Allumwandlung
An
Allumwandlung (
German for "complete promotion", sometimes shortened to
AUW) is a
chess problem where, at some stage in the solution, a
pawn (or sometimes pawns) is promoted variously to a
knight,
bishop,
rook and
queen.
Here is an example composed by Niels Hoeg and first published in 1905. White to move and mate in three:
The key move (white's first move) is f7 (see algebraic notation), and depending on how black defends, white promotes to either a queen, a rook, a bishop or a knight on move two. The lines are:
- 1... e4 2. f8Q any 3. Qe7 mate (or Qf6 mate)
- 1... Kd6 2. f8Q Kc6 3. Qc5 mate
- 1... exf4 2. f8R Kd6 3. Rf6 mate
- 1... exd4 2. f8B Kf6 3. Ra6 mate
- 1... Kf6 2. f8N exd4 3. Rf7 mate
The importance of white's underpromotions can be understood by considering what happens if he promotes to a queen no matter what black plays: after 1... exf4 or 1... exd4 2. f8Q is
stalemate, while following 1... Kf6 2. f8Q Kxg6 there is no mate.