The December issue of the British Chess Magazine includes an excellent account of the World Team Championship by John Nunn. His selection of games and positions features a good mixture of missed opportunities and neat combinations. Try your skill at the following positions.

Position one: White to play in Arencibia-Bareyev. White played 1.g3 to avoid the danger of a back-rank mate. Was there a better move?

Position two (top of next column): One move later in the same game. White now played 1.Qc4. Was there a better move?

Position Three (below): Vaganyan, playing Black against Irzhanov, challenged the central white knight with 1...Ne6. Was this a good idea?

Position Four: Short played 1.Nd5 against Korchnoi. Was 1.cxb5 better?

Answers: 1: The simplest move is 1.Rd8 which just wins a piece, but 1.Re7 also wins - see next answer.

2. Now 1.Re7!! is right: 1...Bxe7 2.Qxf7+ and 3.Qg8 mate, or 1...Rxe7 2.Bxe7 Bxe7 3.Qxf7+ Kh7 4.Qxe7 winning a pawn.

3. After 1...Ne6? White won a pawn with 2.Nxe6 fxe6 3.Rxc4!

4. After 1.cxb5! Nunn gives 1...Bxc3+ 2.Rxc3 Nxe4+ 3.fxe4 Rxc3 4.Rh8+ Ke7 5.Rxc8 Rxc8 6.bxa6, or 1...Nxb3+ 2.axb3 Bxc3+ 3.Rxc3 Rxc3 4.Rh8+ Ke7 5.Rxc8 Rxc8 6.bxa6 Bxb3 7.a7 Rc2+ 8.Ke1 Ra2 9.Bb5 and the a-pawn is too strong.