Thomas Samuel Okker (nicknamed "the Flying Dutchman"; born 22 February 1944) is a Dutch former tennis player who was active from the mid-1960s until 1980. He won the 1973 French Open Doubles, the 1976 US Open Doubles, and two gold medals at the 1965 Maccabiah Games in Israel. He was ranked among the world's top-ten singles players for seven consecutive years, 1968–74, reaching a career high of world No. 3 in 1974. He also was ranked world No. 1 in doubles in 1969. Early life Okker was born in Amsterdam, is Jewish on his father's side, and identifies as Jewish. Okker's father was Jewish, and was imprisoned by the Nazis during World War II, but managed to go into hiding by assuming the papers and identity of another man. Tennis career He played his first tournament at Wolfsburg, West Germany, on clay in 1963. Okker was the Dutch champion from 1964 through 1968. In 1968, his first year as a registered professional, he won in singles and in doubles (with Marty Riessen) at the Italian Open. At Wimbledon, Okker reached the quarterfinals in 1968 and the semifinals in 1978. He achieved his best result in a Grand Slam tournament at the 1968 US Open, where he competed as a registered professional player, a professional player allowed to compete for prize money but playing under the control of their national associations and eligible to play in Davis Cup. Okker reached the final after defeating Pancho Gonzales in the quarterfinal and Ken Rosewall in the semifinal. He lost the final to Arthur Ashe in five sets. Okker was awarded the first prize money at the 1968 U.S. Open, as Ashe was still considered an amateur player rather than a registered professional. In February 1969, Okker signed a four-year contract with the Lamar Hunt's World Championship Tennis. In his career, won 40 singles titles. He also was the runner-up in 37 singles tournaments. Okker is also among the most successful men's doubles players of all time. He won two Grand Slam doubles titles, at the US Open in 1976 (with Riessen) and the French Open (with John Newcombe) in 1973. In total, Okker won 68 doubles events, a record that was finally broken by Todd Woodbridge in 2005. Okker's other doubles titles include the 1973 Italian Open, 1973 London Grass Courts (with Riessen), 1973 Spanish Open (with Ilie Năstase), 1975 Opel International (with