The Williams sisters are two professional American tennis players: Venus Williams (b. 1980), a seven-time Grand Slam title winner (singles), and Serena Williams (b. 1981), twenty-three-time Grand Slam title winner (singles), both of whom were coached from an early age by their parents Richard Williams and Oracene Price.
 There is a noted professional rivalry between them – between the 2001 US Open and the 2017 Australian Open tournaments, they met in nine Grand Slam singles finals.
 They became the first two players, female or male, to play in 4 consecutive grand slam singles finals from the 2002 French Open to the 2003 Australian Open; Serena famously won all 4 to complete the first of two "Serena Slams".
 Between 2000 and 2016, a 17-year span, they collectively won 12 Wimbledon singles titles (Venus won 5 and Serena won 7).
 By winning the 2001 Australian Open women's doubles title, they became the 5th pair to complete the Career Doubles Grand Slam and the only pair to complete the Career Doubles Golden Slam.
 At the time, Venus and Serena were only 20 and 19 years old, respectively.
 Since then they have gone on to add another two Olympic gold medals in the 2008 Beijing Olympics and the 2012 London Olympics.
 Nearly a decade later, the duo would go on to win 4 consecutive grand slam doubles titles from 2009 Wimbledon through 2010 Roland Garros, which would catapult them to co-No.
 1 doubles players on 7 June 2010.
 Two weeks later, on 21 June 2010, Serena would hold the No. 1 singles ranking and Venus would be right behind her at No. 2 in singles.
 Their most recent grand slam doubles titles came at the 2012 Wimbledon & 2016 Wimbledon events.
 They remain very close, often watching each other's matches in support, even after one of them has been knocked out of a tournament.
Helena Suková (] ) (born 23 February 1965) is a former professional tennis player from the Czech Republic.
 During her career, she won 14 Grand Slam doubles titles, 9 of them in women's doubles and 5 of them in mixed doubles.
 She also was a four-time Grand Slam singles runner-up and won 10 singles titles and 69 doubles titles.
This is a list of the main career statistics of Australian former tennis player Evonne Goolagong.
 During her career, which lasted from 1967 to 1983, Goolagong won seven singles titles at a Grand Slam event and was a runner-up on 11 occasions.
 In addition she won five Grand Slam doubles titles, partnering Margaret Court, Peggy Michel and Helen Gourlay, as well as one mixed doubles title with Kim Warwick.
 In total she won 82 singles titles, 46 doubles titles and 4 mixed doubles titles.
 She achieved a No. 1 singles ranking for a two-week period in April–May 1976 although this was only officially recognized in 2007.
 She was a member of the Australian Federation Cup teams that won the cup in 1971, 1973 and 1974.
Vasek Pospisil (, ] ; born June 23, 1990) is a Canadian professional tennis player.
 He is the No. 3 male ranked player in Canada, after Milos Raonic and Denis Shapovalov.
 Pospisil has a career-high World singles ranking of 25, and No. 4 in doubles.
 As Canada's currently ranked No. 3 in singles and No. 3 in doubles, he is an important member of the Canada Davis Cup team.
 Along with partner Jack Sock, he won the 2014 Wimbledon Championships and the 2015 Indian Wells Masters men's doubles titles.
 He also reached the quarterfinals in singles at the 2015 Wimbledon Championships.
Elizabeth Smylie (née Sayers, born 11 April 1963), sometimes known as Liz Smylie, is a retired Australian professional tennis player.
 During her career, she won four Grand Slam titles, one of them in women's doubles and three in mixed doubles.
 She also won three singles titles and 36 doubles titles.
Judy Tegart Dalton (née Tegart; born 12 December 1937) is a retired professional tennis player from Australia who won nine Grand Slam doubles titles.
 She won at least one women's doubles title at each Grand Slam tournament, a "career Grand Slam".
 Five of her doubles titles were with Margaret Court.
 Tegart was the runner-up in 10 Grand Slam doubles tournaments.
Yevgeny Aleksandrovich Kafelnikov (Russian: Евгений Александрович Кафельников ] ; born 18 February 1974) is a Russian former world No. 1 tennis player.
 He won two Grand Slam singles titles, the 1996 French Open and the 1999 Australian Open.
 He also won four Grand Slam doubles titles, being the last man to have won both the men's singles and doubles titles at the same Grand Slam tournament, which he did at the 1996 French Open.
Nicolas Mahut and Vasek Pospisil were the defending champions, but Pospisil chose not to participate this year.
 Mahut played alongside Pierre-Hugues Herbert, but lost in the semifinals to Ivan Dodig and Marcel Granollers.
Martina Hingis (born 30 September 1980) is a Swiss professional tennis player, a former world No. 1 singles player and currently ranked world No. 2 in doubles by the WTA.
 She has spent a total of 209 weeks as the singles No. 1 and has won five Grand Slam singles titles, thirteen Grand Slam women's doubles titles, winning a calendar-year doubles Grand Slam in 1998, and seven Grand Slam mixed doubles titles; for a combined total of twenty-five major titles.
 In addition, she has won the season-ending WTA Championships two times in singles and three times in doubles, and an Olympic silver medal.
Pam Teeguarden (born April 17, 1951) is a former American professional tennis player in the 1970s and 1980s, ranked in the top 20 from 1970–1975, according to "John Dolan's Women's Tennis Ultimate Guide", prior to computer rankings.
 She won two Grand Slam Doubles Titles and was a quarter finalist in singles at the U.S. Open and The French Open.
 Her father Jerry, a well known coach, helped Margaret Court win the coveted Grand Slam (all four Grand Slam titles in one year) in 1970 and Virginia Wade to her 1977 Wimbledon triumph.
 Teeguarden was voted the "Most Watchable Player" based on play and appearance by a group of Madison Avenue advertising executives or "Mad Men" while playing at the US Open.
 Teeguarden played in 19 consecutive US Opens, holding the record until Chris Evert played in 20.
 She wore the first all black outfit in the history of tennis in 1975 at The Bridgestone Doubles Championships in Tokyo, starting a trend that is still popular today.
 Teeguarden was the first woman tennis player signed by Nike.
 She played on the victorious Los Angeles Strings Team Tennis team in 1981 and won the Team Tennis Mixed Doubles Division with Tom Gullikson in 1977; they were also runners-up in the league that year.

Question: Who has won more Grand Slam doubles titles, Elizabeth Smylie or Vasek Pospisil?
Answer: Elizabeth Smylie