# Suuankou — Riichi Mahjong Glossary

> Four concealed triplets - a yakuman where all four melds are concealed triplets. On a shanpon wait it must be won by tsumo; a tanki wait may win by ron.

**Source:** https://www.mahjongmaster.co/learn/riichi/glossary/suuankou/
**Author:** Kenji Tanaka (https://www.mahjongmaster.co/about/kenji-tanaka/)
**Publisher:** Mahjong Master (https://www.mahjongmaster.co)
**Published:** 2026-02-18
**Updated:** 2026-03-10
**Japanese:** 四暗刻
**Category:** hand-structure
**Variant:** riichi

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## Suuankou

**Suuankou** (四暗刻, すうあんこう) is one of the standard yakuman hands, where all four melds consist of concealed triplets (ankou). It pays the full yakuman amount (32,000 points to a non-dealer, 48,000 to the dealer) and is one of the most iconic and achievable yakuman patterns. The famous wrinkle: whether you may win by ron depends entirely on your wait shape.

## How Suuankou plays out at the table

### Requirements

To achieve suuankou, you must:
- **Four concealed triplets**: All four triplets formed from your own draws, without calling pon
- **No open melds**: No pon, chii, or open kan anywhere in the hand (a concealed ankan is fine)
- **A qualifying win**: On a **tanki** (pair) wait, either tsumo or ron works. On a **shanpon** (dual-pair) wait, only tsumo works, because a ron would make the final triplet count as open.

For example: 3-3-3 bamboo, 7-7-7 characters, 9-9-9 dots, South-South-South, plus a pair, all formed without calling melds.

### Shanpon vs. Tanki: The Ron Rule

A triplet completed by ron counts as open for concealment purposes. Which wait you hold decides everything:

**Shanpon wait (must tsumo)**: Your hand is 2-2-2, 5-5-5, 8-8-8, plus 9-9 and 3-3, waiting on a 9 or a 3 to become the fourth triplet. Ron on either tile and that final triplet counts as open: the hand downgrades to toitoi plus sanankou, a big score but no yakuman. Tsumo it yourself and suuankou stands.

**Tanki wait (ron is fine)**: Your four triplets are already complete and a lone tile waits to become the pair. The winning tile joins the pair, not a triplet, so nothing becomes open. You may ron freely, and many rule sets score this suuankou tanki as a **double yakuman**.

### Difficulty and Rarity

Suuankou is considered one of the easier yakuman to achieve because:
- **Triplets are natural**: You often draw triplets accidentally during normal hands
- **No pattern requirements**: Unlike kokushi musou or daisangen which require specific tiles, suuankou accepts any triplets
- **Toitoi foundation**: Any toitoi (all triplets) hand is a potential suuankou if kept closed

However, the shanpon-must-tsumo rule adds real luck dependency: a finished suuankou shape on the wrong wait can be forced to pass on its own winning tile.

### Strategic Considerations

**Closed Hand Commitment**: From the first draw, you must commit to keeping all triplets concealed. Any pon call destroys suuankou potential permanently. This means slower hand development in exchange for yakuman value.

**Shanpon Pressure**: On a shanpon wait, players face a real dilemma when their tile is discarded: ron immediately for toitoi plus sanankou, or pass (accepting temporary furiten) and hope to tsumo the yakuman? Where possible, steering the finished hand toward a tanki wait removes the dilemma entirely.

**Compatibility**: Suuankou naturally includes:
- **Toitoi** (all triplets): Always present but yakuman overrides it
- **Sanankou** (three concealed triplets): Always present but yakuman overrides it

## Walking through Suuankou

You're dealt an exceptional starting hand with pairs that develop into triplets: 4-4-4 bamboo, 6-6-6 characters, White-White-White, and 8-8 dots. You avoid calling any melds and draw the third 8-dots, completing four concealed triplets with a lone 2-circles left over: a tanki wait on the pair. Because the winning tile completes the pair rather than a triplet, you may win by ron or tsumo, and either way the hand is **suuankou** (yakuman): 32,000 points as a non-dealer or 48,000 as the dealer, with many rule sets doubling it for the tanki wait. Had your last shape instead been two pairs (a shanpon), only a tsumo would have preserved the yakuman.

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*This content is from [Mahjong Master](https://www.mahjongmaster.co), a free educational reference for riichi (Japanese) and American (NMJL) mahjong. When citing this page, please link to https://www.mahjongmaster.co/learn/riichi/glossary/suuankou/.*