Christamas moon December 27, 2004
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The Christmas Day full moon, taken freehand with an
image-stabilized digital camera at 400mm focal length.

With Christmas safely behind us we are, hopefully, fighting fit for the next round of puzzles, having of course solved, in communal effort, the three Proof Games supplied by Dr John Nunn to date. For those of you who had difficulties, here are the solutions to the first two.

Tibor Orban, Die Schwalbe 1976

Proof game 1: Position after Black’s 4th move

Solution: One can see that it is easy to get the above position after Black’s third move (by 1 e4 e6 2 Bb5 c6 3 Bxc6 dxc6), and that White can lose a tempo for example, by 1 e4 e6 2 Be2 c6 3 Bb5 pass 4 Bxc6 dxc6. But it is not so easy to provide a pass move for Black. After a little thought we conclude that the idea that Black’s moves are ...e6, ...c6 and ...dxc6 can’t work, because Black doesn’t have a way to lose a tempo. Instead, a completely different method is necessary. The solution is 1 e4 e6 2 Bb5 Ke7! 3 B×d7 c6 4 Be8 K×e8.

Henrik Juel, Thema Danicum 1996

Proof game 2: Position after White’s 4th move

Solution: Once again the problem is the lack of a Black waiting move, for example 1 e4 d6 2 Qe2 Bg4 3 Qxg4 pass 4 Qd1 would solve the problem except that there is no possible pass move. The given logic shows that White’s 4th move must be the one that captures Black’s bishop and hence the last move must be 4 QxBd1. There is an additional finesse that 1 e4 d6 2 Qh5 Bg4 3 pass Bd1 4 Qxd1 fails due to the lack of a White pass move and this gives the complete solution: 1 e3! d6 2 Qh5! Bg4 3 e4 Bd1 4 Q×d1.

Ready for a new Proof Game? It’s time to tackle something a bit more complex. Once again we hand over to John Nunn, who presents proof game four of the series.

Proof game 4: Position after White’s 7th move

In this example it is important to remember that the position must arise after White's seventh move (there are a number of solutions after Black's seventh).

One’s first thought on seeing this position is to try something like 1 e4 d6 2 Ba6 Bf5 3 Bxb7 Bxe4 4 Bxa8 Bd5 5 Bb7 Bxa2 6 Ba6 and now if Black could play his bishop from a2 to c8 in one move White could reply 7 Bf1 and we would have the solution. However, it quickly becomes apparent that this won’t work. White has to play e4 to release his bishop and it doesn’t matter whether the black bishop ends up on a2 or e4 after taking the missing white pawns – it still can’t reach c8 in one move. The light begins to dawn when we have the idea of taking the b7-pawn and a8-rook with a unit other than the f1-bishop.

Please do not send in solutions to this problem. It will be part of our final Christmas Puzzle contest where you can win a valuable prize. The details of the contest will be given on January 1st 2005, the solutions to all the contest puzzles will be published in February.

For those of you who are not directly enchanted by our proof games, here is a charming little example of a traditional chess study which we have cherished for many years now.

F. Kovác, Maroczy Memorial Tourney 1952

White to play and draw
Twin: a. diagram; b. bNb1-a1

This study is a twin, which means that you are expected to solve the above position, and then the position with the black knight on a1 instead of b1. In both cases it is White to move and force a draw. Not too difficult, and charming in the thematic symmetry of the two solutions. Once again you can print out the two puzzles to solve on your living room chessboard or the pocket set you take with you when you travel.

Frederic Friedel