A mistake, but a human one. Black wants to control c7. It was needed to leave the a7-g1 diagonal open for the queen to dream about a possible counterplay.

White has a clear advantage, thanks to the control of the c-file. Now a possible plan is to penetrate on c6-c7.

Take a close look at the pawn structure. What pieces do we want to keep alive on the board?

The knight was threatening to jump to c4 or a4, bothering a lot our pawns on a3 and c3. By eliminating it, White gets a scenario pretty similar to the game Polgar-Anand, where we have a knight that can end up on d5 against a clumsy and passive bishop.

Once the knight arrives to d4, it will protect c3 and will control important squares like b6 or f6. White could then think about continuing to attack on the queenside or bring his forces to the h-file and attack the king.

Naturally, the key to this position is to realize that there is a weak square on d5. At the moment it is well controlled by the f6-knight, so we cannot jump there, since after the trade White would be forced to take with the e-pawn, and this is not ideal, since the weakness on d6 would disappear. That is why we need to see that the b3-knight can be improved, and there is a nice route available to d5!

We will reach a scenario where the white knight is much better than the dark-squared bishop.

The last white move was f3, fighting against the queen and bishop. However, this allows Black to trade one of the most important pieces on the board. Can you find the subtle sequence?

Not only attacking on e3 but also pinning the pawn!

This intermediate move is very strong since forces white to retrear the knight to a more passive square.