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        riddles >> medium >> How Did the Game Go? (II) (Retro)
        
(Message started by: THUDandBLUNDER on Nov 29^th, 2003, 5:11am)

Title: How Did the Game Go? (II) (Retro)
Post by THUDandBLUNDER on Nov 29^th, 2003, 5:11am

I haven't done this one yet. Seems impossible...

Black has just played his 8th move. How did the game go?

Title: Re: How Did the Game Go? (II) (Retro)
Post by Lightboxes on Nov 29^th, 2003, 11:39am

::[hide]
Well...This is definitely hard. There is obviously no promotions.
No en-passants because that wastes moves. The board is not upside (black started from the bottom).

So far, black HAS to move 8 times:
3 moves for rook (it could be 2 if the pawn on the A file captures at an angle then captures back. But it still ends up being 4 moves in total {rook and pawn})
1 move for Black A pawn
4 moves King HAS to.

White HAS to move 5 [edit] 6 times.
1 move for king (no other better alternative)
1 move for rook (because of castleing)
1 move for queen
2 moves for knight
1 move for e2 pawn [edit/add]
That leaves 3 moves for white to help black get to the position. White bishop takes d7 pawn because black has already taken up 8 full moves. It can't be the white knight that does that because of checking the black king as he comes out.
2 moves for bishop.
White has to move pawn up to allow black to kill one of them. The only convenient white pawn for black to kill is b2-b4. The other pawn, c2-? is not on the same path as the black king. It could be...but that is too many moves for white. [edit] So that gives another forced move for white:
1 move for b2 pawn.

So now that is 8 moves for white. If there is a white pawn at c2 that it would be easy. I'm stumped, but hope someone would keep going with what I have so far OR prove one of my analyzations incorrect.
[/hide]::

thanks for the edits THUDandBlunder

Title: Re: How Did the Game Go? (II) (Retro)
Post by THUDandBLUNDER on Nov 29^th, 2003, 8:22pm

Lightboxes, I come to the same conclusion as you. A White pawn on c2 would be enough to solve it. I think the diagram has an error. (A previous diagram I posted from the same source had two pieces advertently transposed.)

Quote:

1 move for a2 pawn.

Typo. I think you mean the e2 pawn.

Title: Re: How Did the Game Go? (II) (Retro)
Post by THUDandBLUNDER on Dec 3^rd, 2003, 9:50pm

Quote:

If there is a white pawn at c2 that it would be easy.

Hmmm...on second thoughts, even with a pawn on c2 it doesn't seem possible.

White must move
O-O
Rf1-d1
Pe2-e3
Qd1-f3
Ng1-f3
Nf3-d5

That's 6 moves. If White is required to capture Black's d-pawn with his bishop he needs 2 moves to accomplish that. That leaves no moves with which to play b2-b4. :-/

Title: Re: How Did the Game Go? (II) (Retro)
Post by THUDandBLUNDER on Dec 18^th, 2003, 7:33am

I have just input this position into a program that I recently downloaded which analyses such puzzles.

It found no solutions in the 16 single moves allowed!
The minimum number of single moves required is 17.
Can you do it now, Lightboxes?

Apologies to anyone who wasted their time attempting the impossible.
If I post any more 'proof game' retro puzzles in future I will make sure that I check them beforehand.

Title: Re: How Did the Game Go? (II) (Retro)
Post by Lightboxes on Dec 27^th, 2003, 10:14am

With a Pawn at C2 I assume:
After already knowing the first few moves, it became simple to find out the rest of the moves:
::[hide]
1. e3, a5
2. b5, a6
3. xd7, e8xd7
4. g1-f3, d7-c6
5. 0-0, a6-b6
6. e5, c5
7. d1-f3, b6-b5
8. b4, c5xb4
9. f1-d1,
I'm pretty sure there are several other possibilities with slight variations.
[/hide]::