Shanten: Difference between revisions

Calculating accurate shanten will give a proper result, -1 indicating a complete hand, any strictly positive integer indicating a distance from tenpai. However, when the result is zero, there is a chance that there are no tiles existing that could lead to creating a winning hand. From 34 possible tiles, trying out every tile ''not present in four copies'' should lead either to a complete hand (-1), or a hand that is "still tenpai" (0). A tenpai hand that can't win does not exist, usually because of the need of a 5th copy of a tile. This does not take into account tiles discarded or melded by other players. Only one's hand and one's melds count against this limit.

If AccurateShanten = 0, for all possibilities of tile: keep lowest AccurateShanten(hand + tile) value (-1 or 0) and add 1 (for 0 or 1). The hand above, when any other tile is added to it, is never complete. A proper test would never make a 5th copy of 3p or 6p.