After this puzzle has been solved, it is time to offer our clever solvers another Loser Chess game to reconstruct...
Do you remember that I often pay a visit to my friends Fabi and Mag on evenings ? Most often I find them bending over a chessboard. They love to play chess, but once in a while, they experiment with Loser Chess instead of the more mundane game. It was the case last night, and when I arrived Mag, sitting in front of the white pieces, was thinking in this position:
Usually Loser Chess involves lots of early captures, but here only one bishop was missing, so I was surprised when Fabi told me that he had already played his 18th move !
Can you help me understand how they reached that position ?
In Loser chess, the rules are the same as in classical chess but for the following points:
The king behaves just as any normal piece and can be captured. There is no check, no checkmate, and the king being under attack is not an issue if you want to castle.
If you can capture a piece, you have to capture it.
If you can capture several pieces, you can choose to take whichever of them.
In case of a promotion, a pawn can be changed into a second king.
You win if and only if you are stalemated, i.e. either when your opponent has taken all your pieces or when none of your remaining pieces can move.
(as a consequence, Mag's next move is forced: he will play 19.Bxh6, and Fabi will have to choose between 19...Rxh6 and 19...Nxh6)
This problem was created by Michel Caillaud in 2006.
The first (easy) step is to find out on which square the single capture has happened.
When this problem was first published, it came with the header "Le refuge secret", which translates to "the secret hiding place".