IN last week’s column I introduced the idea of a “helpmate”, in which both sides combine their efforts to produce a quick checkmate. From there it is only a short step to the “selfmate”, in which one side forces the other to deliver checkmate despite his best efforts to avoid doing so.

At first glance this genre might not seem to offer very fertile ground for interesting problems, but in fact composers have managed to construct a wide variety of examples. These tend to be rather difficult, but I have found some relatively simple examples for an introduction.

Take a look at Diagram A. White, to move, must force his opponent to give checkmate in two moves. Two facts must be observed straight away. First, Black’s only legal moves are with his queen, and second, if White can play 2. Qb2+, 2. Qc2+, or Qd1+ in circumstances where Black can capture White’s queen with his own, it should be checkmate.

A careful scrutiny of all possibilities shows that if it were Black’s turn, and he moved his queen, the only squares to which she could safely go are h3, h7 and e4. Even these would not work if the white rook on g3 were not on the third rank, since then 2. Qxd3+ would force the reply 2. . . . Qxd3 mate. So a rook move along the g-file seems indicated.

It remains only to find a square for the rook which does not ruin any of the other checkmates, and a case-by-case examination leads to the conclusion that only 1. Rg8! covers all possible “defences”. I said these puzzles weren’t easy!

You should now be ready to tackle Problem 4 in the Christmas Quiz, another two-move selfmate. Once again Black has few legal moves and it might be possible to force 2. . . . g2 mate by immobilising the black knight. Or there might be a different mate . . .

For those who prefer traditional problems, Problem 5 is a standard three-mover. It says in my book that an experienced solver would probably spot the solution straight away — I didn’t, but I must say that it seemed fairly obvious once I had laboriously reached the answer.

And now for something completely different. Problem 6 is a position from the 2004 Olympiad, where a respected member of the Bermuda team was handling the white pieces. Black has just played . . . Qc7-c6+.

Our man appeared to be heading for a deserved win, but he now produced a move which instantly turned his position into a dead loss. Can you guess what he played, and why?