50 More deductive problems are coming your way!

For the first one, you need to figure out which side is which. Did White start on the bottom or the top of the board?

white.

Black's king doesn't have a last move even with White's bishop blocked by one of the pawns because there's no way the double check on h2/a7 (whichever it is) could have been delivered by white legally.  This means that on the previous move there must have been another black piece on the board that moved (otherwise it would have been stalemate) and that White's last move simultaneously captured this piece and uncovered the checkmate by the White bishop (which couldn't have moved into that position to deliver check without Black having had to have moved into check on the previous move).

The initial obvious choice is that White must be moving up the board and gxh3# was played, but if this were the last move how did the Bishop get onto the h1 square with a pawn on g2?  This leaves the only other possible alternative as bxa8=B# meaning white is moving down the board and just promoted to a Bishop on a8 to deliver checkmate.

none of them! STALEMATE!

oops, didnt got it first...white is up, as the a1 corner is always black xD and if white is down, the a1 corner isn't black

The a1 corner is black no matter which side is up.

These were shown in an article a while back.

Spoiler

White is going down the board. His last move had to be b7xa8=B#

I am surprised there is not more discussion of this situation.  White's final move must have been a center pawn as it could not have been his checking white square bishop.

Such alone, resolves nothing.  If black's previous move was K(a7) to a8, (column lettering chosen per convention, white on bottom) he was in double check when on a7.  I don't see how white could have double checked him on white's previous move.  I am stumped.  I do not see how a "usual trick" late castling, en passant, or capture of a black piece can help.

Black's previous move must have been moving a piece to a8 (bottom right corner), and White responded by p(b) xa8. If I understand the previous posts correctly.

But how did Black's king get into that double-check?  What possible legal previous move from White could have resulted in the position you describe with the King under attack from both the Queen and the Bishop on a7/h2? 

rooperi

Thank you.  That does make sense, although I don't see how you deciphered it from previous posts.  Well done.