Thanks once again for another really helpful reply. Yes, I can see why the Bg5 plan could be good for White against Black's 8 ...b5/9 ...ba. Also the 10 ...Nb4 line still looks a bit shaky to me, though I've looked at it only superficially.

Interesting that Iordi doesn't discuss the plan of delaying ...b7--b5. I can see why this might look a bit iffy, but after looking at it a bit in conjunction with Fritz I've come to think that it's quite hard for White to keep control and at the same time make progress. The whole system strikes me as interesting. Anyone else got any thoughts on the "Varga Variation"?

I took another look at this late last night/today. I felt that the 10 ...0-0 11 a4 line is indeed a bit better for White. I was tempted to think the same about the 9 ...0-0 10 d5 Nb4 line -- does Iordi say this is equal, or does he think White has an edge here too?

I haven't had time to explore the "Varga Variation", 7 ...ed 8 cd 0-0 9 d5 Na5!?, particularly thoroughly, but it looks very interesting. The main idea seems to be to delay ...b5 until White has committed his Queen's Knight and/or Black is a bit more mobilised and thus better placed to meet a2--a4. 10 Nc3 looks critical and perhaps the main line now is 10 ...d6 11 Re1 b5 12 Bc2. Here Mozes has played 12 ...Bb7!?, Klaric 12 ...c5!? and Franciscs 12 ...h6!?, while "old fox" Murey has won with 12 ...Nc4!? (best?). Does Iordi discuss this? Perhaps he respects it, since otherwise he could have transposed into it with 11 Nc3 instead of his 11 a4!

Apart from this, the lines for Black that I felt looked soundest were 7 ...ed 8 cd b5 9 d5 ba 10 dc Nc6, and 7 ...b5 8 Bc2 ed 9 cd d5!? (also reached of course via 7 ...ed 8 cd b5 9 Bc2 d5). What does Iordi say about the first of these? Does he discuss the second? And what do you (or others) think?

[quote author=Michael Ayton link=1141784971/0#7 date=1142442295]Very interesting, kylemeister -- thanks!

I'd actually seen this game, but hadn't considered the implications of Iordachescu's 11 Bd2 idea! My first thought (and question) is: does Iordachescu give a line that's advantageous for White after 10 ...0-0? This, I believe, is more common than 10 ...d6 here, partly because the position is often reached via move orders such as 3 ...Nge7 4 0-0 g6 5 c3 a6 6 Ba4 Bg7 7 d4 ed 8 cd, and now 8 ...0-0!? 9 d5!? (9 Nc3 b5 10 Bb3 d6 would transpose to the older line) b5!? 10 Bc2 Na5. I assume the point of I's 11 Bd2 is to sac the exchange with 11 ...Bb2 12 Bc3, but does this work if Black has castled instead of having played ...d6?

My second, related ‘solution’ would be again to adopt the 7 …ed 8 cd 0-0!? move order, but to meet 9 d5!? with 9 …Na5!?, which Varga has played a lot. Now 10 Nc3 and 10 Nbd2 seem invariably to be played. I’m not sure why 10 Bc2 might be bad, but in response -- in case I’s idea does work if Black has castled -- Black might have options other than 10 …b5 transposing to the above.

My third question is, after 7 …ed 8 cd b5, why can’t Black meet 9 d5 with 9 …ba? This seems never to have been played. What’s wrong with it?

A fourth idea might be to defer …exd4 until White has played Ba4--c2. This might give Black additional options. For example, 7 …b5 8 Bc2 ed 9 cd d5!? (9 …0-0 10 d5 Na5, as played by Arkhipov, transposes to my first line) has been played once or twice, and might be OK?

There might, earlier, be some subtle move order whereby Black can time …b7--b5 such that Ba4--c2 isn’t critical or dangerous, but if so I haven’t yet seen it. But does Iordachescu comment on any of the lines I’ve mentioned? -- if so I’d love to hear what he says.
[/quote]

Well, Iordachescu doesn't mention 11. Bd2 after 10...0-0 (instead of 10...d6).  He gives instead 11. a4, leading to a slight advantage for White. 

As for 9. d5 ba, he thinks that is as good for Black as anything (i.e. it should lead to a slight advantage for White).

In the position after e.g. 9. Bc2 (instead of 9. d5 as played) 0-0 10. d5, Iordi suggests 10...Nb4 11. Bb3 a5.

BTW, I'm still waiting to see if Mamedyarov plays your "predicted" ...exd4 line in the Neo-Steinitz.  Perhaps he is taking a break from the N-S; he played some other Ruy line in Iceland a week or so ago.   

[quote author=Michael Ayton link=1141784971/0#0 date=1141784971]Is there anything wrong with the Deferred Cozio, I'm wondering. I'm not sure one shouldn't just speak of the Cozio, since the positions I've been looking at are reached via 3 ...Nge7 just as often as via 3 ..a6 first. A common move order (and there are many, giving both sides interesting options) is 3 ...Nge7 4 0-0 g6 5 c3 Bg7 6 d4 ed 7 cd a6!? (instead of the usual 7 ...d5) 8 Ba4 b5 9 Bb3 0-0 (9 ...Na5 intending a quick ...d5, or to transpose, is also played). Now NCO (p. 331/n. 1) just gives 10 Nc3 as slightly better for White, but I'm not sure praxis has borne out this assessment. The main line seems to be 10 ...d6 11 h3 Na5 12 Bc2 b4 13 Ne2 Bb7 14 Ng3 c5 15 a3 ba or ...cd; but 12 ...Bb7 is played too, while 12 ...c5 and 12 ...d5 have also been seen. Players of the calibre of Varga, Arkhipov and Korneev have done really well with this system! Is this then an underestimated line (as opposed to just a tricky one)? Does Khalifman have anything to say about it?[/quote]

I notice that the current Informant has a game (Iordachescu-Sofronie, Romania 2005), in which 9. d5 "!N" (instead of 9. Bb3) was played.  According to Iordachescu's notes, it should lead to a slight advantage for White.

"of course 6 ...Nge7 is possible but seems a bit thankless"
According to Euwe this is playable after 7.Nxd4 d5!
He also thinks 3...a6 4.Ba4 g6 and Nge7 both imprecise because of 5.d4.
Of course his judgment is of a very long time ago and it might be worth the effort to dive in this stuff.

Hi MNb! I would have replied before but at present I'm having difficulties renewing my subscription! -- the technology isn't accepting my card. I'm sure I'll crack it in a few days' time.

I had thought that 3 ...Nge7 4 Nc3 g6 5 d4 ed 6 Nd5 Bg7 was playable after 7 Bg5 h6 8 Bf6 Bf6 9 Nf6 Kf8 10 Nd4 (not the only move, I guess) Nf5. Am I wrong, or can White improve here? (Either way, do you think 4 ...Ng6 is reliable?)

I'd play 3 ...g6 willingly were it not for the line 4 d4 ed 5 Bg5 Be7 6 Be7 Qe7 (of course 6 ...Nge7 is possible but seems a bit thankless) 7 Bc6 dc 8 Qd4 Nf6 9 Nc3! Bg4 10 0-0 Bf3 11 gf 0-0. Isn't White a bit better here after both 12 Qe3 and 12 f4? I've sometimes wondered if this variation can be improved for Black by the insertion of ...a6/Ba4, hoping there's some line where Qd4xa7 would have been possible but now isn't, but I suspect there isn't one!

I've lots more thoughts about the Delayed Cozio, which I'll post as soon as I regain my membership!

Michael Ayton

Is there anything wrong with the Deferred Cozio, I'm wondering. I'm not sure one shouldn't just speak of the Cozio, since the positions I've been looking at are reached via 3 ...Nge7 just as often as via 3 ..a6 first. A common move order (and there are many, giving both sides interesting options) is 3 ...Nge7 4 0-0 g6 5 c3 Bg7 6 d4 ed 7 cd a6!? (instead of the usual 7 ...d5) 8 Ba4 b5 9 Bb3 0-0 (9 ...Na5 intending a quick ...d5, or to transpose, is also played). Now NCO (p. 331/n. 1) just gives 10 Nc3 as slightly better for White, but I'm not sure praxis has borne out this assessment. The main line seems to be 10 ...d6 11 h3 Na5 12 Bc2 b4 13 Ne2 Bb7 14 Ng3 c5 15 a3 ba or ...cd; but 12 ...Bb7 is played too, while 12 ...c5 and 12 ...d5 have also been seen. Players of the calibre of Varga, Arkhipov and Korneev have done really well with this system! Is this then an underestimated line (as opposed to just a tricky one)? Does Khalifman have anything to say about it?