Shousangen

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Shousangen
Type Yaku
Kanji 小三元
English Small three dragons
Value 2 han (Consider as 4 han)
Speed Medium
Difficulty Medium
Examples

Shousangen 「小三元」 is a standard yaku, reliant on all three sangenpai. The hand is composed of two koutsu (triplet) and a jantou (pair) of the third type.

Tile pattern

Tile-2m.pngTile-2m.pngTile-3p.pngTile-4p.pngTile-0p.pngTile-7z.pngTile-7z.pngTile-6z.pngTile-6z.pngTile-6z.png Tile-5z.pngTile-5z-e.pngTile-5z.png Yasume: Tile-2m.png Takame: Tile-7z.png

This hand is a shousangen while winning on the cheaper winning tile. If it wins on the other tile, Tile-7z.png, it would give a daisangen yakuman instead.

Development

The hand requires two out of the four tile groups to be composed of dragon triplets, while the pair is always of the third type. That leaves two tile groups to be based off of any tile composition. Often enough but not always, such a hand may be tenpai for daisangen.

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
SSG 13 green check.png 13 green check.png 13 green check.png 13 green check.png 13 red x.png 13 red x.png 13 green check.png 13 red x.png 13 green check.png 13 red x.png 13 red x.png 13 green check.png 13 green check.png 13 green check.png 13 green check.png 13 red x.png 13 red x.png 13 green check.png 13 green check.png 13 red x.png 13 red x.png 13 green check.png 13 green check.png 13 green check.png 13 green check.png

Shousangen requires yakuhai, from the two groups of dragon tiles. Note that while normally a yaku is not counted if it is guaranteed by another yaku in the hand, shousangen does not guarantee a particular yakuhai and so it is counted separately. Out of the regular four tile groups for a hand, two are dedicated for dragon tiles. So, this yaku has no room for the likes of ittsu, ryanpeikou, sanshoku, and sanshoku doukou, as well as chiitoitsu because the later does not allow any mentsu. Each of those four yaku require at least three tile groups for their specific requirements. Naturally, pinfu, tanyao, junchan, and chinitsu are incompatible because of the dragon tiles.

Value

In general, this yaku is noted as 2 han. However, it is impossible for this yaku to score without two instances of yakuhai from the two groups of sangenpai. In combination, this yaku will never produce a hand worth less than 4 han. Even with both sangenpai groups called open, that is a combination of 8 fu; and then there's 2 more fu from the sangenpai pair of the third type. The hand will almost always score at least mangan.

The lowest scoring shousangen is valued at 4 han 30 fu. The requirements to do so, assuming no additional yaku, are:

  • The hand must be won by ron, as a tsumo would score 2 fu.
  • The wait must be either a ryanmen or shanpon wait, as any other wait would score 2 fu.
  • Both of the other groups must be shuntsu of different suits. If either was a koutsu, it would score at least 2 fu.
  • Both of the yakuhai groups must be open, as they would score additional fu if closed. Note that as this is for the purposes of counting fu, if a group is completed by ron, it counts as being open.
  • Neither of the yakuhai groups may be kantsu, as they would score additional fu as kantsu.

Two examples scoring exactly 4 han 30 fu on a ron:

Tile-2p.pngTile-3p.pngTile-4p.pngTile-3s.pngTile-4s.pngTile-6z.pngTile-6z.png Tile-5z.pngTile-5z.pngTile-5z-e.png Tile-7z-e.pngTile-7z.pngTile-7z.png Agari: Tile-5s.png

Tile-5m.pngTile-6m.pngTile-7m.pngTile-1s.pngTile-2s.pngTile-3s.pngTile-6z.pngTile-6z.pngTile-7z.pngTile-7z.png Tile-5z.pngTile-5z-e.pngTile-5z.png Agari: Tile-6z.png

External links

Shousangen in Japanese Wikipedia