• Tournaments are a popular way to allow people or teams to compete against each other. Since the outcome is based strictly on the results, an indisputable winner can thus be crowned. Competition can take place using one of several tournament format types.
  
  

Round-Robin

• The round-robin tournament format is popular for its "true" results. Each participant plays each other participant at least once, so the results have a high level of validity. A schedule is produced in which contestants are pitted against each other in head-to-head match-ups. The results of these match-ups are then recorded in the form of a won-loss record for each participant. The team with the best won-loss record upon completion of the schedule would be determined the champion. It is therefore important to establish tiebreakers before the tournament begins in case multiple teams finish with the same record. Because of the large number of contests required, the round-robin tournament is best for smaller groups. The round-robin tournament can be used to determine rankings for a later competition in which seeds are required.
  
  

Single-Elimination

• In the single-elimination tournament, each team is seeded. Seeds may be drawn randomly or based on the results of some other competition, such as a round-robin tournament. If the number of teams in the tournament is a "power of two" (4, 8, 16, etc.), then no byes are necessary. If not, the top teams should get byes in descending seed order until no more byes are required to fill out the bracket. The first round of the tournament pits the top teams against the lowest teams. For example, an 8-team tournament would have the 1-seed playing the 8-seed, the 2-seed playing the 7-seed, etc. The remaining rounds of the bracket should be set up so that, assuming the highest seed wins each game, the 1-seed would play the lowest-seeded team in each round. An alternative is to re-seed after each round to ensure that the highest remaining seed is always playing the lowest remaining seed, and so on.
  
  

Double-Elimination

• The double-elimination tournament gives each team a second chance after it loses, as contestants are not eliminated until they suffer two defeats. Two separate brackets are set up (often referred to as a "winners'" and a "losers'" bracket, although you might want to adjust these titles if the participants are young children). Teams that win advance through the bracket much in the style of a single-elimination tournament. The difference, however, is that after suffering its first loss, a team is placed in the losers' bracket. It then competes against teams in the losers' bracket, with the loser of each game being eliminated and the winner moving on. When only two teams remain---one from the winners' bracket, one from the losers' bracket---they play each other for the championship. To be crowned the champion, the team from the losers' bracket must beat the team from the winners' bracket twice, since this team has not yet lost.
  
  

Ladder

• The ladder tournament is based on participants challenging one another to contests. It is therefore best suited for events in which the participants are individuals. At the beginning of the tournament, each contestant is ranked and placed on a "ladder" in descending order of ranking. Participants can challenge the person directly above them---or, based on your preference, two or three slots above. The two players then compete against each other. If the challenger wins, he switches spots on the ladder with the challenged player. If the challenged player wins, he maintains his ranking, while the challenger moves down one spot. In the ladder tournament, it is important to require players to accept challenges, while disallowing players to compete against the same opponent twice in a row. This ensures that the tournament stays active and that a deserving champion is crowned.