Shanten
Shanten 「向聴」 is the number of tiles needed for reaching 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.