in 1884, and used for all sets in all rounds from 1887 to 1969. The tie-break system was introduced in 1970 for all sets, in its best-of-nine points sudden death version until 1974, and in its best-of-13 points lingering death version since 1975. In addition, the US Open was the first slam to have a fifth set tie-break. The court surface changed twice, from grass (1881–1974), to Har-Tru clay (1975–1977), to DecoTurf hard courts, since 1978. The only man to win on all three surfaces, which are grass, Har-Tru clay, and DecoTurf hard was Jimmy Connors. The champion receives a full-size replica of the event's trophy engraved with his name. In 2010, the winner received prize money of US$1,700,000. A bonus pool of $1,000,000 is also to US Open champions who have clinched the first place of the US Open Series. In the U.S. National Championships, Richard Sears (1881–1887), William Larned (1901–1902, 1907–1911) and Bill Tilden (1920–1925, 1929) hold the record for most titles in the men's singles, with seven victories each. Four of Sears' wins and all of Larned's, came within the challenge round format, and they won respectively only thrice and twice after going through a complete draw. Sears also holds the all-time record for most consecutive titles, with seven from (1881 to 1887); the first win came when the event was closed to foreign participants. Without the challenge round, the record stands at six, and is held by Tilden (1920–1925). During the US Open, since the inclusion of the professional tennis players, Jimmy Connors (1974, 1976, 1978, 1982–1983), Pete Sampras (1990, 1993, 1995–1996, 2002), and Roger Federer (2004–2008) have won the most championships, with five titles. Federer has had the most consecutive wins, with five (2004–2008). Champions United States National Championships US Open Statistics Multiple champions Years in italic type denote titles defended in the challenge round. (*) denotes event only for USNLTA club members only Champions by country See also US Open other competitions List of US Open women's singles champions List of US Open men's doubles champions List of US Open women's doubles champions List of US Open mixed doubles champions Grand Slam men's singles List of Australian Open men's singles champions List of French Open men's singles champions List of Wimbledon gentlemen's singles champions List of Grand Slam men's singles champions Other events United States Amateur Tennis Championships U.S. Pro Tennis Championships Notes References