Tennis is widely popular all over the world. It is a kind of sport that is played between two players or between two teams of two players each. This game is played in tennis court, using racquet which is strung to hit a hollow rubber ball covered felt past a net into the opponent's court. The modern tennis sport as we see today is basically originated in United Kingdom in the late 19th century. A tennis match is basically determined through the best of 3 or 5 sets. Typically for both men's and women's matches, the first player to win two sets wins the match. Tennis enjoys millions of recreational players and is also a hugely popular worldwide spectator sport.
There have been not many changes in the rules of tennis since 1890s. A few changes were made from 1908 to 1960; it becomes necessary for the server to keep one foot on the ground at all times. In 1970s, there were adoptions of the tie break. However, the current addition to professional tennis has been the adoption of electronic review technology coupled with a point challenge system, which enables a player to challenge the line (or chair) umpire's call of a point.
In the year 1927, the Association of Tennis Professional (ATP) was established so as to protect the interests of male professional sports tennis players. The counterpart organization in the women's professional game is the Women’s Tennis Association. In most of the professional tennis matches, there is an official head judge or chair umpire who sits in a raised chair to one side of the court. The umpire has got absolute authority to make factual determinations. The umpire may be assisted by line judges, who determine whether the ball has landed within the required part of the court and who also call foot faults. There also may be a net judge who determines whether the ball has touched the net during service.
The ATP Tour comprises different tournament including Grand Slams which especially includes the tournaments of the Australian Open, the US Open, the French Open and the Wimbledon. Besides Grand Slams, the ATP Tour also comprises ATP World Tour Masters 1000, ATP World Tour 500 series, ATP world Tour 250 series, ATP Challenger Series and Futures Tournaments. The ATP also oversees the World Team Cup, played in Dusseldorf in May and the ATP Championships Tour for seniors.