Q: Aspect Ratio & Game 11 (3)

Q: Aspect Ratio & Game 11
by Andy 18 years ago

Re: Q: Aspect Ratio & Game 11
by John 18 years ago

Re: Q: Aspect Ratio & Game 11
by Andy 18 years ago

Re: Q: Aspect Ratio & Game 11
by Justin Roy 18 years ago

The following message (subject: Re: Q: Aspect Ratio & Game 11) was posted by Andy, on 10/24/2006 10:25:23 AM:

Thanks, John. But, with your explanation on "Aspect Ratio", I feel that defensive players (or usually called "choppers") have been treated unfairly!! Imagine that attacking players can have much better equipment (even with "speed glue"), but choppers have limited aspect ratio for their long-pip rubbers.

Also, reasons given by Mr. Rufford Harrison (from ITTF) written for Paddle Palace (enclosed) are unreasonable. He said "table tennis equipment is becoming too high-tech". If sports equipment is not allowed to be too high-tech, Tiger Woods would not win 13 majors with his NIKE balls & clubs!

I totally disagree with ITTF on aspect ratio, and I wonder if other viewers see the way I see.

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Source: http://www.paddlepalace.com/ArticleHowTo/longpips.htm

The New ITTF Long Pips Rule
By Rufford Harrison, ITTF Equipment Chairman
written for Paddle Palace

I’ve said for many years that table tennis equipment is becoming too high-tech. Years ago we didn’t have to bother about coefficients of friction, transverse elasticity, trichloroethylene, dynamic properties.... Now we do, and the latest one is “Aspect Ratio”. It’s a measure of pips length. If I have pips that are 1.5mm long and you have 2mm pips, yours are longer than mine, and are more likely to be banned, right? Not quite; it’s not that simple.

Rightly or wrongly, there is a consensus within the ITTF Council that long pips (I’ll define that in a moment) are bad for the sport. And there is a rationale for that thinking. Let’s switch for a moment from rubber to an ordinary pencil. If you compress a pencil along its length with a gradually increasing force, it will eventually break: it will snap in a quite unpredictable direction. Now let’s look at pips. Suppose you have a pip that’s 1mm long, but 2 mm wide, and press it along its axis. It will compress a little in that direction, and will bulge out a little around its circumference. But you have a different situation if you reverse those dimensions: If the pip is 2mm long but only 1mm in diameter and you compress it, it will initially, at very low force, compress slightly, but as the force increases it will suddenly kink. Like the pencil breaking, it will kink in a completely unpredictable direction. It is that unpredictability that is considered to be inimical to good table tennis. Many believe that it shortens the rally.

But it isn’t just the length of the pip that affects its unpredictability. Earlier I said that my pips were 1.5mm long and yours are 2mm. Will yours kink more than mine? Not necessarily. I neglected to tell you that, while my pips were only 0.75mm in diameter, yours were 3mm. So, my pips will kink, whereas your somewhat longer pips won’t; yours will simply compress, being too wide to kink. So if it isn’t strictly length that governs whether the pips will kink unpredictably, what is it?
It is the aspect ratio, which is the height of the pip divided by the diameter. If the height is significantly greater than the diameter, the pip can kink when a ball is pressed into it--the effect is very easy to detect simply by holding a ball between finger and thumb and pressing it into the rubber--whereas if it is wider than it is high, it cannot.

Sensing that extremely long pips could be detrimental to the sport, some years ago the ITTF decreed that nothing “longer” than what was already on the market would be authorized. We defined that “length” by the aspect ratio. Since the maximum aspect ratio available at that time was 1.3, that became our upper limit. In other words, no height greater than 1.3 times the diameter would be accepted.

But at that aspect ratio, pips can and do definitely kink. So earlier this year the German Association commissioned some research, which concluded that the kinking effect stops at an aspect ratio of about 1.1. Accordingly the Germans proposed to the ITTF Council, in its meeting in May, that aspect ratio be limited to 1.1. And Council accepted the proposal.

The situation, then, is that beginning immediately, no new pips-out racket covering will be accepted with an aspect ratio greater than 1.1. Beginning on July 1, 1999, those currently on the authorization list will have to be withdrawn.

You need to know which rubber sheets will be legal, of course. The latest edition of the ITTF authorization list, almost seven hundred trademarked types, has just gone to press. It is being distributed to all Associations. However, you’ll not know definitely which brands will be legal after July of 1999 until we hear from the suppliers. One could presume that something with an aspect ratio of 1.3 would have to be withdrawn completely. But if it is, say, 1.12, then the supplier could perhaps make only a minor modification, say to 1.08, and you could use the rubber with virtually no discernible change in performance. So watch this space, and we’ll keep you posted.

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