The book move would be 3. c4, building up a strong centre while Black has been concentrating on the flanks.

The problem with this development is that it is too committal against Black's flexible defence. The Bishop becomes a target on c4, and the strike towards f7 is easily covered. On the other hand if it doesn't do much for White's game, it doesn't harm it much either.

Good response!

Rather too defensively minded one is inclined to think. There are probably heaps of things with which White could be occupying his time. Maybe 11,Qe3, with a view to completing his Q-side development. At some point, White might be interested in beginning offensive operations with f2-f4. The pawn advance played costs time.

... as though Black's centre were not already beginning to look a little fragile! Black could have tried to shore it up a little by 12...e5, or, possibly better, just bring out his knights: 12...Nf6, say.

Best was indeed 13.Bxd6, but this knight development is very nearly as strong! Black now has a few problems to solve. The threat to take the d-pawn still stands, and the situation on the a-file doesn't too flash for Black either. Many a tactician playing White here would opt for the text-move.

And yet... White had the opportunity for a lovely tactical shot here with 14. axb5! axb5 15. Nxc4 Qc7 16. Nxd6+ Kf8 17. Nxf7!

Possibly 14.axb5 axb5 15.Nxc4 risks 15...Qxa1 16.Rxa1(?) Rxa1+ 17...bxc4. White has to vary with 16.Nxd6+(!) Ke2 17.Rxa1 Rxa1+ 18.Kf2 Ba8 - and White's powerful centre confers a probably winning edge.

Now 17. axb5 is on again. This time if 17... axb5 18. Nxc4 the queen cannot go to c7, so 18... Qd8 19. Nd6+ and White wins a piece.

White is not making the best of his opportunities, though. 18. d5 would have been a well-timed central strike while the f6 knight was pinned.

White had a fine opportunity here to begin demolishing Black's rickety centre. Something along these lines: 19.d5! Nxe4 (say - there are other defences, but none of them offer better prospects) 20.Bxe4?! ... (Best is Rxe4, but work with me here) 20...Bxe5 21.Nxg6! ... (Ain't this fun? All sorts of tactics going down) 21...fxg6 (Gotta do something about the fork!) 22.Bxg6+ Kf8 (Prospects are no better on the other available squares) 23.Rxe5 Qb6+ (Giving Black a tempo can't be helped) 24.Kh1 Qd8 25.Qf4+ Qf6 (Simplifying down; ...Nf6; dxe6 augurs poorly for Black) 26.Qxf6 Nxf6 27.dxe6 ... and Black's game is toast. That's just a sample line, but it shows the sort of chances that can present themselves to a game more purposefully developed than one's adversary's.

It really can't. This move simply allows 20. Nf4, saving the knight.

Black should have taken the knight. Even so, White would still have had a position strong enough to retain a considerable edge. Black's overall situation after 19...cxd3 20.Bxd3, with nasty threats centred around b5, as well as the floodgates threatening to burst open in the centre, look pretty bleak.

Now White ought to play 21.Rxe4 (Nxe4, 22.Qe1 Ne4-f6 23.Nc5 ... and, the exchange down, White has an attack through Black's disappearing centre, e.g. 23...Ra7 (to defend rank-7) 24,Bxg6! fxg6 25.Qxe6+ ...

In two moves, White goes from a winning game, to one in which he stands to lose.

23... Nxc3! If 24. bxc3 Qxc3 then White's d3 knight is still under attack, and pinned. The move played is a blunder because Black's knight is now pinned, and White has the simple reply 24. Nf2.

id=nuntar is on the money. Admittedly, 23...Nxc3 isn't all that easy to find, but once you notice the double threat after 24.bxc3 Qxc3, well, there's no going back, is there? Unfortunately for Black, the game reverts to 'winning edge for White'.

At some point in the last few moves, White should have exchanged on e4, winning a pawn back with a pretty strong attacking position.