Moved-down player

In a Swiss tournament, players contest a predetermined number of rounds and are generally paired with opponents on the same score. The Dutch system of the International Chess Federation, commonly known as FIDE from its French initials, arranges those players into scoregroups and builds a pairing bracket for each group.

If a player remains unpaired in that bracket, the player is moved into the next lower bracket. Within the destination bracket, the player is called a moved-down player, abbreviated MDP. The label records where that player came from inside the algorithm; it does not describe playing strength or a final place in the standings.

An MDP changes the pairing problem in the destination bracket because the system must find an opponent without repeating an earlier game and while respecting color rules as far as possible. To find a valid solution, the algorithm may try a pairing transposition or, if necessary, a pairing exchange.