Move-in-one, but...

This is a move in one...



...but the white pieces are missing.

Question: Where are the white pieces in order to make it into a 'mate-in-one problem?

Originally posted by FabianFnas
This is a move in one...

[fen]1r6/krp5/q1p5/8/1p2p3/1p1p4/1pp5/8[/fen]

...but the white pieces are missing.

Question: Where are the white pieces in order to make it into a 'mate-in-one problem?

I must be missing something.

With white to move and mate black in one, there are many positions. For instance Kd6, Ra1 Ra2 with winning move 1.Rxa6#

With black to move and mate white in one, idem. For instance Kc5 Bd4 and first move 1. .. Qb5#

I didn't look at white to move and black wins in one or black to move and white wins in one, but I guess this works too.

But what about


I have to say that I found the problem on the net, found it amusing, but haven't really studied it through in order to find other solutions than the one given. This given solution, on the other hand, is very nice.

Are there other solutions than one alone?

Perhaps the constructor of the problem wanted a minimum number of pieces neccesary to make it a mat-in-one? The solution has two pieces, the king and one more.

A knight on b6 and c8 no? edit: never mind 😳

Read this posting before my previous one: (I messed it up a bit...)

Yes, white is mating black with one move. Where are white's pieces?
Your suggestion is that we place a king at d6 and rooks at a1 and a2, right?

Then we have this position:

But this is not a legal position. White has to deal with the king first, it's in check.

I dont know how to post the board thing but what about:

Rook on h8,
Queen on a8,
Knight on b6

King on c5

Can someone post this board?

Looks pretty illegal tho 🙂

Originally posted by aethsilgne
I dont know how to post the board thing but what about:

Rook on h8,
Queen on a8,
Knight on b6

King on c5

Can someone post this board?

Looks pretty illegal tho 🙂

You mean something like this?


The thing is - what was black's last move?

Knight d7
King c5
Queen h8
Queen g8

Knight c6, Blacks last move, pawn x c6

Originally posted by aethsilgne
Knight d7
King c5
Queen h8
Queen g8

Knight c6, Blacks last move, pawn x c6

c6 is occupied with a black pawn...

I think the problem constructor meant a minimal number of white pieces. A king and another piece is sufficient. What, and where?

In twenty hours (or so) I will present the solution.

Originally posted by FabianFnas
Read this posting before my previous one: (I messed it up a bit...)

Yes, white is mating black with one move. Where are white's pieces?
Your suggestion is that we place a king at d6 and rooks at a1 and a2, right?

Then we have this position:
[fen]1r6/krp5/q1pK4/8/1p2p3/1p1p4/Rpp5/R7[/fen]
But this is not a legal position. White has to deal with the king first, it's in check.

Kd6 was a typo, of course. There are plenty of squares where the white king is not in check.

If you remove one white rook and replace it by a piece (or pawn) that attacks the queen, then it works as well. Rook and queen can be swapped too.

Have you all thought about Black's pawn structure? White can have very few pieces.

Originally posted by FabianFnas
You mean something like this?
[fen]Qr5R/krp5/qNp5/2K5/1p2p3/1p1p4/1pp5/8[/fen]

The thing is - what was black's last move?

The thing is... Black is in check and it is White to move?

My answer is wKa5 and wRb6.



1. Rxb6#

Black's last move was ...Qc4-a6+

The idea is that Black's pawns must have captured 14 pieces; so there is left only one piece for White. Now the King must be on a5 to support the mate; adding a white Queen on a random place (i.e. b5) would not be possible because Black has no last move (where does the black Queen on a6 come from?). With the Rook on b6, Black has a possible last move in Qc4-a6+.

Originally posted by heinzkat
My answer is wKa5 and wRb6.

[fen]1r6/krp5/qRp5/K7/1p2p3/1p1p4/1pp5/8 w - -[/fen]

1. Rxb6#

Black's last move was ...Qc4-a6+

Woops - 1. Rxa6#.