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Stefan
11-07-2005, 05:04 PM
After learning to shoot plants that were just off target, I was wandering what is was and why this works. Apparently it's called throw, but I can't find a clear defenition of it anywhere on this forum. Can anyone please give me some sort of defenition, without immediately/only referring to a technical article? Thanks in advance:)

Bob_Jewett
11-07-2005, 05:26 PM
<blockquote><font class="small">Quote Stefan:</font><hr> After learning to shoot plants that were just off target, I was wandering what is was and why this works. Apparently it's called throw, but I can't find a clear defenition of it anywhere on this forum. Can anyone please give me some sort of defenition, without immediately/only referring to a technical article? Thanks in advance:) <hr /></blockquote>
A not-so-technical article is available at:

http://www.onthebreaknews.com/Jewett4.htm#August05

Here is the definition from the RSB FAQ. There's lots of other info there also.

Throw
The divergence of an object ball from the line through the
centers of it and the impacting ball. Throw is induced by the
friction between the two balls and the relative motion of
their surfaces. [Note: in UK usage, "throw" is synonymous
with "squirt", and has nothing to do with friction between two
balls.]

Jal
11-08-2005, 02:06 AM
<blockquote><font class="small">Quote Stefan:</font><hr>... Can anyone please give me some sort of defenition, without immediately/only referring to a technical article? <hr /></blockquote>

I think Bob Jewett's article answered your question. But if you want to explore the effects of throw in a somewhat systematic way, you might try the following setup.

The diagram below shows object balls placed on a circle whose center is at the intersection of the two cushions at a corner pocket, and whose radius is half the length of the table. You can use your cue to locate these points or use the numbers in the diagram. The balls are also placed at half-diamond intervals across the width of the table.

http://ww2.netnitco.net/users/gtech/CircleDrill.jpg

If you shoot the cueball straight toward the end rail but at a sideways offset from the object ball, as indicated by the numbers, without throw the object ball should come pretty close to dropping into the center of the pocket. The offsets are in units of ball diameter, so a 3/4 offset means the cueball and object ball should overlap each other by 1/4 ball diameter at the moment of impact (as seen from the shooter's perspective). Notice that the offsets are equal to the distances across the table the various balls are located, in terms of fractions of the table's width.

So, if you lubricate the contact area of the object ball with some saliva or water to first eliminate any throw, then hit the same shot with a dry ball, you can get a idea of how the spin and speed of the cueball affect the path.

If the cueball has a lot of topspin (follow) or backspin (draw) at the moment of impact with the object ball, throw will be minimal. If it has no such spin (stun shot), the throw will be fairly small for the shots at the bottom of the diagram (1/8, 1/4 offsets), but will increase to a maximum for the ones near the center of the picture (3/8, 1/2, 5/8 offsets), and then diminish again for the remaining shots at the top.

Adding sidespin (english) to the cueball complicates things a little. For stun shots on the balls in the lower half of the picture, maximum throw occurs when using a little bit of left english (inside english), while for the balls in the upper half it occurs with a certain amount of right english (outside english).

For shots with both top or bottom spin along with left or right english, well, I suggest you experiment or take a look at the graphs in this document:

http://www.engr.colostate.edu/~dga/pool/technical_proofs/new/TP_A-14.pdf

A lot of players are unaware of throw and in a way that's good. If you try to figure this stuff out while lining up a shot, it'll probably drive you crazy. If you haven't already, you'll eventually learn to adjust for it automatically. (I played for years without giving it a thought).

But I think a lot of shots are missed because of it, especially the longer ones, and having a general idea of how it varies with different cueball spins can be pretty useful.

Jim

dr_dave
11-08-2005, 08:03 AM
Stefan,

There are lots of links to definitions and descriptions under "throw" in the threads summary area of my website (http://www.engr.colostate.edu/~dga/pool/threads.html).

Happy reading,
Dr. Dave

<blockquote><font class="small">Quote Stefan:</font><hr> After learning to shoot plants that were just off target, I was wandering what is was and why this works. Apparently it's called throw, but I can't find a clear defenition of it anywhere on this forum. Can anyone please give me some sort of defenition, without immediately/only referring to a technical article? Thanks in advance:) <hr /></blockquote>

Bob_Jewett
11-08-2005, 01:48 PM
<blockquote><font class="small">Quote Jal:</font><hr> ... . But if you want to explore the effects of throw in a somewhat systematic way, you might try the following setup....
http://ww2.netnitco.net/users/gtech/CircleDrill.jpg

If you shoot the cueball straight toward the end rail but ... <hr /></blockquote>
I don't think I've ever seen this very neat way of getting to the actual positions for fractional aiming before. Is it your invention, Jim? Among other things, it shows immediately that the location for a (throwless) half-ball shot is not at 4,2 as some have claimed.

supergreenman
11-08-2005, 02:40 PM
Throw? I thought that was what you did with your last meal when you missed an easy shot because you didn't take into account the friction between the cb and the ob when you lined up a cut shot.

James /ccboard/images/graemlins/grin.gif /ccboard/images/graemlins/tongue.gif

Jal
11-08-2005, 05:54 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr>... Is it your invention, Jim?... <hr /></blockquote>
Thanks Bob. I haven't come across it in my limited reading so maybe... I thought that it might be a good way to learn or refresh oneself on the cut angles.

Jim

Keith Talent
11-09-2005, 07:55 AM
Stefan,

Once you get some understanding of throw -- along with squirt and swerve, two of the other major actions that alter the aiming process -- you'll be on your way to making a few balls. If only I'd asked about this stuff 25 yrs. ago, lol. I just thought I couldn't shoot straight and had some kind of congenital defect. /ccboard/images/graemlins/grin.gif

MrLucky
11-09-2005, 11:21 AM
in the most simplistic terms ! For every action there is a reaction! in this case if you put right english / spin on the cue ball the object ball will spin or "throw" to the left in a proportionate amount to the original spin! and visa versa!