White to force the end of the game in two moves I found this hilarious problem and hope people will have fun solving it:

Niels Hoeg, Skakbladet 1907

[FEN "8/8/6p1/5pP1/5P1K/5PpP/4p2p/2Q2Bkr w - - 0 1"]


White to end the game in two moves.

In this case, that means that white plays moves so that, no matter what black moves, the game is finished after black's second move at the latest.
Very nice puzzle! Looks like the solution is as follows:

[FEN "8/8/6p1/5pP1/5P1K/5PpP/4p2p/2Q2Bkr w - - 0 1"]

1. Qe1 g2 (1... exf1=Q 2. Kxg3 Qxe1#) (1... exf1=R 2. Qxg3#) (1... exf1=N 2. Qf2+ Kxf2 (2... gxf2)) (1... exf1=B 2. Kxg3) 2. Bxe2# 1-0


Interestingly, in the different lines, following results are achieved:


White gives a checkmate
Black gives a checkmate  
White is stalemated
Black is stalemated