Carlsen Vs Caruana Game 2 , 2018

White: Carlsen Vs Black: Caruana,  Game drawn , 49 moves.

Game 2 turned out to be much less dramatic than Game 1 but it had some interesting points. Caruana surprised with his choice of defence when he opted for 6.-- c5. He surprised again by playing something that's generally considered unplayable on move 10.

 Diagram after 10 Rd1

Instead of the comparatively staid 10 Rd1, White can mix things up even more by castling queenside with 10 O-O-O, leading to violent attacks and counter-attacks. That queenside castling looks, and is, highly dangerous because both sides will launch pawn storms. Plus, the centre is likely to open up, which means rapid piece transfers from one flank to another are very possible.

After 10. Rd1, black needs to open up the c8 bishop. That leads to jockeying for -- e5.  This line is famous, or notorious, for the stem game, Game 21,  in the Karpov Korchnoi match of 1978. That tactical genius, Mikhail Tal, found a vicious piece sacrifice while working on Karpov's team . Korchnoi refused to take the piece and finally won a crazy, complex fight. The sacrifice is  now generally considered sound but not a winning option.  

That went 10. Rd1 Re8 11. Nd2 e5 12. Bg5 Nd4!!?  13. Qb1 Bf5 14. Bd3 e4 ? when 15. Bf1! probably wins outright. Korchnoi  played 15. Bc2 Nxc2 16. Qxc2 Qa6 17. Bxf6 Qxf6 18. Nb3 Bd6 19. Rxd5 (1-0, 60 moves).  Subsequently black has tried 14.-- Bxd3 15. Qxd3 Ne4!? which is supposedly balanced. There's plenty of not-so-hidden insanity in that position.

Carlsen played a very non-committal response, 11. Be2  to Caruana's "novelty" 10. Rd8. This is not really a novelty - it used to be written off as a bad move but it's been played before, and white is supposed to get an edge with 11. Nd2.  Nigel Short said he always thought Rd8 was just unplayable and he's a long-term connoisseur of this line, which he played in his Candidates match against Speelmann back in the 80s. What idea did Caruana have?

That Kt d2 regroup is the normal move, against the normal 10. -- Re8 - and Re8 is supposedly better than Rd8 because it supports the push e5.  Incidentally, black would be happy if white was provoked into playing (for example ) 11. b4? Nxb4 12. axb4 Bxb4 13. Rc1 Ne4 which has been known to happen in amateur games.  11 Nd2 sets up threats of Nb3 and of b4 perhaps.

Anyway, Carlsen chose to grovel as he called it with Be2. Presumably the Don has found an idea that works against 11. Nd2 in the Rd8 line. We'll probably get to see it, since white can't really avoid these QGD variations, if he's going to play Bf4 instead of Bg5.  But Carlsen will go back and his team will take a long, hard look at this position before he plays Nd2.

Ducking a battle meant Carlsen was now on his own and he took a lot of time. He must have found a line that Caruana had studied since the challenger reeled off his moves almost without pausing for thought. 

Diagram After 16. -- Nxd5

On  move 17, we came to another major cross-road. Carlsen had already spent an hour, while Caruana had spent just 5 minutes. White can try 17. Nxf7!? Kxf7 18. Bxd6 Rxd6 19. Bh5+ Kg8 20. e4 when black can stabilise with 20.-- Bd7 21. exd5 Qxa4 . Or he can try the very unclear 20.-- Nf4 21. Rxd6 Qxh5 22. Rd8+ Kf7 23. Rfd1 e5! - here black will forget about his Ra8 and let it go in many lines playing things like 24. Qb3+ Be6! 25. Qxb7+ Kg6 and try to deliver mate with the formidable combination of B+N +Q against an undefended kingside. The engines say it's equal.

Magnus pulled the emergency brake as Hammer put it by playing 17. Bf3 instead. After that, it's a question of bailing out to a drawn rook ending, which he duly accomplished without much fuss. Maybe black can keep something with 22.-- b6 . In the final position, white just plays Ra4-b4, a4, etc. unless black plays Kf3 when he checks with Ra3+. If black tries to penetrate with Ra6/b6 - a1, white puts his king on g2, and Ra7, f7, e7, etc. to hold the draw. 

Verdict: Moral victory for Caruana, drawing easily with black. But this line is very likely to come up again. Carlsen will repeat 1 d4, and he's likely to face 6--c5. A repeat could be a serious test of the line and we'll learn about Caruana's idea (or ideas).