A natural move, but most prefer 3.d4, here.

Ng5 surprisingly doesn't do much due to 5. Ng5 d5 6. exd5 Nxd5 and black is fine here. The knight on g5 will most likely be chased away with h6 the turn after. That being said, castling here isn't bad here at all.

An amusing drawing line can emerge from 4.Ng5!? The resulting attack is cognate to the Fried Liver in the Two Knights' Defence, but with certain differences: 4.Ng5 d5 5.exd5 Nxd5 6.Nxf7!? Kxf7 7.Qf3ch Ke6 (the knight has to be protected) 8.Bxd5ch!? Qxd5 9.Qg4ch Kf7 10.Qxc8 Qxg7 11.Rf1 Qe4ch 12.Kd1 Qf3ch 13.Ke1 Qe4ch and a three-fold repetition.

Not really an attack. But black could maybe get away with nabbing the pawn on e4 here.

Looks a bit risky in the circumstances. But I don't think I would have liked 5...d5, neither: 5...d5 6.exd5 Nxd5 (better might be something like 6...Na4, as in the Two Knights) 7.Nxf7 Kxf7 8.Qf3ch Ke6 9.Nc3 Nb4 (or ...Ne7) 10.a3. Of course, the 'obvious' 6.f3 is no good on account of 6...Ba5, protecting the f-pawn. White's next move begins to look very attractive!

Why not 6.Nxf7, though? It doesn't seem to get White very much: 6.Nxf7 Bxd1 7.Nxd8 Bxc2 8.Nxc6 ... (8.Nxf7 seems to pick up the Black rook, but at the immediate cost of a piece, and the knight looks trapped at h8) 8...bxc6 9.d3, with maybe a slight edge in development. The bishop check must be preferable.

7. f3 might have been better, avoiding black's follow-up.

I agree wuth cdeburca, I'd have considered f3. Then after he retreats his bisschop I'd have pulled out my own bisschop. I'm up a pawn and denied black the right to castle in exchange for maybe 1-1.5 tempo. Doesn't sound bad eh?

Yes, 7.f3 was much the better option: 7...Bh5 8.Bxh5 Nxh5 9.f4! Nf6 10.Nc3 with an extra pawn and Black's king stuck in the centre.

White is attacking the knight, overlooking that it wants to move anyway.

I think the idea behind this is that after say 8a3 Nxc2 the queen is trapped. But more obvious to me would have been Na3.

I don't really get d3, yes the pawn is attacked once, but the queen is there to protect it. I think Bb3 would have been an interesting defence for white, though that may be overloading the bisschop since it'd also have to watch the d6 square incase the knight ends up there after h6. Na3 is a very reasonable defence here.

8.Bb3 seems to be the right way to go, completing a successful hit-and-run raid. Not only does the bishop protect c2 in this way, but White also threatens 9.Nf7.

But just dropping a piece.

If black takes here with Bxd6 he more or less wins the game.

Bad luck. This is turning into a disaster for White, after such a promising beginning, too. Better was 10.Bc4, and hope at least to get the knight on a1, and then some counter-chances.

A big blunder; just BxB and black is cruising. Backwards moves can often be the hardest to spot for some reason.

Blacvk was over-finessing. 10...Bxe6 was quite good enough. Black should still come out of this with an extra piece, though.