August 13, 2012

Old Glue vs New Glue

Until a few years ago, two different kinds of glue were used by table tennis players; regular attaching glue which only made sure that the rubbers stuck to the blade, and speed glue (also called "booster" or "tuner") which affected the speed properties of the rubbers. In 2007, the ITTF banned both types.

Why the old kind of glue was banned

The old glue was banned because it contained VOC, volatile substances, that can be bad for both nature and humans. What damage that this old kind of table tennis glue has actually done is not clear, but supposedly it could harm mucous membranes when breathing it in, and even cause cancer if you're exposed to high amounts. But the suspicions towards the glue has existed for a long time, and in tournaments players haven't been allowed to perform gluing inside the venue, so the risks have probably been extremely low even for active players unless they've regularly stuck their nose in their glue cans.

The unhealthy substances also usually go away after 2-3 days, so this old kind of glue can still be used by manufacturers when they make pre-assembled rackets - simply because the problem is gone before the product is even sold. And those rackets would probably pass a glue test performed by a referee. There is not really any point in trying to exploit this fact though, since the booster effect disappears within a matter of hours.

How Speed Glue Works

The speed glue does two things. The first is expanding the sponge rubber, which makes it stretch the chemically unaffected top layer rubber which therefore gets more elastic. The second is making the sponge softer, which makes the ball come as close to the wood as possible during hard hits. (That's why hard hits produce more of a woody "click" noise when using tuner - and that's why the whole thing is also called "click effect".) This means that your choice of blade will matter more than usually if you're an offensive player. Unless you use Chinese rubbers, which most of the time have a hard sponge rubber that won't be noticeably affected by booster. If you're a defensive player, speed glue might not do you any good at all. Then even glue sheets can be enough.

How VOC glue was used, varied a little bit. Some people chose to only use the speed glue, since it did stick the rubbers to the blade. Some chose to let the speed glue get into the rubber before applying regular glue. Some simply just mixed the two kinds into one can. Some practically drowned the sponge rubbers so they wouldn't stick to the blade without prolonged pressure. Some put on a sufficient amount of glue and waved the racket towards the rubber so they would both look dry within a minute or two and stick immediately. In the end, most methods probably led to the same result.

After the ITTF had banned glue that contained VOC and glue that affected the rubbers' properties, the manufacturers developed a new, water-based, glue - and suddenly some things had changed.

Water-Based Glue - Applied differently

The old glue is thin, and applied with a brush. The rubber should be attached to the blade when the glue has dried enough to not look glossy anymore, and most of the time the rubber sticks and can be used immediately.

The new glue, on the other hand, is thick and applied with a sponge to even it out (because a brush will make thick trails which can cause bumps in the rubber). The rubber should be attached to the blade when the glue has turned from white to transparent, and then be put in pressure for about half an hour before you can be sure it stays on the blade.

The opinions about the application differs all over the web. Some say it doesn't matter much whether you use a brush or a sponge, while others say using a brush can ruin the rubbers permanently. I also read somewhere that water-based glue can ruin rubbers that have already been used with booster, by expanding both the rubber layers and cause permanent "bubbles".

Slow application and no improving any properties, - are there any advantages...?

Advantages with Water-Based Glue

Earlier, many people re-glued with tuner just for the fun of it, even if they didn't need it. Much money has been wasted on it, and now that's over. Instead, the manufacturers develop rubbers that already have the wanted properties when you buy them, and maybe that will lead to a funnier game for the same price in the future.

Table tennis racket
Water-based glue on rubber and blade
Another advantage is the possibility to remove the glue itself. The picture to the right shows a used racket that I recently bought. Since I'm mainly a collector nowadays, I always remove the rubbers shortly after I get a racket so they won't collect dust. This time I didn't even have to use acetone, because the rubbers just slid right off (even though they were attached strongly enough for play). Then I could easily peel all of the rubber away - from both blade and rubber - with my fingers in 5-10 minutes. Great for collectors who want to try their old blades without affecting the wood! A little different from the VOC glue, which sank into the blade, and that you might remove from the rubbers with gasoline...

Tell about your experience with water-based glue!

If you've used the new kind of glue, and would like to share your experiences, please write a comment below! If you know any differences between different manufacturers' glue, please be specific!

August 11, 2012

Custom Blades with Legal Shapes

We recently went through the different grips used in table tennis - but that post actually doesn't tell the whole truth. The handshake grip, the Chinese penhold grip and the Japanese penhold grip are the most common grips used all over the world. But since the rules allow any shape of the blade and its handle, some people choose more unusual variants or modify and experiment their way to optimized playing. What many people don't know, is that blades no longer need to be approved by any organization before being used in tournaments, as long as they follow the ITTF's racket regulations. You can even change the shape of a retail blade yourself as you wish, or replace the whole handle.

Below, some pictures of modified and custom made blades - all legal to use in professional tournaments (assuming that they contain the right amount of real wood, and so on). But one thing worth knowing, is that it is not allowed to use more than one rubber sheet per side, or to cut it in a way that a referee can't identify it or tell that it's approved by the ITTF.

Blade with wide handleBlade with gun grip (1)

Blade with gun grip (2)Blade with gun grip (3)

Scull bladeCustom C-pen (1)

Custom C-pen (2)Custom C-pen (3)

August 8, 2012

Different Grips in Table Tennis

Most people who have a slight interest for table tennis, have learned that there are two ways to hold the racket. The first is the "handshake" way, and the second is the "penhold" way. The both names are pretty self-explanatory. When using a handshake racket, you grip the whole handle with your hand so the blade is pointing upwards. When using a penhold racket, the blade is pointing downwards and only your thumb and index finger are gripping around the handle, supporting it against the other fingers.

The penhold grip is mostly used by Asian players, while the handshake grip is the most common grip in the rest of the world. This is of course the result of tradition - and it's preserved by manufacturers that focus on only one of the player types. 

Though, there are several big manufacturers that let their customers choose which handle they want on their blade. Stiga has offered six different shapes for many years now, - five different for handshake players and one for the Chinese penholders. And there was a period in the 80's when they offered one unusual type called the Japanese - or Korean - penhold. They only offered it on one of their four different pro blades, and barely promoted it at all in Europe because of extremely low demand. There still are some top-level players who use the Japanese penhold, though. But what is this mysterious "J-Pen"?

Table tennis rackets
1) Handshake 2) C-pen 3) Handshake 4) J-pen
All used in one Olympic game 2012
The shape of the hitting surface on a handshake blade can vary, but usually they look like on the image above. A C-pen can vary a little bit more but are usually very alike a handshake blade. A J-pen leaps out properly, though. It's always significantly longer, and has almost a rectangular hitting area. Often even longer than the rubbers are when they're new and uncut, so there can be some space between rubber and handle on the forehand side where the player can have his fingers.

Practical differences between Handshake, Chinese penhold and Japanese penhold

It might look like the C-pen and the J-pen blades are held the same way, but that's not completely true. A C-pen player typically has the side of his middle finger against the backhand side of his blade, while a J-pen player has the inside of the three fingers against the blade. This brings different advantages and disadvantages.

The biggest difference between using a handshake blade and using an Asian grip blade, is that the Asian blades don't bring any transition between forehand and backhand. That transition makes it difficult for the handshake player to hit shots near the body on the forehand side. The Asian grip player can also hit shoulder-high shots on the forehand with more natural movements while it's easier on the backside for the handshake player. Deep shots on the backhand side is also easier for the handshaker since he doesn't have to twist his arm around and therefore has better reach.

The Japanese penholder has one extra advantage; The blade becomes more of an extension of the arm on the forehand side, which encourages more of a natural swing with high speed and proper spin. But this can be compensated with the length of the blade, which can make it unpractical near or over the table.

Which grip should I use?

Definitely the one that feels the most natural to you. In Europe, the handshake grip is properly established, but in Asia a lot of professional players use it nowadays too. For example 2011 World Champion and 2012 Olympic Champion, Zhang Jike - or defensive player Joo Se-Hyuk, who actually put up a great game against Jike in the team play after the singles final!

Joo Se-Hyuk
Joo Se-Hyuk from South Korea made Zhang Jike work for
the win in the last table tennis game in the 2012 Olympics.
Without the handshake racket, his defensive
play style probably wouldn't work so well.

August 7, 2012

The Racket - Rules and Ways to Exploit Them

Legal racket

As you might have seen in the Olympics lately, the players receive their rackets from the referees before a game starts. This because the rackets are checked for illegal material, substances, and so on.

The following are the regulations that every racket needs to follow (2011/2012)
  1. The racket may be of any size, shape or weight but the blade shall be flat and rigid. 
  2. At least 85% of the blade by thickness shall be of natural wood; an adhesive layer within the blade may be reinforced with fibrous material such as carbon fibre, glass fibre or compressed paper, but shall not be thicker than 7.5% of the total thickness or 0.35mm, whichever is the smaller. 
  3. A side of the blade used for striking the ball shall be covered with either ordinary pimpled rubber, with pimples outwards having a total thickness including adhesive of not more than 2.0mm, or sandwich rubber, with pimples inwards or outwards, having a total thickness including adhesive of not more than 4.0mm. 
  4. Ordinary pimpled rubber is a single layer of non-cellular rubber, natural or synthetic, with pimples evenly distributed over its surface at a density of not less than 10 per cm2 and not more than 30 per cm2. 
  5. Sandwich rubber is a single layer of cellular rubber covered with a single outer layer of ordinary pimpled rubber, the thickness of the pimpled rubber not being more than 2.0mm. 
  6. The covering material shall extend up to but not beyond the limits of the blade, except that the part nearest the handle and gripped by the fingers may be left uncovered or covered with any material.
  7. The blade, any layer within the blade and any layer of covering material or adhesive on a side used for striking the ball shall be continuous and of even thickness. 
  8. The surface of the covering material on a side of the blade, or of a side of the blade if it is left uncovered, shall be matt, bright red on one side and black on the other. 
  9. The racket covering shall be used without any physical, chemical or other treatment. 
  10. Slight deviations from continuity of surface or uniformity of colour due to accidental damage or wear may be allowed provided that they do not significantly change the characteristics of the surface. 
  11. Before the start of a match and whenever he or she changes his or her racket during a match a player shall show his or her opponent and the umpire the racket he or she is about to use and shall allow them to examine it. 

Since the rules in table tennis aren't always very strict, there are some things that should be pointed out in this list of regulations.

The material does not necessarily need to be wood

The regulations clearly says that the areas that the ball will never hit can be covered with any material. There is no rule that forbids the user to have whole handles made out of other materials than wood. Another thing that is not mentioned, is that blades made out of cork and bamboo - which is not wood - can be accepted as legal blades. I have also contacted the Swedish table tennis association (SBTF) about this, and they have confirmed that bamboo should be okay while cork is doubtful. Even though cork is tree bark, and bamboo is grass.

Because of these regulations, blade maker American Hinoki has made a blade completely out of cork and bamboo, and calls it the ITTF Rules Protest Blade.

The regulations can be exploited because of lack of precision

Some players who use penhold blades, don't use the backhand side of their blade to hit the ball. But they're still forced by the rules to wear a rubber on each side. Though, there is no rule specifying any minimal amount of rubber, - it just needs to cover the part of the blade where you don't keep your fingers. But a Japanese penholder keeps his fingers over half the blade, - therefore you often see them have one rubber that covers only about half the blade. This means that their blades get significantly lighter than if the rubber covered the whole surface. They can also cut off a little extra weight by making a nice looking curve - as long as all text on the rubber shows (so the referees can identify it as approved material).

Since there is no rule saying that the handles need to be made out of wood, it should be okay using other materials. Most Japanese penhold blades have cork as handle - and since no rule defines what a handle should be shaped like, they often only have the cork on one side of the blade. In the end, Japanese penhold blades can have a very low weight, which brings higher speed.

The rubbers can be a little too big

The rubbers are supposed to reach the edges of the blade, but aren't supposed to stick out further than necessary. Still, you see professionals play with rubbers sticking out several millimeters. (Maybe enough to save a ball every now and then?) Referees have never seemed to mind this, so it can be utilized. To make it less noticeable, edge tape can be used.


Experiment! Use the loopholes to find the best possible assembly for you. Until the ITTF gets more specific!

Inspected rackets

August 6, 2012

Table Tennis on Google

Just thought I'd post the pretty picture that Google put on their home page the day that the mens' final games were broadcasted. I think it's great that the sport gets some proper exposure like this, - seeing as Google has over 30 million visitors every day.

Table tennis

August 3, 2012

The 2012 Olympics - Umpires Strict...Or Not?

After watching some table tennis games from the 2012 Olympics in London, I've been surprised by how many times the umpire has given away points for incorrect services. Several times in just a few days, the umpire has had the opinion that players haven't thrown the ball as straightly towards the ceiling - or as high - as the rules say they shall. It distracts the players, but is it good or bad? I've also been wondering; Should Natalia Partyka, the female player with only one hand, be allowed to play in the Olympics for normally abled people?

The official table tennis rules say:
Service shall start with the ball resting freely on the open palm of the server's stationary free hand.

The server shall then project the ball near vertically upwards, without imparting spin, so that it rises at least 16cm after leaving the palm of the free hand and then falls without touching anything before being struck.
They also say:
From the start of service until it is struck, the ball shall be above the level of the playing surface and behind the server's end line, and it shall not be hidden from the receiver by the server or his or her doubles partner or by anything they wear or carry.
During this year's Olympics, several players have lost points due to these rules - for example Danish player Michael Maze, Chinese Ding Ning and Wang Hao, also from China. Which of the rules above that the umpire has referred to, hasn't been very clear, though.

Problem 1: Some rules aren't written very clearly. If you're supposed to throw the ball "near vertically upwards" - where do you draw the line? As a player you can't guarantee that the ball will rise/fall with an angle of 0, or 5, or 10 degrees. You just throw it in a way that fits your style.

Problem 2: The two umpires on the floor sits on each side of the table. They don't see the game the same way as the players do. They can't make an absolutely accurate appreciation of what the service receiver sees or not. Players often(!) throws the ball near their body so they hide it with their arm right before racquet impact - but do the umpires say anything? No. Almost never.

Problem 3: The umpires are people and not machines - they use their own opinions, which can differ and change - and even be absurd. All three players that have been mentioned above, have used the same technique in many services, but suddenly the umpires say that they're doing it wrong. Why don't they observe it the first time then? A point that is lost because of these rulings, throws the player's off, they lose their focus and changes their mood and therefore also their performance. If their methods aren't allowed by the rules, they should be told this as soon as possible. Not in an important semi-final where the mood plays a large roll.

On farm auctions, the auctioneer can sometimes start off the event by ignoring bidders and sell quickly - only to make people wake up. Break the rules to force people to follow them. I can partly understand if this is what's going on, but I can't see how something like that would work at all. And when a player does the same thing 20 times in a row and then gets a ruling against him - then something is seriously wrong.

Natalia Partyka from Poland, was born without most of her right forearm. Still, she's one of the best female players in the world. Therefore, she's competing in both the Paralympics for disabled people, and in the normal Olympics. Just that, makes me wonder. If she's so good that she can compete with the best normally abled players in the whole world - should she be allowed in the Paralympics...? I've seen 80 year old people with walking frames compete there. People in wheelchairs. People without arms. And this incredibly gifted girl is gonna go there and run them over like a bulldozer? Yeah, that seems fair.

And now we get back to rules and interpreting again. And have in mind that the condition that she has to accept to compete in the Olympics, is that she has to accept the normal rules.

"Service shall start with the ball resting freely on the open palm of the server's stationary free hand." She doesn't have any free hand. And she's not allowed to rest the ball on the racquet like in the Paralympics. Instead, she has been allowed to rest the ball on the little she has of her right forearm. It isn't even "resting freely", because it's supported by the bottom of her upper arm. And when watching slow-motion replays of her services, you can clearly see that the ball often isn't thrown up near 16 cm before falling. How many times have the umpires given her points away - or even warned her? Zero.

The question is: Where does she belong? Personally, I think she should be judged after her abilities - but it would be interesting to know how she got to bypass direct rules.

Natalia Partyka
Natalia Partyka - Competes in
the Olympics despite handicap