Riichi

Winning within one go-around after declaring riichi, before any call or kan interrupts the turn. Closed-only by virtue of requiring riichi, and one of the cheapest ways to add a free han to a riichi hand — it stacks freely with everything else riichi unlocks.

Winning by self-draw on a fully closed hand (no calls). The default kicker on any closed tsumo win, which is why riichi + pinfu + tsumo is the canonical fast-cheap closed-attack template.

A closed hand of all sequences, with a non-yakuhai pair and a two-sided (ryanmen) wait. Adds zero fu beyond the base — pinfu tsumo stays at 20 fu, pinfu ron rounds to 30. The high-frequency partner of riichi and tanyao in closed-attack templates.