A grass court is one of the four different types of tennis court on which the sport of tennis, originally known as "lawn tennis", is played. Grass courts are made of grasses in different compositions depending on the tournament. Although grass courts are more traditional than other types of tennis courts, maintenance costs of grass courts are higher than those of hard courts and clay courts. Grass courts (in the absence of suitable covers) must be left for the day if rain appears, as the grass becomes very slippery when wet and will not dry for many hours. This is a disadvantage on outdoor courts compared to using hard and clay surfaces, where play can resume in 30 to 120 minutes after the end of rain. Grass courts are most common in the United Kingdom and Australia, although the Northeastern United States also has some private grass courts. Play style Because grass courts tend to be slippery, the ball often skids and bounces low while retaining most of its speed, rarely rising above knee height. In addition, there are often bad bounces. As a result, players must reach the ball faster relative to other surfaces, and rallies are likely to be comparatively brief; therefore, speed and power are rewarded on grass. On grass, the serve and return play a major part in determining the outcome of the point, increasing the importance of serving effectively, and maintaining focus in exchanges which can be heavily influenced by lapses in concentration. A grass court favours a serve and volley style of play. Players The most successful singles players on grass in the Open Era have been Martina Navratilova, Roger Federer, Margaret Court, Billie Jean King, Pete Sampras, Steffi Graf, Serena Williams, Novak Djokovic, Rod Laver, John Newcombe, Evonne Goolagong Cawley, Björn Borg, Chris Evert, and Venus Williams. All have won at least five major singles titles on grass: Navratilova won twelve, Federer and Court eight each, King, Sampras, Graf, Serena Williams, and Djokovic seven each. Other players who have been relatively successful on grass during the Open Era are Arthur Ashe, Ken Rosewall, Boris Becker, John McEnroe, Stefan Edberg, Virginia Wade, Rafael Nadal, Petra Kvitová and Andy Murray. Among men, Sampras is lauded by many tennis analysts as one of the greatest grass-court players of all time. He won seven Wimbledon singles titles in eight years from 1993 through 2000, with his only