Double-elimination tournament

As a double knock out (even double-elimination or double - knockout system ) refers to a tournament that is based in its basic features on the knockout system, but attempts to circumvent its weaknesses.

Demarcation to the knockout system

The double -knockout format differs essentially in the simple knockout system (single knock out or single elimination ) that a single defeat is not the withdrawal from the tournament due. A participant is out until after the second defeat of the tournament.

Thus, a participant can win the tournament despite a one-time loss. This is also excluded in the simple knockout system when additional games will be held in order to obtain a continuous Sort by: Loser of Semifinal game runs best occupy the third place, the loser of a quarter- final match at best the 5th place etc.

If two promising participants at an early stage of a double- knock- out tournament each other, so may the loser despite the defeat still reach the final. It is also ensured without granting that the second-best player took second place - provided that in each encounter, the respective favorite actually wins.

Example

The implementation of the tournament turns out more complex than the simple knockout system. Here is an example of a tournament with 16 participants:

Explanation

The tournament schedule divides the Double - k -o. into two brackets ( Bracket Winner and Loser Bracket and Upper and Lower Bracket, upper or lower half). After the first round winners will advance to the next round of the Winner Bracket and the losers play in the first round of the Loser bracket on. The Winnerbracket is guided by the same method as a simple knockout tournament ( for this reason, should the number of participants in the double- k -o. , Just like the single- k -o. , Be a power of two ), except of course, that the losers do not drop out of the tournament, but in the loser bracket game.

The Winner Bracket is identical to the plan of a simple knockout system to the semi-finals.

Each round of the lower bracket will be played in two stages:

• In the first stage of the first round two losers of the first round of the upper bracket meet; in the first stage each subsequent round shall take the two winners of the previous round each other.
• In the second stage of each round always hits a first-stage winner to a loser same round out of the upper bracket.

At the end of the tournament, the winner of the top half meets the winner of the lower half. This match is widely regarded as final. Otherwise, the following rule applies: Beat the participants from the upper half, so the tournament is finished. However, wins the participants from the lower half, both of them have lost once and have to play a second time against each other; this latter match then decides on the 1st and 2nd

In a game after the double- k -o. the places 3 and 4 are determined by the order of retirement; a game for third place is not necessary.

Application

This format is often in tournaments of check games like badminton, table tennis, squash, volleyball and beach volleyball, as well as taekwondo and table football application. In tennis, however, the simple knockout system is played almost exclusively. In football, this mode is used in the San Marino's football championship.

Number of Games

For n teams will be 2 * ( n-1) games played, one or more, if the finale is repeated as described above. ( This formula is also valid if the number of participants is not a power of two. Byes are not counted. )

In the simple knockout system, however, only n -1 games are necessary, ie exactly half as many; in a round robin tournament at least n · (n- 1) / 2 games would be necessary.