# Unravel this, if you can!

BigDoggProblem
Posers and Puzzles 08 Jul '06 02:46
1. BigDoggProblem
08 Jul '06 02:46
T. Volet and P. Wassong
StrateGems 2001

Release the position
(3 Black Rooks)
(Release the position: Prove that the position is legal, by taking back moves until you reach a position in the past that is obviously legal.)
2. BigDoggProblem
24 Jul '06 18:37
bump
3. sonhouse
Fast and Curious
25 Jul '06 02:30
The guy who came up with that one is demented!
4. BigDoggProblem
25 Jul '06 07:10
Originally posted by sonhouse
The guy who came up with that one is demented!
Two guys, actually. It's too demented for just one person to create.
5. c99ux
'Sir' to you
25 Jul '06 09:051 edit
Originally posted by BigDoggProblem
T. Volet and P. Wassong
StrateGems 2001
[
Release the position
(3 Black Rooks)
(Release the position: Prove that the position is legal, by taking back moves until you reach a position in the past that is obviously legal.)
Seriously, why????
6. BigDoggProblem
25 Jul '06 20:54
Originally posted by c99ux
Seriously, why????
Why what?
7. 25 Jul '06 23:551 edit
Was the last move PxN(f4)?
8. BigDoggProblem
26 Jul '06 16:17
Originally posted by ThudanBlunder
Was the last move PxN(f4)?
No.
9. 26 Jul '06 20:42
For puzzles like this (Retrograde Analysis) read "the chess mysteries of Sherlock Holmes" by Raymond Smullyan - nothing to do with the original Holmes stories but he provides a good character for the author to use
10. 26 Jul '06 20:56
Originally posted by BigDoggProblem
No.
I haven't been able to spend a lot of time (yet) on this, but here are a few considerations that others may use to find a solution (or to contradict my observations):

- f7-f6 seems like a good candidate last move to me. Without that, I do not see an easy way back out for the white king

- white is missing two pawns, nothing else. Black's two pawns that have captured didn't take a white pawn. Hence, white promoted two pawns and they got captured. Must be e- and g-pawns
- black has promoted his pawn for a rook (3 rooks). Has to be the g-pawn.
- how did the two g-pawns pass on the g-file? I see two solutions: the white pawn takes something on f7, and then promotes, or the white pawn takes something on the h-file, let's the black pawn pass, and takes something else on the g-file. Since I think the f-pawn moved last in the game, the first option is not available. So, I think both black knights were captured by white's g-pawn (first to the h-file, then back to the g-file)
- still to be analysed: all the other moves, which I believe (hope) are just move order issues (e.g. the white bishops on the a-file).

that's it so far
11. BigDoggProblem
26 Jul '06 21:31
Originally posted by Mephisto2
I haven't been able to spend a lot of time (yet) on this, but here are a few considerations that others may use to find a solution (or to contradict my observations):

- f7-f6 seems like a good candidate last move to me. Without that, I do not see an easy way back out for the white king

- white is missing two pawns, nothing else. Black's two pawns tha ...[text shortened]... pe) are just move order issues (e.g. the white bishops on the a-file).

that's it so far
You're off to a good start. One caveat: wPc3 captured a black Knight, so wPg can't make two captures. This means White must have played gxf7 to promote, so Black may not retract ...f7-f6 for a long while.
12. BigDoggProblem
26 Jul '06 21:321 edit
Originally posted by Mixo
For puzzles like this (Retrograde Analysis) read "the chess mysteries of Sherlock Holmes" by Raymond Smullyan - nothing to do with the original Holmes stories but he provides a good character for the author to use
That's a good intro to retros, but this one is much harder to solve than anything in Smullyan's book.
13. 27 Jul '06 08:00
Originally posted by BigDoggProblem
You're off to a good start. One caveat: wPc3 captured a black Knight, so wPg can't make two captures. This means White must have played gxf7 to promote, so Black may not retract ...f7-f6 for a long while.
Yes, of course, that was not very bright of me. Well, that certainly doesn't make the unraveling easier....
14. BigDoggProblem