The function of feedback in blades.
Feedback in blades is referred to as “feel” or “touch” and sometimes more directly as “flexibility”. It is often suggested that flexible blades with a good feel or touch will make it easier to hit the ball just right, improving the quality of your strokes - and they do, but still the matter is not as simple as that.
“Feel”or “touch” is what the muscles and nerves in a hand holding the grip of a bat sense of the vibrations in the blade’s head caused by the impact of the ball when it is in contact with the rubber. These vibrations convey information about speed and spin of the ball – the incoming speed and spin as well as the speed and spin which are a result of making the stroke. Speed is felt as intensity of the vibrations. Spin is felt as quality of the vibrations – a ball will feel “heavy” if there is a lot of spin on it, and the way the vibrations change when contacting the rubber will make you feel e.g. whether or not you are putting good spin on the ball, or whether or not you have made the pips of your LP rubber bend.
Feedback actually is there when the vibrations in the blade’s head are transferred to the hand and processed by the brain. The time during which the ball is “on” the blade – or more precisely, is making contact with the rubber – is approximately a thousandth of a second. In contrast, the nerves and the brain need tenths of seconds to process the information felt by the hand and to respond to it. Time, therefore, is far too short to adjust flaws in handling the ball during the interval the ball is on the blade; if you don’t hit the ball just right, there is nothing you can do about it while you are actually hitting it. However, the information processed by the brain is retained; as such it can be used, first, to help interpret the effectiveness of the stroke (feeling adds information to what you see) and, second, to make adjustments the next time you hit the ball. So, “feel” and hence feedback are not functional immediately, but indirectly.
The good feedback can do a player is then, first, helping him to know how well he hit the ball. This is important tactically, for it helps to decide what to expect from the opponent and how to anticipate on his most likely reaction. Visual information is often not enough to decide this: it is difficult to see how much spin and speed there is on the ball. If, however, you can feel spin and speed, you will far better be able to judge the quality of your stroke and the degree of difficulty the opponent will have handling the ball as a result of it, and from that to decide what to expect and how to anticipate it.
Secondly, a player can benefit from feedback because it is extremely helpful in the learning process. Learning how to perform strokes well using only visual information (the trajectory of the ball, if and how it clears the net, where it lands, how it behaves when contacting the opponents bat) is difficult and comes slowly, because the information is not directly linked to what the muscles do. Feeling how you perform the stroke and handle the ball, by feeling the vibrations in the blade and interpreting them, will train the muscles directly. Muscle-memory is subconscious, you are not directly aware of it, but it is there determining your reflexes; that makes it very important in table-tennis. Feeling the vibrations will also add to your general knowledge of the behaviour of the ball as a result of your strokes; this knowledge is a part of the conscious learning-process.
As feedback is important, so is the ability of the blade to generate vibration and transfer it to the grip. The construction of blades may either maximize or minimize this ability. As for the head, vibration will be less and more complex with every ply added. Single-ply blades have optimal vibration – if the wood they are made of vibrates well. The best wood comes from needle-leaved trees; musical instruments are nearly always built from it. A Stradivarius violin is, as it were, a single-ply Hinoki blade. Multiple plies will dampen vibration and/or make it more complex (as every layer has its own vibrations), but this can be (partly) compensated by gluing techniques, choosing woods that combine well, making the plies thin, and so on. Generally, a blade that is flexible will vibrate well. To have good feedback, however, the vibrations have to be felt in the hand, so the vibrations must be transferred to the grip. Several blade-designs purposely prevent this by putting dampening layers between the grip and the wood of the head in some way. Most designs do not prevent it, but do not purposefully improve transference either. Only one design (as far as I know) aims at maximizing transference of vibrations from the head to the grip, and this is patented by Re-Impact. It does make these blades unique.
Transference of vibrations is also dampened by the rubbers on the blade; the thicker, the more. Therefore it makes very good sense to have especially younger players use thin sponge; this will speed up their development. Feedback is especially important too in defensive and all-round playing-styles, as manipulation of spin and speed is essential to them. Blockers also benefit from good feedback. These players will be best off using blades that vibrate well and transfer the vibration the grip. Hitters and quick attackers have less practical need of it.
If you have a short video of you playing it can also help show your abilities and what you might be after.
