Sanankou (Three Concealed Triplets)

A hand made of four triplets (or kans) and a pair — no sequences. Often built from middle-game pon calls; pairs naturally with sanankou (three concealed triplets) and yakuhai for high-han open hands.

Yakuman. Four concealed triplets in a closed hand. The fourth triplet must complete by tsumo to keep all four concealed — a ron win with a shanpon wait counts the winning triplet as open and downgrades the result to san ankou + toitoi instead.

A triplet (or kan) of any dragon, the round wind, or the player's seat wind. Each qualifying triplet scores 1 han, and a triplet that doubles as both round-and-seat wind (renpuuhai) scores 2 under most rulesets. The simplest open-friendly yaku in the game.

Every tile is a terminal (1 or 9) or honor. 2 han. Since terminals and honors cannot form sequences, the hand always pairs with toitoi or chiitoitsu — the resulting stack is typically 4 han or more before dora.

Two triplets and a pair of the three dragon tiles. 2 han for shousangen itself, plus 1 han for each dragon-triplet yakuhai — typically 4 han once the math settles. One pair short of daisangen yakuman, so a shousangen tenpai is always a yakuman threat.