Ametanoitos wrote on 08/19/11 at 14:52:10:


3.Nc3 makes sense if White does want to play the 5.Bg5 Semi-Slav lines while having the option to play the Marshall Gambit against the triangle (3.Sc3 e6 4.e4). Using the 3.Nf3 move order eliminates the "Extra-slav" 3.Nc3 dxc4, but the Marshall-Gambit, too. An if you play 3.Nc3 against the QGD, you need an additional variation against the triangle with 2.c4 e6 3.Sc3 c6

Hi! its my first message in this forum. Im 2200 rated player and im studying the Slav from Vigus book. I also have the problem of "what to play against 3Nc3" (I really dont like lines with 3...dxc4 despite Vigus excellent book) and im watching lines with 3Nc3 Nf6 4e3 Bf5. The most critical is 5 cxd5 cxd5 6Qb3. Now 6...Bc8 is a version of the exchange variation where white has a bishop on c1 and not in f4. Maybe black can equalize despite the ugly manouvre Bc8-f5-c8. I am also watching the gambit 6...Nc6 (thanks for this interesting suggestion!). If its ok i surely play that instead of 6...Bc8!
Anyway its  strange that 4...Bf5 is played seldom...there are not many games to see

Yes there is. This was the continuation of the game i mentioned. Black played 13...Bc5. Take a look at the position and the difference of the development of the two Armies. Also White's one extra pawn is the one at c3, not exactly the definition of a "healthy" pawn. 

Anyway, after 14.Nd4 O-O 15.Be2 Black is fully mobilized, White is not, that's why after 15...Nxd4 16.Qxf6 Nc2+ 17.Kd2 gxf6 18.Kxc2 Rfd8 my assesment that Black is at least not worse probably becomes more clear to you. White held the draw in that corr game, but in a practical game White's task would be far more difficult.

In the corr game Grifoll-Glinz, 2008 Black got the better position after 8.a3 (in general this move looks necessary) 8...Rb8 9.Qa6 e5 10.dxe5 d4. My analysis indicates that Black is at least not worse here. I haven't see any other source where this game is analysed.

4...Bf5 5.cxd5 cxd5 6.Qb3 Nc6! 7.Qxb7 Bd7! with excellent play for Black! Check it 

ErictheRed wrote on 08/19/11 at 16:24:19:


What about 5. cxd5 Nxd5? How should white follow up? I ran into this for the first time recently.

I agree that calling 4...Bf5 dubious is unfair; while I still consider White's position comfortable, I wouldn't label it more than +=. And of course, if you play 6 games and end up with no advantage in any of them, it's very understandable that you choose to switch to the Dutch.

I certainly consider myself lucky, as I have met 4...Bf5 three times against three different opponents, but all of them played 6...Qd7? which is probably just lost. My guess is that all of them were unaware of the difference between the Nc3/e3 and the Nf3/e3 lines, and just assumed they would transpose.

Of course, an alternative is to meet 4...Bf5 with 5.Nf3, transposing to the Nf3/e3 system. It might seem irrational to play 3.Nc3 with that intention, but it makes sense if you plan to play the Marshall against the Triangle (3...e6), and/or if you want to play 3...Nf6 4.e3 a6 5.Qc2.

As a long-time 3.Nc3 player, my opinions on ErictheRed's six points are as follows:

1.-4. Agreed.

6. (as will become apparent, it is easier to reply to 5. when I have replied to 6.) I have never met this myself, but I always thought the plan Nf3, Ne5, f4, Bd3, 0-0 (in some order) was thought to give White a comfortable edge. White's c1-bishop is shut in, but so is Black's c8-bishop, and White simply seems to enjoy an easier game with a strong knight on e5 and good attacking chances on the kingside. True, Nc6-Na5 should probably be answered by Qd1, but the knight doesn't look very strong on a5 afterwards.

5. Following the above reply to 6., the most natural response to 4...Bg4 would be 5.f3 Bf5 6.cxd5 cxd5 7.Qb3 Bc8 8.f4 followed by Nf3-Ne5, which would be a direct transposition to the line above if White starts with 7.f4 there.