What is Tonpusen?
Tonpusen (East-Only Game) is a mahjong format that ends after the East round only. While a standard hanchan has 8 rounds (East 1-4, South 1-4), tonpusen has just 4 rounds (East 1-4), making it a quick ~20-40 minute game.
Popular in online mahjong for its time efficiency, tonpusen demands faster decision-making and carries higher variance.
Basic Structure
| Round | Dealer | Approx. Time |
|---|
| East 1 | First dealer | 5-10 min |
| East 2 | Second seat | 5-10 min |
| East 3 | Third seat | 5-10 min |
| East 4 | Fourth seat | 5-10 min |
| Total | Each deals once | 20-40 min |
Tonpusen vs Hanchan
Tonpusen:
- East round only (E1-E4)
- Base 4 rounds (no renchan)
- Duration: 20-40 minutes
- Fast-paced
Hanchan:
- East + South (E1-S4)
- Base 8 rounds (no renchan)
- Duration: 60-90 minutes
- More strategic depth
End Conditions
| Condition | Result |
|---|
| Normal end | After East 4 (oorasu) |
| Extension | Tie score → South round |
| Bust out | Someone goes below 0 |
| Time limit | If time-restricted |
Strategy Differences
Key Considerations
Tonpusen priorities:
1. Dealer round is precious
- Only one chance
- Renchan very valuable
- Cheap wins acceptable
2. Fast offense
- Only 4 rounds
- Can't wait around
- Aggressive calling
3. Point awareness
- Less comeback time
- Build early lead
- Don't over-defend
Round-by-Round Strategy
| Round | Approach | Reason |
|---|
| East 1 | Aggressive | Set the pace |
| East 2 | Balanced | Read the game |
| East 3 | Push | Only 2 left |
| East 4 | All-in | Last chance |
Pros and Cons
Advantages
| Advantage | Description |
|---|
| Short | ~30 minutes |
| Casual | Easy to fit in |
| High turnover | Many games possible |
| Less fatigue | Easier to focus |
| Beginner-friendly | Simpler rules |
Disadvantages
Downsides:
1. High variance
- Starting hand matters more
- Skill shows less
- Harder comebacks
2. Limited strategy
- No slow builds
- Hard to aim for big hands
- Less reading required
3. Can feel incomplete
- Ends quickly
- Less satisfying
- Not "real" mahjong to some
Recommended Yaku
Speed-focused Hands
| Yaku | Why | Approach |
|---|
| Yakuhai | Quick pon | Call immediately |
| Tanyao | Easy to make | Naki-tan |
| Riichi | Standard | Fast riichi |
| Tsumo | Menzen basic | Quick tenpai |
Harder to Achieve
Difficult in tonpusen:
- Chinitsu (takes too long)
- Sanshoku (hard to align)
- Ittsu (slow completion)
- Yakuman (low probability)
Point Benchmarks
Tonpusen targets:
- 25,000: Starting point
- 30,000: Slightly ahead
- 35,000: Comfortable
- 40,000: Near safe zone
- Below 20,000: Danger
Comeback requirements:
- 3 rounds left, 10k behind: Need mangan
- 2 rounds left, 15k behind: Need mangan+
- 1 round left, 20k behind: Need haneman+
Online Mahjong & Tonpusen
Why It’s Popular Online
Reasons:
1. Time efficiency
2. Easier rank grinding
3. Casual accessibility
4. Shorter queues
5. Less ragequit risk
When to Play Tonpusen
| Situation | Tonpusen? |
|---|
| Limited time | Yes |
| Learning basics | Yes |
| Want quick games | Yes |
| Want deep strategy | Hanchan better |
| Tournament practice | Hanchan better |
| Serious competition | Hanchan better |
Summary
Tonpusen is a quick East-only mahjong format lasting about 30 minutes. With only 4 rounds, every hand counts more - dealer position is precious and aggressive play is rewarded. It’s ideal for beginners or when time is limited, though it offers less strategic depth than hanchan. Master tonpusen basics before graduating to the full hanchan experience.