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.

The light-squared Bishop give Black a nice advantage.

There only move to fight for equality.

21.g3? gxf4 22.gxf4 Kh8 and I would not like to be in White's shoes now.

Now there are a couple of interesting ways to play with the black pieces.

Despite having a terrible structure, the position is around equal. Black has a fantastic bishop on e4 and White cannot put pressure along the files. Plan: ...Rfe8, ...Re6, and ...Qe7 unpinning.

A nice intermediate move, attacking the knight, before we protect the e4-pawn. And now Black has a couple of playable options

19...Na6 Another super important moment. Black is simply intending to capture on e4, so how do we stop that?
20.Bd3! Nb8 21.Rc7 Bxe4 22.Bxe4 Rxe4 23.Rhc1 +/- White has a much better position, with a lot of pressure on the c-file and the seventh rank.