# Is throw influenced differently on clean vs dirty cloth?

#### John Daminato

##### AzB Silver Member
Silver Member
Me and one of my practice mentors always have these controversial "physics like" debates in pool. The latest one was can two frozen balls be thrown differently on clean vs dirty cloth. His answer was basically "absolutely not" As we discussed it more, he brought to my attention that the old knowledge was that when frozen balls are thrown, they slide for one split second together and then split apart. The "new high speed camera" knowledge is that they get "instantly" (is anything instant on a pool table) thrown from the friction of the two balls and cloth has no effect on the shot. Now if they do slide for that split second then my debate is that on dirty cloth they will slide less therefore keeping closer to the original intended throw angle and on clean cloth they will slide more before energy is reached object ball thrown, brand new balls, brand new cloth, maybe the slide can be seen. I guess in the end whats most important is just knowing how the balls will react and not the why.

#### manwon

##### "WARLOCK 1"
Silver Member
Me and one of my practice mentors always have these controversial "physics like" debates in pool. The latest one was can two frozen balls be thrown differently on clean vs dirty cloth. His answer was basically "absolutely not" As we discussed it more, he brought to my attention that the old knowledge was that when frozen balls are thrown, they slide for one split second together and then split apart. The "new high speed camera" knowledge is that they get "instantly" (is anything instant on a pool table) thrown from the friction of the two balls and cloth has no effect on the shot. Now if they do slide for that split second then my debate is that on dirty cloth they will slide less therefore keeping closer to the original intended throw angle and on clean cloth they will slide more before energy is reached object ball thrown, brand new balls, brand new cloth, maybe the slide can be seen. I guess in the end whats most important is just knowing how the balls will react and not the why.

I think this is an interesting subject, and here is my take. Most know that is the balls are dirty extreme throw can be achieved that can not be achieved with clean and polished balls. So if you are playing on a table that has dirty cloth, it would only make sense that balls used will become dirty very fast since rolling across the cloth is how they get dirty in the first place.

Next you have to be much precise when you say that the cloth is dirty. Is it bar dirty, stained from food and such, or is it just chalk dirty, not brushed and vacuumed. I think if it is bar dirty, the cloth could become more slick as grease and such are ground into it with dirty hands, now if it is chalk dirty I agree it would slow any spin on a ball down do to friction!!

JIMO

#### Monk Slayer

##### AzB Silver Member
Silver Member
Manwon hit it on the head, and very eloquently too I might add. I almost didn't post, since he described it so well. : P Cheers!

#### John Daminato

##### AzB Silver Member
Silver Member
I guess that is one way to put it in perspective, where the cloth is dirty the balls must be dirty or will become dirty very quickly. So therefore the cloth has a direct influence.
Im not sure I agree with a bar table being dirty with grease and that actually makes it more slick. Never experienced a extra fast bar table that was really dirty too. Maybe at that exact moment the grease gets on the cloth its slick, but within a very short time dust, ashes, dead skin cells (dust)etc.....is going to stick to those spots and really create some friction.

The question in the debate, I need to make more clear: When two balls are frozen and you attempt to throw one, do they slide a negligible amount before they split or before the front ball takes off?

#### manwon

##### "WARLOCK 1"
Silver Member
I guess that is one way to put it in perspective, where the cloth is dirty the balls must be dirty or will become dirty very quickly. So therefore the cloth has a direct influence.
Im not sure I agree with a bar table being dirty with grease and that actually makes it more slick. Never experienced a extra fast bar table that was really dirty too. Maybe at that exact moment the grease gets on the cloth its slick, but within a very short time dust, ashes, dead skin cells (dust)etc.....is going to stick to those spots and really create some friction.

The question in the debate, I need to make more clear: When two balls are frozen and you attempt to throw one, do they slide a negligible amount before they split or before the front ball takes off?

It is directly related to what the balls have picked up form rolling on the cloth, it they have a slight film on them the throw will be enhanced. If they are clean straight from the ball polisher the spin will Be repeatable. Yes balls will slide when struck the more they slide the greater the opposite reaction (Throw / Spin ) will occur. It is simple physics Newton's third law of motion states that for every action there will always be an opposite and equal reaction along the same lines of force / movement.

When a frozen ball is struck at any angle other than perfectly straight on the gear principle will apply, one ball will turn right and the other will turn left exactly like a set of gear's. The initial movement will cause clean balls to slide, the amount they will slide will be based upon the type of cloth used, how new it is, and how clean it is.

JIMO

#### John Daminato

##### AzB Silver Member
Silver Member
So the two balls slide a negligible amount before they separate, therefore the old adage is true and they don't instantly split apart before sliding occurs...I guess the key word here is "negligible". Maybe the slide is so minute before they separate, its not even something, even on a 8ft throw shot that you should consider when deciding or calculating.

#### manwon

##### "WARLOCK 1"
Silver Member
So the two balls slide a negligible amount before they separate, therefore the old adage is true and they don't instantly split apart before sliding occurs...I guess the key word here is "negligible". Maybe the slide is so minute before they separate, its not even something, even on a 8ft throw shot that you should consider when deciding or calculating.

Yes according all laws of physic's when two sphere's ( Balls) rotate due to a collision and friction is applied (Movement accross Cloth) they must slide to some degree when ever spin is applied to them. So when a single ball or two frozen balls are struck right or left of Dead center spin is induced and they slide.

I hope this makes sense, and I hope it helps.

Have a great day!!!