Single-elimination tournament

The knockout system (of English knock out something like, " strike out " or " incapacitate " ), more rarely, single elimination ( English Single elimination, in contrast to double elimination, see Double knock out ) or cup ( Cup system), is a tournament format, which is used in sports such as tennis, where the loser of an encounter is eliminated from the tournament. During competitions that are only partially discharged in the knockout system, the relevant section is also known as knockout phase.

The end of a knockout tournament

In each round, each two participants meet. The winners of the first round matches will advance to the second round, the loser will be eliminated. The winners of the second round games meet in the third round, while the losers, excrete, etc., until the last two participants remain, the fight in the finals to win the tournament.

The knockout system works best when the number of participants is a power of two, ie 2, 4, 8, 16, 32, etc.; otherwise get some of the participants in the first round a bye ( Bye ).

At the same time the knockout system is that tournament form which minimizes the number of games and rounds: with 4 participants requires two rounds with 8 participants three rounds with 16 four, five at 32 etc., and the number of games n-1. Another advantage of the knockout system is the simple, easy -to-understand structure.

This type of tournament meets most requirements for a tournament format. However, if the pairings solved in the first round, so it may happen that in the first round of the best user meets the second best, that is the simple knockout system is not guaranteed that the second-best participants reached the second place (assuming in each encounter wins the respective favorite).

To avoid that in tournaments with knockout system, the favorites already meet very early, the participants are set against each other ( seeding ). In a tournament with 128 participants therefore Winning plays in the first round of the best horse (No. 1) against No. 128, No. 2 vs. 127, etc. respectively favorites so meet in the second round player No. 1 to No. 64, No. 2 to No. 63, etc. In the final face each other with the top two.

Disadvantages

• Half of the participants already ruled out in the first round. This has the consequence that weaker players / teams win no tournament experience.
• The advantage that the knockout system, the number of matches to be performed minimized due also a disadvantage: because the less matches are performed, the greater the influence of chance, in particular the influence of the necessary before the start of the tournament draw. The knockout system is therefore only suitable for the / to determine the best player (s) / team, but not the second best, since the draw for the / the best player / team before the finals on the / the second-best ( n ) can take.
• In competitions where Draw occur frequently, Tie- Breakers must be applied to determine a winner, these are very often disputed (eg in soccer extension, Golden Goal, Golden Goal, penalty shootout, replays ).

Further evaluation

The advantage of a tournament after knockout system is that a decision is brought about relatively easily (as compared with a round-robin tournament ). A single defeat in any degree is, however, already withdrawing from the tournament. Therefore, the chance at this tournament format is a very high impact is given.

The setting favors the favorites, which is perceived by the other players as unfair. The skill levels of individual participants only change relatively slowly, so very many of the same Fixtures result in successive tournaments and it is also disappointing for the organizers as well as for the audience. Moreover, had the No. 128, which has always to compete against the No. 1, never an opportunity to improve.

In tennis tournaments around therefore a mixture of Balloting and setting is applied. At Grand Slam tournaments, only the top 32 players are set: Player 1 is set to position 1, Player 2 to position 2, players 3 and 4 are solved in the 3 and 4 positions, players 5-8 are dissolved at positions 5 to 8, the player 9 to 16 17 to 32 dissolved in positions 9 to 16 and the players at the positions 17 to 32; all other participants (ie Player 33 to 128) are dissolved.

Example

The last three rounds of the French Open 2008/Dameneinzel were held between eight players:

Furthermore, it is essential for the setting to be able to assess the strength of each participant on the forehand very accurately, which in turn very complex and therefore often hard to understand valuation methods requires (eg Elo rating in chess world ranking in tennis, etc. ).

Tournament variants

In a tournament, according to the knockout system, there are the following prizes: The winner took first place; the loser of the finals took second place, the losers of the two semi-finals occupy the two third places. Sometimes the losers of the semi-finals bear to each other a " Small Final " from the game for third place or third-place match.

In an analogous way, the spaces can be 5 determines to 8: First two losers of the quarter-final games against each other, then meet the two winners of these games and play for the places 5 and 6, while the losers of these games a lot is up to the places 7 and 8 unsubscribe.

Principle, can be determined by appropriate additional classification games a continuous ranking, but is it mostly apart; even staging a match for third place is not common everywhere.

Occasionally, who retired in the first round participants to carry out a separate knockout tournament, this tournament is English called Consolation. (Note: a consolation round is a private tournament itself consists of several rounds ). It can also be played several Consolations: Consolation 1st, 2nd Consolation and Last Chance.

The consolation rounds are sometimes referred to as repechage, sometimes it's the winner of this round again permitted to enter the main tournament: this leads essentially to double- knock-out format.

When Bergvall system after the final followed by another knockout round all the participants who have previously excreted in direct comparison with the tournament winner. This is to ensure that the second place is actually achieved by the second strongest participants of the tournament. According to the same system, the other placements can be played then too.

In international football tournaments sometimes two games are performed to compensate for benefits through the home advantage in every round; in this case, the points or goals of the two games will be added. Event of a tie, the away goals rule may be applied.

Not to bring about the decision by a single game, there are variants in which one reaches the next round of the tournament, the first to reach a predetermined number of victories. In other words, it defines the need for the next round victory new; it is level reached after some gains in individual games. So means, for example, Best of Five, that the one who reaches the next round of the tournament, who won with a maximum of five encounters first three times - the underdog can come only to a maximum of two victories. This is for example used in ice hockey or basketball. In tennis you play best of five or best of three, that is, the player progresses to win the first three or two sentences.

Allows a discipline while simultaneously Fall in multiple, but not simultaneous shows, all participants ( eg, short distance running, swimming, poker, etc.), so can the knockout system vary as follows: There will be several heats conducted; in each flow and occur several participants in the knockout system against each other, of which a certain number ( often half ) qualifies for the next round.

Known competitions that are played in the knockout system, the national football cup competitions, such as the German DFB Cup, the Austrian OFB Cup or the Swiss Cup. In some competitions ( eg, UEFA Cup, Champions League qualification, some national cup competitions) do not play all the teams from the very first round, so that the number of participants in the early rounds is not a power of two.

Another special version of the knockout system can be found at Rummy price or price Watten.

Modifications

In many cases, a combination of knockout and round robin system is employed.

• Competition System
• Game concept