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Chess

Posted: August 28th, 2023, 6:19 pm
by cinelli
Image
In this chess puzzle black is in a hopeless position. But how can white apply the coup de grace by mating in one move?

Cinelli

Re: Chess

Posted: August 28th, 2023, 9:20 pm
by mc2fool
Ha! That's sneaky!!! Took me yonks to work out "what am I missing?" but eventually realised....

Spoiler: Pawn Queens! De Bono would like this one! :D

Re: Chess

Posted: August 28th, 2023, 10:12 pm
by Lootman
mc2fool wrote:Ha! That's sneaky!!! Took me yonks to work out "what am I missing?" but eventually realised....

Spoiler: Pawn Queens! De Bono would like this one! :D

Yeah but it is a bit of a cheat I think. The black square being on the right is the giveaway, but there are certain things you should just not mess with.

Re: Chess

Posted: August 28th, 2023, 10:37 pm
by mc2fool
Lootman wrote:
mc2fool wrote:Ha! That's sneaky!!! Took me yonks to work out "what am I missing?" but eventually realised....

Spoiler: Pawn Queens! De Bono would like this one! :D

Yeah but it is a bit of a cheat I think. The black square being on the right is the giveaway, but there are certain things you should just not mess with.

And one of those on this board is putting giveaways in plain text. :roll:

Re: Chess

Posted: August 28th, 2023, 11:13 pm
by jfgw
I got it fairly quickly. It is ambiguous, however: only one of the two possible solutions can be correct.


Julian F. G. W.

Re: Chess

Posted: August 29th, 2023, 1:22 pm
by GoSeigen
jfgw wrote:I got it fairly quickly. It is ambiguous, however: only one of the two possible solutions can be correct.


Hmm I found two pairs of solutions... does it matter though? Any of the four is a solution to the puzzle as set.


GS

Re: Chess

Posted: August 29th, 2023, 2:02 pm
by Lootman
mc2fool wrote:
Lootman wrote:Yeah but it is a bit of a cheat I think. The black square being on the right is the giveaway, but there are certain things you should just not mess with.

And one of those on this board is putting giveaways in plain text. :roll:

Sorry but I don't know how to do the clever hidden text thing.

In any event at least three people found this very easy. If you are a decent chess player then it is quickly apparent both that there is no conventional mate-in-one and that the board looks funny.

Another giveaway is that in most chess puzzles Occam's Ruler applies, and every piece that is shown is there for a reason. So sometimes to find the key you have to look at a piece that appears not to be in the action.

GoSeigen wrote:
jfgw wrote:I got it fairly quickly. It is ambiguous, however: only one of the two possible solutions can be correct.

Hmm I found two pairs of solutions... does it matter though? Any of the four is a solution to the puzzle as set.

You did? There are obviously two solutions, but I am not sure where you get four from, non-trivially anyway.

Re: Chess

Posted: August 29th, 2023, 2:13 pm
by mc2fool
Lootman wrote:
mc2fool wrote:And one of those on this board is putting giveaways in plain text. :roll:

Sorry but I don't know how to do the clever hidden text thing.

If you'd looked you'd have seen how to do it when you replied-with-quote to my post. ;)

Re: Chess

Posted: August 29th, 2023, 2:16 pm
by GoSeigen
Lootman wrote:You did? There are obviously two solutions, but I am not sure where you get four from, non-trivially anyway.


I didn't exclude any level of triviality!

GS

Re: Chess

Posted: August 29th, 2023, 2:21 pm
by Lootman
GoSeigen wrote:
Lootman wrote:You did? There are obviously two solutions, but I am not sure where you get four from, non-trivially anyway.

I didn't exclude any level of triviality!

GS

Fair enough. Without giving too much away it can be noted that mate may be delivered by one of three different pieces!

Re: Chess

Posted: August 29th, 2023, 2:36 pm
by GoSeigen
Lootman wrote:
GoSeigen wrote:I didn't exclude any level of triviality!

GS

Fair enough. Without giving too much away it can be noted that mate may be delivered by one of three different pieces!


Well, that's a stretch, I'd say one of two pieces or one of two pieces (a different way) can give mate -- depending on the state the board in Schrodinger's box. But maybe that is giving too much away...

Re: Chess

Posted: August 29th, 2023, 2:38 pm
by mc2fool
Lootman wrote:
GoSeigen wrote:I didn't exclude any level of triviality!

GS

Fair enough. Without giving too much away it can be noted that mate may be delivered by one of three different pieces!

Uh? Well (spoiler, just in case): I can only see two, and they're really the same move. To be verbose it's pawn on c7 moves to c8 and becomes a queen or becomes a bishop.

So, now you know how to do the clever hidden text thing (and need to practice it), what else? ;)

Re: Chess

Posted: August 29th, 2023, 3:05 pm
by UncleEbenezer
mc2fool wrote:
Lootman wrote:Fair enough. Without giving too much away it can be noted that mate may be delivered by one of three different pieces!

Uh? Well (spoiler, just in case): I can only see two, and they're really the same move. To be verbose it's pawn on c7 moves to c8 and becomes a queen or becomes a bishop.


Um ...

mc2fool also wrote:Spoiler: Pawn Queens! De Bono would like this one! :D


I (and I think others) assumed that first reply was ingeniously constructed to encompass both possible orientations of the board!

Talking of which, my first impression of the "wrong" board was, it must be truncated to 7x7. The faded sepia effect doubtless helped with such impressions.

Re: Chess

Posted: August 29th, 2023, 3:32 pm
by mc2fool
UncleEbenezer wrote:I (and I think others) assumed that first reply was ingeniously constructed to encompass both possible orientations of the board!

The orientation of the board doesn't change the solution, any more than walking around one does. It's still pawn on c7 moves to c8 and becomes a queen or bishop. There is only one way that "Pawn Queens" irrespective of which side you are looking at the board from. ;)

Re: Chess

Posted: August 29th, 2023, 3:50 pm
by DeBriele
Yes it does Mc2. I'm with GS on 4 solutions

DB

Re: Chess

Posted: August 29th, 2023, 3:54 pm
by mc2fool
DeBriele wrote:Yes it does Mc2. I'm with GS on 4 solutions

DB

No it doesn't. a1, a2, a3, etc, are still the same squares irrespective of which side of the board you are standing.

Re: Chess

Posted: August 29th, 2023, 3:58 pm
by Lootman
mc2fool wrote:
Lootman wrote:Fair enough. Without giving too much away it can be noted that mate may be delivered by one of three different pieces!

Uh? Well (spoiler, just in case): I can only see two, and they're really the same move. To be verbose it's pawn on c7 moves to c8 and becomes a queen or becomes a bishop.

A rook, perhaps?

Re: Chess

Posted: August 29th, 2023, 4:00 pm
by UncleEbenezer
mc2fool wrote:pawn on c7 ;)

Which one?

This is surreal, after that original answer!

Re: Chess

Posted: August 29th, 2023, 4:01 pm
by mc2fool
Lootman wrote:
mc2fool wrote:Uh? Well (spoiler, just in case): I can only see two, and they're really the same move. To be verbose it's pawn on c7 moves to c8 and becomes a queen or becomes a bishop.

A rook, perhaps?

Uh? Rooks don't attack on the diagonal, and as the black king is fenced in and can't move, that would be stalemate.

Re: Chess

Posted: August 29th, 2023, 4:02 pm
by Lootman
mc2fool wrote:
Lootman wrote:A rook, perhaps?

Uh? Rooks don't attack on the diagonal, and as the black king is fenced in and can't move, that would be stalemate.

There are two pawns on the board.

Just sayin'