TT Myth Busters

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No one deserves any respect unless it is earned.

Every single person deserves respect without proving anything.

Disrespect often can be earned also. And what Pnachtwey doesn't understand is that he has really done plenty to earn all our disrespect.

He keeps asking people to prove things that have been addressed adequately not just once but multiple times and ignores when people have asked him to do something simple like use a better camera and put himself, his stroke and his contact into the video so we can show him how his stroke lacks the tangential impulse he thinks is there.

Truthfully, when all this silliness started, I thought Pnachtwey was half normal and could reason and take in information. Like Killerspintt I thought we could possibly help the guy learn to actually make brush contact and loop.

He has enough money. He could have gotten himself that loop wheel even if it was just to test the theory of whether he is making hit contact or loop contact. I remember learning the difference and it being a bit of an eye opener. I thought we could help the guy who does know physics but clearly doesn't understand how what he is doing and what he thinks he is doing could actually be different.

That still isn't what has earned Pnachtwey the disrespect of so many. How he has earned that is verbal attacks, name calling, taking stock phrases out of context and misinterpreting them to try and embarrass others, and a complete lack of ability to observe simple facts like that his strokes are awkward, his technique is at quite a low level and he does not know how to make the correct contact for generating spin.

When you watch his serves it is easy to see that his racket hits into the ball instead of pulling past the ball so that there is very little tangential impulse put on the ball. I am confident, if we saw his contact in his stroke vs backspin we would see the same kind of thing where, even if the racket was closed to some extent the momentum of the contact is into the ball not brushing past the ball.

In the serve and receive video, there are a few shots where he does spin the ball a bit more and gets a bit of arc on the ball. Those all are actually low balls that he has to hit up to get over the net. But on the higher balls, his contact is mostly hit and drive. It is also possible to see that he gets a bit more spin when his FH goes to the opponent's backhand side. When he goes crosscourt his contact is much flatter.

But somehow Pnachtwey is not interested in information that would help him and he is determined to ignore any substantive critiques of the execution of what he thinks is a loop. And he is also determined to throw around insults, while taking simple phrases out of context to try and attack people because his main goal is to embarrass others.

My experience has been that someone whose main goal in engaging in a "discussion" is to embarrass, to make other people look stupid, and to show everyone that he is the guy who made other people look stupid, probably has some other stuff going on under the surface that is more than meets the eye.

So when you are dealing with a guy whose sole purpose in posting is to make other people look stupid, you are probably dealing with a person who is more than just unhappy as a human being. And to add to the general miserableness of the person, when you add the psychological issues that are clearly there and the fact that even though he is functional and runs his own company, he is clearly pretty solidly somewhere on the autism spectrum, I guess, in the end, I actually feel bad for the guy.

Has he earned my respect? Definitely not. Has he earned the disrespect of pretty much everyone on the forum? He really has gone out of his way and gone above and beyond to create the level of disrespect that he has demanded and won.

How has he done it? It is not based on the technical information he has presented. The information itself is fine. It is his people skills or really his lack of them. And it is also his inability to grasp that what he is doing in his videos has very little to do with the theory he has presented about how to loop backspin balls.

Since he won't listen to a guy like Killerspintt who is an engineer/physicist and he is really not posting anything substantive and is happy to call names and repeat the same silly statements totally out of context, I would have to simply agree with the full statement in Killerspintt's last post about the subject of Pnachtwey.

Normal people don't demand proof in theorems for something that is plain to see. So either he is purposely lying to all of us because he just wants to argue. Or, he simply has no clue what the difference between a ball with spin and a ball with very little spin looks like.

Someone somewhere along the line told me that pigs like to roll in mud and other unclean substances like their own feces. And when you try to wrestle with one, you end up covered with it.

It has been sort of fun showing that the guy is missing a few screws and razzing him. But at this point I just feel like the guy is pretty hopeless and I actually feel sorry for him.

Pnachtwey, sorry for calling you PNut and Punchy. As a physicist you may be spot on. Now go and work on your brush contact and your loop so you can be as good at table tennis as you are at mathematical equations.


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I was not the one to throw the first stone. You called me delusional first. You also gave me lots of ammunition when you claimed that the spin stops for a moment when looping back spin. You also can't tell us how I stopped the spin. Then you an Nextlevel said I was slapping the ball when it is clear that my stroke is upwards. It didn't seem to make much difference to you that the balls were going over the net.

Back to the Jumpulse myth.

Here is an example from the jump pulse thread on another forum
zeio said:
Something is off here. Acceleration is the rate of change in velocity. Hence, for the average acceleration of your scenario, you need to take into account both the initial and final velocities and the entire duration of collision.


a avg = (vf - vi)/t = (-22m/s - 20m/s)/1ms = -42000m/s^2.


(Note: The -22m/s denotes the ball returns in the opposite direction.)
If you read the post vf if the velocity of the ball but vi is the velocity of the paddle. What acceleration is zero calculating? The acceleration of the paddle or the ball. To calculate the acceleration of the ball you need the initial and final velocity of the ball and the time of change.

What is sad is that no one on the other forum corrected zero because he is one of the favorites there or don't know enough. Reflecx was right given his assumption because he specified the initial and final speed of the ball. Reflecx should stand his ground.

The thread OP is confused about whether speed or acceleration is more important during contact. Too many say accelerate through the ball.

My spell check correct zeio to zero. It fits.
 
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I was not the one to throw the first stone. You called me delusional first. You also gave me lots of ammunition when you claimed that the spin stops for a moment when looping back spin. You also can't tell us how I stopped the spin. Then you an Nextlevel said I was slapping the ball when it is clear that my stroke is upwards. It didn't seem to make much difference to you that the balls were going over the net.

Back to the Jumpulse myth.

Here is an example from the jump pulse thread on another forum

If you read the post vf if the velocity of the ball but vi is the velocity of the paddle. What acceleration is zero calculating? The acceleration of the paddle or the ball. To calculate the acceleration of the ball you need the initial and final velocity of the ball and the time of change.

What is sad is that no one on the other forum corrected zero because he is one of the favorites there or don't know enough. Reflecx was right given his assumption because he specified the initial and final speed of the ball. Reflecx should stand his ground.

The thread OP is confused about whether speed or acceleration is more important during contact. Too many say accelerate through the ball.

My spell check correct zeio to zero. It fits.

ff163a098501fac4b8a5cf3fbd94b055.jpg


08e1254663665d9d1e2c85e8c5d1d8a4.jpg
 
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The 'wobble balls' are nu illusion. If the ball has little to no spin at all it wil wobble through the air. Just like a wobble ball in football.
A foot ball isn't round. The tip of the foot ball will deflect air around it unevenly. TT balls are round and mostly smooth.

Meanwhile back on the Jumpulse thread, someone mentioned the conservation of kinetic energy. This is new to me. There is a link to how to calculate the speed after impact but it assumes a perfectly elastic collision. How bogus. I posted the speed after impact formula there many times and no one pays attention or understands. That whole forum has a short memory.

I read the document that was linked to written by Wu. There is a lot of valid information to fool the unwary into believing the whole thing. It is clear to me that Wu has little practical experience in motion.

BTW, the terms Wu used like jerk, snap, crackle and pop are valid terms used in advanced motion control. The term Jumpulse is Wu's attempt to apply the same analogous math from acceleration ( impulse ) to jerk ( jumpulse ). The problems are two fold. Baal correctly pointed out one on the other forum. There is no way a person can suddenly change the stroke on contact to change the force during impact. Two, the acceleration rate would be much higher than what a person can manage under normal conditions. To change

We put an acceleration app on a cell phone and swung the phone like we were making a TT shot. Unfortunately the phone's can't measure accelerations greater than 8g. I estimate the acceleration can be as high as 15g but I am not that sure. That is why I am having an accelerometer mounted on a TT paddle that can measure accelerations up to 25g.
When I get it working I will get my coach(2600) to make a few swings. Then we will know for sure.

There is a myth about accelerating through the ball. If the paddle is still accelerating on contact then it should be obvious that the paddle hasn't reached maximum speed yet. The speed after impact formula doesn't use acceleration in its calculation. The conservation of momentum and COR apply. The optimal stroke would hit the ball with 0 acceleration because the paddle is at peak speed. Now I can decelerate the paddle right after impact to recover faster.
 
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Here Pnachtwey, it looks like you really want to go to MyTT and comment on that thread. But I have something else for you to have fun with.

What do you think of this statement?

Outstanding Speed Realised by Advanced High Tension Technology

High Tension technology enhances the reaction of the playing surface by adding tension to the rubber molecule itself; this is made possible by applying special substances to rubber materials.
It was eighteen years ago that the world’s first High Tension rubber BRYCE was released. Butterfly never stopped enhancing its unique High Tension technology and thus the speed produced by the rubbers has kept improving.
BRYCE HIGHSPEED, the fastest rubber in the history of BUTTERFLY, was developed following intense levels of research.

Strong Rotation
Generated by the New Technology “Micro Layer”

BRYCE HIGHSPEED is a rubber that enables heavy top spin to be imparted without losing speed.
It has been developed thanks to Micro Layer, newly developed by BUTTERFLY.

The base of the top sheet is very thin, visible to the naked eye.
The rubber compresses and the surface is “depressed” by the ball on impact; thus enabling a high degree of rotation to be imparted on the ball.
A simple pimple shape was selected from a wide range of options to create the best possible product for speed.
What is Compression?

Now you can tell us about Butterfly marketing since you love this tensioned rubber subject.


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There is also an explanation here

https://thoughtsontabletennis.wordpress.com/2015/03/09/introduction-to-table-tennis-chemistry/

in terms of air cells for those who believe in the "tension fairy" because they have sophisticated enough loops to differentiate between tensioned rubbers and traditional rubbers, even when the former and not tuned in ways that curl up the sponge/topsheet combo. I won't pretend to understand chemistry enough to judge it, but what I do know is that I can tell when a rubber is "tensioned" to play much better for looping because I have the strokes to make it work. Those who don't need to invoke the tension fairy.
 
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but what I do know is that I can tell when a rubber is "tensioned" to play much better for looping because I have the strokes to make it work. Those who don't need to invoke the tension fairy.
What keeps a rubber tensioned? You have never answered that.
Can't I tension a traditional rubber by stretching it before applying it to the blade?
My T05 never came curled.
The only reason why Butterfly uses the word tension is marketing hype for suckers.
What do you think the tension fairy does for you?
 
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Pnachtwey, did you read the link? There is an answer in the link. What do you think of the answer in the link? I am not sure about the answer. But, whatever you want to say, NextLevel has answered your question about what holds the tension by posting this link. Did you read it?


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Yes, I read the link. It says that there is tension DURING impact when the ball is deforming the top sheet and sponge. I AGREE with that. This happens with all normal inverted rubbers. So what? The stretching of the top sheet and restoration to normal is key to making a rubber faster and spinnier.
The TT manufacturers and Nextlevel want us to believe the rubbers come tensioned. Not so.
This was covered on another forum.

Now, what keeps a rubber tensioned?
What do you expect this tensioned rubber to do for you?
How do you use tension in a formula or calculation?

Enough, everyone fails this test.

The key word is elastic or elasticity. If you want a high speed and high spin rubber you want one that is elastic. If the collision is perfectly elastic no energy will be lost in the collision. Motion engineers and physicist use the term COR to indicated how elastic a collision is. The speed after impact formula uses the COR and tension or the tension fairy. The Tieffenbacher document I have posted links to about 20 times also determines the normal and tangential COR at different speeds with different types of rubber. Rodney Cross has also done research on how balls bounce off surfaces and how the conservation of momentum is used to compute the resulting spin.

The way the word tension is a stupid word for describing TT rubbers you buy. Sure the rubber can be tensioned during impact but even anti rubber will be tensioned during impact. Just because a material is tensioned does not mean it will return much energy when released. I can think of stretching play dough. The COR of play dough is very low.

Tensor has two meanings. One is mathematical and doesn't apply at all. The other definition is a muscle that extend or retracts. TT rubbers don't have muscles. TT rubbers don't have active components like pneumatic or hydraulic cylinders that can be thought of mechanical tensors.

So how many times are all of you going to ignore the speed after impact formula, the Tieffenbacher pdf on collisions between ball and paddle and Rodney Cross's research? These are not my documents. If you disagree with me you disagree with many others with PhDs. So what excuse do all of you have for intentionally remaining ignorant? I say all because no one else seems to agree with these documents/research and formulas. I don't mind people like Nextlevel remaining ignorant but he can't expect to make comments like I don't know anything about tensioned rubbers and not get embarrassed in return.
 
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I gotta agree with pnchy calling bullshyt on tt manufacturers on their marketing about tension and Carl has on the sly led pnchy to go there.

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You probably didn't read the link then.
 
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No I sure did not I'm on mobile phone listening to the baseball playoffs in the car after league.

I got in some MX-P but since I recently got a sheet of Omega V Euro to replace my 2 yr old sheet of Aurus... gunna be rough to wait.

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Well, the link that NextLevel posted does explain something about vulcanized rubber. I am not sure I understand it. But I will say, Tenergy gets better spin and speed than Sriver and MX-P gets better spin than Mark V. And the link explains something more than that the rubber is on tension when the ball contacts the rubber. It explains something about a way of getting the rubber molecules to line up to hold tension and rebound from it.

Now, TT manufacturers definitely give us some silly info to believe in. And I don't care if tensors are holding tension or are rubbers that stretch and rebound better. The fact is none of this matters too much. With good technique, Mark V and 2008XP are still decent rubbers to use. Even if they are not quite as good or as high end as FX-P.
 
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But, one thing is for sure, at least Pnachtwey is not trying to post comments on here that are intended for people on MyTT to read since he misses being able to post over there.

Who is this tension fairy? Is she cute? If she looks anything like this:

1831852155782606e4.jpg

Then I would kind of like to meet her.
 
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Yes, I read the link. It says that there is tension DURING impact when the ball is deforming the top sheet and sponge. I AGREE with that. This happens with all normal inverted rubbers. So what? The stretching of the top sheet and restoration to normal is key to making a rubber faster and spinnier.
The TT manufacturers and Nextlevel want us to believe the rubbers come tensioned. Not so.
This was covered on another forum.

Now, what keeps a rubber tensioned?
What do you expect this tensioned rubber to do for you?
How do you use tension in a formula or calculation?

Enough, everyone fails this test.

The key word is elastic or elasticity. If you want a high speed and high spin rubber you want one that is elastic. If the collision is perfectly elastic no energy will be lost in the collision. Motion engineers and physicist use the term COR to indicated how elastic a collision is. The speed after impact formula uses the COR and tension or the tension fairy. The Tieffenbacher document I have posted links to about 20 times also determines the normal and tangential COR at different speeds with different types of rubber. Rodney Cross has also done research on how balls bounce off surfaces and how the conservation of momentum is used to compute the resulting spin.

The way the word tension is a stupid word for describing TT rubbers you buy. Sure the rubber can be tensioned during impact but even anti rubber will be tensioned during impact. Just because a material is tensioned does not mean it will return much energy when released. I can think of stretching play dough. The COR of play dough is very low.

Tensor has two meanings. One is mathematical and doesn't apply at all. The other definition is a muscle that extend or retracts. TT rubbers don't have muscles. TT rubbers don't have active components like pneumatic or hydraulic cylinders that can be thought of mechanical tensors.

So how many times are all of you going to ignore the speed after impact formula, the Tieffenbacher pdf on collisions between ball and paddle and Rodney Cross's research? These are not my documents. If you disagree with me you disagree with many others with PhDs. So what excuse do all of you have for intentionally remaining ignorant? I say all because no one else seems to agree with these documents/research and formulas. I don't mind people like Nextlevel remaining ignorant but he can't expect to make comments like I don't know anything about tensioned rubbers and not get embarrassed in return.

Here, we get back to Pnatchwey's favorite ploy. He is disputing the language, rather than the effect of the change made by manufacturers.

1) Pnatchwey agrees that when you stretch the sponge and keep the topsheet stuck to it that this curled up effect produces tension in the topsheet.

2) When a similar effect is obtained by stretching the topsheet and inserting compounds to keep it stretched, he argues that other rubbers which do not have these compounds are operating under similar principles anyway so therefore, there is no tension in the topsheet.

3) When you put air into the underlying sponge, making the sponge bouncier and increasing the levels of spin and speed because of the sponge's increased ability to be compressed, the fact that it isn't really tension makes it the tension fairy.

And then, to cap it all off, Pnatchwey claims he can loop just as well with Mark V as with Tenergy 05. Well, since he can't loop, that explains that. In the end, it's just another way of saying that we should defer to his inability to be anything other than autistic in his use of language. I wish it made him a better table tennis player but thank God for small mercies.
 
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No I sure did not I'm on mobile phone listening to the baseball playoffs in the car after league.

I got in some MX-P but since I recently got a sheet of Omega V Euro to replace my 2 yr old sheet of Aurus... gunna be rough to wait.

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You may just have to try using Omega V Europe for BH, MX-P for FH and hang out with a bowl of popcorn and the nearest tension fairy around you while you watch the fireworks.

Hopefully at some point Pnachtwey's looping skills will catch up to his curmudgeon skills, or his ignoring key facts and throwing out odd accusation skills. Nah, if he could do that he would be at least 2500. I will settle for his learning how to have a conversation instead of an argument. Wait....now....I know, you are going to say: "that would be like expecting him to learn to loop: asking a bit too much." But we can always hope.
 
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But, one thing is for sure, at least Pnachtwey is not trying to post comments on here that are intended for people on MyTT to read since he misses being able to post over there.

Who is this tension fairy? Is she cute? If she looks anything like this:

View attachment 8258

Then I would kind of like to meet her.

That tension fairy could dwell on my rubber anyday.

HUHUHUHUHUHUHUHUH.
 
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