Question about intentional swerve

I have about as much chance of becoming a pro level player as you do becoming the next Einstein.

But that shouldn't stop someone who knows everything about the physics of the game becoming an expert player. Chop chop!
Then it certainly shouldn't stop somebody who knows how all the pros do things.

Are we having fun yet?

pj
chgo
 
Then it certainly shouldn't stop somebody who knows how all the pros do things.

Are we having fun yet?

pj
chgo

Not particularly.

You appear to have changed direction. There is no way a pro pool pkayer is ever going to waste his time becoming a physics geek. However, as you sciencey types know everything there is to know about the game, you should have no trouble becoming an expert player yourself.

This would give a balanced viewpoint and settle all arguments - do you not agree?

The first step is always the hardest. Patrick. Learning to cue ball is crucially important. Give it a go lad.
 
after the player's mind processes this "dessert," they may have a "game ache".

Lol.

Patrick Johnson, ladies and gentlemen. He's here all week - probably.

Players that are inquisitive about squirting, clinging, and swerving are in for a delicious treat!

Hope no one gets a "truthache". ;)
 
You're welcome, let me know how it works out for you.
Have a great day

SS

SS,

I worked on your tips to me just a bit yesterday as I was waiting for my Wife & Daughter to return from a short trip.

Obviously it works. It's similar in effect to the tip Fran Crimi gave me about controlling the amount of follow for the red circle cue ball which is what I was using yesterday.

I'd imagine it would work even better if the cue ball where the same weight as the OB.

I'd have to practice it to get really good with it as it is a different stroke than I'm use to. But...I can certainly see times when I might use it over what I would normally do. It's now a tool in my tool box & I'm sure I'll give it a go from time to time.

Thanks much for the info & more tips are certainly welcome.

Best 2 You & All,
Rick
 
While filming VEPS, Tom Ross and I had many heated "discussions" about the swoop stroke. Tom was a major swooper and a very good player. Tom and I did many tests and experiments to try to determine if a swoop stroke could apply more spin to the CB (to help settle our "differences of opinion"). Before all of these discussions, tests, and experiments, Tom was a firm believer that the swoop stroke could apply more spin to the CB (seemingly defying the normal miscue limit). After the discussions, tests, and experiments, he was no longer a believer; although, he still used the swoop stroke because that is what he always did, and it worked well for him. He preferred aiming closer to center ball, where it is easier to visualize the exact aim for the shot, and he preferred applying BHE (to compensate for squirt) during the stroke instead of before. It is what came naturally to him, and it is the way he learned to apply english from watching his "old-timer" mentors who did it that way.

Again, I think the main benefit of a swoop stroke is that it allows one to apply the BHE squirt correction during the stroke instead of before the stroke. BHE before the stroke can be awkward, uncomfortable and unnatural to some people. Some, while aiming and aligning a shot, don't like seeing the cue pointing in a different direction than they want the CB to head. Also, some people don't like to change stance and cue alignment after being down on a shot, which is what occurs with a pre-stroke BHE pviot.


Colin,

I agree that if the swooping speed is significant compared to the forward stroking speed, more spin can be created for a given tip contact point. As Jal's diagram clearly shows, the swooping motion changes the velocity vector of the tip creating a different effective tip offset from center (and if this effective tip offset is beyond the miscue limit, a miscue will occur, with or without swoop). However, this velocity vector change would also change the direction the CB heads (as if the cue were aimed in a different initial direction, along the new velocity vector, with a straight stroke). Obviously, this would not be a good effect when trying to aim a shot with sidespin.

I propose the following test:

Setup a straight shot aimed at a ball frozen to a rail like in Diagram 3 of "HAPS - Part II: BHE and FHE" (BD, December, 2014). Then, using fixed CB and bridge positions, aim to hit the CB directly into the frozen ball with near maximum english (on the horizontal centerline of the CB) with the same speed and with the cue at the same near-level elevation and tip position for each shot. Try multiple attempts using both a straight stroke with pre-stroke BHE, and a swoop stroke (starting with a center-ball alignment and using BHE during the stroke instead). Faster speed is preferable to minimize swerve effects and to help reduce possible variability from one shot to the next. Although, if using a video camera, the shot speeds can be checked later (by looking at the time between the hits of the CB and OB), and shots that aren't close enough to the same speed can be thrown out. If this is being done, any consistent shot speed can be used

If desired, adjust the bridge length so the pre-stroke BHE aim adjustment is as good as possible in compensating for net CB deflection (the combined effects of squirt and swerve), resulting in a square hit on the frozen ball.

Does the CB head in the same direction with both the BHE and swoop strokes? If not, make adjustments in the aims so the CB heads in the same direction for both stroke types. Then remove the frozen ball, and hit the same strokes into the rail. Does the CB come off the cushion at different angles due to spin differences between the different stroke types?

Honestly, I haven't done a set of experiments this complete or careful before, but I intend to. I will post a video online when I can find the time to do the tests and video editing, but I also encourage the swoopers out there to give it a try and report back what they find. I think the test and results could help resolve many of the apparent disagreements in this thread and help improve everybody's understanding of the effects involved.
FYI, I finally found the time to do this. Here it is:

NV F.2 - Swoop Stroke Experiment - Can swooping create extra spin on the cue ball?

Check it out,
Dave
 
FYI, I finally found the time to do this. Here it is:

NV F.2 - Swoop Stroke Experiment - Can swooping create extra spin on the cue ball?

Check it out,
Dave
You don't mention the conclusion of your experiments, so I will: swooping does not create extra spin.



By the way, I once posted a question about whether a swoop stroke creates more squirt, but I don't think it was ever answered - do you know?

Here it is:
A New (I think) Question About Squirt - 04-15-2011, 11:18 PM


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?

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

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Thanks, Dave! That was a very well done experiment and video. It was right up there with your VEPS presentations I enjoy watching.

Thoughts I had on the video are that the player's (Mr. Dave Gross) interpretation of swooping the cue and what I do are different. He seems to be applying BHE rather than applying spin as he strokes through the cue ball.

If you watch a guy like Larry Nevel apply a rub across the cue ball, he starts on the side opposite the intended spin. IOW, he addresses the cue ball on the right side for left hand spin. I start about a tip on the opposite side, also.

I did a short experiment similar to your setup with about ten shots each. I used a hard tip on a maple shaft and got different results. Possibly because I'm more familiar with the swiping stroke than in your example.

One last thought, in the first part of the video, a larger result of 11.4 occurred on your swooping demonstrations. Possibly, the answer is in the technique. I won't dwell on this because it is a hotly debated point here, but it is what I'd call digging into the cue ball, or pinning the cue ball.

As soon as I saw the stroke, before I saw the results, I said to myself from experience the player just pinned the cue ball. The audio portion of this stroke is slightly different if you compare it to the previous strokes. There is a small increase in the speed and a slightly different follow through to get these results. Possibly another examination of another type of stroke for another day. :)

Best,
Mike
 
I did a short experiment similar to your setup with about ten shots each. I used a hard tip on a maple shaft and got different results. Possibly because I'm more familiar with the swiping stroke than in your example.
I'd bet it's because you didn't control the variables like Dave did. Did you check chalk marks after each shot? Did you carefully match chalk marks for shots you compared? Did you carefully measure the 1st rail contact point and only compare shots that hit in exactly the right place?

The Devil's in the details...

pj
chgo
 
Great stuff Dave!
Thanks.

Can I assume that parallel english would have garnered about the same results? I can't think of any reason it wouldn't.
"Parrlel english" will "work" only if the amount of swerve happens to cancel the squirt (i.e., there will be no net CB deflection) for a given shot speed, shot distance, cue elevation and conditions. Although, this might depend on what you actually mean by "parallel english" (see the parallel english resource page for more info).

Regardless, if the CB is sent in a certain direction with a certain speed and spin, it really doesn't matter how you aimed or stroked the shot to achieve that CB motion. Now, when some people stroke the shot differently, they get a different CB result. That's what seems to cause a lot of confusion, misunderstanding and debate about things like this. For more info, see: stroke "type" and "quality."

Regards,
Dave
 
You don't mention the conclusion of your experiments, so I will: swooping does not create extra spin.
The video makes the conclusions clear, but thank you for stating one of them here. Although, I think it is more appropriate to say: A swoop stroke can create more spin for a given aim and tip contact point, but it cannot create more spin in general.


By the way, I once posted a question about whether a swoop stroke creates more squirt, but I don't think it was ever answered - do you know?
If anything, based on what causes squirt, I would think a swoop stroke might create slightly less squirt, since the endmass is already partly moving away from the CB at contact). Regardless, since there are so many other things going on with a swoop stroke (e.g., the change in CB direction due to the swiping motion), I can't imagine any squirt-change effect would possibly be noticeable or measurable.

Regards,
Dave
 
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