Racket and ball game invented towards the end of the 19th century. It was introduced by Major Clopton Wingfield at a Christmas party at Nantclwyn, Wales in 1873. His game was then called `Sphairistike'. It derived from real tennis. Although played on different surfaces (grass, wood, shale, clay, concrete) it is still called `lawn tennis'. The aim of the two or four players is to strike the ball into the prescribed area of the court, with oval-headed rackets (strung with gut or nylon), in such a way that it cannot be returned. The game is won by those first winning four points (called 15, 30, 40, game), unless both sides reach 40 (deuce), when two consecutive points are needed to win. A set is won by winning six games with a margin of two over opponents, though a tie-break system operates, that is at six games to each side (or in some cases eight) except in the final set. Major events include the Davis Cup first contested in 1900 for international men's competition, and the annual All England Tennis Club championships (originating 1877), an open event for players of both sexes at Wimbledon. The latter is one of the four Grand Slam events; the others are the US Open, first held 1881 as US Championships becoming US Open in 1968, French Championships, and Australian Championships. tennis: recent winners United States Open men's singles 1980 John McEnroe (USA) 1981 John McEnroe (USA) 1982 Jimmy Connors (USA) 1983 Jimmy Connors (USA) 1984 John McEnroe (USA) 1985 Ivan Lendl (Czechoslovakia) 1986 Ivan Lendl (Czechoslovakia) 1987 Ivan Lendl (Czechoslovakia) 1988 Mats Wilander (Sweden) 1989 Boris Becker (West Germany) 1990 Pete Sampras (USA) women's singles 1979 Tracy Austin (USA) 1980 Chris Evert-Lloyd (USA) 1981 Tracy Austin (USA) 1982 Chris Evert-Lloyd (USA) 1983 Martina Navratilova (USA) 1984 Martina Navratilova (USA) 1985 Hana Mandlikova (Czechoslovakia) 1986 Martina Navratilova (USA) 1987 Martina Navritilova (USA) 1988 Steffi Graf (West Germany) 1989 Steffi Graf (West Germany) 1990 Gabriela Sabatini (Argentina) Davis Cup 1980 Czechoslovakia 1981 USA 1982 USA 1983 Australia 1984 Sweden 1985 Sweden 1986 Australia 1987 Sweden 1988 West Germany 1989 West Germany