PDA

View Full Version : Balls rolling when they collide?.....



Gatz83
03-09-2008, 01:14 PM
So when you hit an object ball with the cueball you want the cueball to be rolling to get a nice clean hit? I noticed if you use more of a center ball shot (like a stun) and the ball is sliding the object ball always skids first off the intended line. So basically if your going to use a stun shot you want to over cut it a bit?.

cushioncrawler
03-09-2008, 03:17 PM
Yes, my potting improovd when i realized this.
And, if u uze skrew, u havta "underkut it a bit" -- koz, with skrew....

...(1) The balltoball friktion helps the Oball'z progress rather than hurts it, ie it puts topspin on the Oball (rather than the backspin u get with a rolling qball, or the zero-backspin u get with a stunned qball).

...(2) Skrew shots are uzually hit harder and hencely there iz less balltoball friktion koz there iz more impakt rezidue, ie more "ball-bearingz & oil" (krapamiths set the standard here).

...(3) Skrew shots are uzually hit harder and hencely there iz an extra perhaps 1dg of "FlatSpotSqeez", ie koz the ballz deform more (and most of this deformation iz probably in the flatspot, hence the name, it inkreecez the kut-angle). madMac.

1Time
03-09-2008, 04:07 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gatz83</div><div class="ubbcode-body"> So when you hit an object ball with the cueball you want the cueball to be rolling to get a nice clean hit? I noticed if you use more of a center ball shot (like a stun) and the ball is sliding the object ball always skids first off the intended line. So basically if your going to use a stun shot you want to over cut it a bit?. </div></div>
You hit the cue ball in whatever way required to execute the shot.

Bambu
03-09-2008, 05:16 PM
Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two.

dr_dave
03-09-2008, 06:55 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gatz83</div><div class="ubbcode-body"> So when you hit an object ball with the cueball you want the cueball to be rolling to get a nice clean hit? I noticed if you use more of a center ball shot (like a stun) and the ball is sliding the object ball always skids first off the intended line. So basically if your going to use a stun shot you want to over cut it a bit?. </div></div>It looks like you are asking about throw and cling. Answers to all of your (and many other) questions about these topics can be found via the links here (http://billiards.colostate.edu/threads/throw.html). My August '06 through July '07 instructional articles (http://billiards.colostate.edu/bd_articles/index.html) are also a good resource. Check them out.

Regards,
Dave

PS: If you want to know where the CB will go in addition to the OB, see this summary (http://billiards.colostate.edu/threads/30_and_90_degree_rule.html#where_CB).

trokinine
03-10-2008, 08:02 AM
Hi madMac, please think to the foreigners reading this board. Your message is very hard to understand because of your orthography. I'm sure it is very interesting though.

dr_dave
03-10-2008, 09:41 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"> Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two. </div></div>You are right about stun resulting in the most throw. However, draw and follow shots (with the same amount of bottom or top spin) throw the same amount. See my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf) for more info on throw for stun, follow, and draw shots.

Actually, with most draw shots, because some of the spin wears off (due to "drag"), many draw shots will have less spin, and more throw, than typical follow shots.

Regards,
Dave

Bambu
03-10-2008, 05:01 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dr_dave</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"> Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two. </div></div>You are right about stun resulting in the most throw. However, draw and follow shots (with the same amount of bottom or top spin) throw the same amount. See my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf) for more info on throw for stun, follow, and draw shots.

Actually, with most draw shots, because some of the spin wears off (due to "drag"), many draw shots will have less spin, and more throw, than typical follow shots.

Regards,
Dave </div></div>

Funny you should say that, Dave. I just took an instructors course, and the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong He followed that up by saying stun throws the most, next is follow, and draw throws the least.
Its not like me not to question things, but I knew it was gonna be a long day. So regretfully, I didnt argue with him. Thanks for correcting me on that, Dave.

cushioncrawler
03-10-2008, 05:15 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dr_dave</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"> Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two. </div></div>You are right about stun resulting in the most throw. However, draw and follow shots (with the same amount of bottom or top spin) throw the same amount. See my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf) for more info on throw for stun, follow, and draw shots.

Actually, with most draw shots, because some of the spin wears off (due to "drag"), many draw shots will have less spin, and more throw, than typical follow shots.

Regards,
Dave </div></div>

Funny you should say that, Dave. I just took an instructors course, and the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong He followed that up by saying stun throws the most, next is follow, and draw throws the least.
Its not like me not to question things, but I knew it was gonna be a long day. So regretfully, I didnt argue with him. Thanks for correcting me on that, Dave.</div></div>Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac.

Bob_Jewett
03-10-2008, 05:17 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong ... </div></div>
It is always fair to ask, "Do you know a good way to demonstrate that?" or "Can you show me?" or even, "About how many degrees of throw are the different cases for typical shots?"

Bob_Jewett
03-10-2008, 05:20 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body"> ... Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac. </div></div>
Do you have a good example shot to demonstrate this? About how many degrees of throw are the three cases for let's say a half-ball contact with medium pace?

cushioncrawler
03-10-2008, 05:26 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trokinine</div><div class="ubbcode-body">Hi madMac, please think to the foreigners reading this board. Your message is very hard to understand because of your orthography. I'm sure it is very interesting though.</div></div>Hi trokinine -- yes i agree that spelling affekts foriegners in particular. But, English possibly haz thoze two good old French words "foreigner" and "orthography" mainly koz the French won a war against England. I woz hoping to change thingz without having to rezort to war, but its starting to look like war iz unavoidable. madMac.

dr_dave
03-10-2008, 05:33 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dr_dave</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"> Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two. </div></div>You are right about stun resulting in the most throw. However, draw and follow shots (with the same amount of bottom or top spin) throw the same amount. See my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf) for more info on throw for stun, follow, and draw shots.

Actually, with most draw shots, because some of the spin wears off (due to "drag"), many draw shots will have less spin, and more throw, than typical follow shots.

Regards,
Dave </div></div>

Funny you should say that, Dave. I just took an instructors course, and the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong He followed that up by saying stun throws the most, next is follow, and draw throws the least.
Its not like me not to question things, but I knew it was gonna be a long day. So regretfully, I didnt argue with him. Thanks for correcting me on that, Dave.</div></div>Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac. </div></div>Mac and Bambu,

See the end of TP A.24 (http://billiards.colostate.edu/technical_proofs/new/TP_A-24.pdf). OB swerve does have a slightly different effect for a follow shot vs. a draw shot, but the effect is very small (unless there is cling, in which case it might be more noticeable). Now, if the draw shot has more backspin than the follow shot has topspin, then the draw shot will definitely have less throw. The closer a shot is to stun, the more throw it will have.

Regards,
Dave

dr_dave
03-10-2008, 05:38 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body"> ... Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac. </div></div>
Do you have a good example shot to demonstrate this? About how many degrees of throw are the three cases for let's say a half-ball contact with medium pace? </div></div>Good questions Bob. I know you know the answers; but for others, I have some example numbers at the end of TP A.24 (http://billiards.colostate.edu/technical_proofs/new/TP_A-24.pdf).

Regards,
Dave

pooltchr
03-10-2008, 05:48 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong ... </div></div>
It is always fair to ask, "Do you know a good way to demonstrate that?" or "Can you show me?" or even, "About how many degrees of throw are the different cases for typical shots?" </div></div>

I would like to see that demonstration /forums/images/%%GRAEMLIN_URL%%/wink.gif
Steve

dr_dave
03-10-2008, 05:57 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pooltchr</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong ... </div></div>
It is always fair to ask, "Do you know a good way to demonstrate that?" or "Can you show me?" or even, "About how many degrees of throw are the different cases for typical shots?" </div></div>

I would like to see that demonstration /forums/images/%%GRAEMLIN_URL%%/wink.gif
Steve </div></div>I don't have a video demonstration, but I do have some experimental data (see the end of my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf)). I certainly couldn't measure any meaningful difference in thrown distances between draw and follow shots.

Regards,
Dave

Bob_Jewett
03-10-2008, 06:52 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pooltchr</div><div class="ubbcode-body"> ... I would like to see that demonstration /forums/images/%%GRAEMLIN_URL%%/wink.gif
Steve </div></div>
I have an experimental setup and results in the May 2006 issue of Billiards Digest. The article is now on-line and for free. See http://www.sfbilliards.com/articles/2006-05.pdf

Dr. Dave presents an extension of this in his article that he referenced above.

I suppose the setup was not so obvious since it took me about 15 years to come up with it after the question was pointed out to me, but once you see it, it is obvious. The trick is to take the player out of the equation as much as possible because any player who can play a lick is quite able to make the object ball go where he chooses by changing the shot line or bridge position or something during the shot.

av84fun
03-10-2008, 10:42 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pooltchr</div><div class="ubbcode-body"> ... I would like to see that demonstration /forums/images/%%GRAEMLIN_URL%%/wink.gif
Steve </div></div>
I have an experimental setup and results in the May 2006 issue of Billiards Digest. The article is now on-line and for free. See http://www.sfbilliards.com/articles/2006-05.pdf

Dr. Dave presents an extension of this in his article that he referenced above.

I suppose the setup was not so obvious since it took me about 15 years to come up with it after the question was pointed out to me, but once you see it, it is obvious. The trick is to take the player out of the equation as much as possible because any player who can play a lick is quite able to make the object ball go where he chooses by changing the shot line or bridge position or something during the shot. </div></div>

<span style='font-size: 17pt'>I PROTEST!!!! </span>

In Bob's article to which he refers, he states that "normal" is another word for "perpendicular" which shocked this English and Business student.

So I looked it up and of course, Bob is correct. However, I lodge this PROTEST against the scientists who made Bob's statement correct.

The rest of civilized society was brought up to understand that "normal" means something along the lines of "standard" or "typical."

But then come the scientists who did THIS to the language!

3. Abbr. n or N Chemistry
a. Designating a solution having one gram equivalent weight of solute per liter of solution.
b. Designating an aliphatic hydrocarbon having a straight and unbranched chain of carbon atoms.
4. Mathematics
a. Being at right angles; perpendicular.
b. Perpendicular to the direction of a tangent line to a curve or a tangent plane to a surface.

Well, I say to HELL with gram equivalent weights and aliphatic hydrocarbons and unbranched chains of carbon atoms.

So, for the rest of my life, if I want to find out a pool player's speed I will ask something like..."Are you normally about an APA 7?"...not "Are you perpendicular to an APA 7?

<span style='font-size: 20pt'>(-;</span>

cushioncrawler
03-11-2008, 04:09 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body"> ... Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac. </div></div>Do you have a good example shot to demonstrate this? About how many degrees of throw are the three cases for let's say a half-ball contact with medium pace?</div></div>Bob -- I just now did some tests on a 12' table with 2-1/16" kraps. Things went badly, i found it difficult to do consistent tests. I drew chalk-marks where rolling & stun & skrew shots hit the rail 9' away, and the chalk marks were up to 10" apart. Stun clearly had more throw, but i couldnt separate skrew and roll. The bad thing woz that all of the test-rezults varyd a hell of a lot.

I think it woz all more of a test of me (my stroke) and the balls (kraps). Possibly Bambu iz correct when he sez that rolling iz eezy to get, but an equivalent amount of skrew iz perhaps impossible.

Theze tests were for a contact of about 5/16thball. I drew a chalk circle around the spots where the qball and Oball sat, and tapped them lightly on the head to mark the spot more accurately, they allwayz sat in the hole. For aim i aimed dead center at a ball sitting against a far rail. Afterwards i replaced the kraps with bonzoz, and straight away started to get "better" rezults (ie more consistent), i might look into this more closely later. madMac.

Bambu
03-11-2008, 01:13 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dr_dave</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body"> Yes. The reason stun needs to be cut a bit more is because it throws the most. Draw throws the least, and follow is in between the two. </div></div>You are right about stun resulting in the most throw. However, draw and follow shots (with the same amount of bottom or top spin) throw the same amount. See my October '06 article (http://billiards.colostate.edu/bd_articles/2006/oct06.pdf) for more info on throw for stun, follow, and draw shots.


Actually, with most draw shots, because some of the spin wears off (due to "drag"), many draw shots will have less spin, and more throw, than typical follow shots.

Regards,
Dave </div></div>

Funny you should say that, Dave. I just took an instructors course, and the first question my teacher asked me was, what throws more, draw or follow? I said they were both equal, and the advanced instructor said I was wrong He followed that up by saying stun throws the most, next is follow, and draw throws the least.
Its not like me not to question things, but I knew it was gonna be a long day. So regretfully, I didnt argue with him. Thanks for correcting me on that, Dave.</div></div>Bambu -- Mr(s) Instruktor woz korrekt. Throw iznt a distance, it iz an angle. Now, if the "throw distance" for a rolling contact and a skrew contact are the same, then the "throw angle" for the skrew contact will be less, koz, skrew adds pace (topspin) to the Oball, whilst rolling puts backspin on the Oball, see????? madMac.</div></div>

I didnt mean to imply there was any distance involved. The point was that draw threw an object ball less than follow did, and stun more than both(throw angle). Dave says follow and draw are equal, as I had originally thought. Though I have not ran any tests of my own, I have to stand by Daves testing. I dont dispute your own test results, mac; I suspect that different ball sets throw differently.

Bambu
03-11-2008, 01:42 PM
Yes, Bob. I didnt argue the test, but I did ask for a demonstration. It looked something like this, but with a piece of chalk to separate the 2 balls(instead of the spot).

http://CueTable.com/P/?@4ATAh4BRli4CPpi1IALH1PALg1dALH4dQvL@

The idea was to use medium speed, and a half ball hit. Then mark the spots where follow, draw and stun hit on the short rail.
While the test was very brief(only one shot for each), I did hit the spots he said I would. Instead of the balls I show in the diagram, chalk was used to mark the spots on the short rail. Stun extended to about ball #3, follow to ball #2, and draw to ball #1.
I thought his test was tough to swallow(based on only 3 shots), but I took his word for it. I trust Daves test was more legitimate, and I assume you agree with him.

Bambu
03-11-2008, 02:25 PM
That makes sense to me. Prior to the short test I took, I never noticed any throw difference between follow and draw myself. Thanks Dr. Dave.