(FAQ) How do you use the tangent line?

Scott Lee

AzB Silver Member
Silver Member
Bruce...Pool Chump is just another alias. He got mad because I politely suggested bumping posts in his own thread about "where is so and so", instead of starting a whole new thread for every person mentioned in his thread. Apparently he took exception to that, and so now I am the troll! :rolleyes:

Scott Lee
http://poolknowledge.com

Amazing how you know so much about Scott, yet have been a member here for a month.

Quick study.
 

justadub

Rattling corners nightly
Silver Member
Bruce...Pool Chump is just another alias. He got mad because I politely suggested bumping posts in his own thread about "where is so and so", instead of starting a whole new thread for every person mentioned in his thread. Apparently he took exception to that, and so now I am the troll! :rolleyes:

Scott Lee
http://poolknowledge.com

Ah, of course.
 

ENGLISH!

Banned
Silver Member
There are some rather unusual things going on here at AZB today.

A post about Pool Chump, etc. seems to have been taken away.

It basically said that I do not think he is the Ram Shot Guy, but seems to have a familiar style of a past poster.

That said, just because one has a new join date, does not mean that one has not just been reading here for a long time & actually has a good idea of the personality traits of the more vocal members.

Some members have a very arrogant, condescending, self promoting 'nature' & often make posts to self promote themselves with little regard to the individual that they slight to do so.

It seems Pool Chump is not naive to such.

Best Wishes to ALL.

PS He also seems to be another individual that does not like to be told what to do by such individuals. A thread about a specific pool individual is NOT the same thing as another thread about a group of such individuals. How about no more threads 'advertising' pool schools? How about just bumping the old ones?
 
Last edited:

erhino41

AzB Silver Member
Silver Member
It is vitally important to understand that the cue ball leaves impact at ninety degrees. It doesn't matter if it is only for a mm, it is something you have to factor in. It can get you into a lot of trouble if you hit an obstructing ball after contact.
 

Skippy27

AzB Silver Member
Silver Member
It is vitally important to understand that the cue ball leaves impact at ninety degrees. It doesn't matter if it is only for a mm, it is something you have to factor in.

Yes and as Dr. Dave has pointed out.... the harder you hit it the longer it stays on that 90 tangent line until the follow or spin sets in to make it veer off that line.

"About" 30 degrees rule and his Trisect rule come to mind with the tangent line.

If I recall correctly, he also shows it still travels about the same angle once the spin takes hold. It just starts further down the tangent line.

As usual, all great information from Dr. Dave.
 

erhino41

AzB Silver Member
Silver Member
Yes and as Dr. Dave has pointed out.... the harder you hit it the longer it stays on that 90 tangent line until the follow or spin sets in to make it veer off that line.

"About" 30 degrees rule and his Trisect rule come to mind with the tangent line.

If I recall correctly, he also shows it still travels about the same angle once the spin takes hold. It just starts further down the tangent line.

As usual, all great information from Dr. Dave.

That is true. I find that just saying about thirty degrees and using a peace sign to measure are nowhere near accurate enough. As the cut angle changes and as the tip offset on the vertical axis changes and as the speed of the hit changes the cue balls path can differ drastically from the "around thirty degrees".
 

ENGLISH!

Banned
Silver Member
That is true. I find that just saying about thirty degrees and using a peace sign to measure are nowhere near accurate enough. As the cut angle changes and as the tip offset on the vertical axis changes and as the speed of the hit changes the cue balls path can differ drastically from the "around thirty degrees".

--------------:thumbup2:-----------------------
 

ENGLISH!

Banned
Silver Member
Rick...Have you been looking in the mirror again? :shocked2: :killingme:

Scott Lee
http://poolknowledge.com

Sorry... but I have been flagged into the pits seemingly for violating the protection clause.

But when I do look into the mirror I do NOT see all of the individuals of whom I was referring...

& I do NOT see the likes of YOU.

But when I turn & look into AZB... I do see those individuals of whom I was referring & there are many many more than you would think that totally agree with me,

All Best Wishes for ALL.
 

dr_dave

Instructional Author
Gold Member
Silver Member
I find that just saying about thirty degrees and using a peace sign to measure are nowhere near accurate enough.
Thirty degrees is just an average over a wide range of shots. If one learns how to adjust the peace-sign angle a little larger for cuts closer to a 1/2-ball hit and a little smaller for cuts closer to 1/4-ball and 3/4-ball, and if one learns to shift the peace sign a little down the tangent line to account for faster speed, the CB direction can be predicted very accurately (e.g., to avoid a scratch, break out balls, get position through tight traffic, etc.).

Regards,
Dave
 
Last edited:

BRussell

AzB Silver Member
Silver Member
That is true. I find that just saying about thirty degrees and using a peace sign to measure are nowhere near accurate enough. As the cut angle changes and as the tip offset on the vertical axis changes and as the speed of the hit changes the cue balls path can differ drastically from the "around thirty degrees".

Hmm, I don't agree at all. You don't get drastically varying paths with the changes you list, not at all. In fact, what's cool about the 30 degree rule is that a rolling half-ball hit results in a CB path so reliably close to 30 degrees, even at different speeds, different amounts of "tip offset on the vertical axis," and, most importantly, different cut angles. Even all the way from 1/4 ball up to 3/4 ball produces close to the 30-degree CB path, unless you have a different definition of "drastically" than me.

Most pool players that I've shown it to think that the CB path is going to vary pretty linearly with cut angle, because they're used to the 90-degree rule, and they're really impressed that there's such high tolerances for the 30-degree path.
 

Straightpool_99

I see dead balls
Silver Member
I don't really have much to add, other than to point out that the 90 degree rule only applies if the balls colliding are of equal weights. If you are playing with a light or heavy cueball, the angles will change. If the weight is very different you will see a significant difference in the cueball path.

It is common for the cueball in a very worn standard ball set to be light, and many bar cue balls are heavy which will change the tangent line or play "dead" which will have a similar effect as a heavy ball in some respects (but will not change tangent line rule as long as the weight is the same). If you have a set containing different balls (perhaps some have been replaced etc) they will have an effect as well. A heavy object ball will have the same effect as a light cueball, and the heavy object ball will have the opposite effect. If you are playing in a run-down place with shoddy balls, it's good to keep this in mind. If you can visibly see a difference between the balls, do a test to determine if the weights are different, otherwise you might get a nasty surprise on that critical drawshot on the hill...The worst part about it is that the 8-ball and the cueball are frequently the ones that are replaced (people tend to steal them). So in a 9 ball match your last shot to play position on the 9 may be from a light or heavy ball.
 
Last edited:

dr_dave

Instructional Author
Gold Member
Silver Member
I don't really have much to add, other than to point out that the 90 degree rule only applies if the balls colliding are of equal weights. If you are playing with a light or heavy cueball, the angles will change. If the weight is very different you will see a significant difference in the cueball path.

It is common for the cueball in a very worn standard ball set to be light, and many bar cue balls are heavy which will change the tangent line or play "dead" which will have a similar effect as a heavy ball in some respects (but will not change tangent line rule as long as the weight is the same). If you have a set containing different balls (perhaps some have been replaced etc) they will have an effect as well. A heavy object ball will have the same effect as a light cueball, and the heavy object ball will have the opposite effect. If you are playing in a run-down place with shoddy balls, it's good to keep this in mind. If you can visibly see a difference between the balls, do a test to determine if the weights are different, otherwise you might get a nasty surprise on that critical drawshot on the hill...
If people want to see demonstrations and explanations of these and related weight effects for both the 90 and 30 degree rules, check out:

weight, size, and wear effects resource page

Enjoy,
Dave
 

FranCrimi

AzB Silver Member
Silver Member
In all the years I've played competitive pool, I never asked myself where the tangent line on any shot was. I also never asked myself what adjustment I had to make to make the cue ball veer off the tangent line at a particular point. That kind of stuff works well on paper and in the classroom, but when you're playing, you either know what to do or you don't. If you don't, you need to play more.

No matter how much you may need technicalities in your life, you can't calculate your way through a pool match. Well, you can try but don't expect great results.
 

ENGLISH!

Banned
Silver Member
In all the years I've played competitive pool, I never asked myself where the tangent line on any shot was. I also never asked myself what adjustment I had to make to make the cue ball veer off the tangent line at a particular point. That kind of stuff works well on paper and in the classroom, but when you're playing, you either know what to do or you don't. If you don't, you need to play more.

No matter how much you may need technicalities in your life, you can't calculate your way through a pool match. Well, you can try but don't expect great results.

:thumbup2:

I said something similar earlier, Fran.

The only thing I have checked for is a possible scratch line to decide how I might want to change my original thought as to how I was intending to hit a shot.

All Best Wishes for You & Yours,
Rick
 
Last edited:

Neil

AzB Silver Member
Silver Member
In all the years I've played competitive pool, I never asked myself where the tangent line on any shot was. I also never asked myself what adjustment I had to make to make the cue ball veer off the tangent line at a particular point. That kind of stuff works well on paper and in the classroom, but when you're playing, you either know what to do or you don't. If you don't, you need to play more.

No matter how much you may need technicalities in your life, you can't calculate your way through a pool match. Well, you can try but don't expect great results.

Fran, you may not have asked yourself, and I'm sure many of the older players never have. However, that does not mean that it is not beneficial to do so. You wouldn't believe how many times I have watched video of top players, and said "if they only knew how to do this or that, they would't have gotten in trouble there".

When you need to send the cb down a precise path for a breakout or safety, knowing just how the cb will react is of a tremendous advantage over just guessing. I just don't understand anyone saying that you can't calculate your way through a pool match. I guess some just don't know what they are missing.??
 

ENGLISH!

Banned
Silver Member
The great artist vs the paint by numbers method.

One just knows & feels their way to the artistry...

while the other must match the numbers on the canvas to the numbers on the tubes of paint & if a tube or canvass area is mis-numbered, the picture gets ruined.

We all have different 'natures' & we all should proceed according to our nature & not how others tell us to do so.

That said, some disciplines are better suited to one nature vs the other.
 
Top