The post that was quoted here has been removed
Its a bit more complicated than I originally thought...
"The FIDE Laws of Chess says in article 9.6:
"The game is drawn when a position is reached from which a checkmate cannot occur by any possible series of legal moves, even with the most unskilled play. This immediately ends the game.""
To keep the implementation simple, I think RHP should implement only K + B v K, and K + N v K. These are vital.
If Russ and Chris were feeling enthusiastic, I think cases 1 to 4 could be implemented.
The others aren't practical to implement.
K + N + N v K can possibly result in a checkmate, so definately shouldn't be included.