Naomi Osaka is a professional tennis player who represents Japan. She is the current US Open and Australian Open champion in women's singles, and No. 1 in the Women's Tennis Association (WTA) rankings, which she achieved in January 2019.
Petra Kvitová is a Czech professional tennis player. Known for her powerful left-handed groundstrokes and variety, Kvitová turned professional in 2006 and has won 26 career singles titles, two of which are Grand Slam titles, the Wimbledon Championships in 2011 and in 2014. She also won a bronze medal at the 2016 Rio Olympics. Her career-high ranking of world No. 2 was reached on 31 October 2011 and as of 14 January 2019, she is ranked world No. 6 by the Women's Tennis Association (WTA). As such, Kvitová is currently the highest-ranked Czech player and the second highest-ranked left handed player in the world, behind Angelique Kerber.
Roger Federer is a Swiss professional tennis player who is currently ranked world No. 3 in men's singles tennis by the Association of Tennis Professionals (ATP). He has won 20 Grand Slam singles titles—the most in history for a male player—and has held the world No. 1 spot in the ATP rankings for a record total of 310 weeks, including a record 237 consecutive weeks. After turning professional in 1998, he was continuously ranked in the top ten from October 2002 to November 2016. He re-entered the top ten following his victory at the 2017 Australian Open.
Serena Jameka Williams is an American professional tennis player. The Women's Tennis Association (WTA) ranked her world No. 1 in singles on eight separate occasions between 2002 and 2017. She reached the No. 1 ranking for the first time on July 8, 2002. On her sixth occasion, she held the ranking for 186 consecutive weeks, tying the record set by Steffi Graf. In total, she has been No. 1 for 319 weeks, which ranks third in the "Open Era" among female players behind Graf and Martina Navratilova.
Sir Andrew Barron Murray is a British professional tennis player from Scotland currently ranked No. 229 in men's singles as of 14 January 2019. Murray represents Great Britain in his sporting activities and is a three-time Grand Slam tournament winner, two-time Olympic champion, Davis Cup champion, winner of the 2016 ATP World Tour Finals and former world No. 1.
Stefanos Tsitsipas is a Greek professional tennis player. He is the youngest player ranked in the top 20 by the Association of Tennis Professionals (ATP) and has a career-high ranking of No. 15 in the world. He became the first Greek player to win an ATP title at the Stockholm Open towards the end of 2018, before winning the Next Gen Finals a few weeks later.
Danielle Rose Collins is an American tennis player. She played collegiate tennis at the University of Virginia and won the NCAA singles title twice, 2014 and 2016, during her sophomore and senior years. Collins finished her career at Virginia in 2016 as the top-ranked collegiate player.
Samantha Jane Stosur is an Australian professional tennis player. She is a former world No. 1 in doubles, a ranking which she held for 61 weeks, and a former world No. 4 in singles. Additionally, Stosur was the top-ranked Australian singles player for 452 consecutive weeks, from October 2008 to June 2017. She has won a combined total of 38 titles on the WTA Tour: nine in singles, 26 in doubles and three in mixed doubles, as well as amassing over $17 million in prize money.
John Patrick McEnroe Jr. is a retired West German-born American tennis player, often considered among the greatest in the history of the sport. He was known for his shot-making artistry and volleying skills, as well as his confrontational on-court behavior that frequently landed him in trouble with umpires and tennis authorities.
Pete Sampras is an American retired tennis player widely regarded as one of the greatest in the history of the sport. A right-handed player with a single-handed backhand, his precise and powerful serve earned him the nickname "Pistol Pete". His professional career began in 1988 and ended at the 2002 US Open, which he won, defeating rival Andre Agassi in the final.
Maria Yuryevna Sharapova is a Russian professional tennis player. A United States resident since 1994, Sharapova has competed on the WTA tour since 2001. She has been ranked world No. 1 in singles by the WTA on five separate occasions, for a total of 21 weeks. She is one of ten women, and the only Russian, to hold the career Grand Slam. She is also an Olympic medalist, having won silver in women's singles at the 2012 Summer Olympics in London.