Thirteen-year-old Luke McShane has had mixed fortunes in recent rounds of the 4NCL, Britain's premier team event. In the sixth round, he jumped carelessly into the mouth of a dragon.

Once he had played the standard anti-dragon K-side pawn advance of g4, h4 and h5, White seemed to be in rather a dither about whether to continue his attack or consolidate his defences on the other wing. He was not doing badly, however, until he blundered with 21.Nxe4?? Instead 21.Qe1 or 21.Qg2 leaves Black still having to prove that he has enough for the sacrificed piece. After White's trusting acceptance of the second piece, it was mate in two.

In the next game, however, McShane showed considerably more circumspection in defence against a former British champion.

Black's opening play was dubious - a6 and b5 does not mix well with the knight on c6 - but when he began to build up threats on the h-file, White needed to find some good moves. The first was 18.Nc5! (when 18...dxc5 19.d6 threatens both dxe7 and Qd5+); then 27.Kf1 and 28.Ke1! calmly walked away from Black's attack.

* * *

If at all possible, you should always try to play the move that your opponent's last move was intended to prevent. It may be worth it for the shock value alone, but also the positional damage can be enormous when a move designed to prevent something turns out not to have the desired effect.

The diagram position comes from the game McNab-Wilson, played in the 4 Nations Chess league last weekend. Black had just played 14...g6, keeping the white knight out of f5 and also stopping White's g-pawn from advancing to g6 itself.

That, at least, was the intention, but the Scottish grandmaster playing White continued 15.Nf5! gxf5 16.g6! combining both moves that had supposedly been prevented. However, the sacrifice is by no means clearly correct. White can calculate as far as 16...hxg6 17.Rxg6+ Ng7 (17...Kf8 18.Bh6+ or 17...Kh7 18.Rh6+ are clearly bad for Black) 18.Rdg1 Be5 19.exf5 Nf8 20.Rh6, but after that it is not easy to be sure that White's queen can reinforce the attack at h3 before Black can summon up some counter-play. As the game went, Black managed to block the a2-h7 diagonal long enough to force White to invest a whole rook in his attack, but once the diagonal became open again, Black could only buy time at the cost of large material loss.

A good game by McNab whose tricky move-order in the opening seemed to lure his opponent into a variation with which he was not familiar. Black could have secured a comfortable position with 4...g6 instead of 4...e6, while 9...Re8 is a serious waste of time. If he is going to play dxc4 and e5, he should do so at once, keeping the rook on f8.

/ GM William Hartston, "The Independent", February - April 1997 /