31 Jul '10 18:27>
Black to move and mate in one.
Originally posted by Thomasterso its either BxP++
To move 1. ... xe3, white must have played e2-e4 last move.
Last move was -e4 because of the bishop that checks on c6, only e3-e4 and e2-e4 remain. Pawn on e3 is not possible because it would check the black king.
Originally posted by iamatigerA pawn on g3 would have checked the black king, so it certainly wasn't there last move.
Now I'm not sure that we can prove white's last move was e2-e4
The other possibilities are: g3xh4; f3xe4; e2xd3; and d3
Can we rule them all out?
Originally posted by ThomasterRight you are. ... good analysis.
A pawn on g3 would have checked the black king, so it certainly wasn't there last move.
f3xe4 and e2xd3 are not possible either: what piece must the pawn have captured? (black's missing three pieces, a knight, a rook, and a queen. Two of those are needed in order to get the pawn on h4 and g5, which leaves only one piece to be captured.)
All seven whit ...[text shortened]... rlier in the game, because the white black bishop had to go out (as well as the white a-rook).
Originally posted by ThomasterNice logic! I didn't see all that.
A pawn on g3 would have checked the black king, so it certainly wasn't there last move.
f3xe4 and e2xd3 are not possible either: what piece must the pawn have captured? (black's missing three pieces, a knight, a rook, and a queen. Two of those are needed in order to get the pawn on h4 and g5, which leaves only one piece to be captured.)
All seven whit ...[text shortened]... rlier in the game, because the white black bishop had to go out (as well as the white a-rook).
Originally posted by SwissGambitLot of superfluous pieces on the board. You should pare it down to minimum needed for mate. Like the rook, not needed, nor the 4 pawns in a row.
[fen]8/pb4p1/p7/p5P1/p2pPkrP/3P3p/PPP2p1P/4n1bK b - - 0 1[/fen]
Black to mate in 1
Try this one. Should be sound now.
Originally posted by sonhouseWithout those pieces, you can't prove that en passant is legal and thus can't mate in one. They're not superfluous.
Lot of superfluous pieces on the board. You should pare it down to minimum needed for mate. Like the rook, not needed, nor the 4 pawns in a row.