Ryuuiisou

Ryuuiisou
Type	Yakuman
Kanji	緑一色
English	All green
Value	Yakuman
Speed	Very slow
Difficulty	Very hard

Ryuuiisou 「緑一色」, or "all green" in English, is a yakuman scored when the hand is composed entirely of the following tiles: 2, 3, 4, 6, 8 of souzu, and/or the green dragon tiles.

Tile diagram

Winning tile: or

Open

Winning tile: or

This example is only possible under the common ruling of optional hatsu.

Value

This hand is a yakuman hand which automatically awards 32000 points to a non-dealer winner, or 48000 points to a dealer winner.

Formation

This yakuman is literally all green, as all the tiles are composed of green tiles. No markings of other color are applied to these tiles, hence its designation as all green. With this yakuman, only six tile types are available:

With the usual four melds and a pair pattern, at least five out of the six tile types are needed to complete this yakuman. Because 2-3-4 can be used in sequences, this yakuman is easier than chinroutou (which requires all triplets). Because there are only six unique tile types, this yakuman is impossible to obtain in chiitoitsu form.

Furiten

Waiting for:

-

or

This hand may regularly be subject to furiten, especially around the range of 1, 2, 3, 4, and 5 sou. While it is necessary to discard 1 sou and 5 sou to build this yakuman, these discarded tiles may lead to a tenpai hand with furiten. That may be particularly true for above example.