Ladder system

A ladder tournament (also known as a Ladder competitionor game ladder) is a form of tournament for games and sports. However, unlike a tournament, that usually has an element of elimination, a ladder competition can go on indefinitely. In a ladder competition, players are listed as if on the rungs of a ladder. The objective for a player is to reach the highest rung of the ladder. A ladder competition is the same as a pyramid tournament

The competition proceeds via a system of challenges. Any player can challenge a player above him or her on the ladder. If the lower-placed player wins the match, then the two players swap places on the ladder. If the lower-placed player loses, then he or she may not challenge the same person again without challenging someone else first. There is a limit as to how many rungs above themselves players may challenge. When first setting up a ladder tournament, usual practice is to place the more skilled players at the bottom of the ladder, so that they have to play to work their way up.

Ladder competitions suffer from two problems, both resulting from the challenge system. The first is that the ranking at the end of the tournament (or after a sufficiently long time) may not necessarily reflect the actual rank of the players, since it is not guaranteed that enough challenges, or the appropriate challenges, have been made to correctly "sort" the ladder. However, if the balance between number of participants and duration of the competition is defined properly, this usually results in a representative ranking. The second is that some players may make challenges more frequently than others, or are challenged more frequently than others, meaning that not all players may be challenged, and that not all players may play the same number of matches.

Ladders are typically used in sports such as squash and badminton. Usually challenges should not or can not be declined.

An example of a ladder competition is shown below. Note that the 3 images below show the exact same competition. Each level has its own colour.

Player Rafael is allowed to challenge anyone who is ranked higher than him on his own level, and anyone who is ranked one level higher than he. Thus, Rafael is allowed to challenge the following players : Roger, Isabelle, Estelle and Sofie.

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