It might be mentioned that there is considerable material pertaining to 3. Nc3 and 3. Nf3, including the Petrosian QID and several NID systems, in Ivan Sokolov's recent pawn-structure book.

Markovich wrote on 05/27/09 at 13:30:44:

 
Last I checked the ...Bb7 variation left white with very good chances of playing for a win (tends to be +=), whereas the ...Ba6 variation leads to unclear positions where black isn't worse. As far as I know it's 4...Ba6 that has really put 4. a3 on the backburner theoretically.

Much like the French the QID has been in my repetoire since I started, so I've usually kept tabs on it theoretically (both in Bb7 and Ba6 variations since I've played both at varying points).

Scott wrote on 05/25/09 at 01:02:51:


A "gambiteer" to me is someone who plays 19th-Century-style gambits.  I don't see how someone can play chess and not be willing to sac any given amount of material for corresponding play.  Pawn-sacs and exchange-sacs are a dime a dozen in modern chess theory, let alone practice.  The ability to spot them and the willingness to play them are just plain essential for good players -- but that doesn't make anybody a gambiteer, necessarily. 

I certainly don't think of people who play the 4.a3 versus the Nimzo as gambiteers, notwithstanding that their c4-pawn very frequently dies an early death.

@ everone who reads this: Is the theory of the Petrosian QID such that White can claim +=, or at least reasonable play for a win?

I think 4.a3 vs the QID and 4.a3 vs the NID are completely different species. The Sämisch is very principled for both sides exactly because it rises the question: pair of bishops or weak pawns?

Antillian wrote on 05/25/09 at 20:19:17:


I am proposing that Scott take up 4.e3 or 4.a3 instead of 4.Qc2.  If you want to learn the Nimzo from scratch, I opine that you will find 4.e3 and 4.a3 easier to start with and, further, that they will do more to teach you the fundamentals of the Nimzo than most of the other lines.  As for 4.Qc2, while it is very fashionable at the pro level, I don't think its all that easy for a beginning Nimzo player to handle.  Just my opinion, your mileage may vary     
 

Scott wrote on 05/25/09 at 01:02:51:



While I understand the sentiment, and I might have written those words once, I now realise that in order to gain an advantage in the opening I have to be willing to sacrifice something.  My gambits usually occur later in the game than the Romantic players, but I still offer material or space in return for an interesting attack or at least counterplay.

The modern lines are replete with gambits, and I don't think it's possible to play theoretically topical chess without playing some sort of gambits.   

I choose 3.Nc3 about as often as I choose lines with 3.Nf3 (usually by transposition).  I usually make my choice based on what I think my opponent is most prepared for and go the other way. The problems, as several have mentioned, go beyond merely whether to play the QID/Benoni/Bogo systems or the NID.  White is even stating what sorts of Queen's Gambit he is likely to play.  I wonder if 3.Nf3 is actually as popular as Scott suggests, or if 1.Nf3 is popular, transposing to the the QGD with Nf3.

I play both.  For me, its purely a matter of mood or opponent.   

If you're going to learn the Nimzo as White, I would recommend starting with 4.e3 or 4.a3.  These will more often lead you to the basic structures that you need to learn in order to understand the opening.