Thinking on Boxing Day - difficult but solvable puzzles

[Jonathan Rogers]

This must be getting very cryptic for some members!

Ok, 1 h4 d5 is the starter for number 1.

I found them quite hard! By contrast, it took me a couple of minutes each to do the 26 December puzzles on chessbase

http://en.chessbase.com/post/fifteen-ye ... as-puzzles

although I expect many forumites will do better and recognise the knight tour within seconds.

[Richard Bates]

As a matter of curiosity, how do you get there with 6 exf8 =N mate?

I can see a couple of solutions, each i think with their own unique move orders, one involving 1...e6 and 1...e5 (otherwise basically equivalent). It's a shame because (assuming no other solutions) it would otherwise make just as nice a puzzle as the original question.

Just to check the solutions are the same as the ones I'm thinking of - the queens are on d5 and h4, right?

Yep, that's about covered the entirety of the solution(s)...

[IM Jack Rudd]

I've now also found solutions for 6.gxh8=N# and 6.fxg8=N#. Neither is unique.

[Alistair Campbell]

Thanks for the clue. It finally clicked. I think Richard and Jack have spotted my, sadly, non-unique solutions to the "exf8" problem.

At least I got the mathematical one...

[Martin Regan]

JR

This must be getting very cryptic for some members!

"Cryptic"! I've taken to drink

[JustinHadi]

Finally got 1). My life is complete.

[John Clarke]

Got #2 fairly quickly, though using a different approach. I drew up a cross-table of all the combinations for a and c, and eliminated all the "impossible" ones (6 x 2 = 12, 2 x 4 = 8, etc). Left only four possibilities (out of 36), and it was soon clear which one fitted.

Puzzle #1 I shall probably have to leave to quicker minds than mine! Never been much chop at these game-construction thingies.

[Jonathan Rogers]

Answers tonight, I think - we might still be in time to save Martin's liver.

I will also give the answer to 6 exf8 = N mate: I solved it last night, making grateful use of their hint that the queens are on d5 and h4 in the final position. I am very impressed that Alistair, Jack and Richard solved it so quickly without that hint!

[Jonathan Rogers]

The answers then - SPOILER ALERT









1 mate in six ending in 6 gxf8= N:

1 h4 d5 2 h5 Nd7 3 h6 Ndf6 4 hxg7 Kd7 5 Rh6 Ne8 6 gxf8 = N mate. It can only be done by that move order.


2 3 x 54 = 162 (presumably Jack has corroborated its uniqueness by now)


3 mate in six ending in exf8 = N:

1 d4 e5 2 dxe5 Qh4 3 e6 f6 4 e7 Kf7 5 Qd5+ Kg6 6 exf8= N mate; but there is a move order choice early on (1...e6 2 d5 Qh4 3 dxe6 and then as per the other line).


I shouldn't spend much more time on this sort of thing; I have already said how long it took me to find no.1 without any clues. So I call on Jack to give clues for the solutions ending in gxh8 = N mate and fxg8=N mate!

[IM Jack Rudd]

1.d4 e6 2.d5 Ke7 3.dxe6 Nf6 4.exf7 Rg8 5.Qd5 Ne8 6.fxg8N#

1.e4 f6 2.e5 Kf7 3.exf6 Qe8 4.fxg7 Nf6 5.Qg4 {pass move} 6.gxh8N#

[IM Jack Rudd]

Oh, and just to add to the collection: 1.d4 f5 2.d5 Kf7 3.d6 Nf6 4.dxe7 Rg8 5.Qd6 Ne8 6.exd8N#