What is Shanpon Machi? Double Pon Wait Tactics Explained for Beginners

What is Shanpon Machi (Double Pon Wait)?

Shanpon machi (双碰待ち) is a tenpai pattern where either of two pairs (toitsu) becomes a triplet (koutsu) to complete the hand. For example, holding and , waiting for either or .

“Shanpon” originates from the Chinese “双碰” (shuangpeng), also abbreviated as “shabo machi.”

Detailed Explanation of Shanpon Machi

Basic Shanpon Machi Form

Complete form: :1m::2m::3m: :4p::5p::6p: :7s::8s::9s: :3m::3m: :5p::5p:
              └─set─┘ └─set─┘ └─set─┘ └pair┘ └pair┘

Waiting tiles: :3m: or :5p: (either completes)

Shanpon Machi Characteristics

Feature	Detail
Acceptance count	4 tiles (2 types × 2 each)
Efficiency	Bad wait but special
Toitoi compatibility	Very good
Chiitoitsu relation	Similar form

Shanpon Machi Patterns

Normal shanpon machi
```
3 sets + pair × 2
```
Toitoi shanpon machi
```
Triplet × 3 + pair × 2
```
Honor tile shanpon machi
```
:6z::6z: + :7z::7z: (both honor tiles)
```

Usage Examples

Real Game Situations

Example 1: Tenpai Declaration

"Shanpon machi on :1z: and :5z:"
"Riichi with shabo wait!"

Example 2: Wait Explanation

"Tenpai on :3m: and :7s: shanpon"
"Shabo wait on dora-dora for high points"

Example 3: Form Selection

"Shanpon has higher points than ryanmen"
"Gamble with toitoi shabo wait"

Advantages and Disadvantages of Shanpon Machi

Advantages

Advantage	Detail
Toitoi combination	2+ han guaranteed
Easy honor tiles	Yaku secured with honor pairs
Furiten avoidance	Can ron on other if one is furiten
Hard to read	Difficult to read from discards

Disadvantages

Disadvantage	Detail
Few acceptance tiles	Only 4 tiles (2 each)
Hard to tsumo	Opponents often hold as pairs
No pinfu	Yaku limitation
Failed chiitoitsu	May miss higher yaku

Toitsu: Two identical tiles
Toitoi: All triplets yaku
Chiitoitsu: 7 pairs yaku
Ryanmen Machi: Efficient wait
Sanankou: Often combined yaku

Common Mistakes and Points to Note

Points Beginners Often Mistake

One side furiten
- Can ron on even if is furiten
- Beware if both are furiten
Overlooking toitoi
- Shanpon machi = toitoi guaranteed
- Minimum 2 han
Wrong chiitoitsu choice
- Judgment with 5 pairs
- Balance points and win rate
Misunderstanding waits
- Forgetting it’s 2 types 4 tiles
- Wall checking also important

Shanpon Machi Tactics

When to Choose Shanpon Machi

Starting hand with many pairs
- 4+ pairs
- Toitoi route
Honor tile pairs exist
- , , etc.
- Yaku certainly attaches
Dora pairs
- High points expected
- Shanpon is sufficient

Shanpon Machi vs Ryanmen Machi

Judgment criteria	Shanpon machi	Ryanmen machi
Points focus	◎	△
Win rate focus	△	◎
Securing yaku	◎	△

Special Shanpon Machi Forms

Suuankou Shanpon Machi

Concealed triplet × 3 + pair × 2
→ Tsumo = suuankou (yakuman)
→ Ron = sanankou toitoi

Comparison with Kokushi 13-Sided Wait

From kokushi complete form
→ Shanpon-like wait more advantageous
→ Than pair tanki wait

Reading Shanpon Machi

Reading Opponent’s Shanpon Machi

Recognize pair-heavy table
- Many triplets visible
- Toitsu-type hand
Discard bias
- Keeping terminals and honors
- Not making sequences
Calling pattern
- Many pons
- No chis

Shanpon Machi Statistics

Win Rate and Points

Win rate: About 20% (equivalent to bad wait)
Average points: About 1.5× ryanmen machi
Toitoi combination rate: 100%

Conclusion

Shanpon machi, waiting on either of two pairs, has few acceptance tiles but unique advantages like toitoi combination and easy honor tile usage. For beginners, it’s important to learn shanpon machi as an option when having many pairs, and become able to choose between ryanmen and shanpon according to situation. Especially when having honor tile or dora pairs, actively choosing shanpon machi enables aiming for high points.