Honroutou

Honroutou 「混老頭」 is a standard yaku, focusing on just the honors and terminals. Any other tile type cannot be used for this yaku.

Honroutou
Type Yaku
Kanji 混老頭
English Terminals and honors
Value 2 han (consider as 4 han)
Speed Slow
Difficulty Hard

Tile pattern

               Agari:   or  

Formation

This yaku requires terminal and honor tiles only. While terminals may be used for sequences, this yaku cannot form those sequences. Otherwise, this yaku would no longer be honroutou but rather chanta.

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
HRO                                                  

Honroutou is not compatible with any yaku which require a sequence, which accounts for most of the incompatibilities (including chankan, which must always win on a sequence wait). Tanyao is incompatible because it requires no terminals or honours, and honroutou requires only those tiles. Chantaiyao is incompatible because it is implied by honroutou. Finally, if honroutou is combined with junchan, the entire hand must be terminals, which gives the chinroutou yakuman.

Value

At minimum, it is impossible to score this yaku without at least either toitoi or chiitoitsu. So, this yaku is actually at minimum, the equivalent of 4 han.

When factoring fu, the combination of ankou and minkou (closed and open triplets) produces a fu count of higher than 10. The lowest possible fu is generated with 4 minkou, leading to hadaka tanki (lone pair wait). Adding the base 20 fu for any hand, this yaku is guaranteed greater than 30 fu; and with the rules of fu, that number is actually rounded up to at least 40 fu. Therefore, a honroutou composed of ankou and minkou is at minimum a mangan.

Example:

               Agari:  

This is the second lowest possible honroutou, if not played in the West round. For each of the open calls, they are worth 4 fu. In combination, they add up to 16 fu. Then add the tanki (pair wait) for 2 fu. In total, this hand has 18 fu, in addition to the base 20 fu; and that makes 38 fu. Per the scoring rules, the number is rounded up to 40 fu. With a minimum of 4 han and 40 fu, this hand is guaranteed at least mangan when chiitoitsu is not involved.

The lowest scoring honroutou is a chiitoitsu won by ron without riichi or dora.

Example:

              Ron:  

This hand scores 4 han and 25 fu for 6400(9600) points.

External links

Honroutou in Japanese Wikipedia