I'd like to compare three lines that have some similarity:

A) Accelerated Ragozin
1. d4 d5 2. c4 e6 3. Nc3 Bb4
B) Flear/Tan variation
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cd5 ed5 5. Bg5 Bb4
C) Ragozin/Vienna
1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3 Bb4 5. cxd5 ed5 6. Bg5


A) Accelerated Ragozin: 1. d4 d5 2. c4 e6 3. Nc3 Bb4
White has a lot of flexibility here, including 4.cxd exd. However, one thing he cannot do is to pin the Black king knight.



B) Flear/Tan variation: 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cd5 ed5 5. Bg5 Bb4
White pins the Black knight and has a choice of continuations.


C) Ragozin/Vienna: 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3 Bb4 5. cxd5 ed5 6. Bg5
This is the same as B, if White were to play 6.Nf3.

My rankings (for Black) would be C, then B, then A. However, the analysis provided by Flear and Tan suggests that line B is playable, with some complicated lines. Line A may be playable too but is my least preferred.

I made some posts elsewhere, but should they should have been made here.

GM Justin Tan, ChessPublishing April 2022, covers the game Bok, B. (2624) Abdusattorov, Nodirbek (2661) which commences:
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cd5 ed5 5. Bg5 Bb4.

Michael Roiz's includes this part 2, QGD Exchange variation, for Modern-Chess. (I would wait for a sale before purchasing).

Flear and Tan each provide plenty of analysis. All that remains is to go through it! I combined their analysis in one Chess Opening Wizard Ebook so that I can see where they deviate and add my own analysis.

Holy patronising attitude!

1) Yes, I'm aware that without Nf3 W can play Nge2 - a highly instructive observation. But with Bb4 W can't get his traditional Botvinnik set up v QGD - or maybe he can, but B has ...Bf5 options, so the game is different.

2) As you say, 5.e3 is a legal move. Well spotted! Anything wrong with it? No. You could also ask why does W shut his QB in with 4.e3 v. the NID. Surely B players should be aware of this possible transposition?

3) "The older classical lines with ..Be7 have been supplanted..." - notice the 's' at the end of the word line. It's plural - therefore have is correct. Then again, you are an American.

The difference with 3.Nc3 Nf6 4.cd ed 5.Bg5 Bb4 is that W hasn't played Nf3 - but I'm not sure if this makes a great difference. B should also be prepared for 5.e3 transposing into a Nimzo-Indian (E50-59) although B is okay there.
I've never trusted 4...Nd5 5.e4, I think W has an edge. Generally the Semi-Tarrasch is arrived at via 4.Nf3 Be7.
Flear may be right! The older classical lines with ...Be7 have been supplanted by the preference of SuperGMs for ...Bb4 lines. After 5.Bg5 Bb4 6.Qc2 is an acceptable line of the Nimzo-Indian (as someone pointed out.) It's playable.

Reverse wrote on 04/20/10 at 19:33:39:


One issue there is that 5. e3 (not committing the knight to f3 yet) Bb4 is standardly considered better for White, as far as I know.

@Markovich something strange with your move numbering there, I suppose?

Regarding White's 6th move alternatives after 4.cxd5 exd5 5.Bg5 Bb4:
6.Qc2 is a direct transposition to a sharp main line of the 4.Qc2 Nimzo-Indian.
6.e3 is also one of Flear's main lines where he recommeds the sharp 6...h6 7.Bh4 g5 8.Bg3 Ne4.
6.Qa4+ gets a brief mention, referencing Djuric-Efimov, Cutro 2002.

And yes, even if Flear's line is playable 4.Bg5 seems to be a big problem for a Ragozin/Bb4 repertoire. But I'm only now discovering this, and it's a bit disappointing...

@RubenKuijper Why are you so certain that 4.cxd5 is the more accurate Exhange move order? I'm currently finding 4.Bg5 much more annoying from the Black side, as explained above!

Viking wrote on 06/18/09 at 09:01:02:

Yes, and 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 seems to be the critical move-order. Altough black can try to get this position 1.d4 d5 2.c4 e6 3.Nc3 Be7