Worst Piece Principle | Puzzle of the day 07/11/2023

There is a positional principle called the "Worst Piece Principle". The idea is simple: Find your worst piece and improve it! How can Black do this?

I agree, and from Nb2 you can hop to d3 which would be a nice fork if the rook didn't move but even then its a great outpost and will chase opponent's queen and you might be able to checkmate if you align the Q with the rooks, maybe after a Bish sac on d5 to remove the defender N/e3...

Right, Nb2 and then Nd3 is threatened, and I don't see a good way for white to respond. If the rook at c1 moves to another file it is less active and no longer a double force with the other rook. Say Nb2, Rd1, Nd3 and the white queen now has to move to a more passive square like f1 as well. The white position is effectively bisected and now the knight will capture the b4 pawn and attack the rook at c2. Quite a horror show for white...