Honroutou

Honroutou

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

Honroutou (混老頭) is a standard yaku, focusing on just the honors and terminals.

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.

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. So, at minimum, honroutou is at minimum at mangan.

Example:

Agari:

This is the 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.