Tennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket strung with a cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The object is to manoeuvre the ball in such a way that the opponent is not able to play a valid return. If a player is unable to return the ball successfully, the opponent scores a point.
The Women's Tennis Association (WTA) is the principal organizing body of women's professional tennis. The association governs the WTA Tour, which is the worldwide professional tennis tour for women, and was founded to create a better future for women's tennis. The WTA's corporate headquarters is in St. Petersburg, Florida, with its European headquarters in London and its Asia-Pacific headquarters in Beijing.
The US Open Tennis Championships, commonly called the US Open, is a hardcourt tennis tournament organized by the United States Tennis Association annually in Queens, New York City. It is chronologically the fourth and final of the four Grand Slam tennis events, held after the Australian Open, French Open, and Wimbledon.
The Australian Open is a tennis tournament organized by Tennis Australia annually at Melbourne Park in Melbourne, Victoria, Australia. It is chronologically the first of the four Grand Slam tennis events every year, held before the French Open, Wimbledon and the US Open.
Billie Jean King, also known as BJK, is an American former world No. 1 tennis player. King won 39 Grand Slam titles: 12 in singles, 16 in women's doubles, and 11 in mixed doubles. King was a member of the victorious United States team in seven Federation Cups and nine Wightman Cups. For three years, she was the U.S. captain in the Federation Cup.
The Grand Slam in tennis is the achievement of winning all four major championships in one discipline in a calendar year. In doubles, a Grand Slam may be achieved as a team or as an individual with different partners. Winning all four major championships consecutively but not within the same calendar year is referred to as a "non-calendar-year Grand Slam", while winning the four majors at any point during the course of a career is known as a "Career Grand Slam".
The International Tennis Federation (ITF) is the governing body of world tennis, wheelchair tennis, and beach tennis. It was founded in 1913 as the International Lawn Tennis Federation by twelve national tennis associations. As of 2016, there are 211 national and six regional associations that make up the ITF's membership.
The Association of Tennis Professionals (ATP) is the governing body of the men's professional tennis circuits – the ATP Tour, the ATP Challenger Tour and the ATP Champions Tour. It was formed in September 1972 by Donald Dell, Jack Kramer, and Cliff Drysdale to protect the interests of professional tennis players, and Drysdale became the first president. Since 1990 the association has organized the ATP Tour, the worldwide tennis tour for men and linked the title of the tour with the organization's name. It is the governing body of men's professional tennis. 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 of the tour was changed again and was known as the ATP World Tour, but changed again to the ATP Tour by 2019. It is an evolution of the tour competitions previously known as Grand Prix tennis tournaments and World Championship Tennis (WCT). The ATP's global headquarters are in London. ATP Americas is based in Ponte Vedra Beach, Florida; ATP Europe is headquartered in Monaco; and ATP International, which covers Africa, Asia and Australasia, is based in Sydney, Australia.
The ATP Finals is the season-ending championship of the ATP Tour. It is the most significant tennis event in the men's annual calendar after the four majors, as it features the top eight singles players and top eight doubles teams based on their results throughout the season. The eighth spot is reserved, if needed, for a player or team who won a major in the current year and is ranked from ninth to twentieth.
The WTA Tour is a worldwide top-tier tennis tour for women organized by the Women's Tennis Association. The second-tier tour is the WTA 125 series, and third-tier is the ITF Women's World Tennis Tour. The men's equivalent is the ATP Tour.
The BNP Paribas Openat Indian Wells is an annual professional tennis tournament held in Indian Wells, California, United States. It is played on outdoor hardcourts at the Indian Wells Tennis Garden, and is held in March. The tournament is part of the ATP Masters 1000 events on the ATP Tour and part of the WTA 1000 events on the WTA Tour.
The Miami Open is an annual professional tennis tournament held in Miami Gardens, Florida, United States. It is played on outdoor hard courts at the Hard Rock Stadium, and is held in late March and early April. The tournament is part of the ATP Masters 1000 events on the ATP Tour and part of the WTA 1000 events on the WTA Tour.
The Canadian Open is an annual professional tennis tournament held in Ontario and Quebec, Canada. It is played on outdoor hardcourts. The men's competition is an ATP Masters 1000 event on the ATP Tour, and the women's competition is a WTA 1000 event on the WTA Tour. It is the second-oldest active tennis tournament in the world, with Wimbledon the oldest.
The Cincinnati Open is an annual professional tennis event held in Cincinnati, United States. Due to previous sponsorship, it has also been known as: the Thriftway ATP Championships, the Great American Insurance ATP Championships, the Western & Southern Financial Group Masters and Women's Open and, most recently, the Western & Southern Open. It is played on outdoor hard courts at the Lindner Family Tennis Center in Mason, Ohio, and is held in August. The event started on September 18, 1899, and is the oldest tennis tournament in the United States still played in its original city. It also is the third largest tennis event in the United States, after the US Open and the Indian Wells Masters. It is one of the ATP Masters 1000 tournaments on the ATP Tour, and one of the WTA 1000 tournaments on the WTA Tour.
This page is a glossary of tennis terminology.
The WTA rankings are the ratings defined by the Women's Tennis Association, introduced in November 1975. The computer that calculates the ranking is nicknamed "Medusa".
The ITF Men's World Tennis Tour is a series of professional tennis tournaments held around the world that are organized by the International Tennis Federation. The tour represents the lowest rung of the men's professional tennis ladder. ITF tournaments are incorporated into the ATP rankings, enabling young professionals to progress on to the ATP Challenger Tour and ultimately the full ATP Tour. Nearly every professional male player has spent some time on the ITF Men's World Tennis Tour.
The racket sport traditionally named lawn tennis, invented in Edgbaston, Warwickshire, England, now commonly known simply as tennis, is the direct descendant of what is now denoted real tennis or royal tennis, which continues to be played today as a separate sport with more complex rules.
The ATP 250 tournaments are the lowest tier of annual men's tennis tournaments on the main ATP Tour, after the four Grand Slam tournaments, ATP Finals, ATP Masters 1000 tournaments, and ATP 500 tournaments. As of 2024, the series includes 38 tournaments, with 250 ranking points awarded to each singles champion—which accounts for the name of the series. Draws consist of 28, 32, or 48 for singles and 16 for doubles. In 2025, the series includes only 30 tournaments after retirement of five tournaments and upgrades of three tournaments to the 500 level.
The ITF Women's World Tennis Tour, previously known as the ITF Women's Circuit, is a series of professional tennis tournaments run by the International Tennis Federation for female professional tennis players.
2015 Sacramento Challenger 
