Chiniisou

Chiniisou

Type	Yaku
Kanji	清一色
English	Flush
Value	6 han (closed) 5 han (open)
Speed	Slow
Difficulty	Medium

Chiniisou 「清一色」 is a standard yaku, scored when the hand composed of tiles in one numbered suit only. Chinitsu is worth 6 han, but it decreases to 5 han when opened. This yaku is usually referred to as chinitsu or, occasionally, chinichi.

Tile patterns

Using pinzu:

Waiting for:

Using manzu:

Waiting for:

Using souzu:

Waiting for:

Formation

As defined, this yaku is formed by collecting tiles of one suit. Therefore, tiles not of a particular suit are regularly discarded. As a consequence, a player aiming for a chinitsu may be very easily detected via discards alone.

Complex wait patterns

Chinitsu is notorious for developing complex wait patterns. Since all 13 tiles are of one suit, it is easy for groups to mix together, forming multi-sided waits. If playing without computers, it can be difficult to tell what your waits are.

Compatibility

Main article: Yaku compatibility

^ Ippatsu requires riichi to be of any use.

RCH

DRI

IPP

SMO

TAN

PFU

IPK

ITT

YAK

SDJ

SDO

TOI

SNA

SNK

CHA

JUN

RPK

SSG

HRO

HON

CHN

CHI

RIN

HAI

HOU

CHK

CHN

Chinitsu requires a single suit with no honors. Yakuhai, shousangen, sanshoku, and sanshoku doukou all require honors or multiple suits, and are thus incompatible. Chinitsu implies honitsu, so they are not counted together. If combined with chanta, the hand is actually junchan, so that yaku is counted instead. Finally, chinitsu and honroutou would require a hand containing at most eight tiles (the 1s and 9s of one suit), which is impossible.

Value

As a standalone yaku, chinitsu is at least a mangan, even when open. To regain the lost han as an open hand, it simply takes a dora, or another yaku, to bring the hand up to its closed value of a haneman.

Yakuman

Due to the relatively high value of this yaku, chinitsu may be involved in the formation of kazoe yakuman, especially when closed. The 6-han from closed chinitsu is almost half the requirement for 13-han; naturally, other yaku and/or dora will need to provide the next. Though, one particular pattern may form as a true yakuman, chuuren poutou.

External links

• 清一色

Chiniisou in Japanese Wikipedia

• Bamboo Mahjong in Gamedesign

Game designed with sou tiles only to train reading chinitsu hands.