Queen’s Indian Defense 4...Ba6-Bb7 ?

After g3 Black would like to strike in the center with c5, but with simply Bb7 this is met by d4-d5 in most lines; even if Black can take on d5 this is quite dangerous. After moves like Nbd2, Qa4 or Qc2 the move c5 is much more effective as the queen loses control over d4 and d5. Going back on b7 is then necessary since the diagonal is open and White is about to play Bg2.

in fact even in this line, 4..ba6 5 qc2 c5 6 d5 is possible as a pawn sac. you can avoid this by not playing c5 but then you're not much better than in the bb7 lines, as you will likely have to go back to b7 anyway once the threat of bg2 and nf3 to somewhere becomes real.

this is why i decided not to take up the qid. no decent way to avoid the d5 pawn sac ala alphazero. i am aware that my opponents will not play as flawlessly, but the point is that black's side is very difficult to play as your pieces will be contorted and your extra pawn is useless for a long time, and you have to defend also for a long time. not very practical for non-gms.

Thank you, sir!  That does clarify something I was so confused about.  It’s true what they say — the more you learn, the more you realize you don’t know.  I didn’t even realize the reason for black’s desire to play c5 was in direct response to white’s g3 move.  Perhaps I oughta stick to the Italian and Zukertort systems for a few hundred more rating points.  

Thank you for the insight.  I agree with your final point, at least in regards to my own skill level.  I’m feeling far too novice for this defense system.  Do you have a defense to d4 you would recommend for an 1100-1200 player?  

you can start looking at the queen's gambit declined family of openings and choose one from there and study it and play it. it is conceptually the easiest to play in my opinion. also there are a number of lines that do not require a million move orders to play. 

i showed 2 lines that are move order friendly. of course white can play something else from move 2 and beyond. my point is that you can play the setup pretty much almost against anything else white can do from move 2. on the other hand, don't ignore what your opponent is doing just so you can complete your setup. if he is threatening something, or attacking something, address that first.