One thing I’m trying to reconcile is that I know others games like chess and connect four often use bitboards to model game state, rather than sets of legal moves. So I wonder if Sudoku is different in some subtle but essential ways. E.g., no loops in Sudoku game states (vs chess) or legal move set sufficiently representing the current game states (vs connect four). Perhaps different networks are better solved by different algorithms, and constraint propagation wouldn’t be as effective in connect four.
One thing I’m trying to reconcile is that I know others games like chess and connect four often use bitboards to model game state, rather than sets of legal moves. So I wonder if Sudoku is different in some subtle but essential ways. E.g., no loops in Sudoku game states (vs chess) or legal move set sufficiently representing the current game states (vs connect four). Perhaps different networks are better solved by different algorithms, and constraint propagation wouldn’t be as effective in connect four.