07 Oct 20
1 edit
@greenpawn34 saidAsking "what is that piece doing?" is a helpful technique for solving many types of chess problems. [It can occasionally be less than helpful, if said piece turns out to be a "cook-stopper".]
Hi BigDoggProblem
I never noticed the Black Knight ends up on it's original square.
This makes it all the more amazing.
I got the idea for that one fairly quickly.
It was the placing of the f6 Knight and why was it there.
(it is how I have stumbled upon a few solutions....what is that piece there for.)
[fen]8/1B6/2r2n2/K7/5b2/5k2/5P2/1r1n4 b - - 0 1[/fen]
I ...[text shortened]... e King is in a mating net
waiting for Bxc6. Then it's just a matter of getting the White King to e1
Speaking of Rundlaufs...
U. Heinonen
Proof Game in 22.0 moves
[which means, find a legal game of chess that produces this position right after Black's 22nd move]
07 Oct 20
I hate these things.
The White b-pawn has been promoted (possibly taking a Knight on c6)
promoting on c8 then N-e7-g6 allowing haxg6 so the h8 Rook can get out.
The black b-pawn has promoted to a Knight (the one I think was taken on c6)
Now have to try and cobble that together and see where I am wrong..
08 Oct 20
@greenpawn34 saidYou are right about the white knight promotion and the sac on g6 and wPb5xNc6 along the way.
Struggling on this one Bigdog.
Given that, White has no other spare moves. Let's count, unit by unit.
Q 1
K 0.5 (castles)
Rg4 4.5 (castles, then e1, e3, g3, g4)
Rh2 1
Pawns 9 (promotion, plus one move per pawn showing)
Bishops 2
Knights 4 (two for the promoted one, and two for Nb1-f3)
22 moves total
Black's moves are less clear. He must always help white keep moving. At what point are you getting stuck?
09 Oct 20
@greenpawn34 saidMay I see a sample idea line?
Hi BigDoggProblem,
I keep running out of Black moves and getting the a1 Rook to g4 or h2.
It's possible the Rook on a8 started on h8.
10 Oct 20
@greenpawn34 saidPerhaps some hints and constraints will narrow the amount of paths to consider:
Keep getting something like this.
[pgn]
1. b4 c5 2. b5 Nc6 3. bxc6 d6 4. c7 Bd7 5. c8=N e6 6. Ne7 b5 7. Ng6 hxg6 8. Ba3 Rh4 9. c3 Ra4 10. e4 b4 11. Bc4 b3 12. d3 g5 13. h4 Rb8 14. Rh3 Rb6 15. Nd2 Rba6 16. Rg3 Rb4 17. Rg4 Rb8 18. Qc2 Ra5 19. O-O-O Ra4 20. Ngf3 Ra8 21. Rh1 b2+ 22. Kd1 b1=N [/pgn]
1) The Rook on g4 came from a1.
2) The Rook on a8 never moved.
3) White's 22-move "game plan", given in my earlier post, is set in stone, and can NOT be deviated from.
11 Oct 20
@greenpawn34 saidTell her to buy you a laptop while she's on there. 😛
Hi BigDoggProblem
I'll give another try tomorrow, only just allowed back the computer.
Sunday is E-Bay day for Mrs Greenpawn. She hogs the thing for the whole day.
12 Oct 20
@greenpawn34 saidThat's better.
Hi BigDogg,
Got it in 23.
[pgn]
1. b4 c5 2. b5 Nc6 3. bxc6 d6 4. c7 Bd7 5. c8=N e6 6. Ne7 b6 7. Ng6 hxg6 8. Ba3 Rh4 9. c3 Ra4 10. e4 b5 11. Bc4 b4 12. Qc2 b3 13. d3 b2 14. Nd2 b1=N 15. Nf1 Nd2 16. O-O-O Nb1 17. Re1 g5 18. Re3 Nd2 19. Rg3 Nb1 20. Rg4 Nd2 21. h4 Nb1 22. Nh2 Nd2 23. Nhf3 Nb1 [/pgn]
You already know that Black's move ...b6 is a wasted move, as is White's Nf1.
You can also see from your try that black has plenty of time to move the promoted N around.
So, instead of white playing a move like Nf1 (with a horse that has no extra time to move) to get out of the way of a horse with tons of time to move, try getting the black N out of the way first... Way, way out of the way!