Sanankou 三暗刻

What It Is

Sanankou (三暗刻) is three concealed triplets: sets of three of a kind made only from tiles you drew. A concealed kan counts as one. The fourth set and the pair can be anything, and they can even be called.

What It’s Worth

Sanankou is 2 han. It doesn’t lose value when the hand is open, because the triplets themselves are still concealed. Concealed triplets earn plenty of fu too, so these hands often score more than their han suggest.

It rarely comes alone. A hand with three concealed triplets is usually one triplet from toitoi as well, and closed, it might be one draw from a yakuman.

The Ron Rule

A triplet finished by a ron counts as open. Take the example above, waiting on 4 Bamboo or 8 Bamboo. Draw a 4 Bamboo yourself and you have sanankou. Ron the same tile from a discard and that triplet is open: two concealed triplets, no sanankou.

If the ron tile finishes a run instead, the three triplets stay concealed and sanankou holds. In the example, a ron on 7 Characters (if the hand had been waiting on 5-6) keeps all three. Know your wait before you count your han.

Closed Or Open

Both. Chi 5-6-7 Characters in the example and draw your three triplets, and it’s still sanankou in an open hand. You just need a yaku that survives, which sanankou is.

A pon of a fourth set is fine too, and gives you toitoi on top. What you can’t do is pon any of the three, since that triplet is then open.

Common Mistakes

• Counting the ron triplet. The single most common sanankou error.
• Counting a pon. A called triplet is open, always.
• Ronning when a tsumo would be suuankou. With four concealed triplets, a ron can turn a yakuman into a much smaller hand. Sometimes waiting for the draw is right.

What It Combines With

Toitoi is the obvious partner: sanankou plus a called fourth triplet is both. Yakuhai and riichi fit, and menzen tsumo comes with the tsumo win when the hand is closed. Four concealed triplets is the yakuman suuankou; see Kam Kam Hu for how each table pays it.