Unsound sacrifice or a novelty?

I want to show me one of my recent games here on chess.com. I sacrificed the exchange for attacking possibilities. However im not sure if it is sound or not and the computer goes crazy. Any high rated care to analyze it?

actually i prefer Rd8 after 18.Nc3

but yur sac looks good subjectively or as a shocker

Well, I think that an engine analyse would be necessary to evaluate the sacrifice.

I feel that the sacrifice is very dangerous for white too, as it allows Kh8(Kh7) with Rg8 following. Then all kind of moves are possible (Rxg2, Bh3, etc...).

So perhaps it is worth to analyse the line a bit further, have you considered/analysed that path before you made a sacrifice?

After Rd8 i can still do Bf3 and Nd5.

Dragec: my computer engine have a hard time analyzing the tactical mayhem of all the variations. There are many interesting lines. The sacrifice was made on intuition and i dont like rooks so i tend to sac the exchange a lot

after Bf3 Qg3 threatening Qh4

Bf3 Qg3 with threat of Qh4. Is it worth your rook? Maybe easy for a computer to calculate, but i doubt there is many who would have the guts to do a move like that. I checked on my computer and he liked Qg3 but black is only slightly better.

no i think Qh5 is worth the rook its practically giving white a piece for amazing attack and pressure just like in the sicilian and i've done that before with no problem i'm not afraid of sacrificing.

i feel the same way about Qc7-g3-h5 the way u did when u played Rxf6: intuitively good

Btw, very nice example of play against Two knights. I use it a lot as a black against Italian, so its good to check some nice ideas.

I find 11.f4 interesting  , main line here is 11.d4, and I must admit that I haven't saw it much, one more reason to study it further.

P.S. your opponent played till mate, and his ranking was really high, this is really annoying.

That was a wonderful sac, candypants! Thanks for posting it

Very nice game Candypants, thanks for sharing.

I haven't had time for extensive analysis (so far), which would obviously be necessary for a qualified evaluation of your exchange sac. Nonetheless I'll give what thoughts struck me when playing through your game hoping there may be something useful gleaned from them nonetheless.

It's my first impression that you are not developed well enough to expect your exchange sac to actually yield a substantial advantage, however it is you who has most threats while Black needs to tread carefully in order not to walk into a quick disaster like he did in the game. First and foremost I think he needs to play a bit more actively so you can't set up such a strong bind, for example 20...Qc5 challenging your centralised knights instead of 20...Qd8. That notwithstanding your sacrifice leads to interesting play and certainly does not seem to be refuted in an obvious way.

The main question is just if you actually need to play that way, a quick database research revealed that your opponent's 13...c5 seems to be inferior, and after 14.dxc5 Bxc5 15.Qxd8 you arrive at a queenless middlegame where Black had difficulties justifying his pawn deficit in several cases. Admittedly the character of play in this line may not suit your style perfectly, but I suspect it is the best try for an advantage from an objective point of view (or at least as nearly as I can guess at that).

Concluding it seems your 14.0-0 seems to be the novelty, but it remains to be shown if it is in fact stronger than the rather natural 14.dxc5.

Just my two cents, I hope it helps in some way.

At move 15 your opponent is developing a kingside attack of his own! That exchange sac steals the initiative. I haven't used an engine, I haven't been thru the analysis already given in this thread (sorry) except to glance at it -- but my gut feeling on seeing that sac is: Instead of a well-posted N and a comfy king in his castle he's got a busted up kingside with White pieces running up the hill yelling and waving torches! Good sac.  You prosecuted the game from there the way you're supposed to... vigorous attack and never mind about the material. Well-played. There's sound and unsound in the pure sense, and then there's "is this sac sound at my level"? I think that latter question is the pertinent one here. At my level... if you'd played that OTB against me I'd be thinking: "oh crap..."

My Fritz rates 18...Rd8 as significantly better for black since this threatens Qe5 winning the knight, and prevents you from getting the attack going with Nd5. Then 19.Bf3 Qg3 threatens Qh4 followed by a discovered check/mate threat by the bishop winning more material, so your sacrifice might not have ultimately been sound. However, you could probably count on your opponent making a suboptimal move in such a sharp position and you played very well. After 21...Bd7? you were totally winning. If 21...Re8 (22.Bxh6? f5 creates threats along the h-file) 22.Bd2! attacking the knight, and when it moves you can play the Nc6 fork, so black has to play Bxd4 23.Qg3+ Kh7 24.Qxb8 when you win the exchange back and the position is equal.

By the way, the Two Knights Defense is awesome. Might also want to try the Ulvestad variation with 6...b5 as black.

Torkil: Now when you say it 14. dxc4 seems a bit obvious. Good that you pointed it out. I usualy only see tactics and not endgames :).

Conclusion:

1. I should have taken the c-pawn and try win the endgame.

2. There are lines that are good for black, however they are very hard to find.

I think most sacrifices are unsound but usualy it is hard for your opponent to find the best defense.