Throw Angle

We’ll discuss the term throw angle in table tennis.

0. Motivation

1. Definition?

The term throw angle is usually based on the arc with which the ball leaves the blade after the impact. Given the same stroke, the rubber with the higher arc would be labelled as high throw.

The problem with the above definition is that a single rubber doesn’t have a single throw angle, but many different ones. Based on the incoming ball(spin and speed) and your stroke (blade angle, stroke direction) you get a unique throw angle for every ball. As we can see (or later see since the explanations follow below), we can only compare different rubbers throw angles on certain stroke types.

However, people aren’t stupid and we’ll see later on why this infamous term enjoys such a high popularity, how and why the usual rubber reviewer labels a rubber as high or low throw and how you can still benefit from these (false or inexact) reviews to make a good decision.

2. How a rubber works

In the picture below we see a ball penetrating a sponge. At this point I’d like to remind every reader that you owe me a new kitchen cleaning sponge, a Battle I topsheet and some TT glue.

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Sadly my kitchen sponge isn’t that elastic, so some effects can’t be seen properly. However, at the 3 minute mark in the following video there’s a nice model of the ball rubber impact.

Let’s go back to our model (click to open bigger version in a new tab).

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We saw the the throw is the result of different forces and their relation to each other, in particular the relation between the upward and forward forces.

Below we see a high throw (blue) and a low throw(red) and the explanation which forces result from which phenomenons (compare with our model above).

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We can also see, that certain manipulations of the spin/speed ratio are possible. By using less forward speed we need less upward force to get a similar high throw angle.

text79v2

3. What makes a rubber high or low throw on a certain stroke with a certain incoming ball spin and speed?

As seen above, different things influence the forward and upward forces. The aspects a rubber can influence are:

  • topsheet tacky or nontacky
  • the sponge hardness
  • the sponge thickness
  • the pimple structure(type, width, distance to each other)

In the next section we’ll do a little case study on these options.

3.1 Case study: Tenergy rubbers T64,T05 and T25

We previously saw how the sponge and the stroke type lead to different types of outgoing ball trajectories. So far we didn’t consider the different pimple types, although they play a major role for describing the rubbers throw.

Sadly I wasn’t able to get a complete list of all ITTF licensed rubbers and their pimple measurements as listed and enforced on the ITTF sheet for rubber approvals.

I even send an E-Mail to Mr. Darren Leong (ITTF equipment coordinator) but he just kindly told me that its a trade secret. That’s a bit strange considering that every firm can measure a competitors rubber easily to a very high accuracy. So my guess is that it’s just another method of keeping the usual ‘stupid’ costumer stupid and robbing him of the ability to discover a similar and possibly cheaper rubber.

Gladly, one of the most used and well known companies published some of their pimple measurements and you might have already guessed it, it’s Butterfly.

We start with the comparison between T05 and T64. According to Butterfly, they have the same pimple type and width, but the pimples are further apart and taller at the Tenergy 64.

Imagine we apply a certain force onto the rubber. This force gets distributed among all pimples below the topsheet which are influenced by the ball. Let’s say the force is distributed among 10 pimples on the T05.

The same force is then distributed among fewer pimples on the T64, because they are further apart, which means that each individual pimple has to withstand more force on the T64. This makes it easier to let them dive into the sponge compared to the T05, especially since the T05 has a harder sponge. It’s thus easier to compress the sponge on the T64 and hence also easier to let the rubber ‘eat’ the ball and get more upward energy out of it.

Now the big question is: If it’s easier to get an upward force out of the T64, why it’s shown in the video at the beginning to have a lower throw?

The answer lies in the different incoming and applied forces and how the rubber can handle them (you might remember the trampoline example from the chemistry article).

For low forces the T64 is sufficient and creates a high arc or throw. But as soon as more force is applied the longer pimples of the T64 can’t withstand the force applied to them and do not bend but rather get smashed without to much resistance. The topsheet failed. Now we lose much of the upward force and can only rely on the ball eating force(yellow in one of our above examples). At the same time, the softer sponge of the T64 is strongly compressed (or even bottomed out) and then applies a great forward force to the ball. Thus the ball goes long instead of high.

The Tenergy 05 on the other hand can handle this high forces, because the pimples are closer together and hence less force is applied to each pimple. Furthermore, the pimples aren’t as tall as the T64 ones and are less susceptible to getting smashed without properly realigning. Last but not least, the hard sponge can handle the incoming force better and provides sufficient upward lift while limiting the forward force.

(Many thanks to reddit user /u/anchorschmidt for pointing out that T05 and T64 have the same sponge hardness, I looked in the wrong column ;).)

The description above already hints at the fact, that different rubbers have a range where they shine. The T64 at low forces and the T05 at medium to medium high forces.

We close the gap for very high forces by introducing the Tenergy 25. This rubber has really massive wide pips which are close to each other. Thus the force applied from the topsheet can be distributed among a great pip surface and can be handled even for very high forces. Additionally they almost never fail to realign themself after being compressed because they are so massive.

Another question might appear at this moment: Why professional players even bother with playing the T64 and T05 and don’t simply to move to T25 since it handles high forces better?

You might have read it a thousand times here already, but again, nothing in life is free. The ability to handle high amounts of spin on the T25 comes at a price. The price is the fact, that you need a very high energy to compress the pimples and the sponge. If you try to make a thin brush loop against a slow ball, you won’t get any upward force. The sponge won’t get compressed because the low incoming force is distributed among the massive pimples and the pimples won’t bend. Hence intermediate players might say the T25 is a low throw rubber, because for them, on most of their ‘weak’ strokes it doesn’t create any arc. However, on power strokes, the arc is higher than the arc of the Tenergy 05 and T64 as correctly shown in the Butterfly video at the beginning.

These thoughts immediately lead us to the next section.

4. Making sense of people and their ratings

On tabletennisdb people rate their rubbers regarding many aspects. Luckily they also rate the throw angle and therefore we can try to understand:

  • which rubbers are rated high,
  • why they are rated high,
  • and what we can do with this information.

Sorting by the throw angle value and accepting rubbers with more than 15 ratings we get the list of the following first 6 entries:

  1. DHS H3 (tacky,pro)
  2. Sanwei T88-I (tacky)
  3. Donic Bluefire M3 (soft)
  4. Butterfly Tenergy 05 (pro)
  5. Butterfly Sriver G3 FX (soft)
  6. Donic Baracuda ()

The words behind the rubber are

  • pro: rubber is used by pro players so the rating might be flawed
  • tacky: rubber has a tacky surface
  • soft: rubber has a soft sponge and rather small pimples

4.1 Tackiness

If we remember our statement of the ratio of upward and forward energy and how to manipulate it, we see why tacky rubbers are rated as being high throw.

text79v2

They reduce the forward forces significantly and hence the ball appears to have a higher throw. The picture above also explains why tacky rubber users should stay close to the table.

4.2 The Sanwei Case

The Sanwei rating is interesting because it a clone of the T25, which has a lower throw angle rating. It has massive pimples aswell. However, the tackiness seems to help people to overcome the lack of a lifting force for brush loops and weak balls in general.

4.3 Soft rubbers

Soft rubbers with rather small pimples bend easily on slower strokes and thus provide a good upward force (ball ‘eating’ /dwell time) even on weak strokes.

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However, as previously stated, they fail at higher impact energies. Nevertheless most amateurs would give their left leg to say that they can generate a higher throw with these rubber types.

4.4 How to use the rubber throw ratings

At first remember the reasons why people give rubbers a high throw rating. They give the rubber a high throw rating, if they get an high arc on most of their shots. Depending on their skill level the same rubber might vary from low throw to high throw ratings (T25 case). If a rubber is neither too soft nor tacky, there’s a high chance that this rubber indeed creates a good arc on most shots (T05,Baracuda).

If you like tacky rubbers (H3,T88), there’s nothing wrong with playing them, but consider the advantages and disadvantages as written on the tacky rubbers article. Also note that the H3 might produce an on average higher throw than the Sanwei rubber because the pimples of the H3 aren’t as massive.

If you know that your playing level isn’t too high, there’s no need to play really hard rubbers which need a high impact energy (T25) to produce a high arc. Then softer rubbers are your choice.

5. Summary

The throw throw angle measures how closely a ball follows a high or low arc as it leaves the blade. The arc is determined by the amount of energy the rubber can store to push the ball forward or upward once it leaves the topsheet. Hence a rubber doesn’t have a single throw angle, but a throw angle which is dependant and hence different based on the incoming ball and our stroke.

If a rubber still gets a throw angle rating it’s usually referring to its average throw on all shots. Hence the T64 was labelled as low throw, although it has a higher throw than the T05 if the impact is rather small. The Tenergy 05 gets a higher throw angle in general, although the T25 produces a higher throw on high energy balls, but fails to produce higher arcs on lower energy balls.

Beside the incoming balls energy and the stroke type, the sponge hardness, the sponge thickness, the pimple type and the tack of the topsheet play an important role.

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17 comments on “Throw Angle

  1. Stiga claims that the 45 degree angle of the
    carbon weave increases the throw angle.
    I always thought that was a function
    of the rubber only. Is this possible?
    Keep up the good work.

    • Hi vectoroperator,

      thanks for the motivation to carry on.

      I wrote an answer to your question in the blade design article in section 3, but I’ll state it here again – in the hope to make the point a bit more clear. If you haven’t already, I’d still recommend you to read the article.

      The 45° angle leads to a worse impact vibration reduction. This means the signal which gets to the blade is ‘fuzzier’ than the signal from the 90° layout. This in turn means that that the blade doesn’t reach as high peaks and is thus slower.

      Given you use the same rubber on the 45 and 90 degree version, the 90 degree version ‘catapults’ the ball back faster at the same spin amount and thus the arc(throw angle) gets lower – or phrased like Stigas claim: the 45 version has a higher throw.

      You’re of course right that the throw angle is based primarily on the rubber, but as hopefully seen, the blades speed can change the throw angle of your then complete setup.

      Formulated differently: A blade has no throw angle itself, it just provides speed. However, if someone claims a blade has a lower throw angle than another blade, he usually wants to say: If I test the two blades with the same rubber, than the ‘low throw angle blade’ is faster than the ‘high throw angle blade’.

      Hope that helps.

      P.S. If you want to buy one of the Carbonados, I’d like to advice against it. You can get the (imho) way better viscaria at a similiar prize. As usual, use the frequency analysis at your local shop to sort out the lemons ;).

      • Thanks so much for your response. You made several good points. My evolving style of play consist of lots of side spin shots. I’m a medium distance RPB penholder. I do very well off the table with two wing loops that send the opponent wide to the left and right.

        BIG QUESTION: Viscaria and many other blades don’t come as cp penhold. Can I still use them. Is getting the handle reshaped going to ruin the blade?

        FYI: Donic M3 gives me great arc and throw angle for my striking the ball on its descent. {Hence the Stiga Carbonado} 145 question. Presently I use Xiom Zetro Quad.

        Thanks again,

        John

        >

        • Hi again John,

          if by reshaping you mean simply cutting something off the handle then I think yes, it changes the blade for worse.
          The reason is the fact, that most blades have a hole in the centerply, located in the handle (see the blade design article). If you now cut the end off, you have an “open hole” and the waves of the blade aren’t reflected anymore but absorpted. Hence your blade would be slower and unstable. Since you cut off weight, you also change the center of mass.

          Thus I think it’s better to buy a CP version directly and don’t change a blade to it. If you like the carbonado because it’s one of the few 5+2 alc blades under 6mm thickness coming with a CP handle, go for it. It’s not a bad blade but imho overprized. Furthermore I’d like to recommend you to use the 190 version, the 145 version isn’t good imo.

          There are other blades with the requirements of 5+2 alc and a thickness of under 6mm. Out of the blue I can think of the Sanwei H9 Yellow Rose and the Palio Legend 1. Maybe you can get these blades in a CP version. I hope that helps.

        • VECTO, I use a lot of unmodified SH blades and I’m a Penhold player. I was reluctant at first because of coarse I’d rather have a CP version but I love my SH Photino and have never felt like the longer handle gets in the way. I also have a Nexy Qabod and Adidas blade in SH and I love playing with them as much as my CP’s. More so than my TBS in CP.

  2. There a good (although rather heated) conversation going on in table tennis daily, related to dwell time, hence also related to this post. 🙂

    • Hi dasrbego,

      I deleted the linked thread because it’s really of no value and sadly provides an example for all the things which can go wrong for a thread.

      Peter initially gave the (trivial) example, that the definition of some people of dwell time (time from first ball/bat contact to the moment where it loses this contact) and the statement “more dwell time -> more spin/speed” isn’t true – because you can simply lay the ball onto the bat, thus create an infinite dwell time and thus this would mean infinite spin and speed. Obviously this isn’t true and hence the statement is false given the dwell time definition. (More clear: Peters initial post is trivial and true)

      In his usual ‘diplomatic’ way, he finished his remark by (indirectly) calling everyone stupid, which – based on my experiences – doesn’t make people more eager to listen to your arguments.

      Then the thread goes on in the usual he said / she said argument chain – and in my opinion – nothing of value can be found in the whole following thread.

      Assuming you are Bego there, I’d like to give you one advice: stay away from responding to certain users. It’s amusing and shocking at the same time, how people which never reached a certain level in the relevant field accuse long time and proven engineers of don’t getting it right – of course contrary to them – without proving their different opinion either. Please don’t waste your precious time with arguing with them. Usually they just say, they did the math, then they throw in all halfway scientific sounding words they have ever heard without a particular order and finish with the statement that the OP is wrong, they are right and that the matter is more complicated than the dumbed down version the OP provided.

      Long story short, stay constructive and search for other constructive people(posters) to achieve a greater common good. This doesn’t mean you have to share the same opinion, but to deliver arguments for each side without getting on each others throat.

      Last but not least (and as usual), don’t feed internet-trolls (not referring to Peter here) by quoting their posts over and over.

      • Someone alerted me to this thread.
        “never reached a certain level in the relevant field accuse long time and proven engineers of don’t getting it right ”
        The fact you think I never reached a certain level shows you really don’t know who I am and I can do. You assumed I was just another TT idiot, the evidence is in the quote. I treated you all the same way you treated me.

        “Usually they just say, they did the math,”
        I can do the math. What is sad is no one else seems to be able to. If you don’t understand then how can you say what I said was half way scientific?

        I can post a long list of things I have done since much of is documented on the internet. There are lots of articles in engineering magazines.

        That thread never got off the ground. The moderators didn’t chastise grandpa for diverting the thread with his blade thickness crap. It all went down hill from there. I agree that there was nothing in that thread that was good after the first post and even I wanted the thread deleted because I had given up on you guys at that point.

        All these years of speculation about different topics could be put at an end but people posts distracting comments and side tracking the threads. I have learned my lesson. I am not going to post on TT forums any more because there is no intelligent life there. No one really cares and I make no money. People like NextLevel need to post there because it makes them feel important. I will save lots of time as you suggested. There are other forums that I post on that are engineering related and they help me make money. The TT forums are full of opinions but no facts. I like watching the videos.

        I can make up a new name or use a VPN to obscure my IP address but what is the point of that?

        I expect this to be deleted just like yogi deleted my posts when I made of fool of him on this same throw angle topic on myth years ago.

        • Hi again Peter,

          you got that in the wrong pipe. First, I did not write that you don’t hold a relevant degree. Even more funny, with your quoted sentence “…accuse long time and proven engineers of don’t getting it right ”, I meant that some people accuse people like you(proven engineers) of don’t getting it right. You were one of the qualified people I had in mind ….

          If you reread my answer to bego again, I hope you believe me and my intention. If not, then I can’t change it.

          My “do the math” remark was about the fact, that everyone just states “do the math” and that’s usually the whole “argument”. As written, this leads to nothing but name calling as the rest of your thread shows. Again, I said you were right with your initial post, but called you out for your undiplomatic way of presenting your idea. If you directly or indirectly insult people who don’t agree with you of just being too stupid, you wont get many people out of the thread who say: Yes, Peter might be right.

          Regarding the problem with tt forums: That’s the reason why I made a personal blog. I can write long articles and lay down my thoughts and arguments to the best of my knowledge. If people now decide that I’m wrong, nuts or both they can tear my article apart in one of the forums. However, people who like the presented ideas can come back to my site if they want. Since my viewer count continually increases even for older articles I hope to provide something for some people. As the overused facebook quote roughly says: You can’t make a million friends without a few enemies.

          Why don’t you do the same? Make a blog, write some of your thoughts down (without (instantly/indirectly) calling people who disagree idiots ;)) and see if you can help some people to get a better understanding of tt. Im sure, that some people could profit from your knowledge and your access to expensive laboratory equipment. Maybe you can make some rubber or blade tests.

          Well, that’s just my (hopefully) constructive approach to provide something for someone out there.

          Edit and PS:
          Remark to other readers: This post neighter means that I agree with everything Peter has said in any forum at any time nor that I disagree. I just stated that he is indeed a proven engineer. Nothing more, nothing less. Oh and incase Nextlevel reads this, just because Peter doesn’t particularly likes you, that doesn’t mean I necessarily agree with him ;).

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  5. The article is pretty good but the green line ( velocity vector ) should have been broken down in the normal component and tangential component. The tangential component would shows that not all the tangential impulse is converted to spin. Some IS converted to speed.

    +1 for showing that balls with the same initial angle can have different arcs and distances.

    This article doesn’t use the term throw or throw angle etc.
    The article is old but the physics haven’t changed.
    http://www.ittf.com/ittf_science/SSCenter/docs/199408014%20-%20%20Tiefenbacher%20-%20Impact.pdf

    I would prefer comparing the tangential to normal COR as in the Tiefenbacher document instead of using the term throw angle since it is hard to tell what people are really talking about. Also, people aren’t calibrated test equipment.

    Another favorite website about spin and collisions
    http://www.physics.usyd.edu.au/~cross/

    • Hi Peter,

      thanks for the extensive feedback.

      I already knew your linked papers/sources but for further reading they might be interesting for other readers aswell.

      You’re ofcourse right with stating that the tangential impulse isn’t completely converted to spin but speed aswell – just as stated in the Tiefenbacher paper ;).
      I omitted this little fact because it might have caused more confusion than clarifiying the matter of how the rebound roughly works.

      As you’ve said, throw is a pretty fuzzy term and not suited for rigorous acedemic studies. But I tried to explain the phenomenon with the vocabulary of layman people without losing too much exactness.
      Since we – as you’ve stated aswell – have no exact values I think we wouldn’t benefit too much by using the correct terms but possibly lose many readers who want to understand the issue.
      Atleast that’s my approach, if someone wants to make rigorous papers with testing equipment I would be the first to happily read it :).

      Nice to hear that I’m not the only one reading such papers :). -Yoda

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