Kabe (Wall) - Defense Theory Using Visible Tiles

What is Kabe?

Kabe (wall) refers to a tile that has all 4 copies visible, or the defensive theory using this state. For example, if all four 3s are visible, ryanmen waits like 12 or 34 become physically impossible, making 1 and 4 safer.

The name “wall” represents the barrier that blocks certain sequences from being made.

How Kabe Works

When all four 3-man are visible:
- 12m ryanmen wait (waiting on 3m) → Impossible
- 34m ryanmen wait (waiting on 2 or 5m) → Impossible
- 23m ryanmen wait (waiting on 1 or 4m) → Impossible

Conclusion: 1m, 2m, 4m, 5m become safer

Safe Tiles from Kabe

Wall Tile	Safer Tiles	Reason
3 is 4-visible	1, 2, 4, 5	Ryanmen shapes impossible
4 is 4-visible	1, 2, 3, 5, 6, 7	Multiple ryanmen denied
5 is 4-visible	2, 3, 4, 6, 7, 8	Center wall most effective

Wall Strength

Complete wall (4 visible)
- 100% that tile can’t be drawn
- Surrounding tiles safer too
3-visible wall
- Functions almost as wall
- Only 1 tile remains (low chance)

Types of Wall

One Chance

When 3 copies of a tile are visible
→ Only 1 remains (one chance)
→ Wait using that tile is unlikely

No Chance

When all 4 copies are visible
→ 0 remain (no chance)
→ Wait using that tile is impossible

Wall Position Effect

Wall Position	Affected Range	Value
1 or 9	2, 3, 7, 8	Low
2 or 8	1, 3, 4, 6, 7, 9	Medium
3 or 7	1, 2, 4, 5, 6, 8, 9	High
4, 5, 6	Wide range	Highest

How to Count Walls

Check discards (river)
Check calls (pon/chi/kan)
Check dora indicator
Check your hand
Calculate total

Combined Reading: Wall + Suji

If 4 is discarded (suji)
AND 3 is 4-visible (wall)
→ 1 has even higher safety

Waits Where Kabe Doesn’t Work

Wait Type	Wall Effectiveness
Ryanmen	◎ (Very effective)
Kanchan	△ (Partially effective)
Penchan	○ (Effective)
Tanki	× (Ineffective)
Shanpon	× (Ineffective)

Kabe Limitations

Kabe theory has limits:

Doesn’t work against kanchan well
Useless against tanki waits
3-visible isn’t 100% safe
Edge tile walls have less impact

Common Mistakes

Missing counts
- Check river, calls, dora indicator, hand
- Count all visible tiles
Over-trusting kabe
- Less effective vs kanchan
- Doesn’t help vs tanki
3-visible handling
- Not 100% safe
- Situational judgment
Edge tile walls
- 1/9 walls have limited effect
- Center walls more valuable

Advanced Uses

Creating Walls

Cut specific tiles early
→ Creates wall for opponents
→ Related tiles more likely to be discarded

Using Walls for Waits

When 3 is 4-visible:
→ 4 tanki wait is more likely to come
→ Tiles near walls are relatively safe

Statistics

Late-Game Wall Occurrence

Turn 17: Average 2-3 wall types
Each tile 4-visible rate: ~10%
Safety increase from wall: ~20-30%

Genbutsu: 100% safe tile
Suji: Ryanmen wait reading
One Chance: 3-visible state
No Chance: 4-visible state
Anzen-hai: Safe tiles general term

Summary

Kabe is a defensive theory where seeing all 4 (or 3) copies of a tile denies ryanmen waits using that tile, making surrounding tiles safer. Along with genbutsu and suji, it’s an important defensive technique - using them together enables more precise defense. Beginners should first practice counting 4-visible tiles accurately and finding safe tiles through kabe.