Global Tennis Teaching Institute

It should be well known that the tennis industry has excellent and interesting advertisements. We are told about the “ thinking racket”, the “speed producing racket” and other useful help to entice into buying their product and some of us do it without questioning their statements. Understandable, competition is challenging and tough. But when again and again TV commentators tell about a new string which produces a better top spin,I don’t like this, as their statements are just not true. Are they paid to make such statements? I don’t think so. But if you are in such a postion, where you can address millions of tennis players, you can express an opinion, but don’t make statements, witch are not true. Most pro players and tennis teachers do not know what happens when the ball is hit by the racket. Why? Because nobody told them and they really don’t care, as they think that what they feel when hitting, is more important than to know about the ball on the strings. I do not agree with them, but let me address this issue at a later time.

When, in 1975, after having spent some time with Prof. Dr. Kopf at the Technical University in Dortmund, Germany, finding out about what is happening during ball contact in a stroke and announced that the tennis ball touches the string only 3,6 to 4,0 thousandth of a second, it meant very little to the tennis world. Would they have known that our nervous system is 1o times slower, some would have reacted. This is also why a tennis player does not see the ball on the strings. During this research and testing, it became evident, that as much top spin you hit, the ball does not move (rotate) during the time it touches the strings. A rolling of the ball on the strings just does not happen. What causes the topspin? It is very simple to recognize, when you have the possibility to use cameras able to take 8000 pictures in a second. Lamar Hunt , founder of WCT, Dallas TX made it possible. This high speed camera shows that when the ball touches the strings at first, only the small part of the strings on the contact spot reacts, before the string-bed stretches to the back. This second movement of the strings is influenced by the string tension on the racket. During the same time, the ball compresses and looses its shape and flattens quite a bit. The string bed begins to move back, and the ball begins getting its shape back. The string bed moves slightly in front of its original flat position. But as the rubber of the ball does not react as quickly as the strings do, the ball remains on the outside still partly flat but on the string side it shapes slightly like a pear. During the last instant the ball has contact with the strings, the strings touch the pointed side of the ball. This is the only moment when the racket influences the ball rotation during the stroke. Flat stroke: the ball will start pulsating straight out by changing from oval to round for a few times until it remains round. Topspin: The moment of separation the racket is moving front and upwards. Consider, the ball is almost round in the front and pear shaped in the back when it leaves the strings . At this moment , the up motion of the racket strings ( top spin) gives to the totally stagnant ball the intended rotation. The ball rotates and pulsates at the same time. In doing so it creates a negative suction under the ball which the ball overcomes and suddenly it is pulled down in to a down curve, witch changes the flight of the ball into the so called “ top-spin “ curve.

Mr. Fischer, a German tennis club player and engineer was influenced by this study and used it to add in a clever way some additional very fine lose string and plastic pellets to the existing string pattern which in the up movement are propelled against the ball and triple the rotation . He created a monster racket with which every beginner could hit a brutal top spin. Illje Nastase won a tournament the first time he used it. Mr.Fischer asked me to help getting approval for his stringing. I refused, as his strings were destroying the tennis game. Shortly after the ITF committee banned the Fischer-String.

Years ago most string manufacturers tried to make strings with different structure, for a better top spin grip. Some strings were square, others rough and looking like stretched roots. Nothing made hitting top spin any easier. The top spin stroke will depend on the way the ball is hit and will continue to need the technical execution to create the ball rotation.

All this is difficult to understand but as nothing is really easy in tennis we can only through knowing about it, improve how to address the tennis technique and game. At the Global Tennis Institute the teaching is based, for the strokes, on the laws of physics, for the movements on the best use of the body structure, muscle and reactions. All our students know that the moment they feel hitting the ball, or hearing the hitting bang, the ball is gone. This means to them that everything they do before touching the ball is the stroke, so they act accordingly. I can assure you, they will not go and buy the new top spin strings!!!