The position below was achieved in a normal chess game, and there are no other pieces left on the board with the exception of the white King. Where is the white King? How was this position achieved?

Black

White

The king cannot be in position C2, because kings can never threaten each other. The king also cannot be in position B3. He cannot move here, since this would put himself in check. He also cannot be double-checked here, since such a move would require him to be in check before this move. (Either the bishop would have to block the rook, or vice versa, and neither is possible.)

So, the black king is in check, and it is black's turn to move. This means that black was just placed in check by white's bishop. However, white's bishop can only have occupied either C2 or B3, both of which would place the black king in check.

If there is a solution to this problem, it's not immediately apparent.

Posted by Eric on 2005-08-05 16:42:00