Shanten

Shanten 「向聴」 is the number of tiles needed for reaching tenpai. It can also be viewed as the minimum number of tile draws or tile calls required to attain tenpai.

Examples:

• Iishanten (1-shanten)

• Ryanshanten (2-shanten)

• Sanshanten (3-shanten)

Open vs closed

Main article: Naki

Often, the decision to open the hand rests on the tiles needed and the yaku most conveniently acquired. In addition, the shanten count may play a factor too, especially at 1-shanten where a discarded tile could put the hand into tenpai.