Cue Tip Contact Myth-Busting Truths in Super Slow Motion

A question for you physicists out there:
With tip hardness and acceleration into the ball having a negligible effect on spin quality (spin to speed ratio), what is the reason some players/strokes can produce higher levels of spin at the same speeds?

Corey Deuel showed a friend of mine a technique for getting more spin at lower speeds. AND it works! The only problem is that he used both of the myths above to explain it, with emphasis on acceleration.

edit: ignore tip offset as a guy like Corey hits the ball where he wants.
 
WobblyStroke said:
... what is the reason some players/strokes can produce higher levels of spin at the same speeds?
...
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That's simple. They hit the ball farther from center. The vast majority of pool players and even some very good ones never hit with quality spin. It's as simple as that.

Getting a veteran player to do that sometimes requires subterfuge since their tendency is to hit closer to the center than they think they are. One way is to tell them to use a much lighter grip. That changes where they hit the cue ball. Is it a bad idea to trick a student like that?
 
I’m sorry Dave, but some of this is just incorrect…or at the very least not explained fully.

It’s obvious to any good player that a softer tip sprays the ball more because it imparts more unintentional English on hit.

I’m not sure if that’s what you mean in tip #3 or not but a soft tip does often put more English on a ball because it grabs more.
 
dr_dave said:
Since every miscue involves sliding contact and pretty much always involves multiple secondary hits, miscues should probably be fouls. But then people would want to call a foul on any shot that sounds funny (like a “partial miscue” shot).
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BIH for any miscue is an extraordinary penalty for an APA 1 (or below).

Anyone positing miscue = BIH is trying to take out what little life remains in pool.
 
So is it a myth or fact that a soft tip imparts more spin than a hard tip?

This video proves that contact time is negligible, so contact time does not support a soft tip imparting more spin. But what about contact shape? The contact patch size (like a tire's contact patch) on a soft tip is greater, per the video, than a hard tip, and visually, it's obvious it's not by an insignificant amount. Does contact patch size influence spin imparted?
 
Hits 'em Hard said:
Your conclusion that the difference in tip contact tip time has no variance on how much spin/speed is imparted on the cue ball needs to be supported with evidence. You have not included any evidence, in this video or in previous videos to make such a claim. You claim that just the numbers are so minuscule that they can’t possibly have any effect. That needs to be supported with evidence to back up that claim.
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Concerning spin, the evidence is in the explanations here:
cue tip hardness effects

I don't think I said anything about the effect on shot speed in the video (although, all tests were done with the same CB speed for each tip). The effect of tip hardness on speed is covered here:
cue tip efficiency
 
dquarasr said:
So is it a myth or fact that a soft tip imparts more spin than a hard tip?
Click to expand...

Myth. If anything, a hard tip might be able to impart more spin (although, with probably a negligible amount). For the reasons why, see Freddie's posts above or the explanations here:
cue tip hardness effects

dquarasr said:
Does contact patch size influence spin imparted?
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I have never seen evidence (or a reasonable explanation) that it does.
 
dr_dave said:
,,, I have never seen evidence (or a reasonable explanation) that (contact patch influences spin)
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There does seem to be a slight indirect connection, since harder tips have a smaller contact patch and they may produce slightly more spin. I think that effect, if any, is much, much smaller than the increased speed a harder tip gives compared to a softer tip.
 
dr_dave said:
Myth. If anything, a hard tip might be able to impart more spin (although, with probably a negligible amount). For the reasons why, see Freddie's posts above or the explanations here:
cue tip hardness effects



I have never seen evidence (or a reasonable explanation) that it does.
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This is where you’ve created a problem. You’re using a set speed for your testing. It needs to be a variable speed. You need a slow/medium/fast strike on the cue ball with each hardness. That way there’s a full table of data to interpret. The math behind all of this says that a soft tip should be able to impart a higher rate of spin for the distance the cue ball travels. For simplicity’s sake, let’s say all tips top out at 2000rpm capable. The soft tip should impart a traveling speed that is less than that of a hard tip. Meaning the soft tip will spin more for the same distance traveled. That’s where the contact time plays a difference. Over 4 feet, let’s say the soft tip at maximum spin, takes 3 seconds to travel. That would imply that the cue ball spins a 100 times in that distance. Now using your data, the hard tip has 33% less contact time. That should mean it travels the same distance in 33% less time, so 2 seconds. So the cue ball effectively in the same distance has spun on 60 times.

Your myth busting isnt working out as well as you claim.
 
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SEB said:
It’s obvious to any good player that a softer tip sprays the ball more because it imparts more unintentional English on hit.
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It's easy to test...

1. Use a marked ball (like the striped ball shown below, with the stripe vertical) so you can check chalk marks to be sure you're hitting at the same horizontal distance from center.
2. Shoot straight across table (like from the spot to the second diamond on the side rail) at just the right speed to rebound back to the near rail (or any repeat distance).
3. Mark the spot on the near rail that the ball hits.

In my experience, hitting the identical contact point and speed with different tips returns the ball to the same spot on the near rail - in other words, they both produce the same amount of spin.

pj
chgo

max spin.jpg
 
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Hits 'em Hard said:
This is where you’ve created a problem. You’re using a set speed for your testing. It needs to be a variable speed. You need a slow/medium/fast strike on the cue ball with each hardness. That way there’s a full table of data to interpret. The math behind all of this says that a soft tip should be able to impart a higher rate of spin for the distance the cue ball travels. For simplicity’s sake, let’s say all tips top out at 2000rpm capable. The soft tip should impart a traveling speed that is less than that of a hard tip. Meaning the soft tip will spin more for the same distance traveled. That’s where the contact time plays a difference. Over 4 feet, let’s say the soft tip at maximum spin, takes 3 seconds to travel. That would imply that the cue ball spins a 100 times in that distance. Now using your data, the hard tip has 33% less contact time. That should mean it travels the same distance in 33% less time, so 2 seconds. So the cue ball effectively in the same distance has spun on 60 times.

Your myth busting isnt working out as well as you claim.
Click to expand...
What math formula are you suggesting? What is the math equation with respect to spin that has time as a variable?
 
WobblyStroke said:
A question for you physicists out there:
With tip hardness and acceleration into the ball having a negligible effect on spin quality (spin to speed ratio), what is the reason some players/strokes can produce higher levels of spin at the same speeds?

Corey Deuel showed a friend of mine a technique for getting more spin at lower speeds. AND it works! The only problem is that he used both of the myths above to explain it, with emphasis on acceleration.

edit: ignore tip offset as a guy like Corey hits the ball where he wants.
Click to expand...
I think the major problem with the explanation using acceleration is that 99.999% of professional players don’t actually know what acceleration is. And without measurements, they don’t actually know if they’re accelerating.

The measured values any time these experiments have been done by any great stroking players, the acceleration right at the moment before impact is always nearly zero. What seems obvious to me is that professionals can efficiently and repeatable accelerate their cuestick to a velocity. It’s the velocity, not the acceleration that matters at impact along with the tip offset.
 
Nice video, I enjoyed all the slow mo and the production value.

I did have the same initial reaction as Hit's em Hard. Dr Dave (and everyone forever), say (paraphrasing): "because the contact time is so small, extending it slightly for softer tips does not make a difference to anything". That never seems to be qualified with anything.

That said, I'm in agreement, that there are not tangible playability differences. The "proof" of that IMO, is every pro under the sun can make every shot under the sun. While one pro will use a 13.5mm shaft with an ivory ferrule and an elk master tip made in 1960, and another pro will use the latest CF shaft and Moori tip.
 
Perhaps it's just me, but I generally don't tell someone with a PhD in physics that he is wrong about physics when I barely made it through Algebra 2 in high school. I find it comical that I see folks arguing traditional pool assumptions with a dude that has a PhD in physics and does experiments. The biggest experiment I ever pulled off was trying to tell my wife "no" on getting a second Margarita. It didn't end well.
 
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