‘Laurel’ is a fairly easy problem with a surprise at the end. ‘Hardy’ follows.
White to play and mate in two moves. (White moves, Black moves, White then checkmates.) There is only one move White can make which will allow certain checkmate of Black in its next move, so the puzzle is finding that first move. That first move can involve any legal move, including checking the Black King or taking a Black piece. When White’s first move, (the “Key”), is discovered, White in its next move can checkmate Black in 4 ways, depending on where Black moves.
Composed by Mark Avery
The solution is below.
Do you think the answer involves . . .
The knight on G6 moving to . . .
f8? No, because Black’s bishop can check White’s king.
e7? No, because Black’s rook takes g8, freeing Black’s bishop.
e5, taking the pawn? No, because Black’s rook takes g8, freeing Black’s bishop.
the queen taking the pawn on b5? No, because Black’s rook on h8 takes White’s rook, freeing the bishop.
Answer: The key move is moving White’s pawn to d6. If . . .
Black’s pawn takes the pawn, White’s queen takes it. Mate.
Black’s pawn takes White’s knight, White’s bishop takes the pawn. Mate.
Black’s pawn on c7 moves forward, White’s knight moves to reveal Bishop’s check. Mate.
If Black does anything else, White’s pawn takes c7. Mate.
The surprise? Place an extra pawn on c2 and you can now checkmate Black in one move! (You couldn’t before, but with that extra pawn, you can.) See below:
It’s the same set up as in the puzzle, ‘Laurel’ except that there is an extra pawn on c2.
The surprise? The same rules apply as above, but White can now checkmate Black in one move!
This problem is harder, because you have to explain why the extra pawn matters.
Composed by Mark Avery
Hint 1. What was Black’s last move? (You can work it out from the layout.)
Hint 2. If you haven’t determined Black’s last move, note that there are fifteen White pieces on the board.
Black’s last move could not be:
- the bishop moving to block the White rook’s check. (The rook could not have just moved there without Black’s king already being in check.)
- the king moving from anywhere, because it would have been in check by two pieces. Impossible in this situation.
- a pawn taking a piece. All eight pawns are on their lines. Had a Black pawn just taken a piece it must have been on another Black pawn’s line, which means it must have taken another piece to get on that line. Not possible, because White has only lost one piece (thanks to that extra pawn on c2). Therefore, no Black pawn has taken a piece.
Black’s last move could only be one move: The Black pawn on e5 must have moved from e7. That means White’s pawn on d5 can move to e6, en passant, revealing the check from White’s queen. Checkmate.
More chess problems:
(Try also the blog, ‘If God played chess‘ and answer the questions posed.)