Christmas puzzles: I'll force you to mate!

Here's an early example of a selfmate, one that will illustrate everything. It will also show you that even a relatively simple position can require a fair deal of thought.

The task is for White to force Black to mate him, on his second move. We quickly spot that White must probably get Black to play 2...Bxg2#. But how can we exhaust all alternative move options. 

Well the black king is immobile, and, apart from the deadly bishop, it is only the black pawn that can move. 1.e6 does not work since Black simply plays 1...exf6 and then 2...f5. Moving the f7-pawn (with 1.f7 or 1.fxe7) removes the guard of the g7-pawn and allows 1...Kxg7.

So we begin to think of promotions: 1.g8Q and 1.g8R don't work because Black can safely play 1...Bxg2+, forcing the promoted piece to capture the bishop. 1.g8B doesn't work either, as it provides White with a defence against the bishop check (e.g. 1...Bxg2+ 2.Bd5 and then 2...Bh1). 1.g8N# simply checkmates Black, which is not what we are trying to do.

Can White achieve anything with the c-pawn? Promoting it to a queen, rook or bishop would make it possible for White to defend against 1...Bxg2+ and a forced mate on the next move. White must underpromote to a knight: 1.c8N! Now if 1...exf6 2.exf6 Black is forced to play 2...Bxg2#, which is the required selfmate in two. But if Black plays 1...e6 does White have a waiting move that will not prevent the mate? Yes he does: 2.g8B! because the e6 pawn blocks the bishop defence after the forced 2...Bxg2#. Lovely, all the promotions, don't you think?

Well now you are on your own. We start with a relatively simple problem:

In the above position it is obvious that Black can mate with ...g4. But he will try to avoid it at any cost, and White must force him to play it. How can he do that – and at the same time avoid providing White with a defence against it? The problem is quite clever. You can move the pieces on the diagram to work out a solution.

Here White has a nice strategy to force Black to checkmate him in five moves. In the above diagram I have added an engine to play the black moves. If you find the correct strategy the engine will be forced to mate in five.

Here it seems unlikely that White’s king, which currently enjoys almost total freedom, might end up being mated in just six moves. Evidently it has to approach Black’s forces if it is to set up a position where it can be mated. Note that Black is currently stalemated, so White can’t move his king immediately. He has to lift the stalemate, while at the same time move towards creating a mating position. Quite a challenge. Hearty congratulations if you find out how he can do this.

The self-stalemate is very much in the same spirit. The requirement in the decorative position on our front page, composed by Thomas Rayner Dawson in 1927, is for White to stalemate himself, against the will of Black, and to do it in four moves. Once again you can move the pieces around on the diagram to try and construct a stalemate. Black will play countermoves.