It seems that  the leading theoritical player Kotronias is playing the Tarrasch defense!
(Something strange happened in the recent World team Championshipswith the Greek team  when they defeated Russia and Armenia but lost to Egypt for example and Kotronias who is a KID expert played the Tarrasch and GM Halkias who is a Tarrasch expert played the KID! )

So, maybe we can start discussing this defence again? He played 3 games scoring just 1 point (2 draws) but he got a minimal advantage in the two of them and the other was against Aronian! Here are the games (with some light annotations):

[Event "WchT 7th"]
[Site "Bursa"]
[Date "2010.01.05"]
[Round "1.1"]
[White "Sasikiran, Krishnan"]
[Black "Kotronias, Vasilios"]
[Result "1/2-1/2"]
[ECO "D34"]
[WhiteElo "2653"]
[BlackElo "2599"]
[PlyCount "65"]
[EventDate "2010.01.05"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "TUR"]
[Source "ChessBase"]
[SourceDate "2010.01.18"]
[WhiteTeam "India"]
[BlackTeam "Greece"]
[WhiteTeamCountry "IND"]
[BlackTeamCountry "GRE"]

1. d4 d5 2. c4 e6 3. Nf3 c5 4. cxd5 exd5 5. g3 Nc6 6. Bg2 Nf6 7. O-O Be7 8. Nc3
O-O 9. Bg5 c4 10. b3 cxb3 11. axb3 (11. Qxb3 Na5) 11... Bf5 12. Bxf6 Bxf6 13.
e3 Nb4 14. Qd2 a5 15. Rfc1 Rc8 16. Ne1 Be7 17. Na4 Qd6 18. h4 b6 19. Nc3 Qd7
20. Bf1 Bd6 21. Na4 Rb8 22. Rc3 g6 23. Rac1 Rfe8 24. Ng2 Be4 25. Nf4 Qf5 26.
Bh3 Qf6 27. Bg2 Bxf4 28. exf4 Bxg2 29. Kxg2 Kg7 30. Re3 Re4 (30... Rxe3 31.
Qxe3 Rb7 32. Qe5 b5 33. Nb2 Ra7) 31. Nc3 Rxe3 (31... Rxd4 32. Qe2 Rd8 33. Na4
Rd6 34. Re8 Re4 35. Rxe4 dxe4 36. Qxe4 Qd8) 32. Qxe3 Rc8 33. h5 1/2-1/2

[Event "WchT 7th"]
[Site "Bursa"]
[Date "2010.01.07"]
[Round "3.1"]
[White "Adly, Ahmed"]
[Black "Kotronias, Vasilios"]
[Result "1-0"]
[ECO "D34"]
[WhiteElo "2591"]
[BlackElo "2599"]
[PlyCount "162"]
[EventDate "2010.01.05"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "TUR"]
[Source "ChessBase"]
[SourceDate "2010.01.18"]
[WhiteTeam "Egypt"]
[BlackTeam "Greece"]
[WhiteTeamCountry "EGY"]
[BlackTeamCountry "GRE"]

1. d4 d5 2. Nf3 c5 3. g3 Nc6 4. Bg2 Nf6 5. O-O e6 6. c4 Be7 7. cxd5 exd5 8. Nc3
O-O 9. Bg5 c4 10. Ne5 Be6 11. e3 Nd7 12. Nxc6 bxc6 13. Bxe7 Qxe7 14. b3 Nb6 15.
Qc2 Rab8 16. Rfc1 Rfc8 17. bxc4 Nxc4 18. Na4 g6 19. Bf1 Rb4 (19... Bf5 20. Qc3
Nd6 21. Qa3 (21. Nc5 Ne4) 21... Rc7 22. Bd3 (22. Nc5 Rb6) 22... Bxd3 23. Qxd3
Nc4) 20. Nc5 Qf6 21. Qc3 Rcb8 22. Bxc4 (22. f4 Bc8) (22. Na6 Rb2 23. f4 R8b6
24. Nc5 Nd2 25. Bg2 Nc4 26. Bf1 Nd2) 22... Rxc4 23. Qd2 Bh3 24. Nd3 g5 (24...
Qf3 25. Ne1 Qf5) 25. Rxc4 dxc4 26. Ne5 c5 27. Rc1 Rd8 28. Qc3 Rd5 29. Qb2 Kg7 (
29... cxd4 30. exd4 Rd6) 30. Qb7 Qe6 31. Qb2 cxd4 (31... f6) 32. exd4 Qf6 33.
f3 Be6 (33... c3 34. Qxc3 Qb6) 34. Rxc4 Ra5 35. Qd2 Rd5 36. Rc2 Qd8 37. Nc6 Qb6
38. a4 h6 39. a5 Qb3 40. Kf2 Qa4 41. Qc3 Kh7 42. Rb2 Qa1 43. Qc2+ Bf5 44. Qb3
Rd7 45. g4 Bg6 46. Ne5 Rc7 47. Nxg6 fxg6 48. Qb4 Qh1 49. Qd6 Rf7 50. Rb3 Qc1
51. Qe6 Qd2+ 52. Kg3 Qf4+ 53. Kh3 Rg7 54. Qe3 Qc7 55. Rb5 Re7 56. Re5 Rxe5 57.
Qxe5 Qc6 58. Qe7+ Kg8 59. Qe4 Qa6 60. Kg3 Kf7 61. Qd5+ Ke7 62. Kf2 Qc8 63. Qe4+
Kf7 64. Kg2 a6 65. Qe2 Qc6 66. Qd3 Qd6 67. d5 Ke7 68. Qd4 Kf7 69. Kf1 h5 70. h3
Qg3 71. Qa7+ Kg8 72. Qa8+ Kh7 73. Ke2 Qxh3 74. Qa7+ Kh6 75. Qg1 hxg4 76. Qxg4
Qh2+ 77. Kd3 Qa2 78. Qd4 Qb1+ 79. Ke2 Qc2+ 80. Ke3 Qc1+ 81. Kf2 g4 1-0

[Event "WchT 7th"]
[Site "Bursa"]
[Date "2010.01.10"]
[Round "6.1"]
[White "Aronian, Levon"]
[Black "Kotronias, Vasilios"]
[Result "1/2-1/2"]
[ECO "D30"]
[WhiteElo "2781"]
[BlackElo "2599"]
[PlyCount "98"]
[EventDate "2010.01.05"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "TUR"]
[Source "ChessBase"]
[SourceDate "2010.01.18"]
[WhiteTeam "Armenia"]
[BlackTeam "Greece"]
[WhiteTeamCountry "ARM"]
[BlackTeamCountry "GRE"]

1. d4 d5 2. c4 e6 3. Nf3 c5 4. cxd5 exd5 5. Bg5 Be7 6. Bxe7 Qxe7 7. Nc3 Nf6 8.
dxc5 Qxc5 9. e3 O-O 10. Be2 Nc6 11. O-O Rd8 12. Rc1 Qb4 13. Na4 Bg4 14. a3 (14.
Rc5 Rac8 (14... Bxf3 15. Bxf3 Ne5 16. Be2 (16. Bxd5 Rxd5 17. Rxd5 Nxd5 18. Qxd5
Qxa4 19. Qxe5 Qxa2) 16... b6)) 14... Qe7 15. Re1 Rac8 16. h3 Bh5 17. Nc3 h6 18.
Nd4 Bxe2 19. Rxe2 Ne4 20. Rec2 Qe8 21. Nce2 Ne7 22. Rc7 Nd6 23. Nf4 Rxc7 24.
Rxc7 Rc8 25. Qc2 Qd8 26. Rc5 Nc4 27. Rxc8 Qxc8 28. Qc3 Nb6 29. Qb4 Qc1+ 30. Kh2
Nc6 31. Nxc6 bxc6 32. Nh5 Nc4 33. Qb8+ Kh7 34. Qf8 (34. Qxa7 Qxb2 35. Qxf7 Nxa3
) 34... Qxb2 35. Qxf7 Qe5+ 36. Nf4 Nd2 37. Qg6+ Kg8 38. Qxc6 Nf1+ 39. Kh1 Qa1
40. Qxd5+ Kh7 41. Qd3+ Kg8 42. g3 Nxe3+ 43. Kh2 Nd1 44. h4 Nc3 45. Qd8+ Kh7 46.
h5 Qb2 47. Qd4 Qxa3 48. Qd3+ Kg8 49. Nd5 (49. Qc4+ Kh7 50. Qf7) 49... Qd6
1/2-1/2

There was also an article by IM Watson giving a solution to Avrukh's line: http://chess.co.uk/twic/jwat91.html. So the critical lines now are those by Schandorff (i don't know them. Can someone post the main line?) and if i remember correctly a series of CBM articles by GM Grivas proposing some Bf4 lines. I suppose that Kotronias has found a solution to them! . Maybe we can try?

Sandman, I've seen those responses at my level also.  I think your approach with 4...d4 is probably best, though I'm not sure that 4...Bxc5 or even 4...Nf6 are all that bad.  I didn't see the line in Aagard's book either, although one move later (after 4 cxd5 exd5 5 dxc5 he points out that 5....d4 was Tarrasch's justification for the whole defense).  If you read Abby Marshall's Chesscafe column, she stresses that you should push that d pawn when you can so I expect your approach is the way to go.  As an aside, although I know Aagard's book is the Tarrasch bible I actually find Schiller's book (can't believe I'm saying that) on Complete Defense to Queen's Pawn Openings a more user friendly book for people new to the defense.

In the other line, I would just follow Aagard's line in chapter five, looks pretty easy to play for black to me.

What i find unique about the Tarrasch is the nature of White's advantage.  In the QG White is accustomed to an advantage in space, in piece activity, and often initiative-- all of which Black has chances to neutralize in the Orthodox QGD lines.  In the Tarrasch, Black has those advantages-- not White-- and White must uncharacteristically and patiently sit on a structural advantage instead.

The big problem with the Tarrasch-- and this is quite a huge problem-- is that Class D players as White can (and do) wheel out the "Schlecter" mainline on robot-mode.  Black really has to outclass White significantly to win from there-- moreso than say the KID where the mainline paths are not so narrow and White has more rope with which to hang himself.  If White players did not know the theory and had to improvise at the board, then Tarrasch would be a devastating weapon indeed, IMO!!  But alas this is an age of information overload re: opening theory.

I tend to think Black has the greater middlegame chances in the Tarrasch QGD (not in the endgame obviously).  Even then, a 4 vs 3 rook endgame is usually an easy draw (ie, if Black gets in h7-h5)-- 4v3 can be reached if the Q-side pawns are exchanged and Black loses the IQP, leaving 4v3 on the K-side.

Schiller's book on Q-Pawn repertoire for black is a useful starting point-- probably his best book, and actually a good one among his dozens of horrible ones.

Just Read in one of Kasparov's books about him playing Karpov that he thinks Bg5 is best!!  And went on to say the b3 for example rather then Bg5 was no problem for him Theoretically.   
Zatara

I always thought that Schandorff's recommendations were quite good. I have never investigated them really closely, but I like the Qa4 idea. I currently have a CC game where Black played 10. Bg5 h6 11. Be3 Be6!?, but I think White is probably a bit better after this move as well.

I was always under the impression that 9. dxc5 was equal for some reason, until Avrukh went with it and worked to show +=. Avrukh went with 9.dxc5 only because he had nothing to show after 9. Bg5 c4.

Aside from that, I play 9. Bg5 and follow Schandorff's recommendation against 9...c4 since Schandorff produced an improvement over the reason Avrukh cited for not giving 9. Bg5, and the rest is Khalifman holdovers from OFWAK 5 (Khalifman's recommendation against 9...c4 is 10. Ne5 Be6 11. e3!?, which should be pretty much equal with energetic play from black).

I'll second what alumbrado said - it's the Tarrasch Defense, black always has a measure of counterplay, the question is always whether or not it's enough to overturn the += evaluation due to structural defects. White's += only turns into +/- when black's counterplay goes away altogether, since it's the only thing that keeps him in the game.

It is definitely not a defense where black accepts a structural flaw with the intent to passively defend.

Hello,

Do you think that White has a route to an advantage against the Tarrasch (1.d4 d5 2.c4 e6 3.Nc3 c5)? If so, which line in particular? When I first studied this opening many years ago I thought that both 9.Bg5 and 9.dc5 give White an advantage, but Black always seems to find counterplay in each line.