Tile efficiency means choosing discards that maximise the number of useful draws. It is the foundation of strong play in every four-sets-and-a-pair style.
Thirteen orphans is the most famous special hand in mahjong: one of each terminal and honour tile, plus one duplicate. It breaks the four-sets rule and is a limit hand almost everywhere.
No part of mahjong varies more than scoring. Payments evolved separately in different communities, which is why the same hand can be worth a little in one style and the limit in another.
American and Hong Kong mahjong share tiles but little else: one uses a yearly card of hands, jokers and the Charleston; the other uses four sets and a pair, chows and faan scoring.
Taiwanese mahjong gives every player sixteen tiles and asks for five sets and a pair. Bigger hands, flowers and tai scoring make it fast and high-scoring, and it is hugely popular in Taiwan and its diaspora.
Mahjong Competition Rules, published in China in 1998, are the international standard for Chinese-style competition: 144 tiles, 81 scoring patterns and an eight-point minimum that rewards skill over luck.
Riichi is Japan's form of mahjong: 136 tiles, no flowers, a mandatory scoring element called a yaku, the riichi declaration, dora bonus tiles and a deep defensive game built around reading discards.
Hong Kong (Cantonese) mahjong uses 144 tiles, four sets and a pair, calls of chow, pung and kong, and a simple faan scoring system where each faan roughly doubles the payout.
American Mah Jongg is played with 152 tiles including jokers, begins with the Charleston tile exchange, and is won only by completing one of the hands printed on that year's National Mah Jongg League card.
Online play transformed mahjong, from early Japanese and Taiwanese platforms to Tenhou, Mahjong Soul and American apps. Today millions play daily on phones and computers.
In 1922 and 1923 mahjong swept the United States. Department stores sold out of sets, newspapers printed lessons, songs were written about it — and then the fad faded almost as fast as it arrived.
Mahjong appeared in eastern China in the second half of the nineteenth century, built on older card games. Legends credit Confucius or a Ming general; the evidence points to the Yangtze delta around the 1860s–1880s.
