Nakabukure - Middle-Heavy Shape in Sequence Candidates

What is Nakabukure?

Nakabukure is a mahjong term for a shape where the middle tile of a sequence candidate appears 2+ times. For example, “23334” has 234 sequence potential but the middle 3 is duplicated.

This shape looks good with many tiles but is actually inefficient with poor acceptance. Recognizing and handling nakabukure leads to better hand building.

Basic Examples

Why Nakabukure is Inefficient

Acceptance Comparison

Problem:

• Middle 3m is redundant
• Drawing 3m is useless
• Effective acceptance reduced

Duplication Issue

【Pattern 1】Make 234
→ Left with 34m (ryanmen)
→ 2,5m wait

【Pattern 2】Make 333 triplet
→ Left with 24m (penchan)
→ 3m wait (already used 3)

【Conclusion】
Either way, one 3m is wasted
Not efficient

How to Handle Nakabukure

Basic Treatment

23334m
  ↓
Cut 3m
  ↓
2334m
  ↓
Pair + ryanmen
  ↓
Flexibility remains

Cutting Order

For 23334m:

1. Cut one 3m

   • 2334m remains
   • Pair + ryanmen

2. Can cut another

   • 234m remains
   • Pure sequence

Selection criteria:

• Need head → keep pair
• Have head → prioritize sequence

Similar vs Different Shapes

Nakabukure vs Aryanmen

Nakabukure:

23334m
Middle 3 duplicated
Inefficient

Aryanmen:

33345m
Pair + ryanmen connected
Efficient

Difference:

• Nakabukure: Middle duplicated
• Aryanmen: Edge (pair) duplicated

Exceptions

When Making Triplets

Toitoi aim:

23334m

【For toitoi】
333m (triplet candidate)
→ Nakabukure has value
→ Draw another 3m = triplet

For Specific Yaku

• Toitoi: Triplet candidate
• Sanshoku Doujun: Confirm sequence
• Iipeikou: Double sequence

Common Mistakes

1. Thinking it’s good

   • Many tiles looks strong
   • Actually inefficient

2. Not knowing what to cut

   • Cut the middle tile
   • Keep just one

3. Keeping all 5 tiles

   • Wastes hand space
   • Compresses options

4. Cutting the edges

   • Cutting 2 or 4 makes it worse
   • Cut the middle

Related Terms

• Taatsu: Sequence candidate
• Shuntsu: Made from nakabukure
• Hai-kouritsu: Nakabukure is inefficient
• Uke-ire: Nakabukure weakness
• Koritsuhai: Handling extras

Summary

Nakabukure is when the middle tile of a sequence candidate appears 2+ times, like 23334 where the middle 3 is duplicated. While it looks tile-rich, it’s actually inefficient with wasted tiles. Beginners should recognize “duplicate middle = nakabukure = inefficient” and generally cut the middle tile. However, keeping it for pair needs or triplet building can be valid. Properly handling nakabukure improves hand building efficiency.