Now this really does look like a Saemisch - one that is going very well for White.

Now, ...Bxg4 is not possible. White can take the N and black has not enough power to counterattack.

None of the available moves looked wonderful.

As black maybe a way out can be to sac a central pawn for the sake of exchanges and loosen white's structure, e.g. 11... Nd4, 12. NxN, exN, 13. BxN, Nd7, trying to force dsb's exchange and then Qf6 (threatening f3) forces the Q's exchange, heading for an early endgame with a pawn less but with a lot of pieces still on the board.

I don't think black has enough for the pawn in those lines.

Not just the knight! The bishop threatens to come in at b5...

Bxg4 doesn't give black enough, it seems...

The "famous" line Bh6 is not always good. I'd say not usuallly.

It is hard to see how he can improve his defence on that wing, right now. But his Q-side counter-action has been too long delayed.

Kf8, to make room for a N, seems a possible try.

Agree with archduke. It's true that a counterattack seems the only possibility, but a6 seems too slow to lead to a fruitful distraction. Maybe 13...Rc8 would have been a more active move? With black's position so crowded up there, the sacrifice on g4 seems less useful now, but it may be the only chance to get something out of it (with no whatsoever analysis from my side to support such idea)

jumping into adangerous variation in which the slightest error spells disaster

I think b4 is an error, after which black is lost. I think black has to try 16....Nh5, even though it loses a pawn.

I think you are right. Black's counter action is much too late.

black certainly missed this zweischenzug (inbetween move) when he started down this path. Good move Charles!

Many thanks Kenneth!

Oddly enough, the alternative, 18.bxc3 didn't occur to me - at least not until I scrolled down to see whether you had indeed played Qh2. But the threat ...cxd2ch had to be dealt with, and this Q move is the only sensible way. Black is as busted as 'busted' can be.

Tactic Trainer's like position. An easy one...  

It was this or 19.fxg7 Kxg7 20.Nxh5ch.

But if 19.fxg7 then Kxg7 is not forced, for instance 19.....c3xb2 may be stronger.

Instead 19...cxb2 would have occupied White with defence for a move or two. E.g. 20.Rb1!? Qa5ch 21.Bd2 Qxa2 22.Bd3 Kf7! 23.Nxg7 Rh8 24.Qxh8 Rxh8 25.Rxh8 Kxf6 26.Ne8ch Bxe8 27.Rxe8, although, as the smoke and flames die down, White must have a winning game. Analysis position after 27.Rxe8:

I think white can even ignore b2xRa1=Q, and with two queens on the board, black is busted all the same!

I don't agree with damalfi. I think after 19...cxb2 white does have to play 20. Rb1.

Possibly, as black would otherwise queen the pawn with tempo and white's attack looks 1 move too slow. But I don't think black could build his own attack strongly enough to prevent white from continuing. Certainly it would be a very sharp line. 19...cxb2 is definitely best for black in this position. After 20. Rb1 (or Rd1 maybe?) Kf7 (If 20...Qa5+ 21.Bd2 Qxa2 22.Nxg7 Qxb1+ 23.Kf2 and I think black has to sac his queen on f1 to take the sting out of white's attack, but white is obviously winning after 23...Qxf1+ 24.Rxf1) 21.Nxg7 Rh8 22.Qxh8 black has either 22...Qxh8 23.Rxh8 Rxh8 24.fxe7 or 22...Qa5+ 23.Bd2 Rxh8 24.Bxa5 Rxh1 and either way white is a lot better, but there is no attack with immediate mating threats.