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toughest mate in one puzzle

Posted: Wed Jan 25, 2017 11:38 pm
by Joshua Gibbs
Does anyone know a trickier mate in one than this?

https://www.chess.com/blog/Giorno/crazy ... -in-1-nr17

Re: toughest mate in one puzzle

Posted: Wed Jan 25, 2017 11:59 pm
by NickFaulks
Nice, it was the last move I considered.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:05 am
by Joshua Gibbs


is another favourite, white to play

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:05 am
by Christopher Kreuzer
(Referring to the first puzzle in this thread.)

There are quite a few red herrings! The total number of checks that seem possible (i.e. including the ones by pieces that you only realise later are pinned) is 19 if I am counting right. Strangely, none of them seem to be checkmate... :?

Oh, I see it now. Managed to see all the checks except the one that delivers mate. :oops:

Re: the second puzzle (above), is that not just mate in two? (Admittedly I have now found three different ways to mate in two.)

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:15 am
by Joshua Gibbs
Christopher Kreuzer wrote:(Referring to the first puzzle in this thread.)

There are quite a few red herrings! The total number of checks that seem possible (i.e. including the ones by pieces that you only realise later are pinned) is 19 if I am counting right. Strangely, none of them seem to be checkmate... :?

Oh, I see it now. Managed to see all the checks except the one that delivers mate. :oops:

Re: the second puzzle (above), is that not just mate in two? (Admittedly I have now found three different ways to mate in two.)
no its mate in one :P

If you PM me ill tell you the answer

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:19 am
by NickFaulks
Joshua Gibbs wrote: is another favourite, white to play
Don't get it.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:26 am
by Christopher Kreuzer
Oh, doh! Yeah, it could be mate in one, but it depends what Black's last move was. (Sorry, that probably gives it away! The puzzle is presumably presented as "mate in one - say what Black's last move was".)

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 12:39 am
by Ian Thompson
Christopher Kreuzer wrote:Oh, doh! Yeah, it could be mate in one, but it depends what Black's last move was.
Problems of this type (White has mate in 1 if Black's move was "something") have a requirement that Black's last move could only have been "something", so the solver's task is to prove that Black's last move was "something". For this problem, there is an obvious last Black move that would give White mate in 1, but it doesn't appear to be the only possible move Black could have just made.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 1:13 am
by Christopher Kreuzer
Ian Thompson wrote:
Christopher Kreuzer wrote:Oh, doh! Yeah, it could be mate in one, but it depends what Black's last move was.
Problems of this type (White has mate in 1 if Black's move was "something") have a requirement that Black's last move could only have been "something", so the solver's task is to prove that Black's last move was "something". For this problem, there is an obvious last Black move that would give White mate in 1, but it doesn't appear to be the only possible move Black could have just made.
Yeah, retrograde chess problems. I have read a few books of those. :D

That was kind of my point, that the problem can't be presented as "prove what Black's last move was", so it has to be presented another way.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 2:30 am
by Joshua Gibbs
NickFaulks wrote:
Joshua Gibbs wrote: is another favourite, white to play
Don't get it.

PM me if you like

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 11:31 am
by Stewart Reuben
I think the second problem would have had to be worded: What was Black's last move for White to have mate in 1?

I devised a problem for the ECF Cerificate of Merit. 'What is White's WORST move. All but one option was chackmate and the solution was stalemate.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 9:55 pm
by Nick Grey
I think the first puzzle was the easiest mate in one in the world - half a second. 1st move I considered.

Re: toughest mate in one puzzle

Posted: Thu Jan 26, 2017 10:08 pm
by Nick Grey
I agree with Stewart & Ian & Chris on second puzzle as very inaccurately worded. If last move was e6-e5 there is no mate in one.

Re: toughest mate in one puzzle

Posted: Fri Jan 27, 2017 4:01 am
by Joshua Gibbs
Nick Grey wrote:I think the first puzzle was the easiest mate in one in the world - half a second. 1st move I considered.
post a harder one then ;)

Re: toughest mate in one puzzle

Posted: Fri Jan 27, 2017 5:51 am
by Roger Lancaster
First problem, admittedly tricky in improbable position, 30-40 seconds to solve. Second, 5-10 seconds.