Mahjong Tile Efficiency (Ukeire) Basics
Nani-kiru (“what would you discard?”) asks you to keep the widest ukeire — the tiles that advance your hand toward tenpai and a win. Even two tiles accept very differently depending on their shape. Knowing the three basic shapes makes the right discard clear. New to mahjong efficiency? Begin here.
Acceptance 8 tiles
Two connected tiles like 4m–5m wait on both sides (3m and 6m) — 8 tiles of acceptance, the widest wait. Keeping ryanmen shapes is the foundation of efficient discarding.
Acceptance 4 tiles
A gap shape like 4m–6m waits only on the middle tile (5m) — just 4 tiles, half of a ryanmen.
Acceptance 4 tiles
An edge shape like 1m–2m waits only on 3m (there is no 0m) — 4 tiles. Prefer ryanmen over kanchan or penchan whenever you can reshape toward it.