Betaori

Betaori 「ベタ降り」 is a general strategy which aims to minimize the chance of dealing into other players' hands. Usually, by employing betaori, a player will abandon the prospect of winning the hand. Points can be lost via opponent tsumo or ryuukyoku, but you'd lose less points than by dealing in.

Determining safe tiles

Main article: Defense

When playing betaori, you should discard the safest tiles. For example, if an opponent declares riichi, you should discard safe tiles against that player. This requires deduction from visible tiles, including all discards, dora indicator, and the tiles in the player's own hand. Of course, it also requires the player's active decision to defend (as opposed to continuing to push the hand towards tenpai).

Genbutsu and furiten

Main article: Furiten

Genbutsu 「現物」 is a term for "safe tile" due to furiten. Tiles applied by the furiten rule are the safest tiles against that particular player.

There are three types of furiten:

• Discard furiten: If a player has discarded any tile they could've won off of, they are in furiten. Thus, any tile that a player discarded is 100% safe against that player.
• Temporary furiten: If a non-riichi hand declines a win, the player is in furiten until their next discard. This means that the tile discarded by the your left player is 100% safe against everyone for that turn only. The tile discarded by the player across from you is 100% safe against your right player, again for that turn only.
• Riichi furiten: If a riichi hand declines a win, the player is in furiten for the rest of a hand. So after a player declares riichi, any tile discarded by anyone is 100% safe against the riichi.

If genbutsu is not available, then defensive strategies like suji and/or kabe should be employed to determine the tile least likely to deal in.

Mawashiuchi

If two tiles are equally safe, it is best to discard a tile that does not reduce hand progress. After all, you can prevent opponents from winning by winning yourself.

Mawashiuchi 「回し打ち」 is a separate strategy aiming to build a hand while discarding relatively safe tiles. This practice is best performed, if and only if, the tiles bring about the possibility of attaining tenpai without discarding any winning tiles.

External links

• Basic Defense Techniques in Mahjong

Written work on defense in Osamuko