What is Ko?
Ko (non-dealer/child) refers to the three players who aren’t the dealer in mahjong. In standard 4-player mahjong, each round has 1 dealer and 3 non-dealers. Non-dealer scores are about 2/3 of dealer scores, and losses are similarly smaller.
“Ko” is a fundamental concept essential for understanding scoring and game progression.
Non-Dealer Positions
| Position | Name | Reading | Role |
|---|---|---|---|
| South | Nancha | South seat | Dealer’s right |
| West | Shacha | West seat | Across from dealer |
| North | Peicha | North seat | Dealer’s left |
Non-Dealer Characteristics
1. Scoring
- About 2/3 of dealer
- Losses also smaller
2. Game progression
- Position changes with dealer
- Will become dealer eventually
3. Strategic position
- Target the dealer
- Cooperate with other non-dealersScoring Comparison
| Hand | Non-Dealer | Dealer | Difference |
|---|---|---|---|
| 1 han 30 fu | 1,000 | 1,500 | 500 |
| 2 han 30 fu | 2,000 | 2,900 | 900 |
| 3 han 30 fu | 3,900 | 5,800 | 1,900 |
| Mangan | 8,000 | 12,000 | 4,000 |
| Haneman | 12,000 | 18,000 | 6,000 |
| Baiman | 16,000 | 24,000 | 8,000 |
| Yakuman | 32,000 | 48,000 | 16,000 |
Tsumo Payment
When non-dealer tsumo wins:
- From dealer: ~1.5x the base
- From other non-dealers: ~0.5x base each
Example: Non-dealer mangan tsumo
- From dealer: 4,000 points
- From non-dealers: 2,000 × 2 peopleNon-Dealer Strategy
Basic Approach
| Situation | Recommended | Reason |
|---|---|---|
| Early game | Balanced | Risk vs reward |
| Dealer riichi | Cautious | Dealer payment hurts |
| Dealer renchan | Stop dealer | Minimize damage |
| Oorasu | Situational | Rank-aware |
Key Points
1. Dealer relationship
- Avoid dealer payment
- Try to end dealer's turn
2. Other non-dealers
- Cooperate when needed
- Sometimes compete
3. Point efficiency
- 2/3 of dealer in mind
- Efficient hand buildingNon-Dealer Terminology
- “Ko-man”: Non-dealer mangan (8,000)
- “Ko-bai”: Non-dealer haneman (12,000)
- “Ko-ppane”: Non-dealer baiman
- “Ko-dabu”: Non-dealer yakuman
- “Ko-ochi”: Dealer turn ending
Special Rules
Double Ron
- Two or more ron simultaneously
- Discarder pays all
Suu-fonrenda
- All 4 players discard same wind first turn
- Abortive draw
Common Mistakes
-
Position confusion
- South, West, North order
- Counter-clockwise seating
-
Score calculation errors
- Mixing dealer/non-dealer
- Not always exactly 2/3
-
Tsumo payment
- Dealer and non-dealer pay differently
- Watch for calculation mistakes
-
Role understanding
- Know player relationships
- Kamicha/shimocha importance
Related Terms
- Oya: The dealer
- Shimocha: Right-side player
- Toimen: Across player
- Kamicha: Left-side player
- Ron: Win on discard
Summary
Ko refers to the three non-dealer players in mahjong. Scoring is about 2/3 of dealer rates, with both gains and losses being more modest. Beginners should first learn non-dealer scoring and understand the dealer difference. As non-dealer, maintain balance while being aware of stopping the dealer and cooperating with others for stable results.