Forehand Loop against UNDERSPIN Technique

I dunno if you will agree with me but with the new ball and better rubbers that we have now, when you dip your racket for a backswing, you would not need to dip lower than your knees unless it is a very heavy underspin ball. I still teach to dip low for beginners because it forces them to bend, dip, and spring up when looping vs. underspin but on intermediate or betterlevels, i think the racket dip should only in the thigh area and not lower than the knee.
 
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The video is bogus. This is how TT myths are perpetuated.
Right off the bat video loses all credibility when he says accelerate at contact and not before.
The paddle is moving at maximum speed when the acceleration is 0 or done accelerating.
Any mathematician can tell you that the minimum or maximum of any function is found there the derivative or slow of the function is zero.

If the paddle is still accelerating when the ball is hit the paddle will be moving faster after the ball is hit. The ball doesn't care how fast the paddle is going after the ball leaves the paddle. Also, it takes extra time to reset if still accelerating when the ball is hit.
Another comment about controlling the penetration of the ball into the rubber is bogus. The penetration into the rubber is dependent on how much energy the rubber, ball and blade must absorb.
Most of the time the looper is returning blocked balls , not under spin.

This is my favorite video on looping chopped balls. William Henzel is playing against a real chopper. You can see the nice arc Henzel gets on the ball. Notice he starts the swing with the paddle behind his knee.
https://youtu.be/Dld67Quv0lg
 
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The video is bogus. This is how TT myths are perpetuated.
Right off the bat video loses all credibility when he says accelerate at contact and not before.
The paddle is moving at maximum speed when the acceleration is 0 or done accelerating.
Any mathematician can tell you that the minimum or maximum of any function is found there the derivative or slow of the function is zero.

If the paddle is still accelerating when the ball is hit the paddle will be moving faster after the ball is hit. The ball doesn't care how fast the paddle is going after the ball leaves the paddle. Also, it takes extra time to reset if still accelerating when the ball is hit.
Another comment about controlling the penetration of the ball into the rubber is bogus. The penetration into the rubber is dependent on how much energy the rubber, ball and blade must absorb.
Most of the time the looper is returning blocked balls , not under spin.

This is my favorite video on looping chopped balls. William Henzel is playing against a real chopper. You can see the nice arc Henzel gets on the ball. Notice he starts the swing with the paddle behind his knee.
https://youtu.be/Dld67Quv0lg

Sorry but I disagree with you. You can play around with the acceleration timing, but if you don’t have the correct feeling, you won’t grab the ball or spin it because the contact will be too harsh. There’s won’t be any brush if you hit the ball wildly without grabbing it first.

The point about rubber penetration is actually quite important. It is possible to engage the sponge even on a dead ball, which is how you can generate power from no spin balls. Also the video is supposed to be looping against backspin, which is why I said it’s important to bite into the ball to create an arc.

I don’t think it’s fair to call it bogus, but I understand if you have a different opinion.

Also, from my understanding of basic physics, torque is what generates rotation to an object. The equation for torque = Moment of inertia x angular acceleration. Meaning you want your acceleration to be non-zero if you want to create lots of topspin, otherwise you wouldn’t have torque.
 
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The "accelerate on contact" thing is a purely mental construct the player uses to increase racket speed. The effect of trying to accelerate on contact is to accelerate somewhat before contact, while still managing to actually make good contact. It is a mental approach that may help some people.

There are all sorts of mental tricks athletes use to get a desired result that don't exactly correspond to what is really happening. Good coaches know all sorts of ways to convey an effective technique. They may say "it's sort of like....", or "think of it like..."

This is sports, not physics. There is psychology, motor learning, and all the other things about PEOPLE actually playing a sport. People aren't robots.

So bringing physics into it is, as is almost always the case in these threads, utterly pointless.
 
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I dunno if you will agree with me but with the new ball and better rubbers that we now, when you dip your racket for a backswing, you would not need to dip lower than your knees unless it is a very heavy underspin ball. I still teach to dip low for beginners because it forces them to bend, dip, and spring up when looping vs. underspin but on intermediate or betterlevels, i think the racket dip should only in the thigh area and not lower than the knee.

Something Eric Owens used to tell me is that if you're having to dip THAT low (e.g. when looping really heavy underspin) you are better off just opening the racket angle a little bit*. My initial response was, "but then I won't get enough spin". His response was, "try it and see". And sure enough, the shot had power and plenty of spin.

* but not too much!!
 
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Hey all, here's a video about looping underspin. It's only 10 minutes, but I tried to pack as much information as I could in. Please let me know what you think and share the video/subscribe if you like it!

https://youtu.be/myijNgE2Pv0

The "accelerate on contact" thing is a purely mental construct the player uses to increase racket speed. The effect of trying to accelerate on contact is to accelerate somewhat before contact, while still managing to actually make good contact. It is a mental approach that may help some people.

There are all sorts of mental tricks athletes use to get a desired result that don't exactly correspond to what is really happening. Good coaches know all sorts of ways to convey an effective technique. They may say "it's sort of like....", or "think of it like..."

This is sports, not physics. There is psychology, motor learning, and all the other things about PEOPLE actually playing a sport. People aren't robots.

So bringing physics into it is, as is almost always the case in these threads, utterly pointless.

I agree with you, in that playing TT is based on feeling the ball. I was just refuting a point to defend myself from being called “completely bogus”
 
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Sorry but I disagree with you. You can play around with the acceleration timing, but if you don’t have the correct feeling, you won’t grab the ball or spin it because the contact will be too harsh. There’s won’t be any brush if you hit the ball wildly without grabbing it first.
What is wrong with you guys? By the time you feel anything the ball is long gone.
Define grabbing? What does grabbing have to do with acceleration? You are side stepping the argument.
Define the contact as being too harsh. These are wishy washy meaningless words. Provide facts.

The point about rubber penetration is actually quite important. It is possible to engage the sponge even on a dead ball, which is how you can generate power from no spin balls. Also the video is supposed to be looping against backspin, which is why I said it’s important to bite into the ball to create an arc.
Show me an equation!
Why does the sponge need to be engaged when brushing? When brushing the penetration in the sponge is minimal?
What happens if there is no grab? What I hit the chopped ball back with nearly frictionless long pips or anti.


I don’t think it’s fair to call it bogus, but I understand if you have a different opinion.
It isn't opinion. What I said was fact.

Also, from my understanding of basic physics, torque is what generates rotation to an object.
Yes! You got something right!

The equation for torque = Moment of inertia x angular acceleration.
An equation! Good for you you got that right too. But because the ball is accelerating it means that is hasn't reached maximum spin, yet. You need to understand what the equations mean.

You forgot that Torque = ForcexDistance*sin(theta). If the direction of the force is 90 degrees from the center of gravity then sin(theta) =1. In the case of TT the tangential force is 90 degrees from the center of the ball so the sin(theta) can be ignored because it is 1.

Meaning you want your acceleration to be non-zero if you want to create lots of topspin, otherwise you wouldn’t have torque.
Wrong! What if you have lots of acceleration but the paddle speed is low?

It is the tangential paddle speed that causes spin. Yes the paddle must be accelerated to achieve a desired speed but again, if the paddle is still accelerating then the maximum speed of the paddle hasn't been achieved.
This will mean maximum tangential speed has not been achieved which all means maximum spin has not been achieve.
 
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Sorry to break it to you but sports aren’t learned through math and equations, it’s a lot of feeling. Grabbing the ball to me feels like the sponge is holding the ball, but it may feel different for everyone. If you cannot understand TT without “hard facts,” then you won’t get very far. There are other physical factors involved in TT such as impulse, which relates to how much time the ball remains on the paddle. That’s is what I call time “holding the ball.” I hope that makes sense, and I hope you can refrain from being so disrespectful thanks. If you are so confident that I’m wrong, you can post your own tutorial and show us the right way to loop.

A simple way to refute your claim that tangential speed is the only factor for creating spin would be to compare the spin of timo bolls loop vs mima itos loop. I’m sure mima’s racket speed is much greater, but I guarantee you timo has more spin. Racket speed isn’t the only factor to consider, because TT has a lot to do with your feeling for contacting the ball.
 
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Sorry to break it to you but sports aren’t learned through math and equations, it’s a lot of feeling.
Your feelings or myths do not override reality.
Grabbing the ball to me feels like the sponge is holding the ball,
The sponge does not hold the ball. The ball will penetrate the rubber all the while slowing down until all the kinetic energy of the ball is absorbed. Then the rubber and blade will return some of the absorbed energy to the ball accelerating it in the opposite direction. The ball is only stopped relative to the paddle that instant when the paddle, ball, and blade have absorbed all kinetic energy.

but it may feel different for everyone.
Are you saying that reality is different for everyone?
I know the laws of physics are the same for everyone.

If you cannot understand TT without “hard facts,” then you won’t get very far.
I have gone farther than any of you can know, it just isn't in TT. I am a motion control expert among other things.

There are other physical factors involved in TT such as impulse, which relates to how much time the ball remains on the paddle.
Good, so you know about impulse being the integral of force over time.
What is the force of a ball impact at 10 m/s. There is no exact number for this because it depends on assumptions of how far the ball will sink into the rubber.

That’s is what I call time “holding the ball.” I hope that makes sense,
This is the time the ball is actually in contact with the paddle. It is on the order of a millisecond depending on the impact speed. Sometimes it is much less but I have seen examples were it is infinite for all practical purposes. You will earn respect when you get past you touchy feelly ideas.
My profession is motion control. I have learned over many years that what people think is happening is not what is really happening. That is why I have a high speed camera and can record motion at 4 KHZ easily.

[quote[
and I hope you can refrain from being so disrespectful thanks.
[/quote]
I haven't called you and idiot....yet. Upside Down Carl has told me to play nice but he knows how I really feel.

I tried posting a thread on dwell time ( contact time ) a few years back but it got deleted.

If you are so confident that I’m wrong, you can post your own tutorial and show us the right way to loop
We are talking about looping backspin. I provided a link above. That is how it is done.
The key is for the tangential paddle speed to meet or exceed the tangential speed of the ball. If the speeds match the ball will not push off down into the net. If the tangential paddle speed exceeds the tangential speed of the ball then the upward stroke of the paddle will cause the ball to go high unless one closes the paddle in proportion to the excess tangential speed between the paddle and ball.
Simple.
I don't fear playing choppers at around my level. Most choppers can't keep the ball low as consistently as Henzel's opponent. Look at the video above. Henzel plenty of time to get into position between balls. The problem Henzel has is that the chopper is very good at returning balls. I don't face choppers of that ability. I haven't faced any since the CCP-virus.
 
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Think it was good! Shadow tabletennis is nice for illustrate how to do the stroke. Much harder to see with the ball.

Feel like the stroke when you do shadow is a bit long whit the arm? Easy to get to slow arm when to long. You do it better and shorter with the ball so that is good!

Maybe I missed this and maybe not good to inform to much at once. But I think maybe like common mistakes could be good to bring up. Maybe like that why a player loops in the net or out against backspin.

Keep up the videos!
 
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Think it was good! Shadow tabletennis is nice for illustrate how to do the stroke. Much harder to see with the ball.

Feel like the stroke when you do shadow is a bit long whit the arm? Easy to get to slow arm when to long. You do it better and shorter with the ball so that is good!

Maybe I missed this and maybe not good to inform to much at once. But I think maybe like common mistakes could be good to bring up. Maybe like that why a player loops in the net or out against backspin.

Keep up the videos!

Thanks for the suggestion. I will try to bring up some mistakes in future videos.
 
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Something Eric Owens used to tell me is that if you're having to dip THAT low (e.g. when looping really heavy underspin) you are better off just opening the racket angle a little bit*. My initial response was, "but then I won't get enough spin". His response was, "try it and see". And sure enough, the shot had power and plenty of spin.

* but not too much!!

Agree, though with the H3 rubbers sometimes your racket angle do not need to be even at a more open angle. This also depebds on the timing of hitting the ball though and you dip the racket probably just beliw waist level assuming it is much lower than the table surface.
 
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You will be wasting your time arguing with people who do not know the correct basic strokes and do not know how to compartmentalize subject matter. I doubt he knows how to properly loop a ball during matchplays.
I can loop very well. I have posted a video of me playing c-pen and looping. It was the last video I made before the ccp-virus.

Yogi, you and I would make a good team. I could explain the physics of the stroke and you could demonstrate the the strokes more consistently than me. We both agree that brushing is good for spinny loops.
However, out side of that you are totally ignorant of the physics of TT.
You also don't know about how the density of wood affects the speed of the paddle. This is from a previous thread. You are not an engineer or have had any training in materials.
I thought back on mytt and years ago you said you have a lot of brothers that are engineers. They should be able to correct your thoughts about physics if they are real engineers.

Again, Yogi makes ad hominem attack buts can't refute what I have said.
 
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Something Eric Owens used to tell me is that if you're having to dip THAT low (e.g. when looping really heavy underspin) you are better off just opening the racket angle a little bit*. My initial response was, "but then I won't get enough spin". His response was, "try it and see". And sure enough, the shot had power and plenty of spin.

* but not too much!!
Opening the paddle works but it reduces the topspin of the return. Opening the paddle is what I do when I get tired but when I am fresh I loop with a closed paddle with lots of body twist to get the paddle speed up.
This is where conditioning comes in. Faster players can swing faster and close the paddle even more resulting in a faster return seen in the Henzel video.
 
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Hard to discuss about correct or less correct technique. Feel like that when start out as a coach you think there is one correct way to do a stroke, but when you have been coaching for a long time it is more like a spectrum.

Have a pretty fun anacdote about this. On an international tabletennis tournament in Sweden, a coach sat behind two high level international coaches that said about a player that they were watching: "his technique is not good enough and he will never win anything" or something like that. Next year he became world champion. They talked about Werner Schlager.
 
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There are a LOT of factors that go into the end result. Like Baal and Brian have said, a lot of it is conveyed to players on how it feels or how you approach it and at the end of the day, the player does have to feel the ball.

All the Korean pros who teach amateur players finer points of impact nearly ALWAYS say expressions like "You should have a feeling of grabbing and throwing the ball at impact" in order to get the player to understand how to impact.

There are so many fine technical adjustments in this shot that it is way beyond just bat angle, bat speed, and bat accelleration... although those are certainly major factors.
 
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Lula said:
Hard to discuss about correct or less correct technique. Feel like that when start out as a coach you think there is one correct way to do a stroke, but when you have been coaching for a long time it is more like a spectrum.

Have a pretty fun anacdote about this. On an international tabletennis tournament in Sweden, a coach sat behind two high level international coaches that said about a player that they were watching: "his technique is not good enough and he will never win anything" or something like that. Next year he became world champion. They talked about Werner Schlager.

Lula, I thought Der_Echte ALWAYS had the most epic record of "Open Mouth - JAM in the Foot" syndrome... those dudes just took the cake as Americans would say.
 
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Hard to discuss about correct or less correct technique. Feel like that when start out as a coach you think there is one correct way to do a stroke, but when you have been coaching for a long time it is more like a spectrum.

Have a pretty fun anacdote about this. On an international tabletennis tournament in Sweden, a coach sat behind two high level international coaches that said about a player that they were watching: "his technique is not good enough and he will never win anything" or something like that. Next year he became world champion. They talked about Werner Schlager.

The world is full of self ordained professors...

Cheers
L-zr
 
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