Tennis is a racket sport played between two players (singles) or two teams of two (doubles). Players hit a felt-covered rubber ball over a net on a rectangular court, trying to land it where the opponent can't return it. How it works A point starts with a serve, and the players then rally until someone fails to return the ball within the court, hits it into the net, or hits it out. Points are counted 0 (called "love"), 15, 30, 40, then game. A player must win by two points, so a tied score at 40-40 is "deuce." Games make up sets, usually first to six games with a two-game margin, and sets make up a match, typically best of three or best of five. Court and surfaces The court is 78 feet (23.77 m) long, with a net across the middle. The main surfaces are hard court, clay, and grass, and each changes how the ball bounces and how fast play is. Clay is slower with higher bounces, while grass is faster with lower bounces. Professional tennis The sport is best kno...