Yaochuuhai
By Kenji Tanaka · Updated
Definition
Yaochuuhai is the collective term for terminals and honors: the 1s, 9s, winds, and dragons. The group defines a whole family of hands: chanta and junchan require one in every block, honroutou uses nothing else, kokushi musou collects one of each, and chinroutou and tsuuiisou are the all-terminal and all-honor extremes. Less flexible than simples, safer to discard, and the raw material of some of the biggest hands in the game.
Yaochuuhai
Yaochuuhai (么九牌, やおちゅうはい) refers collectively to terminals and honors, specifically the 1s, 9s, winds, and dragons. These tiles occupy the extremes of the tile spectrum and form the foundation for several important yaku patterns in riichi mahjong.
The mechanics of Yaochuuhai
Composition
Yaochuuhai consists of two categories:
Terminals (Terminal tiles):
- All 1-man, 1-pin, 1-sou (the lowest numbered tiles)
- All 9-man, 9-pin, 9-sou (the highest numbered tiles)
Honors (Honor tiles / Jihai):
Together, these 13 different tile types (plus their duplicates) make up 52 of the 136 total tiles in a mahjong set.
Strategic Significance
Yaochuuhai tiles are fundamentally different from simples (2-8) in several ways:
Limited Versatility: Terminals and honors cannot form sequences. A 1-man can only be part of a 1-2-3 sequence, never 0-1-2 (which doesn’t exist) or 1-2-3 in a different suit. Honors can only form triplets or pairs, never sequences.
Yaku Requirements: Many yaku specifically require or forbid yaochuuhai:
- Require yaochuuhai: Chanta, junchan, honroutou, chinroutou
- Forbid yaochuuhai: Tanyao (all simples)
- Use only yaochuuhai: Tsuuiisou (all honors), chinroutou (all terminals)
Defensive Value: Because yaochuuhai tiles are less versatile, they’re often safer discards in defensive situations. A 1 or 9 can only complete one type of wait, while a 5 can complete many different sequences.
Hand Construction
Building a hand around yaochuuhai typically means committing to specific yaku patterns. A hand with many terminals might aim for chanta (outside hand where every meld contains a terminal/honor) or junchan (a terminal in every meld and the pair, with no honors). A hand heavy in honors might build toward honitsu (half flush with honors) or even tsuuiisou (all honors yakuman).
The trade-off is inflexibility: yaochuuhai-heavy hands have fewer tile acceptance options and are harder to complete efficiently, but they score higher when successful.
Yaochuuhai in practice
You’re building a chanta hand and already have a triplet of 9-bamboo (terminals) and a sequence of 1-2-3 characters (contains terminal). You’re waiting to complete a meld with 9-dots or honor tiles to maintain the chanta pattern. Every meld must contain at least one yaochuuhai tile. If you accidentally complete a pure 4-5-6 sequence (all simples), you lose the chanta requirement.
Related Terms
Terminal
么九牌
Terminals are the 1s and 9s, the tiles at the ends of each suit. They extend sequences in only one direction, which makes them less flexible than middle tiles but also safer to discard on defense, since fewer waits catch them. Several hands are built on them: chanta and junchan demand a terminal or honor in every block, and the yakuman chinroutou uses terminals alone. Grouped with the honors they form the yaochuuhai family.
Simples
中張牌
Simples (chunchanhai) are the 2 through 8 of each suit, the middle tiles. They extend runs in both directions, which makes them the most flexible tiles in the game and the entire basis of tanyao. The same flexibility is why they are the most dangerous discards against a tenpai opponent: middle tiles complete the most waits, terminals and honors the fewest.