Menzenchin (Closed Hand) - Playing Without Calling

What is Menzenchin?

Menzenchin is the state of not calling any tiles from other players in mahjong. Also called “menzen” for short, it means no chi, pon, or open kan - keeping your hand completely concealed.

Staying closed enables closed-only yaku like riichi and pinfu. The decision between staying closed or calling is crucial in mahjong strategy.

Closed vs Open

Closed (Menzenchin):
✓ No chi
✓ No pon
✓ No open kan
✓ Concealed kan is OK (stays closed)

Open (Fuuro):
✗ Made chi, pon, or open kan
✗ Part of hand exposed

Pros and Cons

Aspect	Pros	Cons
Yaku access	Many closed-only yaku	Limited callable yaku
Scoring	Higher points likely	-
Speed	-	Slower to win
Defense	Hand unreadable	-
Flexibility	Can change direction	Miss needed tiles

Closed-Only Yaku

Closed-only yaku:
1. Riichi - 1 han
2. Ippatsu - 1 han
3. Menzen Tsumo - 1 han
4. Pinfu - 1 han
5. Iipeikou - 1 han
6. Ryanpeikou - 3 han

*Suuankou, Kokushi also closed-only

When to Stay Closed

Stay closed when:
1. Good shape nearing tenpai
   - Riichi for ura-dora
   - Ippatsu possible

2. High-scoring hand
   - Already 3+ han
   - Yakuman potential

3. Many dora
   - Riichi makes mangan+
   - No need to call

4. Early game
   - Still have time
   - Watch the situation

Decision Guidelines

Hand Situation	Closed Preference	Reason
2-shanten good shape	High	Riichi likely
3 dora	High	High score certain
No yaku, bad shape	Low	Call for yaku
Late game noten	Low	Speed priority

When to Break Closed

Consider calling:
1. Guaranteed yaku
   - Yakuhai pair
   - Tanyao certain

2. Big speed boost
   - One call to tenpai
   - Stop opponents

3. Score situation
   - Quick win needed
   - Cheap is fine

4. Defensive reasons
   - Cancel ippatsu
   - Formal tenpai

Closed and Yaku

Yaku with Kuisagari

Yaku	Closed	Open	Notes
Tanyao	1 han	1 han	Rule-dependent
Yakuhai	1 han	1 han	Same
Toitoi	2 han	2 han	Same
Sanshoku	2 han	1 han	Kuisagari
Ittsu	2 han	1 han	Kuisagari

Statistics

General statistics:
Closed win rate: ~20%
Open win rate: ~30%

But average score:
Closed: ~7,000 points
Open: ~4,000 points

Defense Value

Why closed helps defense:
1. Hand unreadable
   - Unknown waits
   - Unknown yaku

2. Discard flexibility
   - Keep safe tiles
   - Cut dangerous first

3. Easy to fold
   - Can break hand
   - Full betaori possible

Common Mistakes

Ankan confusion
- Ankan keeps closed
- Only self-tiles
- Riichi still possible
Kuisagari misunderstanding
- Some yaku lose han when open
- Full value when closed
- Important judgment
Over-valuing closed
- Not always right answer
- Sometimes should call
- Speed matters too
Yaku restrictions
- Many yaku closed-only
- Especially pinfu
- Check beforehand

Fuuro: Calling tiles to expose
Riichi: Closed-only yaku
Menzen Tsumo: Closed tsumo win
Naki: Calling tiles
Ankou: Concealed triplet

Summary

Menzenchin is the state of not calling any tiles, enabling many closed-only yaku like riichi and menzen tsumo. While it offers higher scoring potential, winning takes longer.

Beginners should remember “closed = no calls” and try staying closed early. However, calling is sometimes correct - the key is flexible judgment without being too attached to staying closed.