I've encountered a state that should be considered an automatic draw condition, but the game continues, despite no chance for either player to check the other, due to the kings being the only remaining pieces on the board. I played both sides; it is unlikely that a human player against the AI player would reach the same state, but I think it still makes sense to implement the automatic draw condition.
The screenshot was taken right after the white king captured the last non-king black piece.
According to the article I linked in a previous post (7 Ways a Chess Game Can End in a Draw (With Examples)), there are three ways there can be a draw by "insufficient material" — i.e. the pieces left on the board cannot checkmate an opponent's solo king:
- king vs. king
- king vs. king + one bishop
- king vs. king + one knight
According to the Draw (chess) - Wikipedia article, there is also one other draw by insufficient material:
- king + bishop vs. king + bishop (with the bishops on the same color)
I think it would be worthwhile to account for each of these "insufficient material" draw conditions, since not all players would necessarily be intuitively aware that these conditions prevent a checkmate (specifically king vs. king + one bishop, king vs. king + one knight, and king + bishop vs. king + bishop (with the bishops on the same color)). They may realize it as they continue playing, but it would be ideal if the game would declare a draw based on insufficient material. Hopefully there is enough space in the game's memory (RAM/ROM) to add these rules.
