At what CB Speed, how hard is the hit?

D

duckie

GregH
Silver Member
As not to derail the other thread, there are two aspect being greatly overlooked. Speed and force of hit.

What is the CB speed when squirt and swerve occur?

What is a high, med, or slow hit?

Two unknowns in how something works is not proof.

Are the hits used the same level as one may use in actual play?

Just some points to ponder. Reason I brought this up is because in turning a motorcycle, your speed matters. Below a certain speed, you can turn right by turning the bars right.

But at above a certain speed, to go right, you push on the right bar, meaning you are turning the bars left. This is called countersteering.

When there is no actual value for speed or force of hit, how can you know they are what are used in actual play?
 
Maybe this is better example on real situations and testing situations.

One time, I was the Q/A manager, lead tester for a manufacture of card readers.

I set up a turntable in order to present cards to a reader any rate I wanted.

I could turn it up to a rate where mis reads would occur. Thing is the rate was nothing like would happen in the real world. It was was faster than can ever happen in life.

When I mentioned the mis reads at "high rate" to the engineer. He first question was.."What the hell is a high rate?". I had to quantify the failure rate.

I know......must here like to live in a fanasty world of pool and real life situations just get in the way.
 
It's like, what a life pool players lead!

On an off-center hit or even a hit aimed and executed perfectly where we like to hit the cue ball off center, we might have to account for squirt, swerve, CIT and SIT, speed and plain-old dirt or chalk on the shots that exacerbate the problems. Meanwhile the physicists who teach have deduced how topspin and draw could change the throw on a shot even as some people argue whether backhand english can help.

Some of us use a touch of outside on shots, some a little inside (and it depends on the shot at hand in my case--inside is a nice aiming aid on angles where the english itself takes little or no effect on the object ball). It's a wonder a person can pocket a ball at all. :)

In a practical way, I try to coach people where they are at. Some players, likely few at AZ but the more unlearned type of players, hit the balls too hard and/or use too much outside and/or overcut often. In my opinion, these three tactics compensate, even subconsciously, for throw on a lot of cut shots... anyway, just venting here. Pool is both simple and complicated. I'm sure you'd agree with that!
 
If you think about your example, I bet the engineer thought you lived in the fantasy world of card readers too. I mean you did say that the misread rate was faster than can ever happen in life. So how is this a real world situation?

:cool:

I am sure he was pleased that you wasted his time. How did your boss feel about it?

duckie said:
Maybe this is better example on real situations and testing situations.

One time, I was the Q/A manager, lead tester for a manufacture of card readers.

I set up a turntable in order to present cards to a reader any rate I wanted.

I could turn it up to a rate where mis reads would occur. Thing is the rate was nothing like would happen in the real world. It was was faster than can ever happen in life.

When I mentioned the mis reads at "high rate" to the engineer. He first question was.."What the hell is a high rate?". I had to quantify the failure rate.

I know......must here like to live in a fanasty world of pool and real life situations just get in the way.
Click to expand...
 
I don't understand your point in asking some questions sometimes.

Squirt and swerve are going to be effected by so many things. You have the cloth, the balls, the tip, the chaulk, humidity, where you actually hit the cue ball, "amount of contact" hit of the object ball (full, halfball, 3/4ball), the distance the cue ball must travel before hitting anything at all, the speed the cue is traveling when it hits the object ball or rail.

There are so many variables I must ask, What the hell is the point of your question here?
 
First of all, the terms soft, medium, hard aren't the only terms in defining speed. They are just the main categories and they each have their own sub category (soft, soft 2, soft 3, medium, medium 2 etc.)

Secondly, the terms are not universal, but determined by the table you are playing on. So if you determine that Soft is a lag shot on one table, it doesn't mean it's the same on all tables. On a slower table, it might be Soft 3.

Another factor is the cut angle. If you play two shots at the exact same speed, the CB will travel farther on a 30 degree cut than say a 15 degree cut. In other words, the smaller the cut angle, the less the CB will travel due to loss of energy.


2,000 hours of practice, and you still don't understand the most basic stuff. Sad.
 
Something to consider.....

1 mph = 17.6 inches per second
2 mph= 35.2 inches per second

Next time you are shooting, say to yourself one thousand and one and see how far the CB went.

What speed do you think is needed to balls a CB just 2 inches?

A table is 96 x 48 inches.

So a 2 mph CB speed or 35.1 ips means that in 1 second the CB travels over 3/4 of the width of the table.
 
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Well I guess when they make speedometers for pool cues, this will be useful.

Until then, I will continue to define speed by distance traveled assigned to a number from 1-10, you know a "real world" observation.

duckie said:
Something to consider.....

1 mph = 17.6 inches per second
2 mph= 35.2 inches per second

Next time you are shooting, say to yourself one thousand and one and see how far the CB went.

What speed do you think is needed to balls a CB just 2 inches?

A table is 96 x 48 inches.

So a 2 mph CB speed or 35.1 ips means that in 1 second the CB travels over 3/4 of the width of the table.
Click to expand...
 
Squirt occurs for all speeds above 0. Same for swerve, as a perfectly parallel to table shot is rarely ever played... though I have seen Efren play one, bumping the butt of his cue while it laid on the table.

Can't help much regarding the quantification of the other aspects you mention Duckie.
 
Referring to this pic, left t big for a reason.

Are yall saying that squirt/swerve/deflection is gonna happen when shooting the 15 into the corner at just pocket speed? Pocket speed is the speed of the OB that just gets it into the pocket. The 10 is the next shot BTW.

Oh, it is a very slight cut even tho it doesn't look like it.

Inspiration can come for any where. Couple years ago, I was watching a Christmas program of chamber music songs. The instruments cellos, violins, and harpsichord.

What got my attention has how they used the bow. They way the angle, pressure and speed was varied to create the music. Plus the use of their body to. Their body movements reflected the music being played.

This got me to thinking about my stroke and can I use it like a bow, different angles, different pressures, and different speeds.

Its been a interesting journey......since changing my focus onto the stroke, my consistency has greatly gone up. Being able to stroke the cue at any speed is something not all can do, hence the need for a certain style of play.

Stroke speed is what it's all about. Being able to finely control this like a violinist playing is what makes beautiful pool.

I'm firm believer that squirt, swerve, deflection and only occur under certain conditions and understanding this helps to play within those conditions thereby eliminating the need to be concern with squirt, swerve, deflection.

Bet no one sets up this layout to run all the balls. Talk is cheap.

I do this kinda drill for hours......roll all 15 balls on the table and run as many as I can. You can learn alot about your level of play by doing this. It will show your weakness quickly.
 
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It's more about tip placement than stroke speed.

Set up a straight in shot, and hit it one tip below center. Now do the same thing and use the same speed, but hit two tips below center. If you did it right, the second shot will draw back further despite playing both shots at the exact same speed.

Also, just randomly throwing balls out on the table is the worst kind of practice you can do, but that explains a lot. Please stop posting here and trying to make people worse.
 
Read a book called The Science of Pocket Billiards if you have not already. This the very first book I got when I started shooting in July 2012 and I give it 100% credit into me excelling as quickly as I did.

In there you will find plenty of information that will show you how much angle, speed, spin and cling of the balls effect the things you speak of. Graphs and charts are used.

http://www.amazon.com/gp/product/0962289027/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
 
duckie said:
Referring to this pic, left t big for a reason.

Are yall saying that squirt/swerve/deflection is gonna happen when shooting the 15 into the corner at just pocket speed?
Click to expand...

Squirt and swerve are negligible when just a few inches from the OB. On this shot, throw is the beast one has to overcome, particularly at slow speeds. A touch of sliding left versus a touch of slighting right on this shot can alter the resultant path by a few degrees.
 
I can't find it, so maybe someone else can.

I'm looking for some demos of squirts and such that start at a CB speed of 1 inch per second and then 2 inch per second and so one up to 12 inches per second.

Or is it being assumed that since squirt happens in a demo using a unknown speed it will occur are all possible shot speeds?
 
duckie said:
I can't find it, so maybe someone else can.

I'm looking for some demos of squirts and such that start at a CB speed of 1 inch per second and then 2 inch per second and so one up to 12 inches per second.

Or is it being assumed that since squirt happens in a demo using a unknown speed it will occur are all possible shot speeds?
Click to expand...

It is known a priori from the mechanism that is believed to cause squirt. In the same way that structural engineers know various forces based on weight, angle and length of lever.

While I once thought other factors like speed and tip slippage might contribute some additional squirt, various tests and years of observation since then make me quite confident that there is but 1 mechanism which causes squirt.

The mechanism is this:
When you hit the side of a ball with your tip, the ball tries to rotate. The tip, being still in contact with the ball, resists the rotation. The tip effectively pushes back against the ball sideways. A heavier tip effectively pushes harder, as does more tip offset as the rotation speed (energy) is greater.

The resultant direction of the CB become the vector addition of the force forward along the line of the strike and the sideway push caused by the cue resisting the cue ball's rotation.

With increased striking speed, the forces increase, but in the same proportion, hence, the resultant squirted angle is consistent for the same offset with the same equipment, regardless of speed of shot.

Images and a more detailed explanation can be found here: http://billiards.colostate.edu/threads/squirt.html#cause

A thought experiment: Imagine you're in one of those rotating doors and it has 4 doors at right angles. Imagine pushing a door counter clockwise from the right with your left foot against the door behind and to your left.
That door would push into your left leg sideways to the direction you are pushing the other door with your hands. Now imagine this door isn't bolted down, say it is resting on smooth ice.
If you push it this same way, without the foot against the door, the whole thing travels in the direction of the push. If your foot was resisting the other door, then the whole thing slides off a little to the left of the arm push.
 
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Sorry, I can be a little curt when I post to forums. Some people call it British follow or force follow when you go way above center ball on the vertical axis and pound the ball hard--go way high almost to miscue level with your cue tip on the vertical axis and "tap" or "punch" or "rap" the cue ball. For that 15-ball, a small backstroke and a little "rap".

This of course doesn't change the physics of the shot but can be used as a cueing technique for its aid in alignment and when you get the feel of the punch right and the speed--this stroke helps a lot of amateurs I've assisted who struggle with running balls down the line with the cue ball just off the object ball and a near straight-ahead shot.
 
BilliardsAbout said:
Sorry, I can be a little curt when I post to forums. Some people call it British follow or force follow when you go way above center ball on the vertical axis and pound the ball hard--go way high almost to miscue level with your cue tip on the vertical axis and "tap" or "punch" or "rap" the cue ball. For that 15-ball, a small backstroke and a little "rap".

This of course doesn't change the physics of the shot but can be used as a cueing technique for its aid in alignment and when you get the feel of the punch right and the speed--this stroke helps a lot of amateurs I've assisted who struggle with running balls down the line with the cue ball just off the object ball and a near straight-ahead shot.
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Matt,

That MOST probably happens because they are fouling the cue ball by hitting it after it has contacted the OB.

I did not go back & look at the shot but I can imagine that if one wanted to follow a bit it would require an up swipe stroke so as NOT to foul the cue ball.

Best,
Rick
 
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