Five-Block Theory
Last updated: 2026-06-18Five-block theory views 13 tiles as progress toward 4 melds + 1 pair—five groups of completed pieces, taatsu, pair candidates, and surplus tiles. It supports tile efficiency and discard strategy.
Five Blocks
Before tenpai you may have:
- Completed melds / triplets
- Two-tile taatsu
- Pair candidates
- Floating surplus not in any block
“How many blocks short?” mirrors shanten feel.
Choosing Blocks
- Keep taatsu when possible
- Treat isolated tiles as surplus—discard early
- When shanten ties, prefer splits with wider ukeire
Example split
e.g. 1m triplet + 4m pair + 5-6 / 6-8 taatsu + floating 8m. Shanten 1, 7 types—helps explain ukeire.
Surplus Tiles
Surplus lowers efficiency. Five-block labeling sets discard priority.
Tenpai—blocks aligned; waits 2m, 6m, 9m. Then focus on Wait Types.
Use the analysis tool for detail. Practice discards via Discard Strategy.