For a start, do you mean he plays this?
1. Nc3 d5 2. Nf3 Nf6 3. d4 e6 4. Bf4
Because what you have was impossible moves.
If that was the correct sequence, here's some thoughts.
To answer the question: No, you shouldn't be worried about Nb5. You could always play Bd6, for example. However, after Bf4 you should probably not play e6 a second time, as this violates the rules of chess. Instead, you could consider Bb4, pinning the Knight, with Ne4 ideas if he plays e3.
I agree with the poster who suggested 2...d4 as a refutation of White's opening idea. Especially against a weaker player, moves like this are likely to lead to them dropping material or losing time, and you gain plenty of space.
This seems to transpose into a Veresov attack. Study that a little bit and you should be fine. Like someone said before me Playing Nc3 before c4 is not a good position.
Like someone said before me Playing Nc3 before c4 is not a good position.
Will you prolong this statement to sicilian, vienna, pirc, scotch and petroff?
I am talking about Queen Pawn Openings.
@ Gambitking....
1. e4 e5 2. Nc3 Nf6 (or Nc6) 3. f4
must be more in your style surely ? But I liked that line too....
Here's two patzers messing around with 1.Nc3 d4. 
It was played in 2010, so the opening theory should be cutting edge stuff! 
Perhaps Ivanchuk was trying to avoid Wang Yue's astonishingly strong opening preparation. I've been using some of the ideas Wang Yue has introduced into modern play, and it's really buffed up some defenses, like the line 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nf3 Nc6 6.Bg5 dxc4 7.Bxc4 h6!
Perhaps Ivanchuk was trying to avoid Wang Yue's astonishingly strong opening preparation. I've been using some of the ideas Wang Yue has introduced into modern play, and it's really buffed up some defenses, like the line c
Oh my! Looking at your turn-based rating, you understand what these pros are doing. All I can do is drool and find it all simply amazing. 
What kind of opening line is 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nf3 Nc6 6.Bg5 dxc4 7.Bxc4 h6! It starts out as 100% B12: Caro-Kann Defense and then transposes into a Queen's Gambit. I've never seen that before. Cool!
It's the Panov-Botvinnik, which can result from a huge number of different openings.
No high rated player in the 4.5 million game ChessBase database plays 6.Bg5. Chess engines don't find Bg5 as one of the picks either.
In our Game Explorer, 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 is called B13: Caro-Kann Defense: Panov Attack.
One continuation is 4...Nf6 5.Nf3 Nc6 6.Nc3
6.c5 2 games
6.cxd5 2 games
6.b3, 6.Be3, 6.Bf4, 6.h3 6.Qb3 1 game each.
There's no continuation in Game Explorer with 6.Bg5.
@ cbgirardo - Have you seen 6.Bg5 played? Either way, thanks for sharing what looks like a fun opening to give a spin in blitz matches. 
Hello, im about 1400 in live and i have a friend who is about 1300. I know im better than him, however, he started to do an opening i cant seem to beat, and this makes his win ratio against me 1:1. When he's white, he opens with Nc3. Games explorer says d5 is best, but i seem to lose 70% of the time against my friend when he is white. this is what commonly happens:
1.Nc3 d5 2.Nf3 Nf6 3.d5 e6 4. Bf5
By now he seems to have a relatively strong grip on the middle, and generally has an advantage against me from here. Am i doing something wrong?
Also, what is the best way for a 1400 like me to improve overall, in all aspects of gameplay?