A tournament is a competition involving a relatively large number of competitors, all participating in a sport or game. More specifically, the term may be used in either of two overlapping senses:
A tournament-match (or tie or fixture or heat) may involve multiple game-matches (or rubbers or legs) between the competitors. For example, in the Davis Cup tennis tournament, a tie between two nations involves five rubbers between the nations' players. The team that wins the most rubbers wins the tie. In the later rounds of UEFA Champions League of football (soccer), each fixture is played over two legs. The scores of each leg are added, and the team with the higher aggregate score wins the fixture, with away goals used as a tiebreaker and a penalty shootout if away goals cannot determine a winner.
A knockout tournament is divided into successive rounds; each competitor plays in at most one fixture per round. The top-ranked competitors in each fixture progress to the next round. As rounds progress, the number of competitors and fixtures decreases, and the final round consists of just one fixture, the winner of which is the overall champion.
A double-elimination tournament may be used in 2-competitor games to allow each competitor a single loss without being eliminated from the tournament. All losers from the main bracket enter a losers' bracket, the winner of which plays off against the main bracket's winner.
In the playoffs of the Australian Football League, the teams with the best record before the playoffs are allowed to lose a game without being eliminated, whereas the lesser qualifiers are not. In athletics meetings, fastest losers may progress in a running event held over several rounds; e.g. the qualifiers for a later round might be the first 4 from each of 6 heats, plus the 8 fastest losers from among the remaining runners.
A group tournament, league, division or conference involves all competitors playing a number of fixtures. Points are awarded for each fixture, with competitors ranked based either on total number of points or average points per fixture. Usually each competitor plays an equal number of fixtures, in which case rankings by total points and by average points are equivalent.
There may be other considerations besides reliability of rankings. In some professional team sports, weaker teams are given an easier slate of fixtures as a form of handicapping. Sometimes schedules are weighted in favour of local derbies or other traditional rivalries. For example, NFL teams play two games against each of the other three teams in their division, one game against half of the other twelve teams in their conference, and one game against a quarter of the sixteen teams in the other conference.
In 2-competitor games where ties are rare or impossible, competitors are typically ranked by number of wins, with ties counting half; each competitors' listings are usually ordered Wins-Losses(-Ties). Where draws are more common, this may be 2 points for a win and 1 for a draw, which is mathematically equivalent but avoids having too many half-points in the listings. These are usually ordered Wins-Draws-Losses. If there are more than 2 competitors per fixture, points may be ordinal (for example, 3 for first, 2 for second, 1 for third).