Shanten (Tiles Away from Tenpai) - Measuring Hand Progress

What is Shanten?

Shanten is the minimum number of tile exchanges needed to reach tenpai. For example, “1-shanten” (iishanten) means one more useful tile brings you to tenpai. It’s a crucial metric for evaluating hand progress.

The term means “toward tenpai” - measuring how close your hand is to being ready to win.

Shanten Levels

How to Count Shanten

Basic Formula

For standard 4-meld-1-pair hand:
Required: 4 melds + 1 pair = 5 groups

Count what you have:
- Completed melds (3 tiles each)
- Incomplete shapes (taatsu: 2 tiles)
- Pairs (potential head)

Shanten ≈ 8 - (melds×2 + taatsu + pairs)

Component Values

Examples

1-Shanten Example

123m 456p 789s 35s EE
└meld┘└meld┘└meld┘└taatsu┘└pair┘

Draw 4s → completes 345s → Tenpai!
= 1-shanten

2-Shanten Example

123m 456p 78s 357s E
└meld┘└meld┘└taatsu┘└floating┘└isolated┘

Need two improvements to reach tenpai
= 2-shanten

Strategic Use

By Shanten Level

Shanten Pushback

When shanten pushback is worth it:
1. Acceptance dramatically increases
2. Hand value significantly rises
3. Defensive advantage gained

Counting Tips

Quick Estimation

Rule of thumb:
- 3 melds + 1 taatsu + 1 pair = 1-shanten
- 2 melds + 2 taatsu + 1 pair = 2-shanten
- 2 melds + 1 taatsu + 2 pairs = 2-shanten
- 1 meld + 3 taatsu + 1 pair = 3-shanten

Acceptance by Shanten

Special Cases

Chiitoitsu

• Uses different counting
• Count pairs (need 7)
• 6 pairs = 1-shanten
• 5 pairs = 2-shanten

Kokushi Musou

• Special calculation
• Count yaochuu types
• 12 types + 1 pair = tenpai
• 11 types = 1-shanten

Common Mistakes

1. Chiitoitsu calculation

   • Different from standard
   • Pair-based counting

2. Missing best shanten

   • Multiple structures possible
   • Find the most efficient

3. Keishiki tenpai confusion

   • 0-shanten but no yaku
   • Still ready to win (with restrictions)

Related Terms

• Tenpai: 0-shanten, ready to win
• Taatsu: Incomplete shape
• Hai-koritsu: Tile efficiency
• Uke-ire: Acceptance (useful tiles)

Summary

Shanten measures how many tile exchanges you need to reach tenpai. Counting shanten helps you evaluate hand progress and make strategic decisions. At 3+ shanten, focus on efficiency; at 1-shanten, prioritize good shape. Master shanten counting to improve your hand-building speed and decision-making in mahjong.