Ivan Sokolov has played the Deferred Cozio a couple of times in an ongoing tournament:

[Event "MP Reykjavik Open 2011"]
[Site "Reykjavik City Hall"]
[Date "2011.03.11"]
[Round "3.3"]
[White "Grover, Sahaj"]
[Black "Sokolov, Ivan"]
[Result "0-1"]
[ECO "C70"]
[WhiteElo "2495"]
[BlackElo "2643"]
[PlyCount "64"]
[EventDate "2011.03.09"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nge7 5. c3 g6 6. d4 exd4 7. cxd4 Bg7 8.
O-O O-O 9. Nc3 b5 10. Bc2 d6 11. h3 Bb7 12. Bf4 Na5 13. d5 Nc4 14. Qc1 b4 15.
Nd1 c6 16. dxc6 Nxc6 17. Bh6 N4e5 18. Nxe5 dxe5 19. Bxg7 Kxg7 20. Ba4 Nd4 21.
Qc5 Qg5 22. Ne3 Bxe4 23. Ng4 f6 24. Rae1 Qf4 25. Re3 h5 26. Nh2 Rac8 27. Qxb4
Rf7 28. Qa3 Bd5 29. Bd1 Rc1 30. Ba4 Qg5 31. g3 Rxf1+ 32. Nxf1 Qf5 0-1


[Event "MP Reykjavik Open 2011"]
[Site "Reykjavik City Hall"]
[Date "2011.03.14"]
[Round "7.6"]
[White "Friedel, Joshua E"]
[Black "Sokolov, Ivan"]
[Result "0-1"]
[ECO "C70"]
[WhiteElo "2529"]
[BlackElo "2643"]
[PlyCount "76"]
[EventDate "2011.03.09"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nge7 5. O-O g6 6. c3 b5 7. Bb3 Bg7 8. d4
exd4 9. cxd4 d6 10. h3 O-O 11. Nc3 Bb7 12. Re1 Na5 13. d5 Rc8 14. Bf4 Re8 15.
Qd2 Qd7 16. Bh6 Bh8 17. Qf4 Nxb3 18. axb3 b4 19. Na4 Rb8 20. Rad1 Nc8 21. e5
Na7 22. Re3 Nb5 23. h4 Qf5 24. Qxf5 gxf5 25. Nd4 Bxe5 26. Nxf5 Bc8 27. Ng7 Bg4
28. Nxe8 Bxd1 29. Rxe5 dxe5 30. Nf6+ Kh8 31. Nc5 Rd8 32. h5 Nd4 33. f3 Bxb3 34.
Ncd7 Bxd5 35. Bf8 Be6 36. h6 Nf5 37. g4 Bxd7 38. g5 Rxf8 0-1

@ MNb

Sorry if I was less than clear -- it was just that after 3 ...a6 4 Ba4 Nge7 5 Nc3, I wasn't assuming 5 ...g6. I was speculating about [b]5 ...d6[/b] instead (see Reply #13), when (in contradistinction to after 3 ...Nge7 4 Nc3 d6 5 d4) 6 d4 can be met by ...b5 (for whatever that may be worth). 


@ MartinC, Schaakhamster

From a theoretical viewpoint I'm interested in all variations, but from a practical point of view I very much agree with both of you. And so, judging from the games below, does Arkhipov! How about 4 Nc3 [b]Ng6[/b]? --


Kupreichik-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 exd4 6. Nxd4 Bc5 7. Nb3 Bb6 8. Nd5 O-O 9. O-O d6 10. a4 Qh4 11. a5 Bg4 12. Be2 Bxe2 13. Qxe2 Nd4 14. Nxd4 Bxd4 15. Nxc7 Rac8 

Lanka-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 Bb4 6. O-O Bxc3 7.bxc3 d6 8.Bg5 f6 9. Be3 O-O 10. Qd3 Kh8 11. a4 Na5 12. Qd2 Be6 13. Rfb1 b6 14. h4 Ne7 15.Nh2 Bc4 

Ulibin-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 exd4 6. Nxd4 Bc5 7. Nb3 Bb6 8. Nd5 O-O 9. O-O d6 10. a4 Be6 11. Qd2 a6 12. Nxb6 cxb6 13. Be2 d5 14. exd5 Bxd5 15. c4 Be6 

Berelovich-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. O-O Bc5 6. Na4 Be7 7. Bxc6 bxc6 8. d4 f6 9. Qd3 O-O 10. Qc3 Rb8 11. a3 Qe8 12. Nc5 d6 13. Nb3 f5 14. Qc4+ Qf7 15. Qxf7+ Rxf7 

Mainka-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 exd4 6. Nxd4 Bc5 7. Be3 Nh4 8. Bf1 Bxd4 9. Bxd4 Qg5 10. g3 Nxd4 11. gxh4 Qe5 12. Qd3 Ne6 13. Qg3 d6 14. O-O-O Bd7 15. Nd5 O-O-O 

Mainka-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 exd4 6. Nxd4 Bc5 7. Be3 Bb6 8. Qd2 O-O 9. O-O-O Nxd4 10. Bxd4 d6 11. h4 Bxd4 12. Qxd4 Nxh4 13. Qe3 Ng6 14. Qg3 c6 15. Rxd6 Qe7 

Margoline-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. d4 exd4 6. Nxd4 Bc5 7. Nb3 Bb6 8.O-O O-O 9. Nd5 d6 10. a4 Be6 11. Qd2 Nce5 12. Nxb6 axb6 13. Nd4 Bd7 14. Bxd7 Nxd7 15. b3 Nf6 

Bologan-A
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. Nc3 Ng6 5. h4!? Bc5 6. h5 Nf8 7. Nxe5 Nxe5 8. d4 Bd6 9. dxe5 Bxe5 10. f4 Bxc3+ 11. bxc3 Qe7 12. h6 Rg8 13. Qf3 a6 14. Bd3 d6 15. Ba3 Qf6.


Alas, in the last game here, after 16 0-0-0 the great Cozio warrior was finally downed. So is 5 h4 a serious, or even fatal, threat to this line? My first instinct was to meet it with 5 ...h6, which is what my strongest engine chooses after toying for ages with the complicated 5 ...Nd4!?. Hours of analytical fun could be had here! Do Sokolov or Kuzmin comment on any of this?

[quote author=36353F39580 link=1274532861/19#19 date=1276074296][quote]After some though: perhaps they aren't. After b5 the bishop get on a nice diagonal after Bb3. To my feeling black plays a6 too early.[/quote]

Do you mean you think 3 ...a6 4 Ba4 Nge7 5 Nc3 is actually worse than 3 ...Nge7 4 Nc3 (and if so why?), or is it 5 d4 or 5 0-0 which you believe pose the biggest threat to Black? After 5 0-0 Black needn't transpose to the Modern Steinitz but can play [b]5 ...g6[/b] heading for Palac-Arkhipov. On 5 d4 ed 6 Nd4 Nd4 7 Qd4, Moizes has successfully played [b]7 ...b5[/b] 8 Bb3 d6 -- but maybe this is the sort of position you were thinking of? There are alternatives, I guess: [b]6 ...b5[/b] 7 Bb3 Na5 immediately hunting the Bishop, or [b]6 ...Ng6[/b] intending ...Bc5. I've frankly no idea whether these are adequate. Wouldn't it be great to rescue Black from 3 ...Nge7 4 Nc3?

[/quote]

Well it is more of a general consideration. I don't think the deferred cozio solves the Nc3 problem so why bother unless you like to play against the exchange variation.

Also f7 is a bit of a soft spot in the cozio so unless there is some tangible advantage or black can cover it in a satisfying way I wouldn't "help" point the bishop toward f7.

[quote]After some though: perhaps they aren't. After b5 the bishop get on a nice diagonal after Bb3. To my feeling black plays a6 too early.[/quote]

Do you mean you think 3 ...a6 4 Ba4 Nge7 5 Nc3 is actually worse than 3 ...Nge7 4 Nc3 (and if so why?), or is it 5 d4 or 5 0-0 which you believe pose the biggest threat to Black? After 5 0-0 Black needn't transpose to the Modern Steinitz but can play [b]5 ...g6[/b] heading for Palac-Arkhipov. On 5 d4 ed 6 Nd4 Nd4 7 Qd4, Moizes has successfully played [b]7 ...b5[/b] 8 Bb3 d6 -- but maybe this is the sort of position you were thinking of? There are alternatives, I guess: [b]6 ...b5[/b] 7 Bb3 Na5 immediately hunting the Bishop, or [b]6 ...Ng6[/b] intending ...Bc5. I've frankly no idea whether these are adequate. Wouldn't it be great to rescue Black from 3 ...Nge7 4 Nc3?

[quote author=31010A0303090A030F11160710620 link=1274532861/16#16 date=1276007754]Well you'd be entering virgin theory country. The Cozio is quite light on theory, on the Cozio Deferred I haven't found anything and there are precious few games to be found.[/quote]

De Opening 11C by Euwe/Samarian mentions this: 4...Nge7
a) 5.d4 exd4 6.Nxd4 Nxd4 7.Qxd4 Nc6 8.Qd3 "and White stands well".
b) 5.0-0 d6 6.c3 Bd7 "transposing to the Neo-Steinitz".

In my games there are exactly no games to be found.

I wonder how Black's chances after 3...a6 4.Ba4 Nge7 4.Nc3 are improved compared to 3...Nge7 4.Nc3.

In practical terms I understand (and take) this point completely (though I'm not sure about the 'awkward and unnatural' bit ...). Logically though, there's no reason why the deferral of ...Nge7 should be any more of a barrier to exploration than that of ...Nf6 should -- in each case it's the validity of the move that's what matters.

What might make the (Deferred) Cozio more attractive for some is that, unlike with some other Deferred anti-Spanish systems, the 'deferring' move ...a7-a6 might be played on moves 4, 5 or even later, when the Nc6 is guarded by the Ne7. People will have their own subjective takes on this. My own is that the 3 ...Nge7 4 Nc3!? variation is hugely daunting, for the reason you imply: avoiding this means playing ...a6 on move 3. But the Deferred Cozio remains interesting. And who knows, maybe an antidote will be found to 4 Nc3.

Interesting! Does Sokolov give the same line as me against ...a6, then, and, since he says the Cozio doesn't equalise, does he include the Deferred line in this judgement or exempt it? I'm guessing the former since otherwise you'd think he'd recommend ...a6 at move 3 rather than later! Obviously an early Nc3 (S's route to a White advantage?) is possible after 3 ...a6 4 Ba4 Nge7 too, but the positions are different. When I last looked I thought the critical line might be 5 Nc3 d6!? 6 d4 b5 7 Bb3 Nd4 8 Nd4 ed 9 Qh5 (9 Qf3 Be6) Ng6, but I wasn't sure.

And what is Kuzmin's take on this?