Anti-Marshall: 8. a4 Rb8
What is the theoretical status of the 8. Rb8 anti Marshall?
Now 8. b4 is by far the mainline, and very good and quite interesting, but obviously there's a lot to know there, and there is only source to study it from as the only course on it (Krishnater & Surya e4 e5) recommends some rare, concrete sidelines, although I'm not ruling it out completely, if anyone has this course let me know what you think of their lines in the anti-marshall. There are two big systems with either 9. d4 or 9. d3, and the positions look more or less pleasant, but I'm also considering other directions due to lack of material to study from.
I've always played 8. Bb7 following Gustafsson's lines with the Nd7 stuff, but I've always felt uncomfortable and those lines are not very intuitive, and as far as I know, there isn't any material out there that covers the mainline with Na5.
I recently discovered a course by Cheparinov on modern chess where he covers the 8. Rb8 Anti-Marshall and it got me interested. It's very rare comparatively, only played about 6% of the games, but has been played so many times by Carlsen, Dubov and Esipenko.
I was wondering if there is something inherently wrong with this Rb8 line for it to be so unpopular? and how is it theoretically compared to the alternatives? What i like about it is you kind of get very similar positions from my brief analysis in most lines, with typical ideas of trading in the centre and playing some d5 followed by Ne4: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 O-O 8. a4 Rb8 9. axb5 axb5 10. c3 d6 11. d4 exd4 12. cxd4 d5 13. e5 Ne4 14. Nc3 Nxc3 15. bxc3 Bf5
This is the typical type of position, other other times your pawn is on b4 and you start with bxc3.. followed by exd4 and d5 and Ne4 with a very similar position, and there are other lines where white doesn't open the a-file, but againt you get a similar pawn structure in the centre.
I understand it relinquishes the a-file, but 8. b4 does relinquish the c4 square which is a big source of play for white in the 9. d4 lines, and 8. Bb7 does weaken your king when your bishop is stuck staring at the d3-e4 pawn chain for a long time but discourages any setups with d2-d4, so they all have their pros and cons.
- Rb8 doesn't seem too theoretical, but there is this doubt in my mind that this line is still very rare due to some sort of issue with it, and despite Carlsen playing it in the world championship and many times after, it still hasn't become mainstream. Hoping for someone with experience to explain this.
Thank you.