ReneDescartes wrote on 05/28/10 at 23:21:11:
@kylemeister
You must realize that a lot of White's strategic advantage in the QGD, even the Exchange, stems from the difficulty Black has in developing his queen's bishop satisfactorily. If Black can do that with impunity, he is equal.
After 1.d4 d5 2.c4 e6 3.cxd5 exd5 Black can just play 4...Bf5 straight away, instantly solving this major strategic problem. White's only attempt to exact a price for this is 4.Nc3 Bf5 5.Qb3, which hits d5 and b7. But 5...Nc6! defends tactically (the threat is ...Nxd5 double-hitting c2), e.g. 6.Qxb7?! Nxd4 or 6.Qxd5?! Qxd5 7.Nd5 O-O-O and ...Nxd4, or 6.Nxd5? Be4 and ...Nxd4. So White has nothing better than 6.Nf3 Bb4 (Speelman-Short, Hastings 1989), and Black has at least equalized, with active pieces in return for his blocked c-pawn.
Yet if White doesn't force things with Qb3, then he had better play Bd3 and let Black exchange bishops, else the escapee on f5 will be more active than his own piece. And with that, the game will again be at least equal for Black.
That is why in the good versions of the Exchange White waits until move 3 or 4 to capture on d4. After 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5, the freedom of Black's bishop is only optical, because if 5...Bf5? then 6.Bxf6 and if then Qxf6? Nxd5. Or in that line if 5...Be7 6.e3 Bf5?, then 7.Qb3 really does win a pawn--and so on.
If you did not know about 4...Bf5, you probably also do not know the following, and someone ought to tell you: White cannot play the Exchange with advantage after 2.Nf3 or 3.Nf3 or 4.Nf3 either. The plan Markovich described above (with ...g6 and ...Bf5) again allows Black to solve his bishop problems there.
No, after Nf3, White must play other main lines of the QGD to try for advantage, lines which constrain the black bishop by NOT exchanging. These are fine for White, but more work than the Exchange to prepare.
All of this is undoubtedly in these pages many times over, and we would be off the topic of the Noteboom, except that these are just the reasons why the Triangle System has the virtue of avoiding (all but the harmless lines of) the QGD Exchange.
But only a quick Bf5 does not solve black's problems.
Compare with the common 1. d4 d5 2. c4 e6 3. Nc3 Be7 4. cxd5 exd5 5. Bf4 c6 6. e3 Bf5
Here white has normal chances of an advantage by Nge2-g3 h3,g4,h4 etc.
I suppose the difference is that here black needs an extra tempo to play Bd6, so Bd6 with extra tempo may really be the point.
Perhaps 1. d4 d5 2. c4 e6 3. cxd5 exd5 4. Nc3 Bf5 5. Bf4 c6 (5.. Bd6 6. Nxd5) 6.e3 Bd6
But now some interesting tries are 7. Qb3!? Bxf4 8. Qxb7, 7. g4!?, 7.Bxd6 Qxd6 g4