Chiniisou

Chinitsu 「清一色」 is a standard yaku. This yaku is composed of tiles in one suit only. Chinitsu is worth 6 han, but it decreases to 5 han when opened.

Chiniisou

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

Tile patterns

Using pinzu:

Agari: or

Using manzu:

Agari: or or or

Using souzu:

Agari: or or or or

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 easily detected via discards alone.

Complex wait patterns

Chinitsu is notorious for developing complex wait patterns. This is due to the homogenous nature of the yaku. The number of potential waiting tiles may range from one tile of the suit to all nine tiles. Strings of consecutive numbers enable this complexity. Without the help of computers, determining the winning tiles upon tenpai may become somewhat of a task.

Compatability

Main article: Yaku compatability

^ 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, so that deems this yaku incompatible with other yaku that demand other tile types. That includes yakuhai, shousangen, as well as sanshoku and sanshoku doukou. Since chinitsu implies honitsu, the latter is 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.

Yakuman

Due to the relatively high value of this yaku, chinitsu may be involved in the formation of kazoe yakuman. Though, one particular pattern may form as the yakuman, chuuren poutou.

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 just one dora, or a combination with another yaku, just to bring the hand up to its close value of a haneman.

Possible minimum/maximum point values

Han/Fu	Ron		Han/Fu	Tsumo
	Non-dealer	Dealer		Non-dealer	Dealer
While open			While open
Mangan	8000	12000	Mangan	2000/4000	4000 all
Closed			Closed
Haneman	12000	18000	Haneman	3000/6000	6000 all

External links

• 清一色

Chiniisou in Japanese Wikipedia

• Bamboo flash game

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