Table Tennis Ball
The international rules specify that the game is played with a light 2.7 gram, 40 mm diameter ball. Generally, it is the most-used ball. The rules say that the ball shall bounce up 23 cm when dropped from a height of 30 cm thereby having a coefficient of restitution of 0.88. The 40 mm ball was introduced after the 2000 Olympic Games. However, this created some controversy as the Chinese National Team argued that this was merely to give non-Chinese players a better chance of winning. A 40 mm table tennis ball is slower and spins less than a 38 mm one. The ball is made of a high-bouncing gas-filled celluloid, colored white or orange, with a matte finish. The choice of ball color is made according to the table color and its surroundings. For example, a white ball is easier to see on a green or blue table than it is on a grey table. Stars on the ball indicate the quality of the ball. 3 stars indicates that it is of the highest quality, and is used in official competitions.