It states in the rules that if the king is surrounded on 3 sides, and the throne is on the fourth side, Black wins.
But what if the king has an opening behind him, over the throne and to safety? It is still a legal move, and I'm not sure whether or not Black has to block that exit for the king too ...
For an example see game 406190. Does Black require the piece at E6 to win the game?
harley raised a similiar question on 2003-March-20 15:28, but it remained unanswered. (Except for the tip to resign the game if there's a gap between rules and implementation.)
As far as I understand a very early discussion in this board, the implementation of "moves over the throne" have been modified (a long time ago), but the rules haven't been updated ...?