I am wondering why in the world, after move 16, an engine would give slight advantage to black. Regardless of the fact that engines can be "wrong", what are some of the actual advantages of black's position? I couldn't see any and envisioned the rest of the bullet being pretty painful .. but, tactics aside, black had some serious advantage.
White has a killer pawn on e5, cutting off my piece communication, the 2 bishops, my pawn on d7 is backward (though, now i see that the break was going to be easy), more space, etc.
What does black have?
It‘s the Sicilian cheap trick. The semi-open c-file, the minority attack, an extra center-pawn. The c-file with potential outposts is often better for black than the d-file for white. Think long-term resp. sustainable! White has no prospects, where should he improve? A position which cannot be improved is not good, it becomes worse.
Now you know why the Sicilian is incredibly trendy.
It's an interesting position after 16. My guess as to why the engine thinks the position is -0.4 or 4/10 of a pawn better for black...
1) White has no easy way to attack the black king.
2) Black controls the next pawn break, and can break with the d or f pawn.
3) The e pawn for white is somewhat a liability.
4) Blacks backward d pawn isn't as bad as it could be.
5) Although white has an almighty bishop pair... The position is currently mostly closed
6) The clumsy looking knight on e8 isn't actually as bad as it may seem to be. It does a pretty good job defending the king, and it could even go to c7, also it supports either pawn break.
7) The pin on the black queen is easily broken with Qc7 then white must worry of ever moving his knight as the QR battery may be hungry, also it pressures the e pawn.
So the position on the surface may seem great for white. Got a bishop pair, and a more advanced pawn seemingly more space... It's not so easy to push for a win as white.
Personally I think both sides are fine here, though if I had to play either side I'd choose black. I wouldn't put the evaluation at -0.4 in my head, and it's more like -0.15 a very small advantage
May I quote "Simple Chess", the famous book by M. Stean? Believe it or not, it's 40 years old! Could be written yesterday.
"Minority attacks derive from the Pawn structure, Pawn structures derive from the opening. Go back to the eras of Capablanca and Alekhine and you will see Queen's Gambits, hoards of them, with hoards of minority attacks descending from them. Nowadays [1978; still relevant] the Sicilian Defense is all the rage. Sicilians here, Sicilians there, Sicilians absolutely everywhere. Why this saturation with Sicilians? Does the Mafia's influence really extend this far? The answer lies in the minority attack. The whole idea of the Sicilian is for Black to trade his c Pawn for the d Pawn. White almost invariably obliges: 1.e4 c5 2.Nf3 Nc6 (or d6 or e6 or g6) 3.d4 cxd4, when Black immediately arrives at a minority attack Pawn structure. Half-open c file, extra central pawn, 2-3 minority on the Queenside; these are all the necessary ingredients. Sounds infallible, so where's the snag? Why doesn't Black win every game? The problem is of course that White has a lead in development in the early stages, which may prove difficult to survive. Black's prospects lie later in the game when the winds of White's initiative have blown themselves out."
The structural weaknesses White accepts because he is trying to avoid Black's plan to launch a minority attack to get a winning endgame and must attack. They are not the cause of Black having winning endgames (otherwise White wouldn't weaken his position in such a way); merely they are a symptom of him having to attack the Black King. The root cause of this is the minority attack, and this is why most Sicilian endgames are winning for him. The minority attack is also a theme in any Rook endgames, so it's not just a late middlegame idea."
You can find the structure everywhere in the almighty Sicilian, a practial example:
Black is a bit better because his pawn structure is better.
Now despite that the black pawn structure in the open Sicilian is always better, we see that e.g. in the Stockfish-Houdini Superfinal from the TCEC 2016 black did not win any game: either draw or white wins.
So with best play from both sides the dynamic compensation for white is at least enough to offset the static advantage of black.
This means that white must play actively. Passive moves like 8 Bd2 and 10 a3 violate this principle.
