Why engine recomond b pawn take the bishiop other than d pawn in this position

thank you in advance!

Normally, you should take torwards the center, so that you get move center pawns. By taking with b pawn, you now basically moved a flank pawn (the b pawn) into a more centralized location (c file) meaning you will have more pawns to fight for the center with. On top of that, you now have a partially open b-file to put a rook, which will be especially powerful if the white dark square bishop leaves the defense of the b2 pawn.

Taking with the d-pawn is also valid, as you get your queen to look at that partially open d-file, along with activating the black dark square bishop, but stockfish doesn't like that move as much, as it moves a central pawn (d pawn) into a less central location (c - file)

Wait didnt notice u were 1580 uhh

better development. bxc6 allows black to play d5.

Much simpler than what I wrote and prob easier to understand lol

There's a chess principle" Always try to capture towards the centre" never try to ignore chess principles

your explanation is more than fine🙂. the extra details will probably help him visualize the idea.

I agree. Unless the individual position dictates otherwise. one example would be the Ruy Lopez Exchange variation where dxc6 is better for black than bxc6.

You can eventually play d5 with the help of the doubled previously b-pawn

Thank you for you all

but why in this variation, black take the bishop with d pawn instead of b pawn?what's the difference between these two positons?

@1
It does not matter: 7...bxc6 as well as 7...dxc6 lose a pawn. Black made an error before 6...O-O?.

@10
6...dxc6 opens the diagonal for Bc8, but 6...bxc6 is playable too.

@8
1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Bxc6 bxc6 5 d4 is excellent for white. 4...dxc6 controls square d4 with Qd8 as the d-file is open.

@6
There are many more exceptions
1 e4 e5 2 Nf3 Nf6 3 Nxe5 d6 4 Nf3 Nxe4 5 Nc3 Nxc3 6 dxc3 opening the diagonal for Bc1
1 e4 c6 2 d4 d5 3 Nc3 dxe4 4 Nxe4 Nf6 5 Nxf6+ exf6 opening the diagonal for Bf8

@10 i think that in that position d5 it's not possible because of the knight on d6, that's why taking with the b pawn it's not as powerful. Also you are going to lose the pawn on e5 ando white is already castle, so you need two things: options to block the check after Rxe5 and quick development in orden to catch up