# Betaori — Riichi Mahjong Glossary

> Complete defensive folding strategy where players discard only 100% safe tiles to avoid dealing into another player's hand, sacrificing winning chances.

**Source:** https://www.mahjongmaster.co/learn/riichi/glossary/betaori/
**Author:** Kenji Tanaka (https://www.mahjongmaster.co/about/kenji-tanaka/)
**Publisher:** Mahjong Master (https://www.mahjongmaster.co)
**Published:** 2026-02-18
**Updated:** 2026-03-10
**Japanese:** ベタ降り
**Category:** strategy
**Variant:** general

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## Betaori

**Betaori** (ベタ折り) is a complete defensive strategy in mahjong where a player discards only tiles that are absolutely certain to be safe, completely abandoning any possibility of winning the hand in order to avoid dealing into another player's winning hand (ron).

## Betaori, explained

Betaori represents the most conservative approach to mahjong defense. The term combines "beta" (meaning complete or full) with "ori" (meaning to fold or give up), literally translating to "complete folding." When a player adopts betaori, they prioritize survival over scoring, methodically discarding tiles with the highest possible safety margins.

### How Betaori Works

In betaori, a player identifies which tiles are demonstrably safe based on:

- **Genbutsu**: Tiles matching those already discarded by the threatening player, which the furiten rule makes impossible for them to ron
- **Kabe (wall) counting**: When all four copies of a number are visible, waits that need it are dead, making nearby tiles safer
- **Suji analysis**: Using the furiten logic of two-sided waits to identify statistically safer tiles from the threat's own discards

A player in betaori will typically discard only tiles that fall into these categories, even if it means:
- Disrupting their own hand development
- Completely abandoning winning possibilities
- Discarding tiles that could have been useful for their own melds
- Reducing their score potential to zero

### When Betaori Occurs

Betaori is typically employed when:

1. **Multiple players are dangerous**: Several opponents appear close to winning, making normal play risky
2. **Your own hand is cheap or far from tenpai**: The little you might win is not worth the risk of paying out a large ron
3. **Late game situations**: When the round is progressing and multiple players are advancing their hands
4. **Against obvious threats**: When an opponent is clearly pushing for a quick win with obvious winning patterns

### Strategic Considerations

Betaori is not always the correct play, even in defensive situations. Experienced players must balance:

- **Risk vs. reward**: Will winning a hand help your placement more than avoiding a loss?
- **Opponent proximity**: How close is each player to actually winning?
- **Hand potential**: Could your hand develop into something valuable?
- **Point situation**: Your current score relative to other players

Pure betaori can be exploitative in certain situations, players who fold too early may sacrifice winning opportunities that would have secured better placement.

## Betaori at the table

East declares riichi on turn seven. South's own hand is 2-shanten and cheap, so South adopts betaori immediately, discarding only:

- Genbutsu: tiles already sitting in East's discard row
- Suji tiles relative to East's discards when the genbutsu run out
- Honors with all remaining copies visible

South abandons hand development completely, even when drawing tiles that would have advanced the old plan. The hand ends in an exhaustive draw with East tenpai. South pays the small noten penalty, a fraction of what dealing into a riichi hand would have cost, and moves to the next hand with their position intact.

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*This content is from [Mahjong Master](https://www.mahjongmaster.co), a free educational reference for riichi (Japanese) and American (NMJL) mahjong. When citing this page, please link to https://www.mahjongmaster.co/learn/riichi/glossary/betaori/.*