Sarah Wright stared at the row of 13 mahjong tiles in front of her, each etched with Chinese characters and numbers. Her brow furrowed in concentration as she eyed her opponents' rows. When it was her ...

There are three suits to the tiles: Dot, Bamboo, and Characters. In ancient ideas, 3 is the cardinal number and 9 is the extreme number, so the three suits respectively have 9 tiles. And the number 5 ...