A proof game is a type of retrograde analysis chess problem. The solver must construct a game starting from the initial chess position, which ends with a given position (thus proving that that position is reachable) after a specified number of moves.
Working on a theory the b-pawn takes on a2, b1 Knight off taking things, the
h8 Rook, the e7 pawn and c8 Bishop. a1 rook moves to b1, black pawn on a2
promotes to Rook, that Rook goes to b5 or c6, white b1 Rook goes back to a1
to vacate b1 for Knight to return home. (or something like that.)
Working on a theory the b-pawn takes on a2, b1 Knight off taking things, the
h8 Rook, the e7 pawn and c8 Bishop. a1 rook moves to b1, black pawn on a2
promotes to Rook, that Rook goes to b5 or c6, white b1 Rook goes back to a1
to vacate b1 for Knight to return home. (or something like that.)
A good way to begin is to list each piece and count the minimum number of moves it needs to reach its destination.
For black:
K takes 2 moves
Q takes 1
Rs take 2 each
Bf8 takes 1
Nf6-e4 is 2
Nc6-d8 is 2
c7-c5 is 1
----
13 moves total
Given that the stipulation is 13 moves, black has no spare time.
This means he can't move the b7 pawn. White has to clear that out for him, along with the other missing pawn and B.
@greenpawn34said This is the best I can do so far.
[pgn]
1.Nf3 e5 2.Nxe5 Nf6 3.a3 Bxa3 4.Ng6 c5 5.Ne7 Nc6 6.Nxc8 Rb8 7.Nd6+ Ke7 8.Nxb7 Ke6 9.Nd6 Rb5 10.Nf5 Qb6 11.Nh4 Rc8 12.Nf3 Nd8 13.Ng1 Rc6 {That is 13 moves, I am a move short. It is the e7-e5 move.} [/pgn]
That's a good start.
From the opening, Black has two moves he can play without any help from white: Ng8-f6, and Nf6-e4.
So the new goal is to find some white moves that help black make a move that is on the 'permitted moves' list. White has 3 moves to do something that gives black a move. What can he do?
I'll figure it out...eventually. I was trying to do it whilst watching the football and now
I have to prepare a lecture for tomorrow. I'll give them this. 🙂
Ahh..the a-pawn promotes, my first thought was a promotion but I missed
that one completely because I was getting so close my way. Good fun though.
(please no more for a week or two.)
I thought it was a good intro problem. The theme is sacrificing an N, promoting a replacement, and bring it home (Pronkin theme). The tempo move a3! is a nice touch.
It is good. Very good. I did look at 3.Kxe7 for about 3 seconds a day before
you gave me the hint. Of course I tried pawn to a4 first and it soon dawned on me
that it is a2-a3. Tell the composer I hate him.