the game excessively fast and difficult to watch on television. A few months later, the ITTF changed from a 21-point to an 11-point scoring system (and the serve rotation was reduced from five points to two), effective in September 2001. This was intended to make games more fast-paced and exciting. The ITTF also changed the rules on service to prevent a player from hiding the ball during service, in order to increase the average length of rallies and to reduce the server's advantage, effective in 2002. For the opponent to have time to realize a serve is taking place, the ball must be tossed a minimum of in the air. The ITTF states that all events after July 2014 are played with a new poly material ball. Equipment Ball The international rules specify that the game is played with a sphere having a mass of and a diameter of . The rules say that the ball shall bounce up when dropped from a height of onto a standard steel block thereby having a coefficient of restitution of 0.89 to 0.92. As of 2015, balls are now made of a polymer instead of 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. Manufacturers often indicate the quality of the ball with a star rating system, usually from one to three, three being the highest grade. As this system is not standard across manufacturers, the only way a ball may be used in official competition is upon ITTF approval (the ITTF approval can be seen printed on the ball). The 40 mm ball was introduced after the end of the 2000 Summer Olympics; previously a 38 mm ball was standard. This created some controversies. Vladimir Samsonov, the World No. 1 table tennis professional at the time, threatened to pull out of the World Cup, which was scheduled to debut the new regulation ball on 12 October 2000. Table The table is long, wide, and high with any continuous material so long as the table yields a uniform bounce of about when a standard ball is dropped onto it from a height of , or about . The table or playing surface is uniformly dark colored