Re: Got it. Couple of more problems, though

I have fixed (but not posted the fixes) the 2 I found, and the first 1 you found. Not sure the 2nd is a bug.
I will wait until after I can check chess rules before I post the new code. I know that in a castle, the king cannot cross threatened squares, but I am not sure that the rook can't.

The 2 bugs I found were related to your find yesterday. They were both cases of testing for "not possible" before finishing the "Illegal" tests. One affected a castling king. The other affected a pawns moving forward.

Thank you for the bug reports.
Regards,
Michael