Looks like we are in 'Greek Gift' sacrifice country, here...

Definitely. Hard to imagine someone at this level had not seen this coming. Ng4?! may best the best option here.

after taking bishop with king white Knight dancing at g5!!!!!

It might have been worth examining how such attacks proceed: Suppose th game proceeded 12...Kxh7 13.Ng5ch ... then what? [A] 13...Kg8 14.Qh5 ... and Black has just about to give up the queen (14...Qxg5), which might otherwise go: 14...Re8 15.Qxf7ch!... (you'll see why, presently - it's a well-known mating theme) ...Kh8 16.Qh5ch Kg8 17.Qh7ch Kf8 18.Qh8ch Ke7 19.Qxg7#. A tougher defence lies in ... [B] 13...Kg6(!) How does White proceed? Although Queen moves 14.Qg4 or 14.Qd3ch offer the advantage after Black's reply to both 14...f5! It is not easy to find anything decisive. E.g.: [B1] The plausible looking 14.Qe3ch f5 and 15.exf6e.p. gets White nowhere. Reinforcements are called for: [B2] 14.h4! ... with the idea 15.h5ch and a mating net. Black has to throw back material to try and free his King from the toils: 14...Nxe5 15.dxe5 Ne5 seems to be the only way to stop mate or the loss of the Queen. A piece down, Black would be lost. Does declining the sacrifice avert a disaster? Sometimes it does. At other times... not. This is one of the other times.

instead f7-f5 is more working

even after f7-f5 Nxe6+ is still very strong

[?!] Stronger was 15.Qh3! with the same basic idea. Now Black could fight on - at a big disadvantage, sure - with 15...Qe7, taking it out of the K-Q 'knight fork' configuration. After 15.Qh3 Qe7 16.Nf3! ... (not available after 15.Qh4) 16...g5 17.Bxg5, White's attack is completely unstoppable.

Correct, Qh3 is much more effective here.

Many thanks for pointing that out guys! At the time I thought it didn't make any difference if I put my queen on h4 or h3, but it seems it does make a crucial difference.

yes a brutal attack you form charles.

[?] Walks into a forced mate. Under such pressure, that is hardly to be wondered at. All the same, after 15...Qe7! White might have had to recast his plans. Still with an advantage, of course, but White doesn't seem to have enough in hand to force home at once a direct attack. It would have been interesting to see how the game might have continued after that.

It is interesting, to say the least! Fritz says that after 15.....Qe7! white has Bxg6 winning a second pawn as if black takes the bishop the queen mates on h7. But black can then reply Rh8, forcing Bh7 to keep the piece and then black can capture on d4 or play a5, so maybe 0-0 is better than Bxg6.

I think this is worth a (??) Simply a bonehead decision in such a bad position. If 15...Qe7 I believe you can still have a mate attack beginning with 16.Bxg6! Rh8.

That was a really beautiful game and an excellent annotation!!

Very nice annotation Charles, as always.

really a Charles immortal game

There is always something aesthetically pleasing about the queen and bishops buried deep in the enemy K-side. A good one to annotate, with the added didactic value to readers unfamiliar with it of the 'stock' or 'routine' 'Greek Gift' sacrifice. Not so 'stock' or 'routine' after all!

Well done busting up the kingside Charles

Many thanks everyone - you are all very kind.