spanish opening question (2)

in the spanish main line white threatens some tactics so black has to kick the bishop away 2 times to b3 which is a great position , but wouldn't it be better to position the bishop there while giving black1 tempo instead of 2 ?

You are right that the corresponding variation of the Italian gains 1 tempo.
However, a6 and b5 weaken black and in many variations white can attack with a4.

@tpr said ^

However, a6 and b5 weaken black and in many variations white can attack with a4.

is it weakening because a4 threatens to win the rook ? , but that can be easily defended by bb7

Ruy Lopez fans wants to know your locatıon (just kıddın)
But serıously, I studıed Ruy Lopez, ıf they play a6 and play b5 ımmedıately, ıts "Morphy defense" to "Caro defense" whıch ıs 3.bb5 a6 4.ba5 b5 whıch doesnt change much, Stockfısh says ıts equal, but 3.Bc4 ıs Italıan where whıte doesnt play Bb5 but Bc4 to attack F7 pawn, so your questıon ıs more lıke "Ruy Lopez Idea" vs "Italıan game Idea" the only dıfference ıs tempo but who cares, Bb5 attacks the knıght on C6, Ba5 retreats ıt, Bb3 same ıdea as Italıan but the bıshop ıs safer and doesnt need to retreat, so for that, loss tempos are theorıes here,

same thıng If you saıd "why people play frıed lıver ıt makes the knıght move 4 tımes"
Youre welcome :D (please dont call me chess nerd xD)

3 Bb5 is more 'active' than 3 Bc4 as you're threatening the knight that defends the pawn on e5.
But it's an empty threat that can be ignored as Black can play 3... Nf6, Bc5, Nge7, d6, g6 among others. Or even force White to carry out his threat by 3... a6 when 3 Ba4 is the usual response rather than Bxc6. It's a dance between white and black who can follow up with b5. The bishop goes Bb5-a4-b3 but can argue that those pawn moves haven't helped black and weakened the queenside.

"... let's look at a standard position after, say, [1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Ba4 Nf6 5 O-O Be7 6 Re1 b5 7 Bb3 d6 8 c3] ... Black has compromised the safety of his pawn structure. ... White is ready to attack e5 with d2-d4, and the b5-pawn with a2-a4. ... if Black manages to develop his pieces efficiently, and White plays with insufficient accuracy or vigour, [the pawn on b5] might become a virtue - the spearhead of a queenside pawn advance. But certainly for the opening phase, and often long into the middlegame, the pawn on b5 remains fragile. ... As the game develops, with White playing a2-a4, Black often has to tie down one of his big pieces to defend b5, thereby losing energy. ..." - The Ruy Lopez: Move by Move (2011) by GM Neil McDonald
https://web.archive.org/web/20140627022042/http://www.chesscafe.com/text/hansen153.pdf

Here is an example: with 8 a4 white attacks pawn b5.
https://www.chessgames.com/perl/chessgame?gid=2124130
And here is a more recent one
https://www.chessgames.com/perl/chessgame?gid=3172867
And here is an example of the Italian
https://www.chessgames.com/perl/chessgame?gid=2136417

@kindaspongey said ^

"... let's look at a standard position after, say, [1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Ba4 Nf6 5 O-O Be7 6 Re1 b5 7 Bb3 d6 8 c3] ... Black has compromised the safety of his pawn structure. ... White is ready to attack e5 with d2-d4, and the b5-pawn with a2-a4. ... if Black manages to develop his pieces efficiently, and White plays with insufficient accuracy or vigour, [the pawn on b5] might become a vir...

ok , black could later in the game have trouble defending the b5 pawn because white could attack it with another piece , are there also other treads of a4 like trading the b5 pawn removing the pawn defender ?

( your book link doesent work i can only see a few pages )

Question to the OP:

What actual chess books (if any) do you own?

@ChessPriyome said ^

Question to the OP:

What actual chess books (if any) do you own?

i could read it in a book , but i could also ask it here , i dont think that the question was spamming / unnecessary . if it was then correct me