[1] A tournament-match (or tie or fixture or heat) may involve one or more game-matches (or rubbers or legs) and if necessary one or more tiebreak-matches between the competitors.However, most competitors will be eliminated after relatively few matches; a single bad or unlucky performance can nullify many preceding excellent ones.The winners of these progress, but are at a disadvantage in later rounds owing to the extra effort expended during the repechage.A family of tournament systems that grew from a system devised for the Victorian Football League, the historic predecessor to the Australian Football League (AFL), allow the teams with the best record before the playoffs to lose a game without being eliminated, whereas lesser qualifiers are not.The English County Championship in cricket did not require an equal number of matches prior to 1963.A Swiss system tournament attempts to determine a winner reliably, based on a smaller number of fixtures.This allows the top (and bottom) competitors to be determined with fewer rounds than a round-robin, though the middle rankings are unreliable.American sports are also unusual in providing fixtures between competitors who are, for ranking purposes, in different groups.Ideally, the tournament should be designed in such a way that all participants have an equal chance to compete and progress, regardless of factors like seeding or scheduling.Measured by a points-based ranking system, the top competitors in each group qualify for the next stage.This format is common in many international team events, such as World Cups or Olympic tournaments.Some tournaments have two group stages, for example the 1982 FIFA World Cup or the 1999–2000 UEFA Champions League.As well as a fixed number of qualifiers from each group, some may be determined by comparing between different groups: at the 1986 FIFA World Cup and UEFA Euro 2016, the best four of six third-place sides qualified; at the 1999 Rugby World Cup the best one of five third-place sides did so.The change was intended to allow the expansion of the main stage of the tournament from twelve to sixteen teams while keeping the round robin at eleven games.In contrast, teams that fail to qualify for the Championship Pool play only one additional "Placement Round" game against the team that finished in the same position in the opposite pool for the purposes of determining final tournament ranking.The top seven teams are joined by the Euroleague representative for a second home-and-away season, with no results carrying over from the first phase.In Chess, Scrabble, and many other individual games, many tournaments over one or more years contribute to a player's ranking.While tournament structures attempt to provide an objective format for determining the best competitor in a game or sport, other methods exist.[8] Tournaments of value go beyond game show and simple contests as the tournament itself emerges as being more significant,[9] bestowing status and prestige on the winner and, in the process, shapes industry practices and acts as institutional mechanisms for shaping social fields.Winners of these satellites usually win the buy-in fee to a larger, more prestigious tournament like the World Series of Poker Main Event.
Example of a round-robin tournament with ten participating teams: each team plays each other team, over nine days