The discard decision.
Tile efficiency is the discipline of choosing the discard that leaves you the most routes forward. Over many games, consistently efficient discards mean you reach tenpai faster and more often than your opponents.
A winning hand needs four melds and one pair — five blocks total. Organise your 13 tiles into five blocks as early as possible. If you count more than five, discard the weakest. If you're short, hold versatile middle tiles (4–6) that can slot into multiple configurations as future draws arrive.
This hand is in tenpai — four blocks settled, one fragment waiting on 1 or 4 Bamboo to complete.
Connects to tiles you already hold. Could complete a chow, build a pair, or extend a fragment. Contributes to a block.
No neighbors within 2 in the same suit. No pair partner. No pung plan. Wastes a block slot.
When tiles overlap and you can't keep all of them, you must choose which block to keep. The rule: keep the configuration that leaves you with more outs.
Only one tile value completes this. At most two copies remain in the wall.
Two tile values complete this — four copies of each. Four times as many outs.
The 2-2-3 fragment forces exactly this choice. The outs make the answer clear:
Unless the pair is a high-value honor (seat wind, round wind, dragon), keep the chow fragment. A two-sided wait with 8 outs is rare and worth protecting.
Two terms that formalise what you've already been doing intuitively:
The minimum number of useful tile swaps needed to reach a winning wait. Shanten 2 = two ideal draws away. Every discard should move it down.
The count of tiles remaining in the wall that reduce your shanten. Before each discard, ask: which tile to remove leaves the highest uke-ire?
Chapter 6 covers shanten in full — how to count it and how it shapes strategy at each stage of the round.
The most efficient tenpai hands have two or more winning tiles. Every additional winning tile makes you harder to defend against and more likely to win first.
Lock in three solid melds, keep the fourth flexible. A flexible fragment stays open to more outs than a completed set that closes your hand to a single wait.
Avoid locking your hand into a rigid final shape prematurely. Keep floating middle tiles open — they let you transition into faster or higher-scoring shapes based on what opponents discard.
Blindly chasing the highest uke-ire can make your hand predictable and leave you defenseless. Assess whether slowing down slightly for a better-scoring hand or safer defense is worth the extra shanten.
When you must discard, work through this order — weaker tiles first, more connected tiles last.
Winds and dragons can't form sequences. 1s and 9s connect in only one direction. Isolated copies are dead weight.
A lone 4, 5, or 6 connects in up to four directions as future draws arrive. Their potential is hidden — hold over terminals.
Edge waits (1–2, 8–9) → fewest outs. Closed waits (gap like 4–6) → more tile copies available. Two-sided waits → most outs. Break the weakest shape first.
The drill shows you a partial hand and asks you to identify the best discard. Every session builds the pattern recognition that makes efficiency feel automatic.
Go to the drill →