What is Taatsu? Meaning, Types, and Efficient Usage Explained for Beginners

What is Taatsu?

Taatsu (塔子) refers to a combination of 2 tiles that needs just 1 more tile to become a complete set (mentsu). It’s an incomplete sequence form that greatly affects the efficiency of hand building.

The character “塔” means “unfinished tower,” signifying a shape in progress toward completion (mentsu).

Detailed Explanation of Taatsu

Types and Efficiency of Taatsu

Acceptance Count of Taatsu

Efficiency is determined by acceptance count:

1. Ryanmen Taatsu: 8 tiles (most efficient)
2. Kanchan Taatsu: 4 tiles
3. Penchan Taatsu: 4 tiles

Compound Taatsu

Shapes with 3+ tiles containing multiple taatsu:

Usage Examples

Real Game Situations

Example 1: Taatsu Selection

"I have 3 ryanmen taatsu, looks fast"
"Only kanchan and penchan... bad shapes"

Example 2: Hand Building Decisions

"This penchan taatsu is useless, let's discard it"
"Keep the ryanmen taatsu, process the kanchan"

Example 3: Taatsu Overflow

"I have 6 taatsu! Need to break one"
"Too many taatsu, start cutting bad shapes"

Taatsu Priority

Order of Taatsu to Keep

1. Ryanmen Taatsu (23~78)

   • Highest priority to keep
   • 34・45・56・67 are especially good

2. Kanchan Taatsu

   • Possibility of becoming ryanmen
   • Like 24→234

3. Penchan Taatsu

   • Lowest value
   • Important to cut early

Tiles That Increase Taatsu Value

Related Terms

• Mentsu: Complete 3-tile set
• Shuntsu: 3 consecutive tiles
• Ryanmen: Open-ended wait
• Kanchan: Closed wait
• Penchan: Edge wait

Common Mistakes and Points to Note

Points Beginners Often Mistake

1. Taatsu Overflow

   • Exceeding 5-block theory
   • Causes mentsu overflow

2. Taatsu Shortage

   • Only pairs, no taatsu
   • Hand doesn’t progress

3. Clinging to Bad Shape Taatsu

   • Fixating on penchan/kanchan
   • Missing chances for good shape changes

4. Overlooking Taatsu

   • 135 shape has 2 taatsu
   • Not understanding compound forms

5-Block Theory

Basics of Efficient Hand Building

• 4 mentsu + 1 pair = 5 blocks
• Ideal: 5-6 blocks from starting hand
• 7+ blocks means taatsu overflow

How to Count Blocks

Example: 234m 56p 78p 135s EE GW
         └1┘  └2┘  └3┘  └4┘ └5┘ └6┘
→ 6 blocks (1 too many)

Taatsu Tactics

Early Game Taatsu Selection

1. Create Ryanmen Taatsu

   • Connect isolated tiles
   • If you have 3 and 5, be aware of 4

2. Aim for Compound Forms

   • Create shapes like 233
   • Wide acceptance

Mid-Game Taatsu Management

1. Resolve Taatsu Overflow

   • Cut bad shapes first
   • Consider safety too

2. Taatsu Replacement

   • Switch when better taatsu forms
   • Always maintain optimal shape

Conclusion

Taatsu is a shape one step before becoming a mentsu, an essential concept in mahjong hand building. Building your hand around ryanmen taatsu and properly handling bad shape taatsu like kanchan and penchan is the first step to efficient mahjong. Beginners should start by understanding taatsu types and efficiency differences, and practice hand building while keeping the 5-block theory in mind.