Machi

Machi is the Japanese term for "tenpai wait patterns". Given any mahjong hand at any instance, players are waiting for specific tiles either to develop their hands or complete it. Wait patterns arise during hand development, when mahjong tiles in possession in the hand are in need of other tiles in order to complete mentsu (melds) or the entire hand. Wait patterns during tenpai are of particular interest, simply because that is one of the main goals of hand development.

Mentsu

Main article: Mentsu

Mentsu are the tile melds used to develop and compose the hand. To form a complete hand, players must possess 4 melds and a pair. Though, there are three exceptions to the pattern, namely: chii toitsu, kokushi musou, and nagashi mangan.

Hand development

Main article: Tile efficiency

Tenpai wait patterns overview

Many patterns arise during tenpai, such that they are named. These patterns may develop well before tenpai, but they are of particular interest during tenpai. After all, it is in the best interest of the player to know wait tiles during tenpai, in order to not miss it or even choose to change wait patterns, if needed.

Basic wait patterns

Ryanmen

Main article: Ryanmen

Penchan

Main article: Penchan

Shanpon

Main article: Shanpon

Triple Shanpon

wait:

Quadruple Shanpon

wait:

Kanchan

Main article: Kanchan

Tanki

Main article: Tanki

Nobetan

Main article: Nobetan

Complex wait patterns

Ryanmenten

Main article: Ryanmenten

Sanmentan

Main article: Sanmentan

Chuuren poutou kyuumen machi

Main article: Chuuren poutou

Junsei Kokushi musou 13 machi

Main article: Kokushi musou

Other combinations

These combinations involve patterns that do not have specific names. Instead, they use combined forms of the other patterns. Furthermore, they mostly consist of consecutive, or closely consecutive, numbered tiles. Recognition of these patterns can produce some significantly powerful waits, which may be immune to suji and have large numbers of waiting tiles.