Riichi Mahjong · Yakuman

Chinroutou (All Terminals) in Riichi Mahjong: Yakuman Rules, Examples and Odds

In riichi mahjong, Chinroutou (all terminals) is a yakuman: all 14 tiles are suited 1s and 9s (1 and 9 of characters, dots and bamboo), without a single honor. Calling doesn't matter — it's a yakuman open too.

The rules for Chinroutou

• All 14 tiles are suited 1s or 9s — no honors, no 2 through 8
• Only 6 kinds, 24 tiles, can be used
• It's always four triplets (or kans) and a pair: a chi needs a 2 to 8, and seven pairs needs 7 different kinds
• Pon and kan are allowed; open it's still a yakuman

How Chinroutou is scored

The yaku and points below are computed live by the same scoring code the game uses.

Closed, with all four triplets drawn yourself, chinroutou also gets suuankou — a double yakuman in this game (Mahjong Soul and Tenhou both add yakuman together).

How it relates to other yaku

• Honroutou: 1s and 9s plus honors, a regular 2-han yaku. One honor tile turns chinroutou into honroutou.
• Junchan: a 1 or 9 in every set, but it needs at least one sequence; chinroutou is all triplets.
• Toitoi and suuankou: chinroutou is always toitoi-shaped; four concealed triplets add suuankou.
• Tsuuiisou: the all-honors yakuman, the exact mirror of chinroutou.

Chinroutou odds

Only 24 tiles can be used, under a fifth of the 136. The chance that a random 13-tile start is all 1s and 9s is about 1 in 194 billion, so a chinroutou start practically never happens. It's built by calling, and you need to pon several different 1s and 9s.

It almost never appears when the computers on this site play, so no game numbers are shown here.

Which hands turn into Chinroutou

• Lots of 1 and 9 pairs and triplets and almost no honors: usually a toitoi hand.
• 1s and 9s in the discards: they're the first tiles players throw, so pon chances come — but once two copies of a tile are gone, you can't pon it.
• Three 1 and 9 triplets on the table get noticed: after that, 1s and 9s stop coming out.

To see a yakuman scored, open a table of free online riichi mahjong — it counts points exactly like this page.

All terminals in other mahjong styles

• Hong Kong mahjong "All Terminals": a limit hand (Hong Kong mahjong fan table)
• Chinese Official (Guobiao) "All Terminals": 64 fan (Guobiao fan list)

FAQ

Is Chinroutou a yakuman?

Yes. Chinroutou is a yakuman, open or closed.

Can Chinroutou include honors?

No. With honors it's honroutou (2 han), usually with toitoi.

Can Chinroutou be seven pairs?

No. There are only 6 kinds of suited 1s and 9s, not enough for 7 different pairs, so chinroutou is always four triplets and a pair.

Related yaku

Honroutou Closed 2 / open 2 Only 1s, 9s and honors — 2 han even when open, always with toitoi or chiitoitsu. Examples, combos and odds. Junchan Closed 3 / open 2 A 1 or 9 in every set and the pair, no honors — 3 han closed, 2 open. Junchan vs chanta, and junchan sanshoku. Toitoi Closed 2 / open 2 Four triplets and a pair, still 2 han when open. Examples, scoring combos and how many starting pairs you need.