Why is Bc8 "interesting"? What's the plan for Black if this move was played?

Question

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[Title "Rasulov - Naroditsky, Titled Tuesday 2022-08-16"]

1.Nf3 Nf6 2.g3 g6 3.Bg2 Bg7 4.O-O O-O 5.d4 d6 6.c4 Nbd7 7.b3 e5
8.dxe5 dxe5 9.Nc3 e4 10.Nd4 Re8 11.Qc2 c6 12.Rd1 Qe7 13.a4 a5
14.Bf4 Nc5 15.h3 Nh5 16.Be3 f5 17.Rab1 Rf8 18.Qd2 Ne6 19.Nxe6
Bxe6 20.Bg5 Qc5 21.Rbc1 Rae8 22.Qd6 Qxd6 23.Rxd6 Be5 24.Rdd1
Kg7 25.e3 *

Why is Bc8 in this position "interesting" as per GM Naroditsky (1:00:19 in this video)?

Full game, Lichess, Chess.com

One comment in Reddit is this,

"You first need to understand the move, this is not a waiting move (and, btw, waiting moves are very rare and very specific to some positions, like endgames where time is precious and very dominant positions where you can lose a move and still be almost winning). It is a move that greatly improves the position, as now the bishop is not exposed and liberates the rook. So we improve other pieces without making the bishop worse, as it wasn't doing anything on e6 anyway.

For example, if black plays 1...h6 2.Bf4 Nxf4 3.gxf4 Bf6 White does 4.Rd6 and we can't expel the rook right now with Be7 or Rd8 as we hang the Be6. We need to first defend the bishop to do that. So it's way better if we do that first avoid problems later on.

In general grounds, Bc8 is a good move that can be made in a second as it is a very common pattern. But in general you want to calculate and be aware of your opponent's ideas, that's how you usually find this kind of moves."

What are the other plans?

Answer 1

The bishop on c8 has a few advantages:

• It protects b7 (which is not attacked right now)
• It still protects the entry square d7
• It is not attacked by a Nd4
• Should the Be5 be away too, then the Re8 protects the pawn e4, so h6, g5, f4 is easier to achieve. (but it still is not possible for the moment)
• The Re8 can be brought into the attack with Re6-g6.

These are quite abstract ideas and Daniel's 25...h6 26.Bf4 Nxf4 27.gxf4 was indeed better. But then taking on c3 was not good. He should have played 27...Bf6, keep the bishop pair, and, after optimizing the position, break through with b7-b5. He anyway won, but the position was even at some point.