Toitoi | Four Triplets Plus a Pair
DocumentationToitoi | Four Triplets Plus a Pair

Author: MJ Lab

Toitoi

Last updated: 2026-08-18

Toitoi requires four melds that are all triplets or quads, plus one pair — fixed 2 han. Open or closed. See Riichi Mahjong Yaku Guide and Sanankou.

Requirements

  • Four melds are triplets or quads (no sequences)
  • One pair head
  • 2 han; open or closed

On ron, the triplet completed by the winning tile is not concealed if it was open. Closed double-pon tenpai ron on the fourth triplet often yields toitoi + sanankou, not suuankou.

Valid example

Closed: ron on 8 pin completes the fourth triplet. Toitoi + sanankou (ron triplet is not concealed). Not suuankou tanki.

Invalid or confusing

East round, south seat ron on west triplet: toitoi + sanankou, but west is a guest wind — no Yakuhai. Useful for triplet and wind judgment.

Stacking and open hands

Often stacks with yakuhai, sanankou, honroutou, etc. Open play keeps 2 han toitoi but may reduce concealed triplets.

Scoring

Many triplets raise fu (open vs closed triplets). Toitoi hands often have much higher fu than sequence hands. See Fu Calculation Basics.

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