The sport of racquetball is one of recent origins in comparison to most athletic activities that enjoy a popular following. Joseph Sobek (1918–1998), a tennis professional with the Greenwich, Connecticut, Young Men's Christian Association in the late 1940s, is recognized as the inventor and the developer of racquetball. Sobek, who was also an active four wall handball player, sought to create an indoor activity that would save his hands from the significant stresses of competitive handball, while preserving handball's fitness benefits. Sobek used the available YMCA handball courts to create what he referred to as "paddle racquets," a game that combined many of the features of squash and handball.
The paddle racquets concept gained significant measure of popularity in the northeastern United States, with a governing association created in 1952. The modern name for the sport, racquetball, was confirmed with the formation of the International Racquetball Association in 1968. The sport sustained explosive growth in the late 1970s in the United States, as racquetball became a fashionable recreational sporting activity. In addition to a biennial world championship, racquetball is a medal sport at the quadrennial Pan-American Games; it is also a recognized National Collegiate Athletic Association (NCAA) sport. The country with the greatest participation in racquetball remains the United States, where approximately two thirds of the world's 15 million racquetball players reside.
The rules of racquetball are relatively simple. Played in a four-walled court, the object of the sport is to strike the ball to create a rebound from the front wall (or by a combination of a front wall and side wall carom, or angled rebound), that cannot be returned by the opponent after the first bounce from the floor. The court dimensions are identical to those used in the sport of four wall handball, an enclosed area 40 ft long, 20 ft wide and 20 ft high (6 m by 12 m by 6 m); the rear wall of the court must be at least 12 ft high (3.5 m).
Racquetball may be played in a singles (two player) or doubles (four player) format. In racquet-ball clubs, players will often play an unofficial version known as "cut-throat," where one player serves against the other two players, with the serve rotating among all three players. Racquetball players use a racquet that is constructed from a combination of lightweight composite materials that is strung with a mesh similar in appearance to a tennis racquet. The ball is constructed from a rubber compound, with a hollow center that makes the ball capable of being compressed and generating a resultant velocity on a hard serve or a strong forearm shot at speeds that may exceed 150 mph (250 km/h) when struck by an elite player. The speed of the ball, and not its spin, is the most important characteristic of the racquetball both in flight and after a carom from the walls of the court.
The ball is put into play through a serve, delivered by the serving player from a designated service zone. The opposing players station themselves behind a receiving line. A legal serve is one that strikes the floor of the court before making contact with the front wall; the ball must then bounce into an area marked by the "short line," where it may be played by the opponent. A legal serve may also strike one of the walls, including the back wall of the court, prior to being returned by the opponent. Points are scored on the serve only, with a game concluded when the first player achieves a score of 15 points.
Once the ball is put in play with a legal serve, both players may use all of the walls in their shot making. As a general proposition, the ball remains in play until the ball strikes the floor of the court twice. Racquetball is a game played with one hand on the racquet; players are not permitted to change their hands on the racquet during a rally. Where one player unintentionally impedes the movement of an opponent in making a shot, the opponent may call a "hinder," which results in the serve being replayed without penalty to either player. Deliberate obstructions (in competitive racquetball a referee is empowered to make such determinations) usually result in a point being awarded the hindered party.
The fundamental tactic employed in racquetball is to obtain the control of the center of the court. From the center position, a player can best react to shots struck by the opponent. The center is the position from which the angle of the carom of any shot that strikes any of the walls may best be judged. The player with center position will force the opponent to travel a longer distance to get to shots, as the center positioned player presents a legal obstruction to the opponent.
Rcaquetball is a fast paced sport, with an anaerobic fitness emphasis. A rally often continues with intense physical effort for periods of between 5 seconds and 20 seconds; the interval between rallies is also short, averaging approximately 10 seconds. Aerobic fitness assists in the body's recovery mechanism, especially after long games or during multi-game tournaments. Most racquetball shots are executed by players who assume a low, crouched position, from which they can both move dynamically in all directions on the court, and which permit them to strike the ball with power from a stable physical platform.
For these reasons, muscle strength and an ability to strike the ball with great power is sometimes helpful, but it is not an essential element of racquetball success. Lateral quickness, flexibility, and core body strength (the inter-related function of the abdominal, gluteal, lumbar (low back), and groin muscles to provide stability) are important fitness considerations.