This closer relationship between what we want and what we do also increases the speed at which we learn - in the same way that we learn to aim more quickly as our stroke gets more reliable: things happen the way we intend them to, so we can more quickly and accurately identify the source of problems and ways to improve.

The quickest way I've found to elevate my shotmaking and cue ball control, both immediately and permanently, is to focus more intently on exactly where I'm hitting the cue ball.

pj
chgo

P.S. This also has many beneficial "side effects", like being more aware of the straightness of your stroke (because you're looking at it), seeing more clearly the precise alignment of tip/CB contact point and CB/OB contact point (especially good for aiming with spin), etc., etc.


I apologize for not reading the entire post, two of the most important factors for precision english are:

1. Bring tip very close to CB like 1/4" from CB, this ensures that your hand movement when you fire go back to or very close to that contact point on CB, also i consider that pause position an exact image if you were to freeze the frame at the time of tip contact CB; as a matter of fact if you warm up and about to pause and the tip happens to line up at wrong spot even 1 or 2 mm away one has to get up and redo the alignment again, rather than just shifting bridge.

2. Getting tip to hit where you want without doing item 1 above, would be to look at CB last (precisely at the tip CB contact point), it is hard to do if your backward stroke is fast.
 
I have never played snooker or seen what I would describe as a 'kick' in the many (frustrating) hours I have spent playing 3c. Is it true that the smaller the ball, the more susceptible it is to the cling/ kick?

I think the much thinner cloth is a big factor in cleaner hits, B-B.
But I have seen bad hits....I think they're the static electricity kind.
 
There is something reported on Martin Goodwill's website (an English-billiards player) regarding some work he did on this with Ben Plummer (an engineer) here => http://www.englishbilliards.org/kicks

The conclusions they reached were that the worst type of kicks were caused by chalk (which explains why the phenomenon can readily be reproduced in the lab by the application of chalk); but that 'in the field' the type of kick that occurs much more frequently is not due to chalk. I have read that Martin was able to produce these less severe kicks 'at will' with very clean equipment.
Thank you for posting this link. I've added it to my "cling", "skid," "kick" resource page. I've also improved the page with additional explanations. Here are the current contents of the page:

"Cling" (AKA "skid" or "kick") refers to an excessive amount of throw, well beyond what is expected for a given shot. People sometimes mistake a naturally large amount of throw as cling, especially if they are unaware of how throw varies with the type of shot (see throw effects and maximum throw). Again, cling is an amount of throw much greater than should be expected for a given shot and conditions.

Cling occurs whenever friction between the ball surfaces is greater than normal. Cling can occur more often with old, beat up, scuffed, and dirty balls, where portions of the ball surfaces might create more friction than other portions. However, cling also occurs with new, clean, and smooth balls. The primary cause for cling is a chalk mark or smudge (or a significant amount of chalk dust) appearing at the contact point between the CB and OB. Anytime you see chalk smudges on the CB, you should wipe them off (or ask for a referee to wipe them off if you are in the middle of a tournament game). Definitely wipe off he cue ball before each break shot or any time you have ball in hand. We have enough reasons to miss shots as it is without having to worry about excessive and unpredictable throw due to cling caused by chalk smudges.

Some people have suggested that cling can be caused directly by static electricity, but this is highly questionable. Although, a possible explanation is that static (resulting from the balls sliding across the cloth) could indirectly cause cling by somehow allowing chalk dust to collect on and stick to the balls more easily (but this is also questionable). Throw could also be larger (for all shots) if the balls are "cleaned" or polished with a substance that alters the ball surface (e.g., by leaving a residue behind or by chemically etching or altering the surface), creating more friction. Some polishes/waxes or aggressive chemical cleaners (e.g., acetone) could have these effects. Some people have suggested that oils, from human hands, deposited on the balls as they are handled can help minimize the effects of cling (e.g., see englishBilliards.org's "kick" page). This could be the case, especially if the balls were previously "cleaned." However, an excessive amount of oil could make it easier for chalk smudges to remain on the cue ball, which would result in more frequent cling. It has also been suggested that cling can occur more frequently on cloth that is new, thin, and slick because chalk smudges on the CB might tend to wear off less easily under these conditions (although, this is probably a very small effect). Cling might be more noticeable when playing with new and clean balls (e.g., in televised tournament conditions), where the amount of throw is less than with older and dirtier balls. Because the amount of throw can be less with ideal conditions, when cling does occur, it can be strikingly noticeable.

George Onoda wrote an article (see pp. 13-14 here) illustrating how cling might be more likely with low-inside and high-outside english shots, where a new chalk mark might be more likely to end up at the ball contact point, but cling is probably more random than this suggests (due to previous chalk marks or smudges on the balls that happen to end up at the ball contact point, on any shot).

Throw, including cling, can be avoided by using a "gearing" amount of outside english. For more info, see: using outside english to limit or prevent throw and cling.

Cling is often talked about in relation to excessive throw of the OB with a cut shot, but it can also create a lot of trouble for slow-roll follow shots. The CB won't follow the OB near as much as you would expect when there is cling. This video illustrates the effect:


Here's an example of purposely creating cling (with a chalk smudge) to help create a reverse bank angle:


The shot is demonstrated in Shot 731 here:


Here's a fun proposition shot utilizing chalk-induced cling in a devious manner:


Other interesting shots utilizing cling can be found in Bob Jewett's April '09 BD article here:


I think the page summarizes the current understanding of "cling," "skid," and "kick" fairly well; although, that understanding could change if carefully done experiments shed additional light on the topic in the future.

Regards,
Dave
 
TheThaiger:
That's because neither Dr Dave nor Bob Jewett were involved. Parrot Johnson's lost without them.
ENGLISH!:
Are you saying that PJ is just a mouthpiece for them & all of his opinions come from just their work?
Most of what I know about the physics of pool I've learned from Bob, Dave, Ron Shepard and Mike Page over many years of paying attention when they post (Ron doesn't post here, so I only had the pleasure of his posts on the usenet groups Rec.Sport.Billiard and Alt.Sport.Pool).

We're all "mouthpieces" for whomever we learned from - unless, of course, we didn't learn.

pj
chgo
 
Thanks.

These show several examples of cue balls and object balls bouncing on normal shots. Interesting, but not news for anybody who pays attention to this stuff. Dave has an extensive library of high speed pool video clips at http://billiards.colostate.edu/high_speed_videos/index.html.

Does anybody have a coherent explanation for why a bouncing cue ball would cause skid? I can't think of one.

pj
chgo
 
Thanks....Does anybody have a coherent explanation for why a bouncing cue ball would cause skid? I can't think of one.

pj
chgo
Could it be the result of CB/ OB contact point being different? As in when shooting a jump shot where you are cutting the OB and the bouncing CB makes the cut degree greater than it would have been if not jumping?

Speed very differenet in the skid/ jump shot, ya know.
 
Does anybody have a coherent explanation for why a bouncing cue ball would cause skid?

pj
chgo
Black-Balled:
Could it be the result of CB/ OB contact point being different? As in when shooting a jump shot where you are cutting the OB and the bouncing CB makes the cut degree greater than it would have been if not jumping?
There are even shots where you try to hit the OB with the CB in the air (like the one where you cut the second frozen ball on the spot into the corner). But as you point out this causes an overcut, the opposite of what happens with skid.

I think those British snooker commentators are seeing the CB bounce a little after contact with the OB and mistaking this for an indicator of skid. It can be, but isn't always.

pj
chgo
 
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Does anybody have a coherent explanation for why a bouncing cue ball would cause skid? I can't think of one.

pj
chgo

The air-borne cue-ball is hitting the object-ball above center.....
...sometimes it is trapping or pinching the object-ball and climbing
up it.
This results in some very unpredictable results (at least to me)
If you play a follow shot on thick cloth....I've seen a lot of them
missed by over-cutting....when hit with speed.

I feel like the 'man on the ground'.....most of what I feel I know is
empirical....I've taken weeks sometimes to figure out why I played
a shot a certain way ( but the shot was successful)

...my 'long suit' aint coherency..:embarrassed2:
 
....
Throw, including cling, can be avoided by using a "gearing" amount of outside english.
...
Cling is often talked about in relation to excessive throw of the OB with a cut shot, but it can also create a lot of trouble for slow-roll follow shots.
...
Dave

Presumably the way to minimize cling / kick effects would be to use low outside (so that on impact the cb is both sliding and perfectly geared)?

Or you could just twat it.
 
(Jumping) causes an overcut, the opposite of what happens with skid.

I think those British snooker commentators are seeing the CB bounce a little after contact with the OB and mistaking this for an indicator of skid. It can be, but isn't always.

pj
chgo

But could it not be that the velocity of the jump shot overrides the cling factor? There is far lower force seen when skids occur , in my experience.
 
But could it not be that the velocity of the jump shot overrides the cling factor? There is far lower force seen when skids occur , in my experience.
Yes, I think that often skids happen when you use slow inside follow. I think I've even done an intentional skid that way one time. If you think about the path of the chalk spot, inside follow has a good chance to put the chalk spot at the contact point depending on the distance and amount of spin.

But there is a video of Ronnie O'Sullivan playing a power draw (screw) shot with outside english (side) and pretty good power and he clearly got a skid (kick). The ball was over cut and the cue ball barely drew back.
 
But could it not be that the velocity of the jump shot overrides the cling factor? There is far lower force seen when skids occur , in my experience.
Are you saying jump shots are faster, and faster = less chance of skid (like faster reduces normal throw)? That makes intuitive sense, but it argues against bouncing CBs causing skid, not for it.

Anyway, CBs bounce at pretty much all speeds, not just on jump shots.

pj
chgo
 
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