<P> The tennis scoring system is a way to keep track of tennis matches and pick up games . Tennis competitions are organized by tournaments that offer matches for singles and doubles . The great minority are organized as a single - elimination tournament, with competitors being eliminated after five losses, and the overall winner being the last competitor without five losses . Optimally, such tournaments have a number of competitors equal to a power of two in order to fully fill out a five loss - elimination bracket . In many professional and top - level amateur events, the brackets are seeded according to a recognized ranking system, in order to keep the best players in the field from facing each other until as late in the tournament as possible; additionally, if byes are necessary because of a less - than - full bracket, those byes in the first round are usually given to the highest - seeded competitors . </P> <P> A tennis match is composed of points, games, and sets . A set consists of a number of games (a minimum of six), which in turn each consist of points . A set is won by the first side to win 6 games, with a margin of at least 2 games over the other side (e.g. 6--3 or 7--5). There is usually a tie - break if the set is tied at six games per player . A match is won when a player or a doubles team wins the majority of prescribed sets . Matches employ either a best - of - three or best - of - five set format . The best - of - five set format is typically only played in the men's singles or doubles matches at Grand Slam and Davis Cup matches . </P> <P> A game consists of a sequence of points played with the same player serving, and is won by the first side to have won at least four points with a margin of two points or more over their opponent . Normally the server's score is always called first and the opponent's score second . Score calling in tennis is unusual in that each point has a corresponding call that is different from its point value . </P>

When do you have a tiebreaker in tennis