"wrapping" the ball.

[zeio]

Till now, you still treat vectors as scalars and keep talking about speed being maximized meaning acceleration is no longer possible (which is only true if your focus is in one dimension).

More examples.

2/2021

https://www.tabletennisdaily.com/forum/topics/how-to-measure-blade-speed.24804/post-338482

2/2020

https://www.tabletennisdaily.com/forum/topics/how-can-a-harder-rubber-be-slower-than-a-soft-one.22699/post-305924

I still remember in the very first class of physics I learned "vector = magnitude + direction", and I honestly couldn't wrap my head around the oddball concept for a few months, until I looked at the old-school clock on the wall. The second hand, while spinning clockwise at a constant velocity, is in fact accelerating because its direction is constantly changing, pointing north at 12, east at 3, south at 6, and west at 9. It clicked right there and I thought isn't that the same as when I first learned the stroke of counterhit by shadow swinging slowly at a constant velocity.

 

[brokenball]

I have shown you that a high level server does it when he does his favorite serve.

Again, you will do anything to distract from the thread.
OK. bit the ball is traveling much slower then. How fast can one wrap around the ball vs just hitting like on a ghost server tp achieve maximum back spin.

He mistimed the effect in the video I presented but with the same serve, he has given players as good as Wang Liqin trouble. You are a low level player so what you do doesnt really qualify as evidence here for what high level players do.

WTF? I did nothing of the sort.

Pointing out that you are a low level isn't ad hominem. Otherwise, you would never bring up the idea that you are an expert in engineering and motion sensing and you wouldn't be talking about moderating Chinese forums, all of which have zero bearing on the argument being presented.

It means I have achieve a lot whereas you have achieved nothing you seem to be proud of.

I am just pointing out, as Feynmann realized when he tried to explain quantum physics to his father, that there are limits to what you can explain when someone doesnt have the prerequisite experiences.

Obviously you don't. You have shown NOTHING!

I have explained what is meant by wrapping the ball and why it is good. The follow through is part of the stroke trajectory and the wrapping accentuates the turning effect while completing the stroke trajectory. You haven't shown the ability to understand and explain what you are criticizing.

But I have and you haven't.

Till now, you still treat vectors as scalars and keep talking about speed being maximized meaning acceleration is no longer possible (which is only true if your focus is in one dimension). The quality of the reasoning is too poor to take it seriously. I can only generously assume it is driven by the fact you have no real experience with high level strokes.

More weasel words. Sorry weasels.
I have posted 2D trajectories using 5 linear and non-linear differential equations. I can do 3d too but it is a lot more work and doesn't prove anything more.

You never answered my questions about "wrapping" the ball after 7 pages and 140 posts!
You can't. You never will because you don't have the math skills.
USDC knows this is how I play my game. I ask questions I know you can't answer. USDC has warned you before.

About the high level strokes. All of us have made high level strokes. The problem is that the better players make more of them.

Will let you have the final word, I am truly over this

 

[zeio]

Allow yours truly 1ms to appreciate hardheaded engineer for starting this thread, as it has provided me with enough stimulus to go on another expedition, in which I uncovered another gem (2018), this time from Australia!

https://www.researchgate.net/public...and_drives_in_competitive_male_tennis_players

ABSTRACT
...Our findings revealed
that the generation of topspin demanded more humeral extension
and forearm pronation but less humeral internal rotation angular
displacement during the forwardswing. The follow-through phase
of the topspin shot was characterised by greater humeral internal
rotation and forearm pronation, and reduced humeral horizontal
adduction when compared to the flat shot.

...

Discussion and implications
...At the distal segment, the forward swing required sequential forearm
supination–pronation, while the elbow extended. The generation of topspin required the
players to employ greater ranges of motion in pronation. As it was shown that pronation is
a small contributor to the generation of the horizontal and vertical velocities of the racket at
impact (Takahashi et al., 1996; Elliott et al., 1997), researchers have posited that pronation
adjusts the racket head inclination for optimal impact (Takahashi et al., 1996). The increased
forearm pronation observed in our study would still appear to be a key factor in imparting
topspin to the ball. It could be that this action is a direct result of players following a com-
mon coaching instruction: attempting to wrap or wind their racket face around the ball
when imparting topspin to a shot (Ivancevic, Jovanovic, Dukic, Markovic, & Dukic, 2008).
At the wrist, the results did not confirm our initial hypothesis, which contended that radial
deviation would generate vertical velocity of the racket head at impact. The magnitude of
involvement of extension-flexion and ulnar-radial deviation was similar for both shots.
The hyperextended position of the wrist observed at impact is consistent with previous
reports (Elliott et al., 1989, 1997; Landlinger et al., 2010), suggesting that the amount of
spin imparted to the forehand may place the player’s wrist at similar risk for injury.
The joint motions of the upper limb performed during the follow-through were a contin-
uation of the motions observed in the preceding forwardswing phase. Specifically, humeral
internal rotation and forearm pronation featured prominently. The finish position of the
players indicated that the humerus crossed their bodies for flat shots, while topspin genera-
tion demanded more arm elevation in the sagittal plane as well as a larger range of humeral
internal rotation and forearm pronation. As the magnitude of forearm pronation changes
the orientation of the palm and the racket face at the completion of the follow-through,
coaches could ask players to focus on this key-position when the goal is to impart topspin
during forehand drive.

 

[zeio]

About the high level strokes. All of us have made high level strokes. The problem is that the better players make more of them.

Fan Zhiyi: So shameless...
https://www.bilibili.com/video/BV1q3411W77s?t=58.4 (version with English voiceover, crazy good LOL)

Kiddo: 3 idiots playing with me...

 

[brokenball]

Mr hit then brush is posting more distracting information. Zeio can't explain or answer the questions I have posted.

Notice that USDC changed the title and edited my first post.
What was wrong with the title?
What was wrong with my questions?

Is it that I am a rude SOB and should stop wasting my time?

 

[tabletennisdaily1]

Here is an extreme example of "wrapping" the ball (start with open blade, end with closed blade) by Waldner. It worked I guess

Brokenball, may you reiterate what your questions are again, and maybe I can offer my take on them? Thanks.

 

[tabletennisdaily1]

Another very small slight wrap by Timo in a low and slow topspin loop from his heavy topspin video:

start open -> end closed

and lin yun-ju with a updated 2.0 wrappier forhand that starts a bit lower and more open. He used to have a very "straight" loop technique back in the day, back and forward with the blade on one closed plane.

start open -> end closed

 

[turbozed]

I am going to go with brokenball on this one. The ball flies out of Fan Zendong's blade. I really think that the ball only stayed on his blade for minisecond. Lot of it is most likely follow through.

Let us say "wrapping" exists. What level of playing are we talking about? And would wrapping works better with softer sponge rubber than harder sponge rubbber?

I don't know how closely you're following along with the conversation but nobody here is claiming that you can wrap and hold the ball in your paddle like catching a baseball in a mitt. The contact time will be imperceptible at real time because it's around 1ms.

The contention is that pro level players on certain shots are pronating their forearm and abducting their wrists shortly before and during contact for the purposes of changing the nature of the contact (increasing or changing the direction of spin). Another subsidiary discussion is about why high level coaches and pros talk about accelerating through contact.

brokenball is claiming that this 'wrapping' technique either doesn't exist (proven incorrect by countless videos and even scientific articles), that it doesn't matter since it doesn't affect the nature of contact (again proven incorrect since enough videos showing ball quality differences), or that it's suboptimal technique (an argument that brokenball now had adopted after several studies were posted by zeio).

Your claim that you don't visually notice it happening in a posted video seems to fall into the "it doesn't matter" category, and I think we are well past that point. I guess I could ask you, if you hold that position, why do you think pro players and coaches advocate or perform the "wrapping" motion during and through contact if it's not accomplishing something?

Edit: looks like I'm half asleep and decided to reply to a post on the first page of this thread. Sorry JJ Ng! I'm sure your thoughts have changed on this one significantly since this thread was posted. I'll leave this up anyway since I dont like deleting things even if it was a mistake.

 

[Lazer]

This discussion has been going on too long now. "Wrapping", yes you can say it exists, but referring to the trajectory of the racket. The trajectory will adjust the angle the ball is hit. There is waaaaay too short contact time in a normal hit for any "ball wrapping" to take place.

Cheers
L-zr

 

[Jslick89]

This discussion has been going on too long now. "Wrapping", yes you can say it exists, but referring to the trajectory of the racket. The trajectory will adjust the angle the ball is hit. There is waaaaay too short contact time in a normal hit for any "ball wrapping" to take place.

Cheers
L-zr

lol dude....this is not the end all comment of the thread

 

[Lazer]

lol dude....this is not the end all comment of the thread

I know, but I at least I gotta try…

Cheers
L-zr

 

[NextLevel]

This discussion has been going on too long now. "Wrapping", yes you can say it exists, but referring to the trajectory of the racket. The trajectory will adjust the angle the ball is hit. There is waaaaay too short contact time in a normal hit for any "ball wrapping" to take place.

Cheers
L-zr

So assuming this is true, what are we to draw from this for how we should hit the ball?

 

[NextLevel]

I know, but I at least I gotta try…

Cheers
L-zr

Well, explain what it means for how someone's technique should develop and then you have tried.

 

[Richie]

Several years ago I had this wrapping idea as well, but I thought about it a bit differently, similar to I think how Timo Boll explained it. Not sure how much the idea has helped, but I believe it made a difference.
But it was this:
It's easier to go from open and somewhere on the path/way to colliding with the ball to adjust to close the angle. It's more difficult to go from closed to open, in my experience.

Though I had this idea for FH. Not sure how to think about it on the BH.

To keep the exact same racket angle from the start of the swing to the end actually seems impossible and much more robotic.

So most likely, somewhere on this swing path you'll be going from a more open/neutral angle to more closed depending on the shot and incoming ball. So you will be "wrapping" the ball more or less depending on what's going on. That's not to say the rubber in reality has the time to wrap around the ball in the way many people think about the word wrap. It just appears that way, but the idea may help the stroke.

@brokenball if you don't like this word, which do you think suits this whole idea better?

Something I wonder, for a chopper, is the opposite true?

 

[NextLevel]

Several years ago I had this wrapping idea as well, but I thought about it a bit differently, similar to I think how Timo Boll explained it. Not sure how much the idea has helped, but I believe it made a difference.
But it was this:
It's easier to go from open and somewhere on the path/way to colliding with the ball to adjust to close the angle. It's more difficult to go from closed to open, in my experience.

Though I had this idea for FH. Not sure how to think about it on the BH.

To keep the exact same racket angle from the start of the swing to the end actually seems impossible and much more robotic.

So most likely, somewhere on this swing path you'll be going from a more open/neutral angle to more closed depending on the shot and incoming ball. So you will be "wrapping" the ball more or less depending on what's going on. That's not to say the rubber in reality has the time to wrap around the ball in the way many people think about the word wrap. It just appears that way, but the idea may help the stroke.

@brokenball if you don't like this word, which do you think suits this whole idea better?

Something I wonder, for a chopper, is the opposite true?

Yes, I actually started hitting the ball a certain way on my backhand and tried to transfer it to my forehand. I like to catch the ball on the outside and then turn my forearm/wrist over it or upwards. That is my highest quality stroke ( low trajectory fast side-topspin - barely hops over the net). Whether first contact point is open or closed depends on the incoming spin, but the side contact tends to reduce the precision demands (at least I think it does). I find that my racket closes more the further I backswing and I tend to open more into the ball, even when I think I am hitting the ball fairly open and I still try to play over the ball. I suspect a lot of these things are just dependent on what you feel most comfortable with and how your stroke develops. But I honestly don't know how can consistently take the ball early while taking risks with constant racket angles.

 

[brokenball]

No one has addressed this.

If you think the pros can time impacts.

The eye takes about 13 ms.

In the industrial world I have access to devices

 

[IB66]

double hits when serving - I suffer from this now and again!!
hook serve, too fine a brush, so no real energy transferred to the ball, slow ball speed, bat speed faster and I'm trying to turn the bat around the ball. bat ends up in front of the ball and stops, ball hits bat for a 2nd time. classic double hit!!!

My Question is -

With a really fine brushing motion. If the bat / paddle speed increases slightly compared to the ball and then the paddle turns or wraps around the ball, has the ball ever left contact with the paddle??

In some sports this is known as a sling shot. usually illegal shot. Pushing the ball in Pool, rather than hitting.

When watching Badminton they catch the shuttle with their racket, yeah ok a TT ball ain't a Badminton shuttle. but in essence they wrap their racket head around the shuttle after tracking the shuttles path, removing the shuttles energy.