Effects of English on Cueball A-path

galipeau

galipeau

AzB Silver Member
Silver Member
This is a question that has bugged me for ever. I've always been told that side-spin has NO effect on the "A-path" (aka: tangent line) of the Cueball after contact with the Object ball. I know this is good advice for beginners as it illustrates the general principals of cueball control. But is this actually a true statement? Also, if it does make a difference, how quantifiable is it?

I've had an intuition that this may not be true for a long time now, but have no evidence to back it up. Two reasons I can think of as to why players do this are:

1. english "oils" the cb to help it move farther on the tangent line
2. english putts reverse spin on the object ball to help it cheat a pocket, bank, etc

Any real answers to this question????

Thanks, Ian

If this needs to move to the instructor section, that's fine. Just thought I'd throw it out there.
 
Last edited:
dr_dave

dr_dave

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Silver Member
galipeau said:
This is a question that has bugged me for ever. I've always been told that side-spin has NO effect on the "A-path" (aka: tangent line) of the Cueball after contact with the Object ball. I know this is good advice for beginners as it illustrates the general principal, but is this actually true (and if it does make a difference, how quantifiable is it)?

I've had an intuition that this may not be true for a long time now, but have no evidence to back it up. Two reasons I can think of as to why players do this are:

1. english "oils" the cb to help it move farther on the tangent line
2. putting reverse spin on the object ball to help it cheat a pocket, etc

Any real answers to this question????
Click to expand...
FYI, the following article and resource pages deal with these topics:

"90° and 30° Rule Follow-up - Part IV: english effects" (BD, May, 2005)
"hold" or "kill" shot to limit CB drift
spin transfer resource page

To answer your questions directly:
1.) Yes. Outside english will generally results in slightly faster CB motion down the tangent line.

2.) Yes. Some spin is transferred to the OB, and this can have an effect on some shots.

Regards,
Dave
 
N

Neil

AzB Silver Member
Silver Member
galipeau said:
This is a question that has bugged me for ever. I've always been told that side-spin has NO effect on the "A-path" (aka: tangent line) of the Cueball after contact with the Object ball. I know this is good advice for beginners as it illustrates the general principals of cueball control. But is this actually a true statement? Also, if it does make a difference, how quantifiable is it?

I've had an intuition that this may not be true for a long time now, but have no evidence to back it up. Two reasons I can think of as to why players do this are:

1. english "oils" the cb to help it move farther on the tangent line
2. english putts reverse spin on the object ball to help it cheat a pocket, bank, etc

Any real answers to this question????

Thanks, Ian

If this needs to move to the instructor section, that's fine. Just thought I'd throw it out there.
Click to expand...

English will not curve the cb off the tangent line. That is why it is stated that it has no effect on the tangent line. It doesn't change the tangent line. English will afffect the cb path before contact with the ob. But not it's path after contact with the ob until you hit a rail. Unless you use a masse' shot.
 
BeiberLvr

BeiberLvr

AzB Silver Member
Silver Member
This has always been my thoughts on the matter, but it could be wrong.

Where you strike the CB does not determine the tangent line. It's where the CB makes contact with the OB that determines the tangent line.

So on shots with side spin (especially over certain distances), the contact area on the OB will be different when using left or right spin, then it would be with center. Now if you played a short distance shot where the spin might not have time to take effect, then the tangent lines would be the same, because the contact area on the CB wouldn't change.

Same goes with hitting center on the CB, but playing the OB to different parts of the pocket. That will also result in a different tangent line, but it just goes back to the fact that you're simply changing where the CB contacts the OB.
 
B

bdorman

Dead money
Silver Member
I tested it out because I wanted to see if I could use english instead of (or in addition to) cheating the pocket to create an angle.

For a straight-in shot using 5 and 7 o'clock english I couldn't get the CB to budge off the straight-back line. Massive amounts of spin on the CB but it came back to me in a straight line.

I also tried it with various cut angles but you really can't tell if there's an effect or not beyond the normal variance, i.e no two cut angle shots are going to react EXACTLY the same and any differences were so small as to be immeasurable.

Bottom line: cheating the pocket was the only reliable solution.

Better bottom line: get better position to begin with :D
 
S

Scott Lee

AzB Silver Member
Silver Member
dr_dave said:
To answer your questions directly:
1.) Yes. Outside english will generally results in slightly faster CB motion down the tangent line.

No it doesn't, Dave...unless topspin or backspin are part of the tip placement. While OE may very slightly (how do you quantify "slightly"?) accentuate the speed down the tangent line, it doesn't make the ball curve, so the answer to Ian's question is NO, it doesn't, when shot on the horizontal axis of the CB.

2.) Yes. Some spin is transferred to the OB, and this can have an effect on some shots.

Again, there are several variables that determine whether, or not, sidespin is transferred, at all, and how much...so there is no "blanket" answer there either.

Regards,
Dave
Click to expand...

This is very simple for anyone to test themselves, on their own tables. Place the OB on the footspot. Place the CB a foot away from the OB, on a very slight cut angle (cut angle doesn't change tangent line, so make the shot easy), say a 15 degree cut, or a 3/4 ball aim. Strike the CB dead center, with 2-3 tips of sidespin. If you pocket the OB in the corner, the CB will travel down the tangent line, spinning like a top, and should fall into the side pocket. If your CB hits the rail above or below the side pocket, you're not striking the CB on the exact horizontal axis.

Scott Lee
http://poolknowledge.com
 
dr_dave

dr_dave

Instructional Author
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Silver Member
Scott Lee said:
dr_dave said:
FYI, the following article and resource pages deal with these topics:

"90° and 30° Rule Follow-up - Part IV: english effects" (BD, May, 2005)
"hold" or "kill" shot to limit CB drift
spin transfer resource page

To answer your questions directly:
1.) Yes. Outside english will generally results in slightly faster CB motion down the tangent line.
Click to expand...

No it doesn't, Dave...unless topspin or backspin are part of the tip placement.
Click to expand...
That wasn't part of the original question, but I certainly agree with you that topspin and backspin certain move the CB off the tangent-line path.

Scott Lee said:
While OE may very slightly (how do you quantify "slightly"?) accentuate the speed down the tangent line, it doesn't make the ball curve
Click to expand...
I agree 100%. Sidespin causes no curve off the tangent line, and the speed-change effects due to the type and amount of spin are very small (probably of no practical importance).

Scott Lee said:
dr_dave said:
2.) Yes. Some spin is transferred to the OB, and this can have an effect on some shots.
Click to expand...

Again, there are several variables that determine whether, or not, sidespin is transferred, at all, and how much...so there is no "blanket" answer there either.
Click to expand...
There are many shots where throw and spin transfer have significant effects, allowing shots that would not be possible otherwise. Numerous examples are demonstrated here:

throw-shot examples (with video demonstrations)
spin-transfer-shot examples (with video demonstrations)
CB "hold" shot resource page

CB spin does not have significant or practical effect on the CB's motion along the established tangent line, but it can have significant effect on where the OB heads relative to the tangent line and on what both the CB (and OB with certain types of shots) do after contacting a cushion.

Scott, I'll assume you agree with this (per the video demonstrations). If not, please let me know.

Thank you for helping to clarify the message,
Dave
 
3andstop

3andstop

Focus
Silver Member
A very similar question came up quite a while ago and I pointed out ( assuming contact of the CB is on its equator throughout this example, or at least the same through out the scenario) that while side spin doesn't (in and of itself) affect the tangent line from the point of contact on the OB, side spin can and does affect where you contact the OB in order to pocket it.

Therefore, in a tight spot (very common in straight pool) pocketing a ball that would send the CB down an undesirable tangent line, can be adjusted with side spin.

This, because now you are able to contact the OB in a slightly different spot, either thicker or thinner than the contact point with no side spin (depending on which english is used) to pocket it (turn it into the pocket) and change both the contact point and tangent line.

So, in a sort of indirect way, side spin one way or the other, can change the standard tangent line when speaking relative to the pocketing of an object ball.

It will not change the tangent line when speaking of a carom only, hitting the OB in the same spot regardless of english. Hope that made sense. :scratchhead:
 
dr_dave

dr_dave

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3andstop said:
A very similar question came up quite a while ago and I pointed out ( assuming contact of the CB is on its equator throughout this example, or at least the same through out the scenario) that while side spin doesn't (in and of itself) affect the tangent line from the point of contact on the OB, side spin can and does affect where you contact the OB in order to pocket it.

Therefore, in a tight spot (very common in straight pool) pocketing a ball that would send the CB down an undesirable tangent line, can be adjusted with side spin.

This, because now you are able to contact the OB in a slightly different spot, either thicker or thinner than the contact point with no side spin (depending on which english is used) to pocket it (turn it into the pocket) and change both the contact point and tangent line.

So, in a sort of indirect way, side spin one way or the other, can change the standard tangent line when speaking relative to the pocketing of an object ball.

It will not change the tangent line when speaking of a carom only, hitting the OB in the same spot regardless of english. Hope that made sense. :scratchhead:
Click to expand...
Excellent summary!

Good job,
Dave
 
galipeau

galipeau

AzB Silver Member
Silver Member
To clarify, my question isn't focused on the object ball as much as it is on the path of the cb (I was hinting mostly at speed as a factor)

When I watch the pros and they hit a ball with English (and no cb contact to the rail) I've wondered why this is....

Thanks for the input Scott and Dave

Sent from my SCH-I535 using Tapatalk
 
BeiberLvr

BeiberLvr

AzB Silver Member
Silver Member
galipeau said:
To clarify, my question isn't focused on the object ball as much as it is on the path of the cb (I was hinting mostly at speed as a factor)

When I watch the pros and they hit a ball with English (and no cb contact to the rail) I've wondered why this is....

Thanks for the input Scott and Dave

Sent from my SCH-I535 using Tapatalk
Click to expand...

They use english on those shots to make the shot easier. Although I've never really done any research on the matter, I do know a lot of players swear by hitting those slight cut shots with a little outside spin to throw the ball.

English might also be used to reduce skid. Again, I'm not sure how true that is, only that it's one of the reasons they'll put spin on a ball.
 
ScottK

ScottK

AzB Silver Member
Silver Member
3andstop said:
A very similar question came up quite a while ago and I pointed out ( assuming contact of the CB is on its equator throughout this example, or at least the same through out the scenario) that while side spin doesn't (in and of itself) affect the tangent line from the point of contact on the OB, side spin can and does affect where you contact the OB in order to pocket it.

Therefore, in a tight spot (very common in straight pool) pocketing a ball that would send the CB down an undesirable tangent line, can be adjusted with side spin.

This, because now you are able to contact the OB in a slightly different spot, either thicker or thinner than the contact point with no side spin (depending on which english is used) to pocket it (turn it into the pocket) and change both the contact point and tangent line.

So, in a sort of indirect way, side spin one way or the other, can change the standard tangent line when speaking relative to the pocketing of an object ball.

It will not change the tangent line when speaking of a carom only, hitting the OB in the same spot regardless of english. Hope that made sense. :scratchhead:
Click to expand...

While your premise is correct, it would be more accurate, and therefore less confusing, for you to refer to this as a "new tangent line" as that's what it really is.

Indicating any "change" in the tangent line is incorrect and confusing as the tangent line is a constant. And by constant, I mean constant. You CANNOT do anything to alter the tangent line.
 
dr_dave

dr_dave

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BeiberLvr said:
They use english on those shots to make the shot easier. Although I've never really done any research on the matter, I do know a lot of players swear by hitting those slight cut shots with a little outside spin to throw the ball.
Click to expand...
English allows you to "hold" the CB more effectively when the CB is fairly close to the OB. For more info, and demonstrations, see the throw hold resource page.

BeiberLvr said:
English might also be used to reduce skid. Again, I'm not sure how true that is, only that it's one of the reasons they'll put spin on a ball.
Click to expand...
Gearing outside english can entirely eliminate throw and skid (AKA "cling"). The tricky part is using the right amount of english based on the cut angle (although, this can be learned by "feel" with enough practice). For more info, and demonstrations, see the gearing outside english resouce page.

Regards,
Dave
 
dr_dave

dr_dave

Instructional Author
Gold Member
Silver Member
galipeau said:
This is a question that has bugged me for ever. I've always been told that side-spin has NO effect on the "A-path" (aka: tangent line) of the Cueball after contact with the Object ball.
...
Any real answers to this question????
Click to expand...
FYI, I just created a resource page summarizing answers to this question, with illustrations and supporting resources. Here it is:

90-degree-rule (tangent line) and 30-degree-rule english (sidespin) effects

Check it out.

3andstop and BeiberLvr, FYI, I included quotes of your excellent posts.

Enjoy,
Dave
 
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