Question about the computer's valuation

Question

My friend recommended me this good community. However, I'm new to this format so I had no idea about including a chess game in my text. By looking at the previous questions, there should be some way to include my game, but I couldn't find this so instead I brought the picture of the part I was wondering about.

Why the above position almost winning for me? As indicated in the picture, chess.com's depth 18 engine is marking it as -7.4, but I have no clue about it. I couldn't find any tactics nor throughout the computer's suggestions.

Some information about that would help you answer: My chess.com rating is at 1100~1200, and been playing chess for about six months. I have mo experience in learning chess theory, only solving puzzle rush every day.

Answer 1

White can't defend the a3-pawn. The White king is defenceless on the queenside, and you have the knight on a great outpost near the White king, the bishop a mere ...d5-d4 away from joining the attack. The Black queen is entering the fray either via Qb6 or Qa5. both Black rooks can participate in the attack through Rc6-b6 or Rc6-a6, or along the c-file.

Basically a chess engine can't find a way to defend against the oncoming attack along the a- and b-files aimed at the White king.

Black's immediate threat is to play ...Nxa3 threatening ...Rxc2+. White defends that by playing c2-c3. White's best option at this point is to evacuate the king over to the kingside, so White's best moves of Rd1-f1 are there to clear space for the White king to walk from c1-d1-e1-f2. While he's doing that, Black is bringing his pieces quickly into White's half of the queenside attacking the king directly.

Answer 2

True, there are no immediate (forced) piece-winning or mating tactics, but...

• Your position is safe from counterplay. You do have holes on the dark squares around your king, but White doesn't have their dark-squared bishop any more and the other pieces are far away from getting to your king effectively. A weakness only matters if it can be exploited.
• On the other hand, all of your pieces are ready to aim for the white king: the knight obviously, the queen via a5 or b6 or c7, the rooks via c8 and maybe c6 to b6 or a6, and the bishop as soon as you move your d-pawn, which you can do at any time.
• The white pieces are not only in a bad position to attack your king, they are also (mostly) cut off from their own one and cannot defend it effectively.
• I wrote piece-winning tactics...however, the pawns on a3 and c2 are already extremely weak and will soon fall (netting you connected outside passed pawns, a very nice asset on its own).
• White basically has no better plan but to run away with their king as fast as possible, disregarding safety of the other pieces, so you might end up taking one or two of them down the line. For example, if you want "real" tactics, I can see a nasty pin happening after ...Nxa3, ...d4 and ...Bc4. It will be even more effective after c2 falls (to the Na3 and your rooks on the c-file). White also always has to watch out for back-rank mates by your queen, and so on. The tactics in the position are as said not forced, but White will have a hard time avoiding all threats you can make (and will eventually fail, as the engine suggests).