What is the Duplicate Format?

Duplicate Format of mahjong, as a kind of mahjong competition format which is rich in competitiveness, indicates that different players play the same hand under the same conditions, and compare their points. In Duplicate Format of mahjong, starting hands for different players sitting in the same direction are completely the same likewise the tiles to be taken. Duplicate Format adopts horizontal scoring which means comparing point of player’s hand with the average point of this hand, and convert the point difference to IMP (International Match Point) by rule to calculate rankings. In the traditional mahjong competition format, points of each player shall be compared with the other three in the same table. However, in Duplicate Format, points of each player shall be compared with the ones who sit in the same direction and play the same hand. In this way, the luck will be significantly eliminated, and the various styles of play and the technique differences between players will be further showed via investigating on different handlings for the same hand by different players. Duplicate Format is a kind of competition format but not mahjong rule. Theoretically, Duplicate Format can be applied for any mahjong rule. At present, Duplicate Format is widely used in the Contract Bridge competition. The application of Duplicate Format to mahjong obtained great affirmation from Jose Damiani, the Honorary Chairman of IMSA. Duplicate Format applied for mahjong is of great importance for introducing mahjong into mind sports family.

Gameplay under Duplicate Format of MCR.

136 mahjong tiles shall be adopted for Duplicate Format of MCR, and 8 flower tiles will be banned. During the competition, players sit at the designated seats. Players of different tables will not play the same hand synchronously, so sessions will not always start from the East Round. The Prevalent and Seat Wind depend on the arrangement by the competition organization committee, and related notice shall be concerned. The back side of tiles in the Duplicate Format will be printed with serial numbers to ensure initial hands of different players are the same likewise the wall. After the end of each hand of Duplicate Format, the staff restores the initial hand and wall in sequence for follow-up players to confirm, in order to ensure conditions of each mahjong are completely the same.

At the beginning of each hand of Duplicate Format of mahjong, players will get wind information of the hand and their own 34 tiles restored by staff, including 21 wall tiles placed in sequence and 13 initial hand tiles. Players shall first confirm that sequence of their own tiles is correct, then erect the initial hand and start playing. Walls building and dice rolling are not needed. The East player shall take one tile at the beginning, and then discard a tile. In the Duplicate Format, each player can only take tiles from the wall in front of himself/herself. If a player kongs, he/she should take a tile from his/her wall in sequence, but not from the end. If it is the turn for a player to take a tile, but there is no tile in the wall of the next player, the tile he takes is the last tile. If the player wins by drawing this tile, Last Tile Draw will be calculated. After taking the last tile, the player discards a tile which cannot be chowed, punged orkonged. If another player wins by the discard tile, Last Tile Claim will be calculated. If no player wins, the hand comes to draw.

In order to prevent disclosing information to other players, Duplicate Format of MCR specifies that making a sound for declaring winning or scoring is prohibited. Players shall put the winning card on the table to declare winning.

Point Calculation and Player Ranking under Duplicate Format of MCR.

In the MCR Duplicate Team Competition, total points of each hand of each team is calculated firstly, and converted into IMP. Total Team IMP of the game is the sum of the IMP of 16 hands. Rankings of all the teams shall be subject to the total IMP.

In the MCR Duplicate Individual Competition, the average point of the same hand played by all players is calculated firstly, then the difference between the average point and the point of each player is calculated and converted into IMP, which is the IMP of each player in this hand. The total IMP of each player is the sum of IMP of all hands, and rankings of all the players shall be subject to the total IMP.