in der Retroanalyse
16a - W. Keym
Die Schwalbe, 1971
1./2. Preis im Ceriani Memorial Tournier
14+13. Matt in weniger als einem Zug.
There are 8 possible en-passant captures half-finished.
So the only legal en-passant capture was f4xg3. So Black mates
in 1/2 by removing the white pawn on g4.
Solution by Philippe Schnoebelen
16b - W. Keym
12+6. Füge beide Könige hinzu, dann Matt in weniger als einem Zug!
The white pawns on the queenside captured nine times, these are all
the missing black pieces. This also means that the g5 pawn is the original
g-pawn. Black captures are b5xa4, [h/f]5xg4 and gx[h/f]. The captures
on a4 and g4 are on white squares, so the missing white bishop was captured
by the g-pawn. This also means that the white h-pawn promoted before
it got captured. This means that the capture on g4 was done by the black
h-pawn. So the black f-pawn promoted on f1, breaking both white's castlings.
The promotion on h8 breaks black's kingside castling. So the only castling
allowed in this position is the black queenside castling.
Add the white king on d6, and the black king on c8, and mate
with 'finish 000'
Solution by Werner Keym