TT Myth Busters

[Tinykin]

the words or grammar may not be technically correct. Listen towhat is being conveyed.

The way we use words in ordinary language can always be dismissed by some geeky show-off.

 

[Tinykin]

To me control is about forgiveness. That is, with a boosted Tenergy rubbe on a fast Carbon blade, I have to be much more precise in the way I block than with a Reflectoid on a Stiga All. With the reflectoid, I can almost stop thinking about the incoming spin.

 

[Tinykin]

If you play in local league in England, you'll know all about balls behaving very differently in each playing hall.

 

[Killerspintt]

The way we use words in ordinary language can always be dismissed by some geeky show-off.

Hehe, thats true, just saying "it is so hot today" is physically speaking incorrect and we should say something more like "today there is a lot of heat transfer from the environment to my body".......but who will ?
I won't speak about the usage of the word "power" which most of time is incorrect (espscailly when saying for example that a blade is more powerfull that an other), but who cares since we can just understand each others.

 

[Suga D]

Wobble ball he is correct in his explanation it is when you hit a ball with no spin and the turbulent air currents in the room move it. If you don't believe it look up football knuckle balls. It's the same idea but the bigger ball and larger movement is easier to see

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.

If you play in local league in England, you'll know all about balls behaving very differently in each playing hall.

It's the same in many german 'Kreisklassen'. You can see players hit technically-complete-out-of-order shots with balls that seem to behave against the laws of physics, but somehow the ball lands on the table, 'cause they're so experienced due to 50years of playing....

 

[Der_Echte]

I wont even speak about the fact that the COR, for a given blade, is absolutely not a constant. For, taking measures at slow speed, a Calibra LT speed will have higher COR than a calibra LT+, but at high speed the COR of calibra LT+ is of course higher.

Now you are friggin' talkin'... this is the "Gears" we talk about why such and such blade or rubber exhibits in certain situations.... and the reality totally DEFIES what we scientific minded folk want to quantify precisely.

There are entirely too many factors at play. Masters of TT have great control over HAND PRESSURE that also affects the rebound so much more than any factor we can name.

 

[Der_Echte]

I believe if you wear expensive TT socks you will be a better player.

You just one-upped me like I stepped on a doo-doo mine, Giangt. Well played. Where the "f" did you get Ur sense of humor? Surely I cam into the world before you, but you must have discovered the secret cache of my mold.

 

[izra]

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.

i challenge you to throw a table tennis ball around with little to no spin in a closed hall and catch it "wobbling" on camera.

 

[izra]

...
Izra, it is easy to make the sink ball effect with regular inverted. Actually there is no sink ball force. The ball simply can't be hit as hard without top spin or it will go off the end of the table whereas a loop will drop. Basically the ball hit by a SP just slows down and drops due to gravity. I can readily achieve this effect with my BH. I mix up top spins and sink ball shots. Mostly it screwing up the opponents timing but the slower sink shot will allow a good opponent to kill the ball if he can adjust.
...

i agree but i don't think you can call this a myth. the "sink ball effect" is a subjective perception of a ball that carries less speed and topspin than expected and you get a lot of those with SP rubbers.

 

[brabhamista]

I believe if you wear expensive TT socks you will be a better player.

Pfff... you have regrettably restricted sock EJing ahead of you if you limit the origin and fountain of success to price only. It's a jungle out there, mate. Try adding in exotic materials, say: socks with carbonfiber reenforced heels and toes and we're getting closer to really memorable table tennis achievements

 

[Killerspintt]

Now you are friggin' talkin'... this is the "Gears" we talk about why such and such blade or rubber exhibits in certain situations.... and the reality totally DEFIES what we scientific minded folk want to quantify precisely.

There are entirely too many factors at play. Masters of TT have great control over HAND PRESSURE that also affects the rebound so much more than any factor we can name.

Yup, having an "objective" data about a speed of a racket will require so many experimentations that it's simplier easier to simply test the racket youself and have subjectives values about it.
And yes, just before the impact, the top players put more hand pressure......it's well known but only the greatest players can master it, it's not like eveyone can be gifted like Waldner.....

 

[brabhamista]

Izra, it is easy to make the sink ball effect with regular inverted. Actually there is no sink ball force. The ball simply can't be hit as hard without top spin or it will go off the end of the table whereas a loop will drop. Basically the ball hit by a SP just slows down and drops due to gravity. I can readily achieve this effect with my BH. I mix up top spins and sink ball shots.

So a "sinking ball" ball has no spin.
But how can you produce a ball like that with inverted? And at will?

I guess, first you'd have to read the exact spin, speed and angle of the incoming ball.
Then you'd have to adjust your bat to achieve perfect nullification of that spin as well as make the ball travel far enough - but not too far! - to hit the other side of the table in an awkward spot - hopefully - for the opponent.

To nullify the spin you'd need to read side/top/back spin including the exact combinations of those on all axis. And the incoming speed. And the incoming angle, both vertical and horizontal. And the depth of the ball. It also means you'd have to adjust your bat speed, how loose/tight you grip is, a myriad possible bat angles and? (We'll ignore any footwork needed in a real-world situation for the sake of simplicity.)

So from a purely physics point of view, that's is all you'd need to do. But if you don't do it perfectly, there will be no nullification of spin and thus no sinking ball. To do that at will requires true perfection. Every ball, every time.


That's an extraordinary skill you have there, mate

 

[jasonxian24]

Faster = better

 

[izra]

So a "sinking ball" ball has no spin.
But how can you produce a ball like that with inverted? And at will?

I guess, first you'd have to read the exact spin, speed and angle of the incoming ball.
Then you'd have to adjust your bat to achieve perfect nullification of that spin as well as make the ball travel far enough - but not too far! - to hit the other side of the table in an awkward spot - hopefully - for the opponent.

To nullify the spin you'd need to read side/top/back spin including the exact combinations of those on all axis. And the incoming speed. And the incoming angle, both vertical and horizontal. And the depth of the ball. It also means you'd have to adjust your bat speed, how loose/tight you grip is, a myriad possible bat angles and? (We'll ignore any footwork needed in a real-world situation for the sake of simplicity.)

So from a purely physics point of view, that's is all you'd need to do. But if you don't do it perfectly, there will be no nullification of spin and thus no sinking ball. To do that at will requires true perfection. Every ball, every time.


That's an extraordinary skill you have there, mate

well you don't really have to COMPLETELY nullify the spin. a light and controlled chop block would take away some of it which is enough to make the ball seem to sink for your opponent.

 

[brabhamista]

well you don't really have to COMPLETELY nullify the spin. a light and controlled chop block would take away some of it which is enough to make the ball seem to sink for your opponent.

When using "a sinking ball effect" we are not talking about chop blocks (at least not in table tennis lingo). A “sinking ball" is used for a common ball behaviour when hitting hard with SP, or moreso with MP. It does not apply to the behaviour produced by a chop block.

Consistent, successful chop blocking will not produce something similar. Mis-executed chop blocks could (possibly), but that has nothing to do with producing it consistently at will, which is what I find so extraordinary considering the alien-like skills needed in reading and perfectly dealing with incoming spin, speed, etc to nullify the spin and achieving "a sinking ball".

 

[Pnachtwey]

........changing the mass is changing also the COR, why are you assuming that the COR will be unchanged ? This makes no sense, of course a 95gr viscaria will have higher COR than a 80gr one (most of time, you will always find me a 95gr ultra soft viscaria with a low COR).

Where is your evidence?
A 95gm viscaria will be faster than a 80 gm one due to the difference in mass. Obviously a soft paddle will be different from a hard one. That is taken in account by the COR.

Yes you are right, if you find me a bat of 160gr that has the same COR than a 200gr one, indeed the increaseof speed wont be as much as the weight increase............but........this is assuming that the two bats have the same COR, why do you think that the COR of a 95gr viscaria is the same as a 80gr one ? Because I tell you : it's not, not the same at all.

Again where is your evidence? How does the mass affect the COR? If I keep increasing the mass how does it increase the COR? There is a limit to how high the COR will go. I would like to see your explanation.

The Teiffenbacher tests show COR does vary as a function of impact speed.
http://www.ittf.com/ittf_science/SSCenter/docs/199408014 - Tiefenbacher - Impact.pdf
I think most of the drop in the COR as a function of impact speed is caused by the different amounts of deformation of the TT ball.

 

[Old School]

i challenge you to throw a table tennis ball around with little to no spin in a closed hall and catch it "wobbling" on camera.

In baseball pitchers can throw a Knuckleball that is a no spin/low spin ball that is known for it's erratic flight path.
So I would not beat my life on your belief that it is an illusion.

 

[BeGo]

To answer to PNachtwey,

For control, you are right, but,
That the very reason I did not take the control rating as how controllable a blade is, rather as the probability that the next person will say this blade controllable.

For power, you are right. I choose COR to represent blade power cause, more elastic bounce means the ball return faster on passive block, from the same ball speed.

On terminal velocity,

Terminal velocity can also be taken as speed where total air drag and ball forward / drop pressure reach equilibrium

If the terminal velocity for table tennis is 8 m / s, or 28.8 kph, then I admit I were wrong, a good flat smash can make the ball easily affected by air drag and start to swerve, like a balloon thrown hard.

I believe the value hold true for 38 mm ball. For current ball, I guess the value should be higher, cause I never seen table tennis ball swerve that much in pros videos.

To add to the list,

The spin rating in rubber is not the amount of spin that the rubber capable to generate, that is in the player, but the capabilities of rubber to impart spin and being affected by spin.

In short, the spin created by tackiness chop (spin rating 9) and flextra (spin rating 6) from same hand speed should roughly the same.

 

[Persistence TT]

thicker rubbers up to a certain point are definitely faster than thinner ones end of story. Of course I am talking about keeping all the other factors the same. Same stroke, same speed and spin of incoming ball and we suppose that the energy of the incoming ball is enough to compress both rubbers at their max deformation

 

[Persistence TT]

Its not easy to generate no spin. If you have some basis in physics, read some litterature about the magnus effect. The table tennis ball is submit to magnus effect and (almost) everything about the relation between trajectory and spin is caused by the magnus effect for our beloved table tennis balls.

Every ball even "dead" balls produced by pimples have some light spin on it. Only if we had "no air" conditions we could produce a 100% no spin ball