Queens gambit accepted, where do the knights go?

After 1.d4 d5 2.c4 dxc4 3.e3 Nc6 4.Bxc4 Bf5 stockfish wants to develop the king's knight to e2. Later, it wants to play f2-f3. Can this really be good and if so, what is the idea behind it?

Another QGA question tangentially related to knights is about the c4-square. After development in the QGA I usually begin a minority attack with a3 and b4. The problem is that this quickly creates a hole at c4, however my bishop and possibly a rook are both controlling that square. Is this fine or should one wait with b2-b4 in the QGA?

 Regarding, e3, it is what Boris Avrukh recommends, in the Grandmaster Repertoire Books. I don't see what's wrong with it, but I'm happy to learn.

yeah, Nc6 is weird and prevents a c5-break, but at my level I face it often.

Why a3 and b4 are bad I don't understand, but this lack of understanding is the heart of my question. My idea is to attack black's queensdie majority in hopes of creating a weakness. i thought this was called a minority attack.

Five is a disturbed mind.

Keep him away from those swords.

After 3 Nf3 and 3 e4  the third most common move for white in the QGA is 3 e3 and my database says it actually scores better than 3 Nf3 but not as good as 3 e4 .  I prefer 3 e4 myself ... 

3.e3 isn't best, but it's perfectly fine for White as long as you know the resulting lines.  As for the line 3...Nc6?! 4.Bxc4 Bf5?!, you can also play 5.Qb3, attacking both the pawns on f7 and b7.  I can see either square being fine for the knight, although I myself would probably place it on f3 sometime after playing Qb3, as after Black plays e6, the e5 square is weak and ripe for the picking after Qxb7, while there's no pin to worry about with the knight against the queen (and it would lose a tempo anyway).  Besides, anyone who plays 3...Nc6 against e3 probably doesn't know how to play the QGA well anyway, although it is certainly playable against e4.

You can't give a move a question mark unless it's a bad move.

What do you guys think about 3. Nc3? Be gentle...I've only played for about a year.

3,Nc3 can be sharp especially if White plays a real gambit after 3...a6 4.Nf3 b5 5.e4. 3,Nc3 a6 4.e4 b5 5.a4 can also be sharp. 

6 out of the first 11 posts were by Fiveofswords.

Excellent help as always. I have a lot to look at now.

I do not agree that e3 gives black that many more interesting options nor do i agree that it is worse then Nf3.  It is a matter of what system you rather play against with white. 

• e3 allows e5 where white allows an isolated queenpawn for development and attacking changes.
• Nf3 allows the system with 4. ... Bg4 that is pretty solid and can lead to nimzo like play especially if black develops his dark squared bishop to b4 and exchanges of c3. 

In both the 3 e3 and 3 e4 lines black can play 3... e5 but this does not solve black's problems as white does very well in both lines .... Its just a matter of personal preference between 3 Nf3 , e3 , e4  and even 3 Nc3 has its fans as well ....