TN,

I hadn't gotten around to looking at 16.Kb1, a strong move.  I just now looked at it for a while, and I think my preference might be for 16...Bd7 17.b3 as in Kharlov - Popov, 2004 (a corr game, I believe, but am not sure).  However instead of 17...e5 as played, I recommend the prosaic 17...Qc7 and then 18.h5 Na7.  This transposes into Hermansson - Rytshagov, 2003 (I don't have a venue), where the position arose via 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e6 7.f3 Nc6 8.Qd2 Be7 9.O-O-O O-O 10.Kb1 Qc7 11.g4 b5 12.g5 Nd7 13.h4 Nde5 14.Qg2 b4 15.Nxc6 Nxc6 16.Na4 Rb8 17.h5 Bd7 18.b3 Na7.

Here a draw was strangely agreed after 19.Bd4; Black presumably would play 19...Nb5 with unclear relative prospects.  But say 19.g6 Nb5 (but not 19...h6 20.Bxh6!) 20.gxh7+ Kxh7 and it's all quite unclear to me.  I have no idea if Black's counterplay is sufficient, but at least he has some.  For instance, it appears that 20.Bxb5 axb5 21.Bg5 Bxg5 22.Qxg5 bxa4 is tenable for Black.  Or instead of 21.Bg5, 21.Nb2 Ra8 22.Nd3 Bf6 23.e5 Bxe5 24.Nxe5 dxe5 continues in an unclear vein.

I'd be interested to hear your thoughts.

Yes, but in all those opposite-castling Sicilians Black takes time with his piece play while White plays with his pawns. Black has the 'c' file, so he doesn't need to open lines against the King as White does. That's why White should be quick and losing time with piece play is not usual. But OK, who am i kidding? The position is so complex that giving such guidlines is just useless. I agree with your criticism over my comments.

Your analysis in the ...Nd7 line starts to interest me more. I'll look more on it and i'll contact you personaly. I also have to say that i received some advice from a titled friend of mine for the Nd7 (not Nc6)-b5-b4 variation where Black is considered OK there.

Yes, both lines (with Nxd4 and not) have the same ideas. Maybe it would be a nice search topic to discover which one is best of the two. As i said the ...Nxd4 line was the one that was shown to me when i was young that's why i have some positive feelings for it. Also this was Rowson's trusted weapon for some years. I don't know what Rowson now plays though.

So, it seems that De la Villa has nothing to discourage us. Maybe Khalifman is more successful on this? Also does the site's pdf you mentioned has something concrete against my above recommended variations?

When i'm referring to Emms i mean his book "Play the Scheveninghen Najdorf style". Mark, don't get me wrong but these "complicated" piece manouvres like Nd7-Nde5 etc never seemed logical to me. Chess is of course a logical game but also an illogical one in the sense that many things work better than others that seem more logical. Maybe their logic is on another level.  

So, after:

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e6 7. f3 Nc6 8. Qd2 Be7 9. O-O-O O-O 10. g4 Nxd4 11. Qxd4 Nd7 12. h4 Ne5 13. Be2 b5 14. Kb1 Nc6 15.Qd2
(15. Qb6 Qd7 is also given by Emms) 
15... Qa5 
According to Emms this move takes away the possibility of f4+Bg2 or something like that. The main idea of these ...Qa5 moves is to play ...b4 and take away the possibility of Na4 that will block the attack with a5-a4. So in a way the Qa5 helps this idea! (of course the Q has to move later on). Now the idea is ...b5 and White has to lose time:

16. Bd3 b4 17. Ne2 Ne5 18. Nd4 
I could never believe in White's position here. He has lost so much time with Bd3+Ne2+Nd4 and he will lose more because he will have to play Bxc4 in the future. I don't want to sound dogmatic here. I may be wrong and i'm aware of this. This is just my understanding of the position. I'm not a GM, so i'll try to provide some blindfold analysis (i dont have a database here where i am) and please tell me if my understanding is false.

18...Bd7 
Not blind on this. I just remember that this is my analysis. Idea is clear: play Rfc8-Nc4 and then move the Q and push that a pawn
19. Qf2
I think that this may be critical which anticipates the ...Nc4 manouvre. I don't know what else has been played here but after the other logical continuation:
19. h5 Rfc8 20. g5 Nc4 i'd prefer Black because he has the simple plan of Qb5(c7) and a5-a4-b3 with the rook on a8 or b8 or c8 (after Bxc4 Rxc5+Rac8) If g6 is played i do nothing and after gxh7 play Kh8 or even Kxh7 and after h6 play ...g6 with the move ...Be8 always a nice possibility (when f4-f5 comes).

19... Rfc8 20. h5 Nc4 21. Bc1 Qc5 
Typical idea tha FM Pountzas (former Greek champion who lives in my town) has played in similar positions with the Q on f2. ...e5 is a minor theat as is Bd8+Bb6. Also the manouvre Rab8+Na3+ gains some strenght
22. Rdf1 Rab8 
(maybe 22... Bd8 23.f4 Bb6 works?)

and i'd like to be Black here. Maybe i have missed some tactical possibility but overall you can understand my logic here.

After 

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e6 7. f3 

reading Ftacnik analysis i got the feeling that Black plays with fire and the whole Topalov approach (b4-Qa5) is quite risky while White has also ways to make it a positional game (with ...b4 Na4+c4 a la Anand). I started to find for an alternative solution for Black and i remembered the following line that i used when i was younger:

7...Be7 8. Qd2 O-O 9. O-O-O Nc6 
(Kasparov says in his "Revolution on the 70s" book that the ...Nc6 lines give White the initiative. It is true but Black has also his chances and the most important is that he doesn't care about move-orders or other nuances, his play is very very simple)
10. g4 Nxd4 and now two moves:

a) 11. Qxd4 Nd7 12. h4 
(12. f4 b5 13. g5 Rb8 has proved to be great for Black in practise) 
12... Ne5 13. Rh3 
(or 13. Be2 b5 14. Kb1 Nc6 15. Qd2 Qa5 as given by Emms) 
13... b5 14. h5 Nc6 15. Qd2 Qa5 16. Kb1 Rd8 like the game Mastrovasillis-Cvitan, 2006 or simply 16... b4 seems adequate for Black. I even prefer his chances slightly but that's just personal taste (or sweet memories from the past? )

b) 11.Bxd4 b5 12. g5 Nd7 13. h4 b4 14. Ne2
(14. Na4 was used by Fisher but Emms gives 14...Qa5 15. b3 Bb7 16. Kb1 d5 17. e5 Bc6 18. Nb2 Qc7 19. Nd3
(19. f4 is met by Nc5 and if 20. Qxb4 a5 with great play for the pawn) 
19... Bb5 20. f4 Nc5 which is at least equal for Black) 

14... a5 15. f4
(Other moves are not troubling  either:

15. Be3 Ne5 16. Nd4 Bb7 17. h5 b3 or 17... d5 

15. Kb1 Ne5 16. f4 Nc4 with Qc7+Rfc8)

15... Bb7 16. Ng3 e5 17. Be3 exf4 18. Bxf4 Ne5 19. Be2 Qc7 20. h5 Rfc8 with a5-a4-b3 etc as given by Emms.

I looked into Emms Najdorf-Scheveninghen book and i searched chess informants and my database (human and corr) and also my engine. I couldn't find anything for convincing for White. I don't have Khalifman's recent work and De la Villa's recent book was given by me in a friend and i don't know when he will give it back to me . So, i don't know what these sources recommend against this simple solution for Black. Can anyone help here? If they don't give something convincing then i'd definately choose this line for Black because it's "value for money" in terms of simplicity and theoritical value.