Why do pros risk tossing the ball outside the 30 degree window?

[MOG]

There is actually a third alternative - change the rules. Everyone will be happy.

99,9 % of the games won't have cameras and professional umpires.

You must be an illegal server who wins lots of points with illegal serves to be so defensive of the process!!

 

[NextLevel]

looking back at the SF of ITTF WC 2024, Ma Long should have been faulted for his reverse pendulum

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Ma Long should have been faulted on a lot of his serves, even when he doesnt hid the contact, thr ball tends to disappear at some point behind his head. I still think he was thr biggest reason why TTR did not get traction early. It faulted him so much when he played Liang in one of the Grand Finals that the TTR didnt show up until after he retired. Okay not entirely unarguable but that is my narrative and I will defend it.

 

[NextLevel]

It's necessary to throw the ball a little bit towards you for a good serve motion. Otherwise you'd need to throw the ball in front of your chest (which some people do), or move backwards. For a typical pendulum serve at least, I don't find any benefits on axe type backhand serves.

I don't think the translation velocity of the ball matters that much to be honest. I've tried it both ways and the only thing which has a real benefit is throwing the ball higher. You do get a measurable spin increase if you throw it to the rafters. It's just in general much riskier, but the benefit is visible enough that I still do an overhead throw.

I haven't calculated it but I'm pretty sure the force increase from the minor translation velocity into the racket isn't that impactful. Most of the time you're not serving for maximum spin anyway, so it might even complicate things if your motion is not built for it.

But what do I know.

None of this is quite true in terms of practical play.

 

[NextLevel]

For the people who think it's about physics:
That's 1% of the reason.
I've tested with spinsight. It hardly matters.

The 99% reason is for hiding your serve.
Hide (most of) your arm.
Hide (most of) your racket.
The more you hide, the better.

Don't pretend to be clever, talking about subtle physics.
Talk about the obvious hidden serve.

Sure, feel free to share your spinsight data even as it misses the point. One of the issues with non vertical tosses is that they aren't easy to pick up for the opponent in many cases. So it isn't purely about the physics but also about the perception of the receiver. Keep the height the same, from the side view, toss the ball backwards on a backspin serve and keep the toss purely vertical and cut into it. The opponent will tend to perceive less spin on the first serve. Whether that is physics or perception is not entirely clear to me but that is my experience. Very oten when I am getting a heavy serve, and the toss looks vertical but 6 inches, it is usually because i am not picking up the toss in the backward plane. That's a good umpires job.

 

[Archosaurus]

None of this is quite true in terms of practical play.

None, as in 0%? I guess I don't know anything about serving in matches. Feel free to pick into it if you're going to say that *none* of it is true.

 

[NextLevel]

None, as in 0%? I guess I don't know anything about serving in matches. Feel free to pick into it if you're going to say that *none* of it is true.

I gave an example in my response to @songdavid98 . You can't see backward tosses when the direction is not side on to the table ao the balls are deceptively heavy. I remember playing a guy and wondering where all the spin was coming.from. A rules enforcing umpire faulted his serves during a doubles match.

 

[andymagata]

Even with all the cheating, servers have a hard time winning more then 50% of their serves anyway. On amateur level numbers look different - and there is less cheating?

But the toss angle rule must stay, I do not want to see volleyball serves.

But ITTF needs to redefine what a hidden ball is.

 

[andymagata]

ITTF need to change the rules. A net serve should be legal. A faulty serve should be a net if called out. If server do two faulty serves in a row it is stupidity and should be punished with a fault. And hawkeye needs to handle the serves. The umpires either see nothing or are against certain players,

 

[MOJOJOJO-74]

ITTF need to change the rules. A net serve should be legal. A faulty serve should be a net if called out. If server do two faulty serves in a row it is stupidity and should be punished with a fault. And hawkeye needs to handle the serves. The umpires either see nothing or are against certain players,

It seems like you just want free points of net serves lol They definitely need to be more strict about serves being hidden since majority of the pros do so.

 

[Archosaurus]

I gave an example in my response to @songdavid98 . You can't see backward tosses when the direction is not side on to the table ao the balls are deceptively heavy. I remember playing a guy and wondering where all the spin was coming.from. A rules enforcing umpire faulted his serves during a doubles match.

That's fair and I agree, but I don't think I commented about that. My post was purely about the performance of the serve, not the human or psychological aspect of the serve.

 

[NextLevel]

That's fair and I agree, but I don't think I commented about that. My post was purely about the performance of the serve, not the human or psychological aspect of the serve.

I dont think it is right but I am not a physicist so I don't put too much into physics. What I do know is that very often , things that people who understand physics argue have no practical effect on table tennis. My favorite example is peole saying that only the time the ball is in contact with the rubber matters (true) and that time is realy short (true) and then from that, some draw the implication that large follow throughs are wasted (false, because you don't instantaneously contact the ball so the follow through is often determinedby how you intend to hit the ball). You can hit the ball efficiently for sure and reduce your follow through but the follow through is often part of the stroke and a smaller follow through can imply a slower swing.

In my experience, throwing the ball into the rubber allows for different ball trajectories. The spin may no be more but the forward motion of the ball is deceptively different. And the physicist will always come along and tell you that it has no effect. The physicist can be right but he has to help people play better, not take pride in telling people things that don't improve their play so he can feel smart.

 

[Archosaurus]

I dont think it is right but I am not a physicist so I don't put too much into physics. What I do know is that very often , things that people who understand physics argue have no practical effect on table tennis. My favorite example is peole saying that only the time the ball is in contact with the rubber matters (true) and that time is realy short (true) and then from that, some draw the implication that large follow throughs are wasted (false, because you don't instantaneously contact the ball so the follow through is often determinedby how you intend to hit the ball). You can hit the ball efficiently for sure and reduce your follow through but the follow through is often part of the stroke and a smaller follow through can imply a slower swing.

In my experience, throwing the ball into the rubber allows for different ball trajectories. The spin may no be more but the forward motion of the ball is deceptively different. And the physicist will always come along and tell you that it has no effect. The physicist can be right but he has to help people play better, not take pride in telling people things that don't improve their play so he can feel smart.

Well, I do have a physics simulation background, so I guess I have that inclination. I do understand what you mean though. I just think it's important to separate the things to avoid magical thinking. It's probably better if we know more precisely what effects actually happen from what things.

Even if the spin performance of the ball is only improved slightly, there's other effects. You can't just look at one thing in a very absolutist way. So I agree on that part and I'm not contesting it at all. My point was just basically that if you're going to do it, you will do it for other reasons.

 

[NextLevel]

Well, I do have a physics simulation background, so I guess I have that inclination. I do understand what you mean though. I just think it's important to separate the things to avoid magical thinking. It's probably better if we know more precisely what effects actually happen from what things.

Even if the spin performance of the ball is only improved slightly, there's other effects. You can't just look at one thing in a very absolutist way. So I agree on that part and I'm not contesting it at all. My point was just basically that if you're going to do it, you will do it for other reasons.

Well lets collect data like @songhas and see what the experts do. The we can determine. I have seen too many physicists with unimpressive playing levels use their experience to argue these issues when they might not rven know how to serve well illegally.

 

[Archosaurus]

Well lets collect data like @songhas and see what the experts do. The we can determine. I have seen too many physicists with unimpressive playing levels use their experience to argue these issues when they might not rven know how to serve well illegally.

There'd be little downside to collecting empirical data and quantifying some things. In a perfect world of course.

I suspect nobody will do it because acquiring the dataset is difficult unless you have personal access to hundreds of professionals and measure their parameters. I'd love to see it though, there would definitely be some surprises in there and a lot of explanations.

It probably wouldn't be very helpful to most people though. It's not quite the same, but beginner simulation engineers often focus a lot on really minor and gimmicky things while the important, big parameters are crap. Many technical minded people have a lack of perspective and don't seem to understand first, second etc. order effects.

If we quantified the sport entirely and somehow presented all the data, I'm sure most people would not meaningfully improve their game from it, because *analyzing* the data is always the very difficult part. Only experts would benefit from it and the analysis would need to be done by someone who is both an expert athlete and an expert data analyst and mechanical engineer. Such people hardly exist to begin with.

But maybe I'm reaching, I dunno. I'd still like to see it.

 

[NextLevel]

There'd be little downside to collecting empirical data and quantifying some things. In a perfect world of course.

I suspect nobody will do it because acquiring the dataset is difficult unless you have personal access to hundreds of professionals and measure their parameters. I'd love to see it though, there would definitely be some surprises in there and a lot of explanations.

It probably wouldn't be very helpful to most people though. It's not quite the same, but beginner simulation engineers often focus a lot on really minor and gimmicky things while the important, big parameters are crap. Many technical minded people have a lack of perspective and don't seem to understand first, second etc. order effects.

If we quantified the sport entirely and somehow presented all the data, I'm sure most people would not meaningfully improve their game from it, because *analyzing* the data is always the very difficult part. Only experts would benefit from it and the analysis would need to be done by someone who is both an expert athlete and an expert data analyst and mechanical engineer. Such people hardly exist to begin with.

But maybe I'm reaching, I dunno. I'd still like to see it.

Won't stop the physics experts from speaking confidently on the game though unfortunately.

 

[Archosaurus]

Won't stop the physics experts from speaking confidently on the game though unfortunately.

Everyone's entitled to be as much of a goober as they like.

I do feel like the goober-index has risen a few levels since I last posted here, though. Everyone just talks about equipment and drama now and not so much about, you know, hitting the ball.

 

[allencorn]

After reading this discussion and pondering the toss mechanics, I think it is mainly biomechanics. The differences in amount of spin generated is probably not crucial, as it is the deception of the amount of spin that seems to be most important. And it seems that to toss a ball consistently high enough, it is easier to use an outstretched arm, and then you want the falling ball close to your torso. So if you are wanting to serve from the backhand corner, it would be easier to toss it from somewhere near the midline with an extended arm. The trick then is to toss it high enough so it is "near vertical" when it would drop to the ideal contact spot closer to your body, I guess now defined as within a 30 degree angle.

 

[Creek]

Two main reasons for me:
1. hiding
2. spin

Hiding:
The biggest intention behind the angled throw. It is clearly visible, that all those angled throwers are hiding the ball with their head much more than with a vertical throw.
In Addition to that, hiding is the worst thing to prove, as there is only one camera for it and this should be at the receiving players Point of view according to the rules, but it is NOT!

Spin:
with the same hand motion, the spin can only be influenced by the speed of the ball:
- the higher you throw, the quicker is the ball. BUT the higher, the harder to Hit properly
- the more angled you you throw, while making an active step into the ball when hitting, the more you have a Counter motion, which also minimally increases the speed.
BUT, this is only super slight increase.

Conclusion: hiding is the Most important in it and most unfair. There Are a lot of players, e.g. WCQ, LSD, who even exagerate this practice on intention when the match is in the crunch time

 

[songdavid98]

Sure, feel free to share your spinsight data even as it misses the point. One of the issues with non vertical tosses is that they aren't easy to pick up for the opponent in many cases. So it isn't purely about the physics but also about the perception of the receiver. Keep the height the same, from the side view, toss the ball backwards on a backspin serve and keep the toss purely vertical and cut into it. The opponent will tend to perceive less spin on the first serve. Whether that is physics or perception is not entirely clear to me but that is my experience. Very oten when I am getting a heavy serve, and the toss looks vertical but 6 inches, it is usually because i am not picking up the toss in the backward plane. That's a good umpires job.

Actually I played against an old guy who did this.
But the effect was in the opposite direction.
He made his no spin serve look like it was backspin.
I stood from the side after I saw him serve against my buddy.

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As for the spinsight data, after adjusting to the new toss (because a new toss feels weird), there's literally no change in spin RPS.
Max pendulum RPS stays at 76.
Haven't tested hook serves yet, but I'll gather more data when I can (usually im playing instead of practicing serves).
Ironically 42andbackpains has time to test this thoroughly.
Maybe I'll ask him to volunteer as a test subject.

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Non-vertical toss is purely for deception.
Your post has emphasis on backwards toss.
My post has emphasis on hidden serve.

Umpires can easily check the backwards toss though.
They can't check the hidden serve.
It's why my post is about the hidden serve.
But I do understand your post.

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On the side note:
If ITTF made serving stricter ( from 30 degree toss to 15 degree toss ), the pros can all adjust.
They have the time to change and practice their serve, just like I did.
It's not that hard.

Even Lin Gao Yuan had to change his toss from 52 degrees to 30 degrees