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Griffin · Daedalian Member

(this is actually my second stab at this puzzle, I deleted the first one since there was some bad alternate solutions. Hopefully it's better now.)

Zag · Tired of his old title

Tricky. A lot of things that look like they should work are foiled because black never could have gotten in that knot. But I think this works.

Instead of Nd7xBb8 he should have moved Nd7 to b6++

Griffin · Daedalian Member

Hmm, no, let me try fixing it ...

ralphmerridew · Daedalian Member

Nothing major yet.
The bishop on F1 never left its home square; A4 is promoted. It must be the pawn from H2. H2 made at least one capture before promoting, and B3 or B4 has captured. Also, one white pawn promoted and there are seven on the board, so all other pieces are original.

Griffin · Daedalian Member

Okay, the board is fix. Looks like that solution works, Zag Revenge most foul!

. Unfortunately it wasn't the intended solution Embarrassed

. Maybe I'll work on it a bit more ...

Zag · Tired of his old title

It is easy enough for you to say that black has never promoted a pawn, because a black bishop is (I think) the only piece that could have been in there and doesn't spoil the checkmate.

(What had you done to make the board display sideways? I saw a puzzle somewhere else that depended on you noticing that the board was sideways, so we must be playing left-to-right and right-to-left. I had wanted to post it here but couldn't figure out how to get the board to do that.)

edit 2: I finally figured out what ralphmerridew was saying -- that the bishop on A4 must be a promoted pawn, because white's original white bishop can not ever have left his starting spot. Is this inference intended and important? I can't see how it could be.

Griffin · Daedalian Member

Actually, my intended solution was white underpromoted to knight on b8 from c7, and then Na7#. But as ralphmerridew points out, that's actually impossible. So maybe Zag's solution is unique?

Now I remember why I gave up trying to make up chess puzzles Felicitous

.

Griffin · Daedalian Member

It was carridge returns within the chessboard tag. I guess there is some sort of bug, or perhaps it was done on purpose. This made it sideways: