OOAK Table Tennis Forum


A truly International Table Tennis Community for both Defensive and Offensive styles!
Live Table Tennis Videos Table Tennis News Live OOAK Forum Links About OOAK Table Tennis Forum OOAK Forum Memory
It is currently 26 May 2018, 21:28


Don't want to see any advertising? Become a member and login, and you'll never see an ad again!



All times are UTC + 9:30 hours




Post new topic Reply to topic  [ 216 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7 ... 15  Next
Author Message
PostPosted: 27 Aug 2014, 09:24 
Offline
Full member

Joined: 25 Aug 2014, 19:55
Posts: 57
Location: Munich, Germany
Has thanked: 2 times
Been thanked: 32 times
Debater wrote:
Torsten wrote:
mynamenotbob wrote:
What about how current plastic balls people purchase and get used to playing now will become illegal in 2016 due to weight?

No worries here. They will not become illegal. According to our requirements, all ball packages have a datecode reflecting their time of production. In the random testing programme, the tolerance limits applied by the ITTF lab will then depend on the date of ball production. If produced before January 1, 2016 --> wider limits, even if the test is later. If produced after January 1, 2016 --> original limits.
This means that approval is not withdrawn simply because we cross the date line.


Thank you for clarifying this... to a degree. Approval will not be withdrawn, however, just to remove any doubts or room for misunderstanding, there is a world of difference between still authorised and suitable for use in ITTF tournements. So, please confirm if

1. all plastic balls produced pre January 2016 will be allowed to be used in ITTF tournements post January 2016 or
2. no plastic ball produced pre January 2016 will be allowed to be used in ITTF tournements post January 2016 or
3. Some plastic balls produced pre January 2016 will be allowed to be used in ITTF tournements post January 2016 - and if this option is true, how will we know which ones

This is important because where the ITTF lead, national association invariably follow.

Thanks


I cannot confirm any of 1-3 (however betting on 1., of course with prescribed brand, as usual), but it is the ITTF - National link which is not quite clear to me here. For example, ITTF World Tour events are played with a specific ball brand, due to sponsoring contracts. But the national assocations do not normally prescribe the use of exactly that ball brand, do they? Because if so, all other balls would not be on the market. (The German association for example does not even take over the obligatory plastic ball use lower than league #2.)

For the same reason, I cannot imagine a national association restricting the use of approved balls to any date code just because ITTF would decide so for any ITTF-specific reason for ITTF events. Which -as to my knowledge- is not planned and would perhaps raise some practical questions. And logical ones, because the spec release was agreed only after the professionals' feedback that it is a tiny issue for them.

PS to next post: We also have these funny comments about decisions being "illegal" on the German forum. I assume from the same user. As far as I could read, no one has ever understood the arguments for this claim, so no reply to that (it's not a technical issue anyway).


Top
 Profile  
 

PostPosted: 27 Aug 2014, 09:47 
Offline
Super User

Joined: 06 Dec 2008, 10:22
Posts: 624
Has thanked: 0 time
Been thanked: 6 times
Torsten wrote:
The German association for example does not even take over the obligatory plastic ball use lower than league #2.


This is not true.

In the German leagues there is no "obligatory plastic ball use" at all. The 1st league made a voluntary decision among themselves and in the 2nd league there is a team using a celluloid ball for their home matches.

This is easy to prove. Here is the list of equipment the 2nd league uses (http://dttb.click-tt.de/temp/2014082702 ... ialien.pdf). The team TTC Ruhrstadt Herne uses "Stiga Optimum Zelluloid" ball.


Top
 Profile  
 
PostPosted: 27 Aug 2014, 09:57 
Offline
Super User

Joined: 06 Dec 2008, 10:22
Posts: 624
Has thanked: 0 time
Been thanked: 6 times
Torsten wrote:
Debater wrote:
So, please confirm if
1. all plastic balls produced pre January 2016 will be allowed to be used in ITTF tournements post January 2016 or...

I cannot confirm any of 1-3


But you have already said the opposite a day ago:
Torsten wrote:
This means that approval is not withdrawn simply because we cross the date line.


"Approval is not withdrawn" is equal to "will be allowed to be used".

Why exactly did you say a thing and then deny it when asked directly?


Top
 Profile  
 
PostPosted: 27 Aug 2014, 10:08 
Offline
Super User

Joined: 06 Dec 2008, 10:22
Posts: 624
Has thanked: 0 time
Been thanked: 6 times
Torsten wrote:
no one has ever understood the arguments for this claim,


I thought any sane person had an understanding of the notion of "illegal". But I can explain it to you in a few words. Illegal means in violation of the rules. Since there are rules in the Chapter 1 of the ITTF Handbook (Constitution) about how rule changes may be legally made, those rules can be violated. Then such rule changes made in violation of the ITTF Constitution are illegal. Get it? Of course you do. I am absolutely sure you are fully aware of which exactly changes are illegal. But let us stick to the balls issue here.


Top
 Profile  
 
PostPosted: 27 Aug 2014, 15:35 
Offline
Goes to 11
Goes to 11
User avatar

Joined: 13 Jan 2014, 20:27
Posts: 6489
Has thanked: 1 time
Been thanked: 778 times
Ah. So Palio seamless = XSF seamless. I'll go get some perhaps..

Just out of curiosity - what's the difference between two and three star balls? I notice the Palion 2* don't have "ITTF Approved" on them, while the 3* do.

Iskandar


Top
 Profile  
 
PostPosted: 27 Aug 2014, 18:29 
Offline
Full member

Joined: 25 Aug 2014, 19:55
Posts: 57
Location: Munich, Germany
Has thanked: 2 times
Been thanked: 32 times
iskandar taib wrote:
Ah. So Palio seamless = XSF seamless. I'll go get some perhaps..

Just out of curiosity - what's the difference between two and three star balls? I notice the Palion 2* don't have "ITTF Approved" on them, while the 3* do.

Iskandar


It is not a difference which is coupled to technical properties. The number of stars does not indicate any specific tolerance - it is more or less a pure branding / advertising issue, ie suppliers indicate the quality level. The only "official" requirement being that the number of stars must not exceed 3. Theoretically, a manufacturer could have approved a 2-star-brand, but normally they use these to indicate practise-level balls, I think.


Top
 Profile  
 
PostPosted: 27 Aug 2014, 18:52 
Offline
Full member

Joined: 25 Aug 2014, 19:55
Posts: 57
Location: Munich, Germany
Has thanked: 2 times
Been thanked: 32 times
Smartguy wrote:
Torsten wrote:
Debater wrote:
So, please confirm if
1. all plastic balls produced pre January 2016 will be allowed to be used in ITTF tournements post January 2016 or...

I cannot confirm any of 1-3


But you have already said the opposite a day ago:
Torsten wrote:
This means that approval is not withdrawn simply because we cross the date line.


"Approval is not withdrawn" is equal to "will be allowed to be used".

Why exactly did you say a thing and then deny it when asked directly?


This is a technical question, so no problem to answer it: The statements are dealing with different aspects, so do not oppose each other.

Statement #1 (bottom of your quotes) is, that balls found exceeding the original tolerances in random testing after Jan 1, 2016 will not lead to suspension of the brand from the List of Approved Balls if they were produced before that date. This is my report about the current situation of decisions.
Statement #2 (top of your quotes) is that ITTF will for every of "their" tournaments pick a specific ball brand from the approved ones, as any tournament organizer does, and that it is not me to confirm whether or not balls produced before Jan 1, 2016 will be used for these specific tournaments later on (and also not me to discuss who will be deciding that).

#1 means: "will be allowed to be used" (you are right here), #2 means "will (or will not) be used in specific tournaments".


Top
 Profile  
 
PostPosted: 28 Aug 2014, 20:33 
Offline
OOAK Super User
OOAK Super User

Joined: 16 Oct 2007, 13:44
Posts: 2907
Location: Houston
Has thanked: 7 times
Been thanked: 139 times
Shouldn't you be mandating that companies put an actual date of production stamp on the box so that buyers in the future will know what they are getting? By that, I mean an actual date, not some code where you need a secret decoder ring to know what it means. When 2016 comes, I for one would want to know that I was getting good balls, not some of the really bad ones that are being sold now with ITTF approval stamps. I have bought lots of these balls and have made a good-faith effort to adapt, but the problems, especially with the seamed balls I have seen so far, are really frustrating. My experience so far has been, to my profound surprise, that the current seamless balls are better.

_________________
Butterfly Viscaria Black tag
2.2 mm Nexy Karis M on FH and BH


Top
 Profile  
 
PostPosted: 29 Aug 2014, 08:39 
Offline
OOAK Super User
OOAK Super User
User avatar

Joined: 02 Mar 2010, 19:16
Posts: 1400
Has thanked: 0 time
Been thanked: 62 times
Torsten wrote:

#1 means: "will be allowed to be used" (you are right here), #2 means "will (or will not) be used in specific tournaments".


Based on ITTF precedents, I am willing to bet any amount that it "will not be used" in any ITTF sanctioned tournaments by then even if "it will be still allowed". Shall we simply call it a "soft" ban instead of a "hard" ban? ;)


Top
 Profile  
 
PostPosted: 29 Aug 2014, 23:04 
Offline
Full member

Joined: 25 Aug 2014, 19:55
Posts: 57
Location: Munich, Germany
Has thanked: 2 times
Been thanked: 32 times
Baal wrote:
Shouldn't you be mandating that companies put an actual date of production stamp on the box so that buyers in the future will know what they are getting? By that, I mean an actual date, not some code where you need a secret decoder ring to know what it means. When 2016 comes, I for one would want to know that I was getting good balls, not some of the really bad ones that are being sold now with ITTF approval stamps. I have bought lots of these balls and have made a good-faith effort to adapt, but the problems, especially with the seamed balls I have seen so far, are really frustrating. My experience so far has been, to my profound surprise, that the current seamless balls are better.


The sentiment within ITTF to do so may increase if it turns out that this first issue ever where the production date becomes of public interest, will not be the last one. I hope it will, though - and therefore, as a first step, I have asked the PIT (Polyball Intelligence Team) to decode the current version. It turned out that the code is primitive and not very hard to crack (did you expect anything else of us? ;) )

The datecode has four letters, the last two are the year or production:
AD = 2014
AE = 2015
AF = 2016
AG = 2017

and so on with AH, AI, BA, BB, BC etc.

So basically, scaled to your personal feeling, up to AE are the bad guys, from AF are the good guys. See also chapter C.4 of the T3.


Top
 Profile  
 
PostPosted: 01 Sep 2014, 10:11 
Offline
Super User
User avatar

Joined: 10 Jun 2007, 09:24
Posts: 431
Location: Universe
Has thanked: 15 times
Been thanked: 33 times
Image

C.4 Date Code, original document.

You are well adviced to not purchase product with early date of origin, before September2014.
ALL the early products is merely preliminaries, with poor quality.


Top
 Profile  
 
PostPosted: 01 Sep 2014, 20:54 
Offline
Goes to 11
Goes to 11
User avatar

Joined: 13 Jan 2014, 20:27
Posts: 6489
Has thanked: 1 time
Been thanked: 778 times
roundrobin wrote:
Torsten wrote:

#1 means: "will be allowed to be used" (you are right here), #2 means "will (or will not) be used in specific tournaments".


Based on ITTF precedents, I am willing to bet any amount that it "will not be used" in any ITTF sanctioned tournaments by then even if "it will be still allowed". Shall we simply call it a "soft" ban instead of a "hard" ban? ;)


I don't see how it could be otherwise. ITTF can't mandate what anyone chooses to use at their own club/tournament/basement, so there's no ball police that will show up if you play with stuff that's not used at ITTF tournaments. Or, for that matter, isn't on ITTF's approved list at all.

Iskandar


Top
 Profile  
 
PostPosted: 10 Sep 2014, 00:41 
Offline
Senior member

Joined: 20 Dec 2012, 07:57
Posts: 181
Location: Tennessee, USA
Has thanked: 0 time
Been thanked: 21 times
Torsten, can you tell us a little more about the random testing of retail samples that you describe on page 11 of your presentation? In particular, has this testing already begun, or will it indeed begin before 9/21 (end of summer, 2014) as described in your document? If any testing has begun, can you please tell us how many different brands have been randomly tested and if there are any brands that did not pass all ITTF published standards and are due to have their approvals suspended?

In my own non-professional testing of 8 different brands of poly balls, I've found 4 brands that did not meet ITTF published standards. Here's the results of my tests:

Brand/Model---Stars--Avg Dia--SD Dia--Hi Dia--Lo Dia--Avg Wgt--SD Wgt--Hi Wgt--Lo Wgt----#--Seam?
Double Fish-------3-----40.19----0.034--40.32---40.12----2.73-----0.009----2.75----2.70-----49----Y
Double Fish-------1-----40.15----0.035--40.28---40.00----2.73-----0.017----2.76----2.67-----50----Y
Nittaku SHA-------3-----40.16----0.052--40.35---40.03----2.79-----0.019----2.82----2.75-----36----Y
Joola Super P------3-----40.16----0.048--40.24---40.02----2.79-----0.011----2.80----2.76-----24----Y
Donic 40+--------3-----40.18----0.065--40.33---39.88----2.79-----0.020----2.84----2.75-----24----Y
Cornilleau P-Ball---3-----40.13----0.056--40.26---40.00----2.79-----0.037----2.89----2.74-----24----Y
XuShaofa Sports---3-----40.29----0.028--40.35---40.24----2.80-----0.051----2.95----2.74-----24----N
Palio-------------3-----40.21----0.027--40.30---40.16----2.78-----0.022----2.85----2.75-----24----N
Nit. Prem. Cell-----3-----39.70----0.040--39.81---39.54----2.75-----0.012----2.77----2.74-----24----Y

From the above results, we can see that:

Two brands did not meet the published standard for Weight Regularity of 0.03g--Cornilleau (0.037) and XuShoafa Sports (0.051).
Four brands surpassed the upper weight limit of 2.82g of any one ball--Palio (2.85 with 2 balls over), XuShoafa (2.95 with 4 balls over), Donic (2.84 with 1 ball over), and Cornilleau (2.89 with 4 balls over).
One brand was less than the minimum diameter allowed (40mm)--Donic (39.88).
One brand was over the Size Regularity limit of 0.06mm--Donic (0.065)

Now I realize that my personal tests are not official, and they were not conducted in a laboratory environment, but if the ITTF indeed found such results in their own tests, would those approvals face suspension as described in your document?

In particular, can you explain this statement in T3--Statistical "outliers" are ignored when calculating means and standard deviations, but all values within a normal distribution but outside the permitted limits are included. What determines an outlier? How many outliers are permitted in the samples tested?

Your presentation includes the following statement on page 11 in reference to the random testing program--Repeated failure to meet the tolerance ranges is resulting in suspension of the approval. What happens to the approval after one failure? Two failures? Three failures? Exactly how many repeated failures is one brand allowed?

Besides my lack of the proper scientific laboratory environment, is there anything else I missed in my informal testing, and my calculations of results from those tests, that will allow me to obtain more accurate results?

Thank you for participating in this forum and enlightening us on how this random testing program is structured, conducted and what happens to brands that fail random testing.

Larry


Top
 Profile  
 
PostPosted: 10 Sep 2014, 01:11 
Offline
Goes to 11
Goes to 11
User avatar

Joined: 13 Jan 2014, 20:27
Posts: 6489
Has thanked: 1 time
Been thanked: 778 times
larrythoman wrote:
Brand/Model---Stars--Avg Dia--SD Dia--Hi Dia--Lo Dia--Avg Wgt--SD Wgt--Hi Wgt--Lo Wgt----#--Seam?
Double Fish-------3-----40.19----0.034--40.32---40.12----2.73-----0.009----2.75----2.70-----49----Y
Double Fish-------1-----40.15----0.035--40.28---40.00----2.73-----0.017----2.76----2.67-----50----Y


Interesting. The one star balls are just slightly above the three star balls in terms of diameter variation and weight variation. In neither case do the balls depart from ITTF specs. So this tells me that Double Fish is capable of holding much tighter tolerances than mandated by ITTF (no big surprise - look at how uniform celluloid balls are, even from brand to brand) and apparently balls that fall outside the very tight company standards get sold as one star. Which is why I can't really tell the difference!

Quote:
XuShaofa Sports---3-----40.29----0.028--40.35---40.24----2.80-----0.051----2.95----2.74-----24----N
Palio-------------3-----40.21----0.027--40.30---40.16----2.78-----0.022----2.85----2.75-----24----N


And I'm pretty sure these two come off the same assembly line.

Iskandar


Top
 Profile  
 
PostPosted: 10 Sep 2014, 23:41 
Offline
Full member

Joined: 25 Aug 2014, 19:55
Posts: 57
Location: Munich, Germany
Has thanked: 2 times
Been thanked: 32 times
larrythoman wrote:
Torsten, can you tell us a little more about the random testing of retail samples that you describe on page 11 of your presentation? In particular, has this testing already begun, or will it indeed begin before 9/21 (end of summer, 2014) as described in your document?

Yes, the random testing started in September, because now we have a reasonable amount of retail stock to buy anonymously from (as planned, we try to compile a sample from different lots out of different countries and preferrably different continents).

Quote:
If any testing has begun, can you please tell us how many different brands have been randomly tested and if there are any brands that did not pass all ITTF published standards and are due to have their approvals suspended?

As to #1, the random testing applies to all brands (poly and celluloid), therefore the amount of tested items is now rising and therefore I can not yet tell, how fast the whole thing will actually go.
As to #2, no. Failure of meeting the ITTF standards will become public only when, after the third failed test (see last question at bottom), the brand is suspended from the List of Approved Balls.

Quote:
In my own non-professional testing of 8 different brands of poly balls, I've found 4 brands that did not meet ITTF published standards. Here's the results of my tests:
<Data sheet>
From the above results, we can see that:
Two brands did not meet the published standard for Weight Regularity of 0.03g--Cornilleau (0.037) and XuShoafa Sports (0.051).
Four brands surpassed the upper weight limit of 2.82g of any one ball--Palio (2.85 with 2 balls over), XuShoafa (2.95 with 4 balls over), Donic (2.84 with 1 ball over), and Cornilleau (2.89 with 4 balls over).
One brand was less than the minimum diameter allowed (40mm)--Donic (39.88).
One brand was over the Size Regularity limit of 0.06mm--Donic (0.065)

Now I realize that my personal tests are not official, and they were not conducted in a laboratory environment, but if the ITTF indeed found such results in their own tests, would those approvals face suspension as described in your document?

For weight, 1 out of 24 balls failing is allowed (see T3). Apart from that, Yes. Provided our lab would find such results, these would be failures in the sense of ITTF procedures. After the third failure, the brand is suspended without further notice.

Quote:
In particular, can you explain this statement in T3--Statistical "outliers" are ignored when calculating means and standard deviations, but all values within a normal distribution but outside the permitted limits are included. What determines an outlier? How many outliers are permitted in the samples tested?

An outlier is a value that is so unlikely that it is regarded as an error in measuring, data capture or also an absolute singularity in the production line, not representing the "real" mass production. Such a value is derived by taking the values of, say, 1000 balls, calculating the mean and variance of a Gaussian Normal Distribution that fits these observations best - and then determining the value that will be exceeded with only an extremely low probability (usually the so-called "3 sigma interval"). For the current T3 this was done some years before I started. Since I started in May 2013, I have never seen an outlier in the lab results.

Quote:
Your presentation includes the following statement on page 11 in reference to the random testing program--Repeated failure to meet the tolerance ranges is resulting in suspension of the approval. What happens to the approval after one failure? Two failures? Three failures? Exactly how many repeated failures is one brand allowed?

After the first failure a second sample will be tested (of course not after 2 years, but shortly) and the brand owner will be informed about that. The same happens after the second failure. If this third test then fails again, the brand will be suspended.

Quote:
Besides my lack of the proper scientific laboratory environment, is there anything else I missed in my informal testing, and my calculations of results from those tests, that will allow me to obtain more accurate results?
Nothing I would see at a first glance. There is no "trick" behind the process description in T3, especially in weight and diameter measurement. It's indeed mostly a matter of equipment.

Quote:
Thank you for participating in this forum and enlightening us on how this random testing program is structured, conducted and what happens to brands that fail random testing.

Larry

You're welcome. :)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 216 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7 ... 15  Next


Don't want to see this advertisement? Become a member and login, and you'll never see an ad again!



All times are UTC + 9:30 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Copyright 2012 OOAK Table Tennis Forum. The information on this site cannot be reused without written permission.

Powered by phpBB® Forum Software © phpBB Group




Don't forget to 'LIKE' our forum on Facebook if you enjoy the content: