SquareIsAttackedByOpponent is not always Working

[PetePete]

I make board.MakeMove and then board.SquareIsAttackedByOpponent in order to check if a Square is safe to go to, but this does not always work correctly, leading my bot to make silly moves....

Also, for debugging purposes, a forward/backward-functionality would be very helpful in order to analyse certain behaviour.

[draeg82]

Are you understanding board.SquareIsAttackedByOpponent() returns whether your bot is attacking the square after board.MakeMove()?

[PetePete]

Hi draeg, I do, I tried it otherwise without move first, but with similiar mixed results. But it is no problem, I created my own check-Method based on the opponents legal capturing moves targeting my position, this way it is working fine. I suspect a problem with the frameworks BitBoard logic but it could be me as well misunderstandig the methods purpose

[SebLague]

Hi, could you maybe provide some code where the function is not doing what you expect?

[MarcusOtter]

EDIT: The white rook is probably blocking the attack from the rook on h8.

Workaround for this case (good bye tokens 😉)

public MyBot()
{
    var board = Board.CreateBoardFromFEN("2kr3r/ppp5/2nb1n1R/4p1p1/Q2p2b1/3P2P1/PPP1PPP1/RNK2BN1 w - - 1 16");

    var move = new Move("h6h1", board);
    board.MakeMove(move);
    board.TrySkipTurn();
    var isAttacked = board.SquareIsAttackedByOpponent(new Square("h1"));
    board.UndoSkipTurn();
    board.UndoMove(move);

    Console.WriteLine(isAttacked); // True
}

I am also having bugs with board.SquareIsAttackedByOpponent(). Here's a minimal repro:

public MyBot()
{
    var board = Board.CreateBoardFromFEN("2kr3r/ppp5/2nb1n1R/4p1p1/Q2p2b1/3P2P1/PPP1PPP1/RNK2BN1 w - - 1 16");
    Console.WriteLine(board.SquareIsAttackedByOpponent(new Square("h1"))); // False
}

White to move. Is h1 attacked by black in this position?

The method seems to think that it is not. Maybe I am misunderstanding something about how this method is supposed to work?

I know that the API will not change, but I thought I'd still report it)