Your kids’ hobbies are yours, too
by Katja Fischer
No tennis match without a tennis ball. Depending on the surface and the level of the players, different tennis balls are used. While beginners are best off using slower, pressureless tennis balls to learn the basic hitting techniques, the much faster inner-pressure balls are used in competition. These contain a rubber bladder filled with compressed air and thus provide increased bounce. Since the compressed air escapes over time, the balls must be replaced regularly. In professional tennis, inner pressure balls are replaced after a few games during the match. The International Tennis Federation (ITP) defines various requirements for tennis balls: For example, the diameter of the balls must be between 6.54 and 6.86 centimeters for official tournaments. Certain specifications must also be met in terms of weight (between 56.7 - 58.6 grams) and bounce height (between 135 - 147 cm when the ball is dropped from a height of 254 cm onto a hard surface).