Context: World Championship Tennis (WCT) was a tour for professional male tennis players established in 1968 (the first players signed a contract at the end of 1967) and lasted until the emergence of the ATP Tour in 1990. A number of tennis tournaments around the world were affiliated with WCT and players were ranked in a special WCT ranking according to their results in those tournaments., John Albert Kramer (August 1, 1921  September 12, 2009) was an American tennis player of the 1940s and 1950s. A World No. 1 player for a number of years, and one of the most important people in the establishment of modern men's "Open"-era tennis, he was the leading promoter of professional tennis tours in the 1950s and 1960s. He was a relentless advocate for the establishment of Open Tennis between amateur and professional players. An International Tennis Federation (ITF) proposal to introduce Open tennis lost by five votes in 1960, but became a reality in 1968. In 1970, he created the Men's Grand Prix points system. In 1972, he helped found the Association of Tennis Professionals (ATP) with Donald Dell and Cliff Drysdale, and was the first Executive Director. He was unpaid at his request. In that role, he was the leader of an ATP boycott of Wimbledon in 1973, for the banning of Nikola Pili from the tournament., The Association of Tennis Professionals (ATP) was formed in September 1972 by Donald Dell, Bob Briner, Jack Kramer, and Cliff Drysdale to protect the interests of male professional tennis players. Drysdale became the first President. Since 1990, the association has organized the worldwide tennis tour for men and linked the title of the tour with the organization's name. In 1990 the organization was called the ATP Tour, which was renamed in 2001 as just ATP and the tour being called ATP Tour. In 2009 the name was changed again and is now known as the ATP World Tour. It is an evolution of the tour competitions previously known as Grand Prix tennis tournaments and World Championship Tennis (WCT)., Mercedes-Benz is a global automobile manufacturer and a division of the German company Daimler AG. The brand is known for luxury vehicles, buses, coaches, and trucks. The headquarters of Mercedes-Benz are in Stuttgart, Baden-Württemberg, Germany., The ATP Tour is the elite tour for professional tennis organized by the Association of Tennis Professionals . The ATP Tour includes the four Grand Slam tournaments , the Tennis Masters Cup , the ATP Masters Series , the International Series Gold and the International Series tournaments ., Eric Clifford 'Cliff' Drysdale (born 26 May 1941, Nelspruit, South Africa) is a former top-ranked professional tennis player of the 1960s and early 1970s who became a well-known tennis announcer. He was one of the Handsome Eight, a group of players signed by Lamar Hunt in 1968 for the newly formed professional World Championship Tennis (WCT) group. He became President of the Association of Tennis Professionals (ATP) when it was formed by Jack Kramer, Donald Dell, and himself in 1972. Drysdale was ranked World No. 4 in 1965 by Lance Tingay of The Daily Telegraph., Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The object of the game is to play the ball in such a way that the opponent is not able to play a valid return. The player who is unable to return the ball will not gain a point, while the opposite player will., Felt is a textile that is produced by matting, condensing and pressing fibers together. Felt can be made of natural fibers such as wool, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood pulp-based rayon. Blended fibers are also common. , Donald Dell (born June 17, 1938 in Savannah, Georgia, United States) is an attorney and was a professional tennis player, U.S. Davis Cup captain, and administrator. Dell was one of the first professional sports agents, having represented professional tennis players Arthur Ashe, Stan Smith, Jimmy Connors, and Ivan Lendl during pro tennis' golden age (1975 to 1985). He was also the founder of Professional Services (ProServ), one of the nation's first sports marketing firms established in 1970 with co-founder, Frank Craighill, a fellow law partner. His younger brother, Dick, worked for ProServ managing US Open champion Gabriela Sabatini, and played Number One Singles for the University of Michigan. He was Big Ten #1 Singles Champion in 1969., The ATP Masters Series was a series of nine tennis tournaments that formed part of the men's Association of Tennis Professionals (ATP) tour, held annually throughout the year in Europe, North America. The tournaments were important for the top male players on the professional circuit as the series constituted the most prestigious tournaments in men's tennis after the four Grand Slam events. The events were known as the Championship Series, Single Week from 1990 to 1995, the Mercedes-Benz Super 9 from 1996 to 1999, the Tennis Masters Series from 2000 to 2004 and the ATP Masters Series until 2008., Subject: 2007 atp tour, Relation: instance_of, Options: (A) 12 (B) administrator (C) age (D) association (E) atp world tour (F) august (G) automobile (H) cliff (I) company (J) contract (K) eight (L) era (M) game (N) headquarters (O) june (P) law (Q) manufacturer (R) name (S) nation (T) nine (U) number (V) object (W) organization (X) part (Y) point (Z) professional ([) promoter (\) proposal (]) role (^) september (_) series (`) single (a) sport (b) strike (c) system (d) ten (e) tennis (f) textile (g) tournament (h) world championship
Output: atp world tour