What is Chinroutou? The All Terminals Yakuman Explained for Beginners

What is Chinroutou?

Chinroutou (清老頭), also called “All Terminals,” is a yakuman in mahjong where your entire hand consists of terminal tiles (1s and 9s of suited tiles only). With no honor tiles allowed, this is a pure form using only the edges of the number tiles - “chin” means pure/unmixed.

With only 6 tile types (24 tiles total) available, the occurrence rate is about 0.0018% - an extremely rare phantom yakuman. The hand necessarily forms a toitoi shape, and calling is allowed.

Detailed Explanation of Chinroutou

Conditions for Completion

To complete chinroutou, you must meet these conditions:

Available Tiles

The 6 types for chinroutou:

Usage Examples

Real Game Situations

Example 1: Starting the pursuit

"All 1s and 9s, can I make chinroutou?"
"Switching from honroutou to chinroutou"

Example 2: Achievement

"Chinroutou!!"
"Finally got chinroutou!"

Example 3: Surprise

"An unexpected chinroutou"
"First time seeing chinroutou"

Chinroutou Shapes

Basic Form

Hand: 111m 999m 111p 999p 11s
Complete: 4 triplets of terminals + terminal pair

Practical Form

With calls:

Pon: 111m (exposed) 999p (exposed)
Hand: 999m 111s 9s
Wait: 9s (tanki wait)

Related Terms

• Routouhai: Terminal tiles (1s and 9s)
• Honroutou: Terminals + honors (2 han)
• Toitoi: Necessarily combined
• Tanyao: The opposite yaku
• Yaochuuhai: Terminals and honors combined

Common Mistakes and Points to Note

Points Beginners Often Mistake

1. Confusion with Honroutou

   • Chinroutou: 1s and 9s only
   • Honroutou: 1s, 9s + honors

2. Including Honor Tiles

   • Even 1 honor tile invalidates
   • Must be purely terminals

3. Limited Tile Pool

   • Only 6 types, 24 tiles
   • Extremely restrictive

4. No Sequences

   • 123 or 789 not allowed
   • Toitoi shape only

When to Aim for Chinroutou

Starting Hand Guidelines

Conditions to consider chinroutou:

Transitioning from Honroutou

Decision points:

Aiming for honroutou
↓
No honor tiles coming
Terminals gathering
↓
Switch to chinroutou

Chinroutou in Practice

The Path to Chinroutou

Typical flow:

Starting hand: Abnormally many terminals
↓
Early game: Discard all middle tiles
↓
Mid game: Pon terminals to shape hand
↓
Late game: Wait for final triplet

How to Collect Tiles

Efficient methods:

1. Call early

   • Don’t miss opportunities
   • Pon aggressively

2. Cherish pairs

   • Keep all of them
   • Triplet candidates

3. Discard middle tiles immediately

   • 2-8 not needed
   • No hesitation

Difficulty of Chinroutou

Severe Constraints

Why it’s so hard:

1. Few tiles available

   • Only 6 types
   • Less than the 7 honor tile types

2. High demand

   • Used in honitsu
   • Terminal tiles are popular

3. Limited shape

   • Toitoi only
   • No alternatives

Probability Analysis

Mathematical analysis:

Value of Chinroutou

Rarity

Yakuman rarity ranking:

1. Suukantsu (~0.0001%)
2. Tenhou (~0.0003%)
3. Chiihou (~0.0005%)
4. Daisuushii (~0.0016%)
5. Chinroutou (~0.0018%)

Meaning of Achievement

Value of chinroutou:

1. Purity

   • Ultimate numbered tiles
   • Completely unmixed

2. Rarity

   • Once in a lifetime memory
   • Legendary

3. Beauty

   • Simple shape
   • Ultimate symmetry

Defending Against Chinroutou

Warning Signs

Chinroutou possibility:

1. Discards

   • All middle tiles
   • 2-8 lined up

2. Calls

   • Pon of 1s and 9s
   • Multiple times

3. Pair situation

   • Few terminals visible
   • Table conditions

Defense Strategies

Preventing chinroutou:

1. Hold terminals

   • Don’t release 1s and 9s
   • Especially pairs

2. Quick win

   • Before they complete
   • Speed priority

3. Disrupt with honitsu

   • Use terminal tiles yourself
   • Create competition

Chinroutou Combinations

Possible Combinations

Simultaneous yakus:

Ultimate Chinroutou

Combined with Suuankou:

Hand: 111m 999m 111p 999p 99s
Tsumo: 9s
→ Chinroutou + Suuankou (Double yakuman)

Local Rules

Point Variations

Regional differences:

• Standard: Single yakuman
• Some regions: Double yakuman
• Rarity is valued

Special Rules

Adoption examples:

1. Starting hand chinroutou

   • Special treatment
   • Legendary

2. Pure chinroutou

   • Closed only
   • Increased value

History and Culture

Position of Chinroutou

Evaluation in mahjong history:

1. Ultimate purity

   • Limit of number tiles
   • Extreme simplicity

2. Phantom yakuman

   • Few witnesses
   • Passed down stories

3. Mathematical beauty

   • Symmetry
   • Perfect form

Origin of the Name

Meaning interpretation:

• “Chin” (清): Pure, unmixed
• “Rou” (老): Old, end
• “Tou” (頭): Head, edge
• Pure form of only edge tiles

Conclusion

Chinroutou is an extremely rare yakuman made entirely of terminal tiles (1s and 9s). With only 6 types (24 tiles) available and a 0.0018% occurrence rate, it’s a phantom yaku, but its pure and simple form has a unique beauty. Beginners should remember the basic “1s and 9s only,” and if you ever encounter the miraculous situation of having 8+ terminals in your starting hand, definitely try for it. Chinroutou is a special yakuman you might encounter once in your mahjong lifetime.