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Kabe (the tile wall)
Kabe means counting every visible tile to spot the waits that have become impossible, so you can discard safer no-chance tiles on defense.
The principle
Kabe (壁, "wall") is a defensive reading technique built on counting. Every tile exists in four copies: by counting the ones that are visible (your hand, every player's kawa discards, the dora indicators, and the chi/pon/kan melds laid out on the table), you deduce which wait shapes an opponent can no longer hold. You never see concealed hands or the wall, only what is public.
Rule and example
Once all four copies of a tile are visible, no sequence can contain it anymore. The canonical example: if all four 8s are dead, the only ryanmen that waits on the 9 (the 78 shape) is impossible, and no kanchan or penchan ever waits on a terminal. The 9 then becomes a "no-chance" tile. In an ordinary hand, it can only be waited on by tanki or shanpon. A kokushi musou wait on that terminal is still possible if its structure allows it. Likewise, a wall of 2s makes the 1 no-chance.
What changes
If only three of four copies are visible, you have one-chance: one copy remains unseen and the affected sequences are still possible. This clue removes some possibilities but is not enough to call the tile low risk. Under Tenhou, a red five counts among the four copies of that tile; WRC 2025 uses no red fives.
Mistake to avoid
Kabe only rules out sequence waits (ryanmen, kanchan, penchan); it never protects against a tanki or shanpon. A no-chance tile therefore reduces some risks without becoming perfectly safe. In real defense, combine kabe with genbutsu against each threat and suji to pick the least risky discard.
Rules references
- Tenhou rulesReference profile used for game mechanics and scoring.
- WRC Rules 2025International rules compared whenever their options differ from Tenhou.