2.Nf3 is less flexible than 2.c4 but avoids a few lines. Quite comparable to 1.Nf3 vs 1.c4.

Incidently, there is a new book on Benkö, Albin, Budapest and Blumenfeld gambit, "Squeezing the Gambits" from the white perspective. I would assume that it is suitable for the 2.c4 player who is a bit uncomfortable of these lines.

I am a permanent resident of the 2. Nf3 crowd. Why should I allow black these silly openings that I don't want to play?

Also, you will see alot of QID as now NID is not possible.

Thank you. Very informative. I'll look up those minor lines. Flexibility is important. Fortunately, I have long been a 1.d4 2.c4 3.Nc3 player, so moving to 2.Nf3 would represent a broadening of my repertoire.

On a lighter note, I think that a certain type of player who, deep down, sees 1.e4 as chess and 1.d4 as something else, will often feel oppressed by 1.d4 and SEEK REFUGE in the Benko, the Budapest, or the Albin--particularly in the Budapest, if I'm not mistaken. As silly as it sounds, I think the presence of the move 2...e5 there actually creates the illusion of (or at least an allusion to) an open game. Most such players are weaker than those found here, but I know one expert who fits that description. Of course, many strong attacking players all the way up to Morozevich and Topalov have chosen to play these systems for their true merits, and I do not wish to offend anyone or paint all tactical, attacking, or gambit players as helpless cavemen--as enjoyable as it is to paint our opponents' virtues as vices. 

But one pleasant thing about 2.Nf3, if it works the way I think it does, is that it seals off these refuges and forces any actual cavemen one might encounter deep into the dark forests of d4-land proper.

ReneDescartes wrote on 05/18/10 at 00:56:34:

2.c4 if played aggressively avoids the QGD non-Exchange lines, the Queen's Indian and the QGA main lines. These openings are not "dangerous" in the sense that White is in trouble, but may be dangerous in practice because they don't suit his style of play.

The main point is definitely that White can still play the Nimzo-Indian, the Sämisch or 4 Pawns King's Indian, the Bc4 Exchange Grünfeld, the Exchange QGD in its dangerous form, 3.e4 in the QGA and so on. I think it's mostly 1.d4 players with aggressive intentions (like myself) who are interested in keeping these options open. Though note that Avrukh (in his recent 1.d4 Volume Two) plays 1.d4 Nf6 2.c4 for a different reason: He wants to keep open the option of playing g3 before Nf3 after 2...e6.

There could be a further psychological point: Some black players with wide repertoires may feel more comfortable and employ a wider range of openings when White has committed to Nf3. For example the Semi-Slav, QGD or Ragozin without worrying about the Exchange QGD, the KID with no 4 Pawns, or the Grünfeld without many of the most dangerous lines. But this is more of an issue on Super-GM level I guess.

The Benko Gambit is probably the most dangerous defence you're avoiding with the early Nf3. It may also be pleasant to avoid the Albin, the Budapest and the Tango, but personally I think of these openings as positive arguments for 2.c4: White is better against all of them and why shouldn't I take that opportunity to get a good game! 

Can anyone comment on the drawbacks, if White intends to play main-line-ish non-fianchetto positions, of playing 1.d4 Nf6 2.Nf3 and only then 3.c4? I have not seen this matter discussed anywhere.

It certainly has advantages, in that it allows White to rule out several defenses designed to give Black an early initiative--the Budapest and the Albin, as well as the Benko/Volga (e.g. if 1.d4 Nf6 2.Nf3 c5 3.d5, then c4 can be omitted).  But what are the disadvantages? 

Put another way, what is so great about 2.c4 for a positional/classical player who intends to play systems with  Nf3 anyway, such as the main lines in QGD and QGA, the Russian or the Bg5/Carlsbad systems against the Gruenfeld, the Knight Tour against the Benoni, and the Gligoric or Petrosian against the KID? Does 2.c4 AVOID anything particularly dangerous? Or is the main good point about 2.c4 precisely that it allows certain agressive non-Nf3 systems like the flick-knife Benoni, and the sole drawback to 2.Nf3 that it forgoes these?