22 октября 2007 | Автор:
geokond | Просмотров: 5 324 |
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Ok, lets get back on a more serious note. Although there is a huge range of different long pimpled rubbers, they all share some common characteristics, and all to different degrees. These characteristics are commonly referred to as ‘long pimple effects’, and are summarised below:
| 1. | The small surface area of the tips of long pimples results in minimum contact between the ball and the rubber. This reduces the friction between the ball and rubber significantly, resulting in the rubber being very insensitive to incoming spin, and allowing a lot of the incoming spin to be returned back to the opponent. This is commonly referred to as 'Spin Reversal'. |
| 2. | The pimples bend under impact with the ball, the higher the impact the more they bend. Now as the pimples bend, more of the rubber (sides of the pimples) is exposed, resulting in a greater contact surface area between the ball and the rubber, which changes the characteristics discussed in 1. In addition to this, the texture of the tip of the pimples may be different to that of the sides of the pimples, which changes the effect it has on the spin on the ball. |
| 3. | The pimples bend back after releasing the ball. This results in some of the pimples giving the ball a bit of a ‘flick’, which can add some random spin to the ball. Although this effect is far more pronounced in soft, long and skippy long pimples, the effect is present for most long pimples rubbers. |
| 4. | The long pimple rubbers are generally significantly slower than most other types of rubbers, often taking the pace off the ball. This generally improves control but diminishes attacking ability. |
| 5. | The effects described in the 4 points above, can be significantly changed by the three main factors: |
| | - | Choice in sponge thickness. This usually ranges from ‘no sponge’ (commonly referred to as ‘OX’) to thicker sponges usually up to 1.5mm. Most ‘long pimple effects’ are greatest for OX, and decrease with the thicker sponges. As discussed later though, there may be good reasons to choose a thicker sponge. |
| | - | The hardness of the sponges also has an effect. Most ‘long pimple effects’ are greatest for harder sponges, but again there can be good reasons for choosing softer sponges. |
| | - | The choice of blade can make quite a difference in how the pimples perform. Since the choice is often a compromise between the different rubbers on either side of the bat, the choice of suitable blades for the required style is often much harder than for inverted players. Most ‘long pimple effects’ are greatest for harder blades. |
Over the next few articles I will attempt to explain these 5 points in details, and explain what advantages and disadvantages these characteristics offer. Examples of rubbers where these effects are most obvious will be included.
1. Spin reversal:
The key and most important feature of long pimpled rubbers is it so-called ‘spin reversal’. Although some of the other properties of these rubbers are important too, without ‘spin reversal’ they simply would not be effective.
So what’s this ‘spin reversal’, and how can this magical rubber ‘reverse’ the spin I hear you ask? Well the reality is, it’s not magical at all and it’s actually simpler to explain than the effect of the smooth and spinney inverted rubbers. All that the long pimple rubbers do, is allow the spinning ball from your opponent, to continue spinning in the same direction when you return it. It’s as simple as that! So technically it should really be called ‘spin continuation’, but there’s a good reason why it’s more commonly referred to as spin reversal, as illustrated in this example:
1. Your opponent feeds you a ball with topspin:
2. You hit the ball with your long pimpled rubber and the ball rebounds off:
3. The ball rebounds off your bat, with reduced speed and spin, but notice that the ball is still spinning in the same direction, but because it’s traveling in the opposite direction, it’s now backspin:
Now the tricky and deceptive part of this is (put over-simplistically for illustration purposes), that it does not matter what type of stroke you play, the ball WILL return with backspin. So even if you play a stroke where you appear to impart topspin, the ball will still return with backspin. Just make sure you get it on the table.
Similarly if your opponent feeds you backspin, or any other spin for that matter, you will return the opposite spin when you hit it with your long pimpled rubber. The fact that the spin is opposite, is where the term ‘spin reversal’ comes from.
In other words the key difference between spin coming from an inverted or long pimple rubbers from your opponent is:
- The spin coming from an inverted rubbers basically depends on what type of stroke your opponent plays
- The spin coming from a long pimple rubber depends on the type of spin that you send to your opponent, with the type of stroke that your opponent makes having much less impact (the extent of this depends on the type of long pimple rubber used).
At the lower levels of table tennis, this property alone can win you points and often whole games. If your opponent imparts a lot of spin on the ball, and does not understand that this comes back in reverse, it will draw many errors or easy balls to put away.
At the higher levels, the principle of the spin-reversal is often well understood, and can actually be taken advantage off. The main advantage that this property offers at this level is it’s relatively insensitivity to incoming spin, and the ability to return heavy spin when you receive heavy spin. For example your opponent feeds you a loops with heavy topspin, you return it with the long pimples, and heavy backspin comes back, which may make it hard for your opponent to attack again, or he may even hit it into the net!
The spin reversal in association with some of the other properties of the long pimple rubber is what makes the rubbers powerful. The spin reversal just by itself has limited potential. The amount of spin reversal that your rubber produces, actually depends on many factors. The type of long pimple used is one factor. However how you play the stroke has an impact too, and varying the spin reversal is actually one form of deception, but this will be discussed in a later section.
2. Compressing and bending the pips:
As mentioned before, spin reversal is one of the key properties of long pimple rubbers. However once you climb the grades ladder and get to play to more experienced players, this property alone may not be enough. If these players know that whatever spin they feed to your long pimple rubber, will come back with almost the exact reverse, they can control the spin completely, and can feed you spin, so that just the right spin comes back to suit their own game… Of course you still have control over the speed and placement of the ball, but this may not be enough. Other options are still available for the more advanced players, such as twiddling to use the other side of the bat, or running around to play the ball with the rubber on the other side, but this will be discussed in the strategy section.
OK so what options are available to combat your opponents from dominating play by exploiting the spin reversal property? Well the concept of the spin-reversal was described with an ‘ideal’ long pimple rubber, where spin reversal is maximized. Some rubbers have hard pimples and very glassy and slippery tips come close to this ideal long pimple rubber, and are suited for a style where maximum spin reversal is required. Examples of these are Dr Neubauer “Super Block” and Hallmark “Super Special”. These rubbers are commonly referred to as “Frictionless long pimple” rubbers, and are a very important class of rubbers. However there is another main class of rubbers, commonly referred to “Grippy” or “Friction” long pimple rubbers, and these have some other interesting properties which will be discussed here.
The reality is that ALL long pimple rubbers DO have some grip and therefore the type of stroke played WILL have some effect on the spin that is returned. Many long pimple rubbers also have softer pimples, which means they’ll bend under impact, the harder the impact, the more they bend. By bending the pimples, more of the rubber surface is exposed to the ball, so the contact area between the rubber and ball is increased. This has the effect of reducing the spin reversal, but increasing the amount of spin you can impart. Some of these Grippy long pimple rubbers are designed to have significant grip on their tips and sides, and are often made softer so that the pimples can bend more easily.
So what use is this property if it reduces the key spin-reversal property of long pimple rubbers? Well it offers another key feature of grippy long pimple rubbers, which is the ability to manipulate and control the spin, which can be used as a form of deception. This will be described below. Just as in section 1 we used an ideal frictionless rubber to illustrate the principle of spin reversal, here we’ll use an ideal grippy long pimple rubber for illustration purposes. This rubber will have grippy tips, will bend under impact, and will have grippy sides.
Consider the following…
1. Your opponent feeds you a ball with topspin:
2. The ball strikes your bat. But because the pimples are soft, they compress and push in as shown, resulting in many more pimples contacting the ball surface. The pimples are grippy, so they grab the ball and try to stop it from spinning.
3. The ball rebounds off with reduced speed and with virtually no spin.
The extent of how much of the spin is taken off the ball depends on quite a few other factors. The grippier the pimples, the better they can grip the ball and take off the spin. Also the longer the ball is in contact with the rubber (i.e. dwell time), the better the pimples can take off the spin. So a soft blade and/or a sponge will also increase the ability of taking off the spin. Finally the speed of the ball has an effect, the slower the ball, the slower the rebound, so the pimples have more time to take off the spin. An actual picture of the ball compressing the pimples is shown here:
This property by itself can already be very useful. A spinney loop that is returned short with no spin can be hard to attack again. However the player can actually control how much spin is taken off the ball as well, by the movement of the bat upon contact.
By brushing the ball in the same direction as the ball is spinning, you can control whether you take off all the spin, return all the spin back to your opponent, or even add a little spin if you brush the ball faster than it’s spinning:
1. Your opponent feeds you a ball with topspin:
2. You strike the ball with a brushing action in the same direction as the ball is spinning. Note the squashing of the pimples while you’re brushing exposes even more contact area for the ball to grip the rubber, allowing more manipulation of the spin. Because the bat travels in the same direction as the surface of the ball, some of the spin is continued on:
3. A reduced amount of spin is returned to the opponent, you control the amount:
The amount of spin returned is obviously also dependent on other factors. There will often still be a moderate amount of spin reversal, depending on factors explained earlier. By disguising how fast you’re brushing the ball at the point of contact offers a form of deception, drawing errors from opponent who misjudge this.
A picture of a ball making contact with a brushing action of a bat is shown here:
Note that if you brush the ball fast enough, you can actually add some spin to the ball as well. Against fast loops this may be very hard to do, and this is not really unique to long pimple rubbers.
There are a variety of different strokes that can offer further manipulation of the spin, but this will be discussed in the ‘Long Pimple Strokes’ section.
Written by Alex
