5...c5 or 5...b6 in a3 (sämisch) Nimzo-Indian line

It's not that one move is better than the other. They each have their pros and cons.

5...c5 fixes White's double pawn on c4, conquering terrain, preparing Qc7 and Rc8 and attacking the white centre. The disadvantages are that White gains dxc5 opportunities and Black's black squares are weakened, especially d6.

5...b6 tries to discourage a white e4. Black still plays towards c4 as in the 5...c5 variants, only without having used a move on c5, but in some variants the pawn on c4 can go to c5.

Choose according to your gut feeling and/or what your idols play - and then get to know the variation you choose more thoroughly before you start studying the other one.

@Toldsted what is Dc7 and Tc8 ???

Sorry! Danish notation for Qc7 and Rc8. I do it again and again :-) I have corrected it now.

@Toldsted by analysis, I found that after 5...c5 by black 6.d5 followed by 7.f3 for white, is not so much better for Black, for practical play for humans; may be except some top GMs in general.

Do you agree with my point?? Please reply after some analysis of your own.

After 5...c5 then 6.d5 looses time even if it hinders Nc6. Black plays 6...d6 7.f3 0-0 and soon it could be White's King who come into trouble. Better is 6.f3 immediately. Both players will have to play sharp and don't waste any time.

As Black in the Sämish you will have to accept White's impressive centre. Your counterplay shall be the sharp and fast attack at c4 (Nc6-a5, b6, Ba6 etc.). Weaker Black players do often not understand this, and against them Sämish promises White a great game.

What are the pros and cons of each of the move/variation (6...Nc6 / 6...o-o / 6...b6) in 'Nimzo-Indian Samisch' variation after white plays (5...c5, 6.Nf3) line.

Chess books doesn't have much explanation on direct 6.Nf3 line.

6.Nf3 is probably a slight incorrectness, as the knight rarely belongs on this square in Sämish (it blocks the f-pawn). But it develops, and if it confuses Black, much is obviously won for White.

Black can play almost anything. 6...Nc6 is considered the sharpest, 6...0-0 is also excellent. In the next moves Black have to respond to White's follow up.

I think that 5...b6 (idea: Nc6, Ba6, Na5 with quick pressure against c4) is the most ambitious line (and it can get really sharp), but I also like 5...0-0 6.f3 Nh5 7.Nh3 f5, which is a more solid (and easy to play) option.