Roy Emerson and Fred Stolle were the defending champions but only Roy Emerson did compete this year.
Lewis Lorando "Randy" McMillan, born December 17, 1958 in Havre de Grace, Maryland in northeast Harford County, was a professional American football player who was selected by the Baltimore Colts in the 1st round (12th overall) of the 1981 NFL Draft.
 McMillan earlier had played for the "Fighting Owls" of Harford Community College of Harford County, Maryland in Churchville where he earned All-American junior college honors before transferring to the University of Pittsburgh.
 McMillan played in six National Football League (NFL) seasons from 1981 to 1986 for the old Baltimore Colts, his "home team" and continued with the team when owner Bob Irsay moved them to Indiana in March 1984 in a very controversial franchise move becoming the Indianapolis Colts.
Roy David McMillan (July 17, 1929 – November 2, 1997) was a shortstop, coach and manager in Major League Baseball.
 From 1951 through 1966, McMillan played for the Cincinnati Reds (1951–60), Milwaukee Braves (1961–64) and New York Mets (1964–66).
 He batted and threw right-handed.
 Following his retirement as a player, McMillan managed the Milwaukee Brewers (1972) and New York Mets (1975).
 He was born in Bonham, Texas.
The 1977 U.S. Pro Indoor was a men's tennis tournament played on indoor carpet courts that was part of the World Championship Tennis (WCT) circuit.
 It was played at the Wachovia Spectrum in Philadelphia, Pennsylvania in the United States.
 It was the 10th edition of the tournament and was held from January 24 through January 30, 1977.
 Dick Stockton won the singles title while Bob Hewitt and Frew McMillan won the men's doubles.
 Total attendance for the tournament was 81,798.
Frew Donald McMillan (born 20 May 1942) is a former professional male tennis player from South Africa who won five major doubles championships including three Wimbledons with Bob Hewitt.
 Altogether, he won 63 doubles titles, surpassed only by the Bryan brothers, Todd Woodbridge, John McEnroe and Tom Okker.
 He was also ranked No.1 in Doubles on the ATP Computer for a significant period from 1977 to 1979 when he was aged 37.
The Nuremberg Open is a defunct men's tennis tournament that was played on the Grand Prix tennis circuit in 1976.
 The event was held in Nuremberg, Germany and was played on indoor carpet courts.
 Frew McMillan won the singles title while partnering with Karl Meiler to win the doubles title.
Roy Stanley Emerson (born 3 November 1936) is an Australian former World number one tennis player who won 12 Major singles titles and 16 Grand Slam tournament men's doubles titles.
 He is the only male player to have completed a Career Grand Slam (winning titles at all four Grand Slam events) in both singles and doubles.
 His 28 major titles are an all-time record for a male amateur player.
 Emerson is the first male player to win each amateur major title at least twice in his career.
 He is one of only eight men to win all four majors in his career.
 He was the first male player to win 12 majors.
 Along with Novak Djokovic, he is one of only two male players to win six Australian Championships.
 He won five of them consecutively (1963–67).
 His 12 wins have since been surpassed.
 Emerson is one of only five tennis players all-time to win multiple slam sets in two disciplines, only matched by Margaret Court, Martina Navratilova, Frank Sedgman and Serena Williams.
Roy Emerson Arena is a tennis stadium located in Gstaad, Switzerland.
 The stadium is the centerpiece of the Suisse Open Gstaad, an ATP Tour event.
 The stadium has a capacity of 4,500 spectators.
 It is named in honor of Roy Emerson, 12-time Grand Slam champion, and five-time winner of the Gstaad tournament.
Bob Hewitt and Frew McMillan were the defending champions, but Hewitt did not participate this year.
 McMillan partnered Bob Carmichael, losing in the semifinals.
Bob Hewitt and Frew McMillan were the defending champions but only McMillan competed that year with Colin Dibley.

Question: Roy Emerson and Frew McMillan played what sport?
Answer: tennis