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Throw on touching ball plant?

Postby rekoons

:dizzy:

What causes a dead set ,straight to the middle of the pocket, lined plant with the 2 balls effectively touching to veer off line when hitting the first ball exactly in the middle?

By hitting that first red in the middle you effectively strike the second red where the ‘ghost ball’ would be, so the second red should follow the line in to the pocket, right?

What I find is that when I do that the second red veers off to the left, missing the pot.

I need to hit the first red to the left in order for the second red to pot.

But why? I thought with dead set plants (with balls touching!) it didn’t even matter where you would hit the first red because they’re already aligned and touching…

I’m aware of the throw on angled pots: the momentum or impact of the white in it’s direction of travel will very shortly ‘drag’ the object ball off line in the direction the white was traveling when it hit, throwing the object ball off line.
But in this instance the 2 reds are touching?

Can’t figure this one out… :shrug:

the blue line is striking the first red bang in the middle, causing the second redd to miss to the left
the green line is striking the first red on the left, causing the second red to follow the intended path

Image

Re: Throw on touching ball plant?

Postby McManusFan

This is the reverse plant effect isn't it? I spent some time the other year trying to get my head around this the other year - there isn't much stuff out there on the internet for this!

I'm fairly sure what's happening with the blue line is that the friction between the two reds is causing them to briefly 'move as one', causing the second red to move in the direction of the first red before shooting off.

Re: Throw on touching ball plant?

Postby rekoons

Hmmm yes that may be what's happening, sounds plausible.
Counterintuitive but it is what it is.

Re: Throw on touching ball plant?

Postby Prop

McManusFan wrote:This is the reverse plant effect isn't it? I spent some time the other year trying to get my head around this the other year - there isn't much stuff out there on the internet for this!

I'm fairly sure what's happening with the blue line is that the friction between the two reds is causing them to briefly 'move as one', causing the second red to move in the direction of the first red before shooting off.


Pretty much. They call it a reverse plant, or squeezing the plant. Interestingly it doesn’t only apply to touching object balls - close enough and they’ll still move as one ball. But we’re talking tiny distance, probably one millimetre or less. There will be an equation that explains it, two key factors being diameter of balls and distance between them.

Re: Throw on touching ball plant?

Postby acesinc

Prop wrote:Pretty much. They call it a reverse plant, or squeezing the plant. Interestingly it doesn’t only apply to touching object balls - close enough and they’ll still move as one ball. But we’re talking tiny distance, probably one millimetre or less. There will be an equation that explains it, two key factors being diameter of balls and distance between them.


Hi all. Been losing sleep busy with the new puppy so I haven't even checked in much on the Island lately. About the bolded passage, yes, there is, and in fact you can buy that equation in tee shirt form so you shan't forget:

https://drdavebilliards.com/products/T-shirt/

Wear it at the table so you can always refer back to it when faced with such potentially perilous table positions.


McManusFan wrote:This is the reverse plant effect isn't it? I spent some time the other year trying to get my head around this the other year - there isn't much stuff out there on the internet for this!

I'm fairly sure what's happening with the blue line is that the friction between the two reds is causing them to briefly 'move as one', causing the second red to move in the direction of the first red before shooting off.


Au contraire, mon frère. This exact topic has amazed and astounded me for over 35 years now. I learned American Pool as a lad and knew nothing of Snooker, unaware of its existence, until I was nearly 20 years old. To be clear about my position, knowledgeable and talented Snooker players are over and above knowledgeable and talented Pool players in 99% of the technical aspects of cue sports. However, in this regard, the Snooker world is a flop. Sorry, no offence intended, but so few proper Snooker players grasp this concept well, but the information is out there. Has been for decades. You are just looking in the wrong place.

Even the Break from Life guy, whom I revere as probably the most unique and entertaining of all of the Snooker instructors to be found, has seemed to deny this for a long time but he literally just put out a video this morning that I think will contain the truth. I haven't watched it yet so I won't post the link here. But I think I know what I will find in that video and I will link it here after I watch and it is what I suspect.

But now to give accolades, the first instructional book I read was Byrne's Standard Book of Pool and Billiards. Still one of my bibles for cue sports. Written originally in the 70's this gave insight into the "secret society" understanding of the concept of "throw". Throw had been known about and understood and kept secret by the old timey players for decades at that point already. Bob Byrne spilled the beans and released the concept to the unwashed masses, if they were smart enough to listen. Apparently, that knowledge has not yet crossed the Atlantic. (By the way, "throw" is a beautiful term, one of the few Pool terms I like. I generally go with the Snooker terms such as "double" or "cushion" as being more fitting, but, again sorry, "squeeze" is just an awful term and ought to be let go. Rekoons, I was very happy to see you use "throw" in the original post.)

So here is a page about it from Bob Byrne's book, may he Rest in Peace:

https://www.google.com/books/edition/By ... frontcover

Bob's corroborator for his masterpiece Standard Book was another Bob, Bob Jewett in this case. Mr. Jewett is a wonderful human being. Had dinner with him a couple times at US Nationals. Bob Byrne rightly so referred to Bob Jewett as one of the planet's foremost authorities regarding the physics involved in colliding rotating spheres on a flat surface.

While these two are absolute giants on the topic, they somewhat pale in comparison to (in my view) the ulitmate "Einstein" of this particular topic, Dr. Dave Alciatore, (now retired, I believe) Professor of Mechanical Engineering from Colorado State University. (EDIT: I will add....that tee shirt up there with the equation? It's not a joke. The guy has a doctorate in Mechanical Engineering and has taken the time and done the research to model this information in mathematical form. Truly art meeting science.) He has spent a lifetime studying these things and disseminating the information. Most of it freely available. Sadly, few listen. I advise that you swallow up anything, ANYTHING that Dr. Dave has to say about cue sports. None of it is specific to Snooker, but it all applies all the same. Here are a few gems:

[youtube]G6ojo1xliT4?t=62[/youtube]

https://youtu.be/G6ojo1xliT4?t=61

(Sorry, this video won't embed properly for some reason. :-( )

Transfer of spin when playing a double is incredible. I use this information regularly. Last night, I hit my doubles 80%, 4 out of 5, two corner doubles and two back doubles to the middle. Dan-cat posted something about a similar concept a while back. See this:



https://www.youtube.com/watch?v=9br8xdXEs7g

Here is some more about that:



https://www.youtube.com/watch?v=4PGXUld5A24

__________________________

The Break from Life guy's video is fantastic, as always:



https://www.youtube.com/watch?v=1te88neqsbE

Re: Throw on touching ball plant?

Postby McManusFan

Great post Aces! That's the equation I was looking for! I think I struggled to find much information as all the research is done using pool terminology that I don't have a clue about. This Dr Dave stuff looks very interesting, thanks for sharing.

Re: Throw on touching ball plant?

Postby rekoons

I'm watching the first video with my mouth open, had no idea all of this is possible with cit and sit. This is like a revelation to me lol!

If pool players know and apply all this knowledge I have a newfound respect for pool. Didn't have a clue what was going on under the seemingly simple game of pool!

Re: Throw on touching ball plant?

Postby acesinc

rekoons wrote:I'm watching the first video with my mouth open, had no idea all of this is possible with cit and sit. This is like a revelation to me lol!

If pool players know and apply all this knowledge I have a newfound respect for pool. Didn't have a clue what was going on under the seemingly simple game of pool!


The truth is that most "pool players" don't know and apply this knowledge. I believe quite a few "apply" this knowledge just from practical experience and Pavlov's dog and all, but I think it is rather a small percentage that "know" this knowledge. That said, I still think there are a hundred pool players that grasp this concept for each snooker player that does.

Snooker, Pool, probably any cue sport, is grounded in science, but those individuals that excel are primarily artistic in nature. The artists that play the games at their highest level in all likelihood understand very little about why things happen the way they do, and they don't need to. But they do understand how to make things happen the way they wish. Three Cushion Billiards arguably has the highest requirement of a mathematical understanding of what is actually occurring on the table surface and in my opinion, it is the most difficult cue sport by a margin.

Bob Byrne - lifelong Civil Engineer, well studied in architectural drawing. His signature work praised as the most accurate instructional diagrams ever presented. He even included wood grain hatching on the rails of his pool table diagrams!

Bob Jewett - Electrical Engineer, UC Berkley, former US National Collegiate Billiards Champion. See this: https://engineering.berkeley.edu/news/2 ... le-life-2/

Dr. Dave Alciatore - Professor, Mechanical Engineering, you can easily find the guy's life's work on video now.


Anyone notice a common theme among these individuals? Do you know the difference between a scientist and an engineer? A scientist will tell you all the reasons that something cannot be done. An engineer will do it.

___________________________________________


I have often wondered why, with all the debate about "kicks" in Snooker, the people who make the decisions have never gone to the people who would actually know the answer? Or, if they don't already know, they are at least the ones most well equipped to figure it out. Because kicks, no doubt, have the same underlying cause as CIT and SIT. Did you know that kicks never occurred with the old ivory balls a hundred years ago? I also suspect there was no CIT or SIT then either. Yin and Yang. I am NOT suggesting we go back to ivory obviously, but even if we could develop some synthetic with similar properties to natural ivory, I believe the game would lose a great deal. The scientifically evolved phenolic resin from which snooker and billiard balls are made unfortunately cause the occasional kick, but on the plus side, they also allow for the precision control we see from the greatest artists in the game, control that likely would not be possible with some arbitrary "non-kick" material.

A lot of this is probably a ramble, didn't get a whole lotta sleep last night, but hopefully, I have made a point or two here.