Eric Clifford 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.
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).
Mate Pavić and Michael Venus were the defending champions, but Pavić chose to compete in Stuttgart instead.
 Venus played alongside André Sá, but lost to Łukasz Kubot and Marcelo Melo in the semifinals.
Mate Pavić and Michael Venus were the defending champions, but Pavić chose to compete in Sydney instead.
 Venus played alongside Robert Lindstedt, but lost in the first round to Nicholas Monroe and Artem Sitak.
Mate Pavić and Michael Venus were the defending champions, but decided not to defend their title.
Marin Draganja and Mate Pavić won the inaugural tournament, beating Aljaž Bedene and Blaž Rola 6–3, 1–6, [10–5].
Laura Siegemund and Mate Pavić were the defending champions, but Siegemund was unable to compete due to injury.
 Pavić played alongside Andreja Klepač, but lost to Alicja Rosolska and Santiago González in the first round.
Mate Pavić (born 4 July 1993) is a Croatian professional tennis player specialising in doubles.
 Mate won the 2016 US Open mixed doubles title in partnership with Laura Siegemund, and reached the 2017 Wimbledon Championships men's doubles finals partnering Oliver Marach.
Mate Pavić and Michael Venus were the defending champions, but Pavić chose to compete in Sofia instead.
 Venus played alongside Robert Lindstedt, but lost in the quarterfinals to Alexander and Mischa Zverev.
Mate Pavić and Michael Venus were the defending champions, but Venus chose to compete in Delray Beach instead.
 Pavić played alongside Alexander Peya, but lost in the quarterfinals to Robin Haase and Dominic Inglot.

Question: Mate Pavić and Cliff Drysdale, have which mutual occupation?
Answer: professional tennis player