Dwell time

[ttpshot]

Been reading through studies from other sports and found this one on golf fascinating because it sounds very familiar.

https://dspace.lboro.ac.uk/dspace-j...ime in Short Duration Sports Ball Impacts.pdf

Here, they investigated contact time between wood, titanium and steel club head in golf.

In the players interview, it was quoted:

“I think the ball probably stays on the club head a bit longer with a traditional wood so you feel that you can shape it a wee bit more...”

The result was surprising as the titanium head had the longest impact time and the steel head the shortest.

What was more surprising was that the ball and its composition affected the impact time a lot more than the club head and yet hardly any players felt the difference which is what you expect when the impact time is 0.5ms.

The study concludes that there are other factors such as sound that gave a player the percieved impact time.

The aim of this experiment was "If the mechanism for generating these perceptions can be understood then it may be possible to design this ‘feel’ into a golf club." which was what I had in mind too.

There might be a day when it's possible to develop very fast and spinny blade with lots of "feel" so that the control and faster improvement can be achieved without sacrificing speed and spin.

 

[UpSideDownCarl]

Well, that is pretty easy. Softer woods like Hinoki and Limba let you feel as the ball can stay on the blade face longer. Harder woods like Ebony or certain kinds of Walnut make it harder to have that feeling of keeping the ball on the blade face longer.

Of course there are versions of Limba that are a little harder and some that are softer. There are versions of Koto that are harder and softer. When an outer ply is harder, it makes it feel harder to hold the ball on the blade face and when the outer ply is softer it makes it feel easier to keep the ball on the blade face longer.

Of course, this is a little over simplified as well. There are blades where the outer ply is hard and the ply under that is soft and you get this nice crisp feel but you also get that feel of good dwell time. Then there are blades where the outer ply is soft and thin but the ply underneath is springy and you get this crisp feel and a catapult but the soft top ply still allows the feel of extra dwell time. Blades like a Clipper have this.

This is also why blades with Arylate+Carbon give the feel of extra dwell. Like, in a Viscaria, the top ply is Koto which is kind of hard and the Carbon keeps it crisp and adds to the speed but the Arylate gives a softness under the top ply that helps you get more spin and helps you feel as if you can get extra dwell time.

I would say that is the short version. This info is also why it is worth knowing the construction of the plies of different blades so when you feel them you start feeling how different ply constructions work.


Sent from the Subterranean Workshop by Telepathy

 

[UpSideDownCarl]

Here is a link to a page on Ooak Forum that lists the ply construction for many blades:

http://ooakforum.com/viewtopic.php?f=43&t=7194


Sent from the Subterranean Workshop by Telepathy

 

[Baal]

Been reading through studies from other sports and found this one on golf fascinating because it sounds very familiar.

https://dspace.lboro.ac.uk/dspace-j...ime in Short Duration Sports Ball Impacts.pdf

Here, they investigated contact time between wood, titanium and steel club head in golf.

In the players interview, it was quoted:

“I think the ball probably stays on the club head a bit longer with a traditional wood so you feel that you can shape it a wee bit more...”

The result was surprising as the titanium head had the longest impact time and the steel head the shortest.

What was more surprising was that the ball and its composition affected the impact time a lot more than the club head and yet hardly any players felt the difference which is what you expect when the impact time is 0.5ms.

The study concludes that there are other factors such as sound that gave a player the percieved impact time.

The aim of this experiment was "If the mechanism for generating these perceptions can be understood then it may be possible to design this ‘feel’ into a golf club." which was what I had in mind too.

There might be a day when it's possible to develop very fast and spinny blade with lots of "feel" so that the control and faster improvement can be achieved without sacrificing speed and spin.

Yes. Somebody else once mentioned that article in a thread at OOAK Forum-- on dwell time. Probably 2 years ago? I didn't think at the time it could apply to TT. Now i think differently. That is the basis for something I wrote earlier on this thread about how we use all kinds of senses in TT, sometimes without knowing it. So I'm glad you posted this.

 

[ttpshot]

Yes. Somebody else once mentioned that article in a thread at OOAK Forum-- on dwell

Would you be able to provide the link to that?

 

[Baal]

I'll try. Not sure which thread. It was a bit of a flame war. Guy who posted it was a golfer new to TT. I think now he may be right about some of what he was saying. I didn't think so at the time. I'm curious now what I wrote then.

 

[Baal]

Here is the thread that references sound in golf. The commenter Iacas was arguing that feel in table tennis is mostly sound. He was basing it on the article you just mentioned.

http://ooakforum.com/viewtopic.php?f=9&t=27131&p=288532&hilit=+Dwell+time+golf#p288532


It is a pretty extreme view. Way too extreme for me still. But maybe sound is some of how we synthesize in our brain a perception of "feel".

The original subject of the thread was what matters more? Blade or rubber? I argued both matter, in agreement with 99.9999% of experienced TT players. The golfer dude Iacas argued only rubber matters, and differences due to blade were a complete illusion based on sound. I know with 100% certainty that is incorrect.

 

[ttpshot]

Here is the thread that references sound in golf. The commenter Iacas was arguing that feel in table tennis is mostly sound. He was basing it on the article you just mentioned.

http://ooakforum.com/viewtopic.php?f=9&t=27131&p=288532&hilit=+Dwell+time+golf#p288532


It is a pretty extreme view. Way too extreme for me still. But maybe sound is some of how we synthesize in our brain a perception of "feel".

The original subject of the thread was what matters more? Blade or rubber? I argued both matter, in agreement with 99.9999% of experienced TT players. The golfer dude Iacas argued only rubber matters, and differences due to blade were a complete illusion based on sound. I know with 100% certainty that is incorrect.

Thank you baal! Hmm, it is very extreme and sounds very much like from a person with little or no TT experience.
The study itself had drawn no conclusion on the factor of the perception.

I had a hit with my daughter's racket(Nittaku Sanalion&Vega Euro) and it felt that the ball stayed so much longer than my Gergery&T80 setup. Of course I could spin more with T80, but it got me thinking that it must be so hard to conduct golf-like experiment when factors such as spin/throw angle/actual dwell/type of stroke comes into consideration.

 

[bobpuls]

There might be a day when it's possible to develop very fast and spinny blade with lots of "feel" so that the control and faster improvement can be achieved without sacrificing speed and spin.

The day already passed by . . . .
Im playing with this type of blade.

 

[NextLevel]

Here is the thread that references sound in golf. The commenter Iacas was arguing that feel in table tennis is mostly sound. He was basing it on the article you just mentioned.

http://ooakforum.com/viewtopic.php?f=9&t=27131&p=288532&hilit=+Dwell+time+golf#p288532


It is a pretty extreme view. Way too extreme for me still. But maybe sound is some of how we synthesize in our brain a perception of "feel".

The original subject of the thread was what matters more? Blade or rubber? I argued both matter, in agreement with 99.9999% of experienced TT players. The golfer dude Iacas argued only rubber matters, and differences due to blade were a complete illusion based on sound. I know with 100% certainty that is incorrect.

I do think feel in table tennis is clearly mostly sound. That's why we talk about vibrations. OF course, other senses are important, but sound is a big part of it, not just the ears, but the hands obviously. I think because kids are growing, all kinds of body parts are augmented for table tennis specialization if they play at a young age. The idea that there is no correlation between feeling and the contact time of the actual shot... that is interesting. Blade stiffness does tend to correlate with rebound speed.

 

[Baal]

I do think feel in table tennis is clearly mostly sound. That's why we talk about vibrations.

Sound is constructed for us by detecting vibrations in our inner ear using cells (with cilia that can vibrate at very high frequencies). During hearing (audition) we are detecting vibrations caused by sound waves moving through the air. By contrast, we detect vibrations in the blade itself using mechanoreceptors in our skin (which don't use cilia and which have a much reduced frequency response by comparison). So at a certain level, in both cases we are detecting vibrations. But the vibrations are passing through different media, and we process sensory input originating from inner ear and skin mechanoreceptors using completely different neural pathways (at least until we integrate them at some very high cortical level to figure out what just happened on a shot).

For many reasons based on playing TT for a long time, and from physiology, I reject the idea that "feel" is mostly sound, at least in our sport. It is very much not something that is "clearly" evident. It may be partly sound, but not mostly. It is way too complicated to be reduced to any one thing or one sensory modality. We use sound. Certainly shots when you attack the ball at different angles and impart more or less spin clearly sound different. I am sure that tells us something or maybe even a great deal about what we are doing. Those various shots will also produce different impact on the blade.

It is widespread experience that two closely related blades with the same rubber can sound the same and still play a bit differently because they may require that you approach what is basically the same shot with slightly different racket angles. We feel our racket angle by "proprioception" which we derive from sensory receptors in the muscle tendons (that measure tension) and sensory receptors in the center of the muscles (which tell us how extended the muscle is). I don't want to get into another flame war over this here. But it is never a good idea to oversimplify complicated things.

 

[NextLevel]

Sound is constructed for us by detecting vibrations in our inner ear using cells (with cilia that can vibrate at very high frequencies). During hearing (audition) we are detecting vibrations caused by sound waves moving through the air. By contrast, we detect vibrations in the blade itself using mechanoreceptors in our skin (which don't use cilia and which have a much reduced frequency response by comparison). So at a certain level, in both cases we are detecting vibrations. But the vibrations are passing through different media, and we process sensory input originating from inner ear and skin mechanoreceptors using completely different neural pathways (at least until we integrate them at some very high cortical level to figure out what just happened on a shot).

For many reasons based on playing TT for a long time, and from physiology, I reject the idea that "feel" is mostly sound, at least in our sport. It is very much not something that is "clearly" evident. It may be partly sound, but not mostly. It is way too complicated to be reduced to any one thing or one sensory modality. We use sound. Certainly shots when you attack the ball at different angles and impart more or less spin clearly sound different. I am sure that tells us something or maybe even a great deal about what we are doing. Those various shots will also produce different impact on the blade.

It is widespread experience that two closely related blades with the same rubber can sound the same and still play a bit differently because they may require that you approach what is basically the same shot with slightly different racket angles. We feel our racket angle by "proprioception" which we derive from sensory receptors in the muscle tendons (that measure tension) and sensory receptors in the center of the muscles (which tell us how extended the muscle is). I don't want to get into another flame war over this here. But it is never a good idea to oversimplify complicated things.

I

By feeling, I mean the sensation of the ball on your racket. You probably mean touch or ball manipulation or something else, which people might define as feeling a well?

If you ask a deaf person how/why they can dance or listen to music, they will tell you the feel the vibrations. In the end, words are words and sometimes, being overly informed or technical can create the problem that rather than interpreting what the other person is saying the way a layman would, you end up interpreting them the way a specialist would or the definition is never agreed upon. Maybe that is a cause of flame wars?

Feel is mostly vibrations might be an oversimplification. But I am speaking like the deaf person here. And of course the deaf person may be wrong. But maybe you could eliminate the vibrations and see if they could still dance to the music. Or you could eliminate the blade vibrations and see if people still "feel" anything.

 

[Baal]

Terminology is important. I explained the difference between hearing, proprioception and cutaneous mechanoreceptors clearly in my posts. We hear the ball hit the blade. We also feel it with our hands. We also know where our hands and arms are (from vision and proprioception) and how much force we are using (proprioception). There are distinct receptors and neural pathways for each of these different sensory modalities. To get at how some of these things affect play requires some experiments which would actually not be that hard.

Try playing with ear plugs (to reduce sound input). Try wearing gloves (to reduce or alter input from cutaneous mechanoreceptors). You can't alter proprioception and still play. That would be impossible.

I think there is no doubt that hearing is something that helps us know what just happened on a short.

By the way, totally deaf people (and hearing people too) can detect sound waves using their body by detecting vibrations (using non-auditory receptors). The sound has to be quite loud (like in a bar or on a dance floor) and the frequency range is very limited (because detection is by mechanoreceptors in the body that don't have cilia). They can detect the bass and the drum and feel they rhythm of the music (I sometimes have the sensation of feeling that in my chest when it is really loud). They probably don't feel much of the guitar solo, since the frequency is too high for detection by their body. Similarly, they can't hear or "feel" ordinary speech and they would not hear a ball hit a racket but they would still know when it happened.

 

[NextLevel]

So they would not hear a ball hit a racket they are holding? Which is just about the only relevant thing to the definition of feeling that I provided?

 

[Baal]

No. But they would still sense the ball hitting the blade through the other various senses. Also, if you wore thick padded gloves you would hear the ball hit just like normal even if hands didn't sense the usual impact. So how would one play with ear plugs? I've never tried it. Overgrip didnt seem to affect my ability to execute in shot game. But that would mainly affect higher frequency vibrations. On an ALC blade there is less of that anyway.

 

[NextLevel]

Well, I think you are wrong and they would feel the vibrations of the ball on their racket. But since I haven't performed the tests, I cannot say and I could be very much wrong. The impact of the ball on my racket is often more significant to me than music.

 

[Baal]

Well, I think you are wrong and they would feel the vibrations of the ball on their racket.

That is exactly what I said! Deaf people would still feel the vibrations on the racket. With their hands and through proprioception. But they wouldn't hear it (using apparatus in their ears which by definition in a deaf person is dysfunctional).

To whit: I wrote, "they would still sense the ball hitting the blade through the other various senses". Not sure how I could have made it any clearer than that.

 

[NextLevel]

That is exactly what I said! Deaf people would still feel the vibrations on the racket. With their hands and through proprioception. But they wouldn't hear it (using apparatus in their ears which by definition in a deaf person is dysfunctional).

To whit: I wrote, "they would still sense the ball hitting the blade through the other various senses". Not sure how I could have made it any clearer than that.

By making it clearer that when deaf people sense a ball on their racket, they are doing it in a similar way to how to get can sense music even when they don't hear it. And this kind of sound perception, whether it is related to prior prioception or to auditory perception, is still sound related.

In physics, sound is often described in terms of frequencies, some which we may not even hear. I don't get why you are interpreting my statement that sound is involved in feeling in the narrowest sense possible.

 

[James Livesey]

Carl talked about how the hardness of outer ply greatly affects feeling of dwell. What about flex? I'm still a bit confused about the feeling of a stiff, soft blade vs a flexy, hard blade. which do you think personally contributes more to the feeling of dwell?

 

[Baal]

By making it clearer that when deaf people sense a ball on their racket, they are doing it in a similar way to how to get can sense music even when they don't hear it. And this kind of sound perception, whether it is related to prior prioception or to auditory perception, is still sound related.

In physics, sound is often described in terms of frequencies, some which we may not even hear. I don't get why you are interpreting my statement that sound is involved in feeling in the narrowest sense possible.

I don't want to argue about it because I fundamentally agree that sound affects the way we play, but the fact is that I am using the most precise possible language to describe this, and if you decide you don't want to understand...????? Well Ok. But that is pretty much exactly what I said.

To reiterate: Sound is vibrations carried as pressure waves through the air. It is detected by our auditory system normally, except if it is really loud and low enough frequency you can feel it in other parts of your body. The question is whether the normal sense of hearing is actually the thing that makes us say, for example, that one setup is different from another has been raised. I personally don't think it is a major contributor, but I have not done the thing experiment that would determine for sure. We all know that it sounds different when you drive the ball with an open racket angle as opposed to brushing it. Sound narrowly defined may tell us more than we think about what just happened on a shot and determine how we play.

Still, it is obvious that other organ systems in our body can detect when we hit the ball (and also how we know what racket angle we used and even how hard we hit). I personally think the MULTIPLE sensory systems that allow us do to this are a lot more important to our "feel" than sound. And they are not vibrations that are carried as waves through the atmosphere (which is why sound does not exist in space and is different underwater). Those vibrations are instead carried through the medium of the rubber/blade/handle and from there to your hands and from there to your wrist, arm, etc. (and also to the atmosphere). Those vibrations within the handle are by definition NOT SOUND. And those vibrations are detected by a set of completely different organs not found in your ears and which deaf people certainly have. Deaf people would not need functional auditory system to know when they hit the ball.