Annotated chess game

I'd try 21.c4, gaining some space in the center, though black probably stands better after 21...b5! with excellent play on the Q-side.

In order to play c4, white have to release the pin on his queen first, so to be able to prevent the black's lsb to go to b5. But the best chance for white to attack is still f5. Otherwise, why o-o and f4?

!

As said, now white has to waste a move protecting his queen, and cannot use the knight to prevent a possible cxb5. Granted that b5xc4 is good for black!

exd6, Bxd6 opens another line for black. I don't like it.

This definitely gives black a winning endgame. 23...d5 might lead to a slightly better position, but as a human, I'd prefer to simplify into a won endgame rather than have a more complicated position that might be better. I'm less likely to blunder away my advantage in the simpler position  

Nice insight  . White is thinking about e5xd6, once the queen is gone. But the d6 pawn is simply a target!

White calculated (probably) that now, having taken with the pawns (provided that e5xd6 is dangerous for black, - and this is to be proved, since I don't think white can hold the pawn), he can recapture bxc4, and the position looks equal. But it is not, since black's bishop pair becomes really strong.

Rc1, in my view, was better. Of course, black will try to penetrate with the rook on the b column... The poor Nc2 can go only to the sad e1 (on e3 it is just a target, since f5 is not a plan anymore).

As I said before, this knight is doing nothing here, while on e1 it would have shielded the column. Of course, black still has Rb8 / Bd8 / Ba5 / Rb1 or b2... and white cannot do much!

Black has a won position. There are lots of winning plans, it's just a "matter of technique" at this point.

No prizes for guessing blacks next move

Yes. Out of resources, white has to use his very King to help defending the position.

Yes but black must always look out for white counter play i.e. Rb2 (if Rxe3?? then Rb8+ wins after Bd8 Rxd8+ Be8 Rxe8#) but this can be dealt with h7 but white should then start an attack on the k-side with g4,h4 etc. after of course protecting the e3 knight

Good attempt (thedesertfox's), but I think white has no time or material enough to transform it into an attack. By the way: do you see a knight had to go to e1, finally?