The game is played with two or four players hitting a ball with rackets back and forth to each other on a table, in a manner similar to tennis. The rules are slightly different, but the concept is very similar. In singles play, the serve is not required to cross from the server's right-hand court to the receiver's right-hand court (or left to left) as it is in tennis. However, serving across is required in doubles play. Ball spin, speed, placement, strategy and tactics play an important part in competitive table tennis matches. The speed of the ball can vary from slow serves with much spin to smashes that travel as fast as 112.5 kilometers per hour (70 mph).
The game is played on a 274 cm × 152.5 cm × 76 cm high (9 ft × 5 ft × 30 inches high) table. The International Table Tennis Federation requires a total playing area not less than 14 m long, 7 m wide and 5 m high for competitions. No limitations in size or shape are specified. You cannot win on a let. It is counted as a redo.
Modern rackets are usually covered with a thin layer of rubber on the racket's striking surface. The rubber may have pimples pointing outwards or inwards, as well as a thin layer of sponge between the wood center and the rubber surface. Since spin plays a large role in the modern sport of table tennis, the composition of the rubber and the combination of sponge and rubber is designed to maximize the amount of spin and speed a player can impart onto the ball. Other technological improvements include the use of carbon or other synthetic layers as part of the blade to increase the size of the sweet spot or the stiffness of the blade. Rackets vary in price range from cheap, recreational paddles, to expensive, more competitive rackets.
The ball used in table tennis has a diameter of 40 mm (formerly 38 mm), is made of celluloid, and is hollow. A three star rating on a ball usually implies a top quality ball, in relation to its bounce, roundness and their respective consistency between balls of the same make and type.
The winner is the first to score 11 points or more while being ahead by 2 points or more. Players alternate serves every two points. At 10-10 (or deuce) the players alternate with every serve; the winner is then the first person to gain a two point advantage over his opponent. The 11 point game is an International Table Tennis Federation (ITTF) change which occurred in 2001. Previously, the first player to gain 21 points (except in case of a deuce, handled as described above) won the game. All games played at national level and at international tournaments (ITTF) are now played to 11 points in either a best of five (5) games (preliminaries) or best of seven (7) games format (championship matches).