A New (I think) Question About Squirt

Patrick Johnson

Patrick Johnson

Fargo 1000 on VP4
Silver Member
If the cue tip hits the CB on the same point, from the same angle and at the same speed, does changing only the cue stick's orientation with "swooping" backhand english change the amount of squirt?

swoop vs straight stroke2.jpg

I'm thinking that if the cue is angled toward the CB's center compared with the tip's direction of travel, then its effective endmass increases, creating more squirt. Anybody know?

pj
chgo
 
Last edited:
Patrick Johnson said:
If the cue tip hits the CB on the same point, from the same angle and at the same speed, does changing only the cue stick's orientation as shown below (and as may happen with "swooping" backhand english) change the amount of squirt?

View attachment 178691

I'm thinking that if the cue is angled toward the CB's center, then its effective endmass increases, creating more squirt. Anybody know?

pj
chgo
Click to expand...


Both of the shots are shown hitting "center CB"

The problem I see is that BHE is applied by hitting just left or right of center.

BHE...typically uses the angle more like the first picture....

The second picture is near impossible to produce because in order to achieve the "stroke path" shown and at the same time keep the cue angle shown....both the grip hand "and" the bridge hand need to move to the left as you make the stroke.

IF you keep the bridge hand stable...the stick will pivot about the bridge hand and produce a cue angle like the first picture.....

The way I apply BHE is to align through "center" CB and then pivot about the bridge hand....That creates the cue angle of the first picture...but it also produces a tip offset from center CB....The "tip offset" is what then becomes responsible for the deflection back on line.
 
BRKNRUN said:
The second picture is near impossible to produce because in order to achieve the "stroke path" shown and at the same time keep the cue angle shown....both the grip hand "and" the bridge hand need to move to the left as you make the stroke.

IF you keep the bridge hand stable...the stick will pivot about the bridge hand and produce a cue angle like the first picture.....
Click to expand...

Yep... what Ken said. You would probably have to grip the cue firmly with the bridge hand and slide your bridge hand across the table to achieve the contact as diagrammed on the right.

I also agree with Ken that a "swoop" stroke will, as a practical matter, deliver the cue pretty much as diagrammed to the left.

With all of that, I suspect that the two hits as you've described them would likely create very different amounts of squirt (and spin as well), as the directional forces of contact are being applied very differently relative to the "spine" of the cue's shaft. The amount of deflection would accordingly be different as well.

Not very practical, but an interesting thought exercise, PJ.

(P.S. I'm mourning the loss of your "Professor Johnson" avatar.)
 
G@d&##!t....

... you changed the diagram while I was posting!

Now I have to think this through all over again!
 
OK, I've thought about it...

1) The amount of swooping in the stroke on the right is still unlikely to be produced at the table. The player would almost have to whip his back hand across his body to achieve this.

2) As the sticks are still not parallel in the revised diagram, there probably will be modest differences in squirt and spin (for the same reasons as stated above). Because they are much closer to parallel, however, the effects will be very minimal.
 
ChazL said:
1) The amount of swooping in the stroke on the right is still unlikely to be produced at the table. The player would almost have to whip his back hand across his body to achieve this.
Click to expand...
It's exaggerated for illustration.

2) As the sticks are still not parallel in the revised diagram, there probably will be modest differences in squirt and spin (for the same reasons as stated above). Because they are much closer to parallel, however, the effects will be very minimal.
Click to expand...
So you think the cue's orientation makes a difference even if the tip is traveling in the same direction. Why?

pj
chgo
 
The question is interesting. What caused you to think of it?

If we use something quite flexible - a really flexible straw, say - with a tip that's as "sticky" as a cue's tip, then in the left picture, the straw will bend a lot to the right, and the ball will move forward and squirt a little bit to the left, correct?

In the right picture, given the straw's orientation at the time of contact, I'd expect it's initial bend to be to the left. Then, as the ball's inertia is overcome and it starts to move away from the contact point, the tip would start to unbend and as it comes to the point of being straight, if contact has not yet been broken then it would start to bend right. (I'm ignoring the tip's own inertia here, which may wrong. I'm also ignoring the fact that the tip is actually moving along an arc at time of contact rather than in a straight line that's "diagonal" to the cue ball; that may also be wrong.)

So, yes, I think you're right about there being more squirt. I don't know if it's technically correct to attribute it to an effective increase in end mass, but I think the effect would look like that was the case.

I've got a couple of other questions about whether the energy transferred to the ball is the same in the left and right images, assuming that the ball moves away from the contact point with the same velocity and rate of spin. It's too late to think about those right now, though. Nice problem.
 
"Swooping" english absolutely does work ... 100% guaranteed ... provided you have an off-weighted 8 ball as shown in the video that was linked.

Contact point is contact point ... twisting, turning, swooping ... none of it matters. The only way all these things matter is that they tend to make the intended contact point and aiming line other than what was intended. Provided the same cue is used (as I can already see someone saying that differences could exist depending on deflection characteristics), the contact point is what matters regarding your original question.
 
Patrick Johnson said:
If the cue tip hits the CB on the same point, from the same angle and at the same speed, does changing only the cue stick's orientation with "swooping" backhand english change the amount of squirt?

View attachment 178698

I'm thinking that if the cue is angled toward the CB's center compared with the tip's direction of travel, then its effective endmass increases, creating more squirt. Anybody know?

pj
chgo
Click to expand...

I have no technical proof to offer but I made at least two such shots in games last night and when I was figuring them allowed for more squirt. Since I made both of the shots and I got tons of spin out of the cue ball in order to complete the severe back cuts at slow speed I would have to say-----Yes.

336Robin
http://274928807619529663.weebly.com/
 
I dont know about changing the effective end mass. Seems unlikely if the tip is hitting the same spot on the ball. Solid hit vs glancing blow, the tip mass is the same the energy transfer would change.
I think most discernible difference in squirt from aiming parallel english vs bhe likely comes from the tip NOT hitting the ball in the same (intended) spot. Would need to be tested with a marked ball like the Rempe training ball to see where the tip impact was. Im betting bhe results in a hit closer to the vertical centerline of the ball than intended.
Chuck
 
Patrick Johnson said:
If the cue tip hits the CB on the same point, from the same angle and at the same speed, does changing only the cue stick's orientation with "swooping" backhand english change the amount of squirt?

View attachment 178698

I'm thinking that if the cue is angled toward the CB's center compared with the tip's direction of travel, then its effective endmass increases, creating more squirt. Anybody know?
Click to expand...
First of all, I think a better comparison would be a straight stroke with a BHE pre-stroke pivot versus a swoop stroke with the same fixed-bridge pivot position. But there, the actual tip positions on the ball would need to be slightly different to create the same effective tip offset (i.e., the perpendicular distance between the CB center and the line of action of the tip's total velocity should be the same in both cases). The swoop stroke would look a little like your 2nd diagram (although, not nearly as exaggerated) with the tip position a little to the left of that in the 1st diagram to create the same effective tip offset. I hope that makes sense.

Now, the effect of the swoop stroke is still demonstrated by your 2nd diagram (albeit in exaggerated form). The cue is effectively moving forward at an angle. In this case, I agree with you that the amount of squirt would be larger as compared to the cue moving straight at the same effective tip offset. There would be more effective endmass because the cue will deliver more force along its axis (with a sideways component) and present more stiffness in the squirt direction. And with more squirt would come less spin (see TP B.7)!

Having said all of this, I think all of these effects are too small to have any practical significance at the table.

Some people like the swoop stroke because it allows a center-ball alignment at the beginning of the stroke. However, the pre-stroke-pivot BHE approach will obviously result in better tip contact point accuracy and consistency (and possibly less squirt and more spin). Physics certainly doesn't suggest swooping offers any advantage, IMO.

Regards,
Dave
 
Patrick Johnson said:
If the cue tip hits the CB on the same point, from the same angle and at the same speed, does changing only the cue stick's orientation with "swooping" backhand english change the amount of squirt?

View attachment 178698

I'm thinking that if the cue is angled toward the CB's center compared with the tip's direction of travel, then its effective endmass increases, creating more squirt. Anybody know?

pj
chgo
Click to expand...

I think you may be right...

because the end mass is moving with a combination of forward and tangential direction in relation to the OB's path (rather than just forward), so the apparent squirt would be less in relation to the starting angle, but what I think it is doing is mimicking a wider starting angle with greater side spin, actually enough side spin to almost certainly cause a miss cue if the approach angle was changed prior to stroke.

I don't think that it's beneficial though, because it's too unpredictable and difficult to reproduce.

Jaden
 
Patrick Johnson said:
So you think the cue's orientation makes a difference even if the tip is traveling in the same direction. Why?
Click to expand...

I'll answer this by quoting Dr. Dave. He expresses the same idea that I had, and probably a good bit more clearly than I could write it.

dr_dave said:
[In the second diagram]... the cue is effectively moving forward at an angle. In this case, I agree with you that the amount of squirt would be larger as compared to the cue moving straight at the same effective tip offset. There would be more effective endmass because the cue will deliver more force along its axis (with a sideways component) and present more stiffness in the squirt direction. And with more squirt would come less spin (see TP B.7)!

Having said all of this, I think all of these effects are too small to have any practical significance at the table.
Click to expand...
 
The cue ball doesn't know what the cue stick is doing until contact. Then all is pretty equal.
randyg
 
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