Sanankou

Sanankou is 2 han, open or closed. You hold three triplets built from your own draws. The fourth set can be a call.

The name players use is sanankou (三暗刻). This site's glossary also lists it as Three Concealed Triplets, and the EMA 2025 rules use the same English name.

What counts as concealed

A triplet is concealed when every tile in it came from your own draws. A pon is open. A closed kan still counts, because the EMA 2025 entry accepts concealed quads.

The catch is the last tile. A triplet you finish with a discard counts as open. Tenhou's rules say so directly: a triplet completed by ron is an open triplet.

Two concealed triplets are done: 2 man and 4 pin. The hand waits on or , a wait on two pairs. Every tile is 2 through 8, so the hand is also tanyao.

Draw yourself and the 6 pin triplet is concealed too. That's sanankou, tanyao, and menzen tsumo: 4 han. The fu are the base 20, plus 2 for the tsumo, plus 4 for each closed simple triplet. 34 rounds up to 40, and 4 han 40 fu is paid as a mangan. A non-dealer collects 2,000 from each other non-dealer and 4,000 from the dealer.

Win the same tile by ron and the 6 pin triplet counts as open. Two concealed triplets aren't sanankou, so the hand is tanyao alone. The fu are 20, plus 10 for a closed ron, plus 4 and 4 for the closed triplets, plus 2 for the open one: 40. At 1 han 40 fu, a non-dealer collects 1,300. The dealer collects 2,000. The 8 sou works the same way.

Those payments have no dora, no honba, and no riichi sticks. The scoring guide lists every triplet's fu.

The glossary entry is the short form: three triplets formed without calling, 2 han, and the fourth set can be open.

Open or closed

Tenhou's yaku list puts sanankou at 2 han and doesn't mark it as losing a han after a call. The EMA 2025 rules file it with the 2 han yaku and add that the whole hand doesn't have to be concealed. Their fifth scoring example is a closed hand of four triplets won on a discard. The triplet the discard finished isn't counted as concealed, so the hand scores three concealed triplets, not four. That's the row on this site: 2 han, open or closed.

Sanankou with a call

You called chi on 345 sou: . These ten tiles are still in your hand.

Three triplets are concealed: 2 man, 6 pin, and 8 sou. The hand waits on or .

pairs the lone 4 pin. All three triplets stay concealed, so the open hand still scores sanankou, plus tanyao: 3 han. The fu are the base 20, plus 4 for each closed simple triplet, plus 2 for the single wait. 34 rounds up to 40. At 3 han 40 fu, a non-dealer ron collects 5,200. The dealer collects 7,700.

makes 456 pin and leaves 6 pin as the pair. The 6 pin triplet is gone, so the hand is tanyao alone. The fu are 20, plus 4 and 4 for the two triplets left, plus 2 for the middle wait: 30. At 1 han 30 fu, a non-dealer ron collects 1,000. The dealer collects 1,500.

Four of them

Four concealed triplets is suuankou, a yakuman. A closed hand of four triplets on a wait on two pairs is sanankou on a ron and suuankou on a tsumo. The toitoi page walks through that hand.

Common mistakes

• Counting a ron triplet as concealed. The triplet the discard finishes is open.
• Counting a pon. A called triplet is open from the start.
• Dropping the yaku after a call. The fourth set can be a chi or a pon.
• Missing the tsumo. On a wait on two pairs, a tsumo can score sanankou where a ron on the same tile can't.

What sits with it

Toitoi fits when the fourth set is a triplet too. Tanyao fits when every tile is 2 through 8, as in both hands here. Yakuhai fits when one of the triplets is a dragon, your seat wind, or the round wind.