why b5 is a bad move (sicilian najdorf)

9....b5?
It's a move I often play in order to play Nb7 right after in order to add a pressure on e4 and also getting the diagonal towards the kings.
I know Nd7 is more seeing in games and theories, but i never got an explanation of why not b5 and Nb7...

Your 9... b7 loses material after 10. e5.

b5 is a thematic move in the Sicilian. If played early, it's a little bit risky. You don't need to worry about it at your level, though.

Yes here it loses because of the line-up Bf3 and Ra8.
Sometimes it loses because of the sacrifice Nxb5 or Bxb5.
Most of the time it works fine.

@okgo
ok, in this particular case, you are right, I was loosing after 10.e5, didn't see that. but my question was more for the general cases
b5 followed by Nb7
I will try to see if I find the thematic move you are talking about.

@tpr
thank you :)

Usually if b5 is played before nd7 white can respond with a4 and sort of put pressure on the b5 pawn. Especially in some variant in najdorf i tend to play it a bit one ore two moves later than to start of with. Compare the line c5 a6 and b5 right away. White can attack the b5 quiet esally without any piece sevelopment from black.

In your game it looks like some kind of schweningen because of the pawn on e6. I tend to move it to e5 inte be2 line.

@RegisLakrids The thematic move I was talking about is, as I've written, b5.

People, you know that chess is always concrete.

b5 is thematic but not in every position, winning the Queen is also thematically good but not in every position.

@Sarg0n No, winning the Queen is not an opening theme. And chess is far from being always concrete. Are you really a CM?

@okgo If a player marked as a titled player he is a titled player 100%.

^ TFW didn't get the /s/ tag