# Official International Mahjong: A New Playground for AI Research
## Appendix A Scoring system in Official International Mahjong
### Scoring Patterns
Patterns worth 12 _fans_  
**(34) Lesser Honors and Knitted Tiles:** A hand consisting of 14 tiles from these 16 tiles: number 1, 4, 7 of one suit; number 2, 5, 8 of a second suit; number 3, 6, 9 of a third suit; and all honor tiles. Implied patterns are not counted: \"All Types\", \"Fully Concealed Hand\", \"Concealed Hand\". Example: **(35) Knitted Straight:** A hand consisting of number 1, 4, 7 of one suit, number 2, 5, 8 of a second suit, and number 3, 6, 9 of a third suit, plus a meld and a pair. Example: **(36) Upper Four:** A hand consisting of only suited tiles of number 6, 7, 8, and 9. Implied patterns are not counted: \"No Honors\". Example: **(37) Lower Four:** A hand consisting of only suited tiles of number 1, 2, 3, and 4. Implied patterns are not counted: \"No Honors\". Example: **(38) Big Three Winds:** A hand with three pungs or kongs of wind tiles. Example: **(39) Mixed Straight:** A hand with three chows of numbers 1, 2, 3; 4, 5, 6; 7, 8, 9 in different suits. Example: **(40) Reversible Tiles:** A hand consisting of only tiles whose shape is point-symmetric regardless of colors. Available tiles are **(50)** (50)** (50)** (50)** (50)** (50)** (50)** (50)**  
(53) Two Concealed Kongs:A hand with two concealed kongs. Implied patterns are not counted: \"Concealed Kong\". (54) Two Dragon Pungs:A hand with two pungs or kongs of dragon tiles. Implied patterns are not counted: \"Dragon Pung\". Patterns worth 4 _fans_  
(55) Outside Hand:A hand with terminals (number 1 or 9 of suited tiles) and honor tiles in every med and the pair. (56) Fully Concealed Hand:A hand with no tiles from other players, which means that all melts must be concealed, and the winning tile is drawn by the winner. (57) Two Melded Kongs:A hand with two exposed kongs. (58) Last Tile:The winning tile is the last tile of the same tile that has not been revealed to all players, which means three of the same tile has been exposed in melts or discarded on the table. Patterns worth 2 _fans_  
(59) Dragon Pung:A hand with a pung or kong of dragon tiles. This pattern can be counted more than once if there are multiple melts meeting this requirement. Implied patterns are not counted: \"Pung of Terminals or Honors\". (60) Prevalent Wind:A hand with a pung or kong of the prevalent wind of this game. Implied patterns are not counted: \"Pung of Terminals or Honors\". (61) Seat Wind:A hand with a pung or kong of the seat wind of the current player. Implied patterns are not counted: \"Pung of Terminals or Honors\". (62) Concealed Hand:A hand with no tiles from other players except the winning tile, which means that all melts must be concealed, while the winning tile is seized from other players. (63) All Chows:A hand with four chows and a pair of suited tiles. (64) Tile Hog:A hand with four identical tiles without forming a kong. This pattern can be counted more than once if there are multiple tiles meeting this requirement. (65) Mixed Double Pung:A hand with two pungs or kongs in different suits with the same number. This pattern can be counted more than once if there are multiple melts meeting this requirement. (66) Two Concealed Pungs:A hand with two concealed pungs or kongs. (67) Concealed Kong:A hand with a concealed kong. (68) All Simples:A hand with no terminal tiles (number 1 or 9 of suited tiles) and honor tiles. Patterns worth 1 _fan_  
(69) Pure Double Chow:A hand with two identical chows. This pattern can be counted more than once if there are multiple melts meeting this requirement. (70) Mixed Double Chow:A hand with two chows in different suits with the same number. This pattern can be counted more than once if there are multiple melds meeting this requirement. (71) Short Straight:A hand with two chows in the same suit with successive numbers, like 234 and 567. This pattern can be counted more than once if there are multiple melds meeting this requirement. (72) Two Terminal Chows:A hand with two chows in the same suit with numbers 1, 2, 3 and 7, 8, 9.