1./2. Preis im Ceriani Gedächtnisturnier
11+11. Weiß nimmt einen Zug zurück; dann Matt in 2 Zügen
Last move could be Nc2xBa1+. Earlier in the game
White captured bBc8 on c8, b6xNa7, c6xNb7, and gxPf, and promoted Pe2
on e8, while Black captured the h-pawn on its file and exPdxcxbxPa,
and promoted Pg7 and Ph7 to bishops on g1 and h1. Solution:
Retract Nc2xBa1, and play forward 1. Nca3+ Kb2,Kc1 2. Qc2#
Last move could be gxf6 e.p.+, and it is possible
to preserve White's castling right: White captured bBc8 on c8, b6xNa7,
and gxPhxNg, and promoted on e8, while Black captured exPdxPcxbxa and
g2xf1=B. (Or White captured the g-pawn on its file, axNb, b6xRa7-a8=R,
and b6xNa7, and promoted on e8, while Black captured exPdxPcxbxa and
hxg-g1=R). Solution: Retract g5xf6 e.p., and play forward 1.
0-0+ Bd1 2. Rxd1#.
Solution by Henrik Juel
The (b) solution doesn't work in (a), because there it is impossible to
construct a game where wRh1 hasn't moved.
The (a) solution doesn't work in (b), because there promoting to B on e1
requires too many captures.