|English||Terminals and honors|
|Value||2 han (consider as 4 han)|
Honroutou 「混老頭」 is a standard yaku, focusing on just the honors and terminals. To score honroutou, the hand must contain only honors and terminals. If the hand is all honors or all terminals, then tsuuiisou or chinroutou will be scored instead.
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. Naturally, a concentration of honor and terminal tiles are required to even consider this yaku. A majority of honroutou hands are open, especially when they only utilize pon to call tiles.
^ Ippatsu requires riichi to be of any use.
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.
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.
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.
This hand scores 4 han and 25 fu for 6400(9600) points.
- Honroutou in Japanese Wikipedia