One-Shanten Discard
Last updated: 2026-06-18One-shanten (shanten 1) is one step from tenpai—discards here swing ukeire sharply, a critical efficiency spot.
What Is One-Shanten
Fourteen tiles with shanten 1. Tiles that bring shanten to 0 after your discard are effective. Many discard puzzles focus on this transition.
Maximize Ukeire
Default rule: maximize types × remaining tiles. Exceptions:
- Tenpai value differs a lot (tanyao vs honitsu)
- Discard is safe (genbutsu)
- Wall is thin—theory vs reality
Discard example
Shanten 1. Discard 4m for 19 tiles on 1m–3m, 5m–7m, 9m. Discarding 7m leaves only 6—much worse.
Comparison
After drawing to 14, compare discards with Counting Effective Tiles.
Scoring Trade-off
Speed alone builds small hands. When chasing honitsu, verify you can stay one-shanten. When unsure, take max ukeire; fix scoring after tenpai.
See Discard Strategy and Tile Efficiency.