Tennis

Tennis is a sport played between two players (singles) or between two teams of two players each (doubles). Each player uses a strung racquet to strike a hollow rubber ball covered with felt (most of the time Optic Yellow,but can be any color or even two-tone) over a net into the opponent's court.The modern game of tennis originated in the United Kingdom in the late 19th century as "lawn tennis" and had heavy connections to the ancient game of real tennis. After its creation, tennis spread throughout the upper-class English-speaking population before spreading around the world. Tennis is an Olympic sport and is played at all levels of society at all ages. The sport can be played by anyone who can hold a racket, including people in wheelchairs. In the United States, there is a collegiate circuit organized by the National Collegiate Athletics Association.

Except for the adoption of the tiebreaker in the 1970s, the rules of tennis have changed very little since the 1890s. A recent addition to professional tennis has been the adoption of "instant replay" technology coupled with a point challenge system, which allows a player to challenge the official call of a point.Along with its millions of players, millions of people worldwide follow tennis as a spectator sport, especially the four Grand Slam tournaments (sometimes referred to as the "majors"): the Australian Open, the French Open, Wimbledon, and the US Open.

Tennis is played on a rectangular, flat surface, usually grass, clay, or a hardcourt of concrete and/or asphalt. The court is 78 feet (23.77 m) long, and its width is 27 feet (8.23 m) for singles matches and 36 ft (10.97 m) for doubles matches. Additional clear space around the court is required in order for players to reach overrun balls. A net is stretched across the full width of the court, parallel with the baselines, dividing it into two equal ends. The net is 3 feet 6 inches (1.07 m) high at the posts and 3 feet (91.4 cm) high in the center.

The design of the lawn tennis court has undergone much development. It was Major Walter Clopton Wingfield who, in 1873, designed a court approximate to the current one for his stické tennis (sphairistike). This template was modified in 1875 to the court shape that exists today; the markings homogeneous with Wingfield's design, with the hourglass shape of his court changed to a more linear framework.

The lines that delineate the width of the court are called the baseline (farthest back) and the service line (middle of the court). The short mark in the center of each baseline is referred to as either the hash mark or the center mark. The outermost lines that make up the length are called the doubles sidelines. These are the boundaries used when doubles is being played. The lines to the inside of the doubles sidelines are the singles sidelines and are used as boundaries in singles play. The area between a doubles sideline and the nearest singles sideline is called the doubles alley, which is considered playable in doubles play. The line that runs across the center of a player's side of the court is called the service line because the serve must be delivered into the area between the service line and the net on the receiving side. Despite its name, this is not where a player legally stands when making a serve.The line dividing the service line in two is called the center line or center service line. The boxes this center line creates are called the service boxes; depending on a player's position, he will have to hit the ball into one of these when serving. A ball is out only if none of it has hit the line upon its first bounce. All the lines are required to be between 1 and 2 inches (51 mm) in width. The baseline can be up to 4 inches (100 mm) wide if so desired.

A competent tennis player has eight basic shots in his or her repertoire: the serve, forehand, backhand, volley, half-volley, overhead smash, drop shot, and lob.Players use various grips during play, including the continental, eastern, and western grips. Different grips generally are used for different types of spin and shots.