Sankantsu

Revision as of 20:26, 15 July 2015 by KyuuAA (talk | contribs) (→‎Value)

Sankantsu 「三槓子」 is a standard yaku. This yaku requires kan to be called three times by one player. Due to this requirement, this yaku is actually the most difficult of the regular yaku.

Sankantsu
Type Yaku
Kanji 三槓子
English Three kans
Value 2 han
Speed Very slow
Difficulty Very hard

Tile pattern

                  Waiting for:  

Per the yaku's name, kan must be called three times; and as a result, the tenpai hand has at most four tiles remaining as closed. If necessary, the hand can call as far as a single tile remaining.

Development

Of all the standard yaku, sankantsu is the most difficult and least frequent. Its rate of occurrence is comparable to that of some yakuman. As the name implies, kan must be called three times before the end of the hand. A fourth kan converts the hand to the yakuman, suukantsu. The difficulty stems from the need to call kan three times; but overall, the use of kan is risky play due to additional kan-dora, which may benefit the other players. This is true even for a single kan call, let alone three times.

Viability

Sankantsu's difficulty stems from its various pitfalls during hand development. For starters, attaining the tiles necessary to call kan three times is difficult onto itself. In order to call kan in the first place, a player has to draw three out of the four tiles.

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
SNK                                                  

No sequential based yaku can combine with sankantsu. Three out of the four possible tile groups must be called for kan, and they can be referred as "triplets plus one extra". This rules out pinfu, iipeikou, ryanpeikou, ittsu, and sanshoku doujun. Chiitoitsu is incompatible due to its usage of pairs. Every other yaku is compatible.

Value

This yaku is set at 2 han. However, the number of kans significantly increases the hand's value. Even with the minimum 3 open kan of simples, they generate a fu count of 8 fu each, for a total of 24 additional fu to the base 20. So, at a minimum, this yaku is valued at 2 han and 50 fu, which is the equivalent of 3 han and 25 fu.

Even with a base of 2 han, the number of kan calls adds the probability of additional dora, which may have an immediate impact on the hand value. Just one dora and adequate fu may bump the hand already into mangan. If any of the tiles used for kan became dora, that's instantly 4 dora.

External links

Sankantsu in Japanese Wikipedia