5...Nc6 may not be the best for idea Black because it limits the mobility of his pawns and thus ability to challenge White's strong centre.

There is a lot to say here, for this series of moves is the key turning point of the game. Like much of this game, this series merits a deeper analysis than you give it. Even letting ChessMaster look at the moves for a minute or two (which is what I did for tactical variations) provides important insights into the game. Now anyway... Black's first mistake was actually his 5th move, but 7...a6 is unnecessary and wastes a tempo. And 8. a3 can be delayed for White: 8. d3 is an excellent place for your Bishop. And, after 8. a3, I think Black should have retreated back to e7, or just exchanged on c3. And, finally, 9... g5 is just a blunder. Best is just to admit "defeat" and retreat 9...Be7.

10. Nxg5 hxg5 11. Bxg5 Be7 12. h4 isn't half bad for white...

Actually, 10. axb4 gxh4 11. b5 is winning for White.

Best to just take the c3 Knight now, I think. As for 11. c5, I do not like breaking the central tension so quickly. 11. Be3 or d3 could have been played, developing without committing to anything specific is always good.

blsck should have exchanged his Bishop when white pressed with a3 also he would have been better to have moved to e7 giving too much tempo to white

Rook on open file attacking a backwards pawn which is protected only by the King. Ouch!

12...Ng4 might be a better defence in the long run, though. The more I look at it, the more I prefer 12...Ng4 - the knight can't be forced off the square, and it can pose something of a threat to f2 as well.

13, Bd3 exerts a bit more control on the centre. As for things "taking a few more moves" than expected -- that is chess. Rarely are victories easy, but rather they are the result of slow pressure and continuing exploitation of weaknesses. Black has a huge weakness on h7, and though victory is anything but sealed, exploiting that weakness over time can prove decisive.

Bd3 has the added virtue of putting pressure on the light squares around the Black king. But from e2 the bishop can discourage a Black knight from entering g4, perhaps, and prepare the way for a White knight to occupy the place. A judgemant call...

Inconvenient? Opponents rarely go down without a fight, and this is a logical and to be expected move. After ...h5, Black's weakness is a little less weak...

14. Ne5 (!?) is interesting. And, again, real people across the board have a way of thwarting the best laid plans... Still, your positional advantage is significant, what is needed is patience to exploit it.

I don't really like this - I think you had him hopping a bit, and 16. 0-0-0 (if you want to get another rook in play) or even 16. Qa4 (threatening 17. Qf4) would both be better.

Agreed. I am not sure what the point of 16. f3 was. You should prioritise centralising your pieces. Even. 16. b4 or Nb3 are better. As it is, the pawn structure that results is actually somewhat of a middle game weakness for White.

Possibly 16.f4 is another idea, especially if White doesn't mind 16...gxf3 e.p. 17.gxf3, transposing into the game. After 16.f4 Ng6 17.0-0-0, with 18.e4 in mind, White seems to obtain a very fine game. However, in principle I prefer 16.0-0-0 at once, developing whilst retaining options. In the coming attacks on kings in opposite corners, White would have a huge head start.

Black should NEVER have exchanged these pawns, that was a blunder. White cannot exchange on g4 because his own pawn structure would be horrendous. Therefore, Black should instead safely develop and improve his position. ...Qe7 for example attacks White's now weak e-pawn, and ...Nc6 backs up the very disruptive d5 push. Once again the lesson of not being so quick to relieve the tension of the pawns comes into play...

17 ...d4 is the move here.

N at b3 is a less awkward place than d2, and not a bad way to defend, really.

I'd be tempted to let Black take the pawn, and simply 18.0-0-0. Black's K-side weaknesses must be worth a pawn for White, surely... A possible line is 18.0-0-0 Nxc5 19.Nde4 Ncxe4 20.fxe4 with mounting pressure on Black's game.

That is the thing.... 18. b4 created a strong pawn chain in appearance only -- 18 ...a5 puts the test to it, a good move.

Ummm...19. bxa5? Rxa5, I think? Unless I'm missing something, of course!

19. Rd1 solves your problems.

19.Rd1 lines up on Black's queen and avoids rook exchanges. Although in principle I like Kf2, the rook exchange probably suits Black more than White, and ought therefore to be avoided.

I like this - my only concern would be that it weakens your potential responses to 20...Re8 - but as that isn't what he plays, it works out!

Hit in the centre with 20. e4!