Racquetball is a popular indoor sport, played with wood rackets and a hollow rubber ball. While at first view racquetball seems to incorporate many of the rules of tennis and handball, the truth is that racquetball is a unique sport. Invented in 1951 by Joe Sobek, who was looking for a fast-paced alternative to tennis, it quickly caught on.
By 1952, Sobek had formed the National Paddle Rackets Association and codified the rules of the sport. Because racquetball could be played in existing handball courts, the game easily spread throughout the country. Racquetball hit the peak of its popularity in 1974, with an estimated three million players in the US alone.
While a racquetball court is clearly defined by a series of red lines indicating service and reception areas, the standard rules of inbound and outbound don't apply in a racquetball court. For starters, there are no out-of-bounds areas in the court: the walls, floor, and ceiling are acceptable bouncing areas. The 40 x 20 foot (about 6 x 12 meters) room has a service box and a receiving line, which the players must respect during serve, but there are no other restrictions once the serve has been made.
The rules of racquetball are pretty straightforward. As long as the ball hits the front wall without bouncing on the floor, the serve is valid. The ball is allowed to bounce an unlimited number of times on any walls and on the ceiling before touching the front wall, as long as it never reaches the ground. A point can only be scored by the server, either because the ball is not returned by the opposite player or because the ball bounces on the floor before reaching the front wall. Points can also be scored if the ball hits a player, or if a player switches hands during a rally or touches the ball with his or her body.
Racquetball is usually played by two players, though some variations include up to four. Players can choose to make offensive or defensive shots, which are defined by the height and speed at which the ball is struck against the wall. Offensive shots aim for the low corner, making it difficult for the opposite player to reach the ball before it hits the ground. Defensive shots are aimed primarily to the ceiling, based on the idea that this will make the ball bounce deep into the court, usually traveling over the player.