"wrapping" the ball.

[NextLevel]

You have a chance to show you are more intelligent than the rest of the forum.
Answer my questions above or be wise, make some popcorn and drink a beer. Enjoy the show and don't feel being left out..

@forum, notice that after all this time, no one has presented ANY FACTS! No calculations, just opinions.
How much of the ball gets wrapped?
How fast is the rotation of the wrist that wraps the ball.

It is clear that too many have been talking about stuff they know nothing about.

He who asks for the time as proof that the sun has risen and then chastises people (as opposed to explaining the basis of his skepticism) when they ask him to look outside is truly blind.

 

[SlowPower]

Maybe wrapping is easier to show on bh shots?

 

[Jslick89]

I am always curious about how long the ball actually stays on the rubber and how much it traverses the rubber on my shots.

From a purely sports point of view, back swing and follow through 100% matter in determining the quality/placement of your shots. It's the same in all sports from soccer, to basketball, to tennis to our lovely sport of table tennis.

Also, there's no denying that wrist action / or wrapping over the ball is having some of effect on the ball. If it wasn't, why would ex world #1 Timo boll be speaking about it? Why would high level players on this forum make claim to its effect?

In terms of measuring things.....you can easily say that the further back you swing...the faster you could swing when you go forward. There is no denying that (although a very far backswing is not the most optimal in this high speed game). I think it's also pretty easy to agree that "wrapping" or using a little wrist action is also adding to the total racket head speed. so when you "wrap", you have the speed of your arm movement+ the added speed from the wrist action. Even assuming a single point of contact on the rubber, the faster the paddle swings, the more spin will be imparted on the ball if you assume a 45 degree single point of contact on the ball. For me, those simple facts alone justify the "wrapping" technique, even if you disregard one of the greatest players on earth talking of the benefits.

The big variable here....what is the impact of the rubber / and or the blade on the ball. Logically, you cannot deny that different rubbers have different effects on the balls. I use tenergy 05....i get some pretty spinny balls...and they catapult off the blade and rubber with a high arc. I used my buddy's W698 the other day with DHS hurricane 3....these balls (with essentially the same forehand stroke) were faster, lower, and spinnier than my viscaria/tenergy set up. Is it because the blade has more flex? because the rubbber grips and RIPS the ball faster? Either way, you cannot deny that different rubbers / blades have different effects on the balls.

I am apt to believe that there is NOT a single point of contact between the ball and rubber, but rather the ball does traverse, depending on the blade and rubber, some small distance across the rubber, and due to this, a wrapping motion can create extra spin. Can i measure that distance? no. i don't have the tools. i think you would need an extremely slow motion camera to do this sort of experiment and measure the results. However, for us normal folk, we can take the word of some of the world's greats.

 

[Jslick89]

I am also thinking...from a purely energy transfer point of view....the reason follow through is so important is because when you follow through, you can actually gain an acceleration in speed through the whole stroke (which means you are accelerating up to and THROUGH the point of contact).

Say you didn't have the extra wrist action, or you didn't swing and follow through but rather stopped right after the point of contact. This would mean you actually started a DEACCELERATION before point of contact otherwise it would not be able physically possible to stop directly after the point of contact......surely any physicist or an oh so wise engineer could measure this simple path of acceleration vs deacceleration......

 

[turbozed]

I am always curious about how long the ball actually stays on the rubber and how much it traverses the rubber on my shots.

From a purely sports point of view, back swing and follow through 100% matter in determining the quality/placement of your shots. It's the same in all sports from soccer, to basketball, to tennis to our lovely sport of table tennis.

Also, there's no denying that wrist action / or wrapping over the ball is having some of effect on the ball. If it wasn't, why would ex world #1 Timo boll be speaking about it? Why would high level players on this forum make claim to its effect?

In terms of measuring things.....you can easily say that the further back you swing...the faster you could swing when you go forward. There is no denying that (although a very far backswing is not the most optimal in this high speed game). I think it's also pretty easy to agree that "wrapping" or using a little wrist action is also adding to the total racket head speed. so when you "wrap", you have the speed of your arm movement+ the added speed from the wrist action. Even assuming a single point of contact on the rubber, the faster the paddle swings, the more spin will be imparted on the ball if you assume a 45 degree single point of contact on the ball. For me, those simple facts alone justify the "wrapping" technique, even if you disregard one of the greatest players on earth talking of the benefits.

The big variable here....what is the impact of the rubber / and or the blade on the ball. Logically, you cannot deny that different rubbers have different effects on the balls. I use tenergy 05....i get some pretty spinny balls...and they catapult off the blade and rubber with a high arc. I used my buddy's W698 the other day with DHS hurricane 3....these balls (with essentially the same forehand stroke) were faster, lower, and spinnier than my viscaria/tenergy set up. Is it because the blade has more flex? because the rubbber grips and RIPS the ball faster? Either way, you cannot deny that different rubbers / blades have different effects on the balls.

I am apt to believe that there is NOT a single point of contact between the ball and rubber, but rather the ball does traverse, depending on the blade and rubber, some small distance across the rubber, and due to this, a wrapping motion can create extra spin. Can i measure that distance? no. i don't have the tools. i think you would need an extremely slow motion camera to do this sort of experiment and measure the results. However, for us normal folk, we can take the word of some of the world's greats.

There is some high speed camera footage out there that shows that the ball does traverse the rubber. I saw one where you could see the ball clearly crawling up the face of a sticky rubber (wish I could find it now).

Here's one that's less obvious with a stationary blade and you can clearly see the ball traverse the rubber

[MEDIA]

 

[Jslick89]

There is some high speed camera footage out there that shows that the ball does traverse the rubber. I saw one where you could see the ball clearly crawling up the face of a sticky rubber (wish I could find it now).

Here's one that's less obvious with a stationary blade and you can clearly see the ball traverse the rubber

[MEDIA]

wow! what an interested video with a close up super slow motion of the very evil long pips lol. I'm seeing even a slight traverse on just the bare wood.

 

[turbozed]

wow! what an interested video with a close up super slow motion of the very evil long pips lol. I'm seeing even a slight traverse on just the bare wood.

Yes there's also the warping of the blade and of the ball itself to consider which adds an extra layer of complexity.

 

[brokenball]

There is some high speed camera footage out there that shows that the ball does traverse the rubber. I saw one where you could see the ball clearly crawling up the face of a sticky rubber (wish I could find it now).

Here's one that's less obvious with a stationary blade and you can clearly see the ball traverse the rubber

[MEDIA]

A good video but un-related to wrapping. The paddle is stationary. The ball speed is just about 20.5 m/s
Yes, the ball does seem to roll a bit, but it could be just the rotation. The ball doesn't seem to slide. I didn't expect it to slide. The ball doesn't have any spin before it hits the paddle. The initial translational kinetic momentum is converted to translational and rotational kinetic energy. If the exit speed and rotation rate were measured, we could see how much energy was lost.
My video shows how much force is required to deform the ball.

Notice that this blade is slow. The ball pushes the blade back, but the blade does not push the ball back. All the energy that went into the blade is lost. All those vibrations are wasted energy.

VLC can be used to step through the video frame by frame to measure how many frames the ball seems to be in contact with the rubber.

 

[pingpongpaddy]

I have always thought that wrapping around the ball refers to the follow through after contact where the racket angle closes as the arm folds bringing the racket back to a central ready position. I think Boll refers to wrapping for instance but doesn't describe in detail what he means by it.
I think we are all aware of making fh where the racket path seems "convex "and at other times ''concave" but this is.just the stroke shape and does not imply changing the racket angle during contact

 

[brokenball]

I am also thinking...from a purely energy transfer point of view....the reason follow through is so important is because when you follow through, you can actually gain an acceleration in speed through the whole stroke (which means you are accelerating up to and THROUGH the point of contact).

Say you didn't have the extra wrist action, or you didn't swing and follow through but rather stopped right after the point of contact. This would mean you actually started a DEACCELERATION before point of contact otherwise it would not be able physically possible to stop directly after the point of contact......surely any physicist or an oh so wise engineer could measure this simple path of acceleration vs deacceleration......

The accelerating the paddle through the ball is a myth, In short, you can't accelerate the paddle fast enough to make a difference. If the paddle is still accelerating then it is not at maximum speed. It would be better to hit the ball at a higher speed. So how fast do you think you need to accelerate the paddle to maintain contact with the ball?
It is possible to accelerate something like being in a car that accelerates and it pushes you back into the seat.

 

[brokenball]

I have always thought that wrapping around the ball refers to the follow through after contact where the racket angle closes as the arm folds bringing the racket back to a central ready position. I think Boll refers to wrapping for instance but doesn't describe in detail what he means by it.
I think we are all aware of making fns where the racket path seems "convex "and at other times ''concave" but this is.just the stroke shape and does not imply changing the racket angle during contact

Because the arm tends to rotate around the shoulder joint the strokes tend to be convex. This is not good either.
I agree that the paddle orientation should not change during the time the ball and paddle can make contact.

 

[brokenball]

There is some high speed camera footage out there that shows that the ball does traverse the rubber. I saw one where you could see the ball clearly crawling up the face of a sticky rubber (wish I could find it now).

Here's one that's less obvious with a stationary blade and you can clearly see the ball traverse the rubber

[MEDIA]

The video assumes that the ball shape doesn't change. The circle in the video extends into the wood. That is not right. Again my videos I made two weeks ago show that both the ball and rubber compress. Since I compressed the ball and rubber on a hydraulic cylinder there was no wood to deform.

 

[Dr Evil]

So how fast are you "closing the angle"?

Depends on the shot. There's plenty of biomechanical sports research (especially in baseball, not much in tt) assessing things like degree and speed of pronation and supination, often involving fancy 3-D motion capture equipment. You can look it up if you're interested, but it's really besides the point which is that you're wrong about wrapping the ball being a "misguided myth."

It's an observable fact that it works. (An interesting question is why it works, not whether it works.) Apparently this is news to you. So experiment with a practice partner. If that doesn't convince you, then hire a coach.

 

[brokenball]

Depends on the shot. There's plenty of biomechanical sports research (especially in baseball, not much in tt) assessing things like degree and speed of pronation and supination, often involving fancy 3-D motion capture equipment.

Weasel words ( sorry weasels ). Give a range and a rate for "wrapping" the ball in TT.

You can look it up if you're interested, but it's really besides the point which is that you're wrong about wrapping the ball being a "misguided myth."

No one has given any data on how fast they rotate the paddle or how much of the ball gets "wrapped"
It is still a myth.

It's an observable fact that it works. (An interesting question is why it works, not whether it works.) Apparently this is news to you. So experiment with a practice partner. If that doesn't convince you, then hire a coach.

You think it works. I can give reasons why it doesn't but I want someone to take up the challenge and provide proof?
If there is no proof then wrapping is still a myth. I think it is a bad idea.

 

[NextLevel]

BB: Curving the ball trajectory in soccer with a wrapping kick is a myth. The ball only spends milliseconds in contact with your foot so you can't make it spin any differently based on how your follow through. Did you know that the ball compresses? Your model for spinning the soccer ball doesn't take into account that the ball compresses.

NL: Free kick takers have been spinning the soccer ball for decades now with a wrapping kick. It isn't about whether they can spin the soccer ball better by kicking it a certain way but why that way works.

BB: It is fiction. Did you know that the ball compresses?

NL: No, it isn't fiction, it works.

BB: It is fiction. The ball only spends a few milliseconds in contact with your foot so the wrapping doesn't matter. And you keep forgetting that the ball compresses!

The END,

 

[zeio]

The video assumes that the ball shape doesn't change. The circle in the video extends into the wood. That is not right. Again my videos I made two weeks ago show that both the ball and rubber compress. Since I compressed the ball and rubber on a hydraulic cylinder there was no wood to deform.

The above is the perfect example of "interpretation gone wrong".

Right or wrong. Is binary reasoning the only logic your brain is capable of processing? Has it ever crossed your great mind that circle merely serves as a visual clue to aid the viewers in assessing how much the ball has deformed upon impact?

"The video assumes that the ball shape doesn't change." MFSB, is the caption "Max. ball deformation" invisible to you? Consider consulting an eye doctor.

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stupid people: 87
he/she/they/it: L8

 

[zeio]

The frog said with a smile:" The reason why I am proud of myself is because I am smart.”
The turtle said: " That is very nice."
"Could you tell me how smart you are?”
The frog said with a smile:" Because I know everything about the world!”

https://ctext.org/zhuangzi/floods-of-autumn/zh?en=on#n42145

秋水: 北海若曰：「井蛙不可以語於海者，拘於虛也；夏蟲不可以語於冰者，篤於時也；曲士不可以語於道者，束於教也。
The Floods of Autumn:...: Ruo, (the Spirit-lord) of the Northern Sea, said, 'A frog in a well cannot be talked with about the sea - he is confined to the limits of his hole. An insect of the summer cannot be talked with about ice - it knows nothing beyond its own season. A scholar of limited views cannot be talked with about the Dao - he is bound by the teaching (which he has received).

 

[Der_Echte]

@zeio...

You are tempting me to break out my classic "frog" pun about the man with a 75 cm long taliwhacker and his consultation with the witch doctor and the said frog in his attempts to cure his condition.

 

[zeio]

I am always curious about how long the ball actually stays on the rubber and how much it traverses the rubber on my shots.

In the abstract of an earlier draft of the study where 6 Japanese women elite players, 5 righties and 1 lefty (one of them likely Ito from the silhouette) get tested for spin rate, measurements of the contact duration and contact distance were actually attempted.

Contact duration and contact distance were found to be difficult to observe at 2000Hz (near the limit of the Nyquist rate) but contact durations for various shots were still reported.

From high to low:
Serve 1.3007±0.2740ms (n=5)
Chiquita 1.0787±0.18454ms (n=32)
Drive against backspin 1.0468±0.20077ms (n=54)
Knuckle (no-spin shot?) 1.0303±0.21054ms (n=84)
Drive 1.0005±0.0000ms (n=4) The mean for Drive is very close to the sampling rate here, as noted by the author.

No statistical significance was found among them, but I wonder what if they take the contact velocity, angle etc. into account. Whatever the interpretation, this is the only study that I've come across that measures contact duration for various shots by world class players using recent high quality rubbers (as stated in the study).

Below is the Butterfly slow-mo footage that I mentioned once.

I have highspeed footage done by none other than Butterfly for Tenergy and presumably Bryce in an oblique collision that shows the balls dig into the rubber at the same time, but leave at slightly different times. That's far more realistic and thus comparable to how we loop.

And Mizuno Q series (Sumitomo Riko) and GF series (ESN)

 

[latej]

The ball contact is not a point, take a new ball, make a hit, and you can see the area is like 15 mm in diameter.

If the ball travels 72 km/h, it is 20 mm/ms. The hand can also travel that fast to give that impuls/speed to non-moving ball.

Now FZD does some wrapping (pronation/supination, I'm not sure which is which.), we can see that during the stroke the angle changes, let's say it changes 30 degress on 30 cm stroke, which is 1 degree on 10 mm. Since arm speed is 20 mm/ms, we get his angular speed is 2 degree/ms. (There is a big range obv.)

Even if we estimate the ball contact time to be 1ms. Actually I think what happens during the ball contact is super complex. But even if we estimate the ball contact to be 1ms, and we know its diameter 40mm, and we know FZD's angular wrapping speed 2 degree/ms. That wrapping during that time on that diameter produces a length, which is "comparable" to ball contact area diameter 15 mm, it can easily make 5% of it.

I've made these crude calculations to myself, I am convinced now, these things are real. Now, for the next season my goal to improve my ranking percentile by 5%.

EDIT: I wrote it before I read your last post zeio. Imagine the delight when I read that the contact time is 1ms ;-)