[title "Radjabov- Gelfand, London 2013"]
1.Nf3 c5 2.c4 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g3 Qb6 7.Nb3 Ne5 8.e4 Bb4 9.Qe2 d6 10.f4 Nc6 11.Be3 Bxc3+ 12.bxc3 Qc7 13.Bg2 e5 14.c5 b6!N
With the novelty
14... b6! Gelfand shows all his class. According to the official website Gefand said
"Mostly great preparation, it's my strong quality. Any computer would show you c5"
14...b6 goes with the move
13...e5. Gelfand likes "the concept because it cuts two pieces." The Bishop in g2 becomes very passive and the Knight in b3 is deprived from its natural square in d4.
From now on white has to come up with concrete ideas and find counterplay to maintain the game balance. Otherwise, it could be quickly worse as in the game.
Taking in b6
At first glance, taking in
b6 looks weird. On general principle, we don't want
- to exchange an active pawn (
c5) against a passive pawn (
- to open the
a line for free
- to give the square
a6 for the bishop.
On a more concrete note, taking in b6 create two weaknesses
b6. In particular, White can target the
b6 pawn, like in the following variation
[title "After taking in b6"]
1. Nf3 c5 2.c4 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 6. g3 Qb6 7. Nb3 Ne5 8. e4 Bb4 9. Qe2 d6 10. f4 Nc6 11. Be3 Bxc3+ 12. bxc3 Qc7 13. Bg2 e5 14. c5 b6 15. cxb6 axb6 16. O-O Ba6 17. c4 O-O (17... Nd4?? 18. Bxd4 exd4 19. e5! Bxc4 20. Qc2+-) 18. Rab1
White got some counterplay and the position is very sharp.
Taking in d6
Radjabov reacted slowly and his position collapsed quickly. In the following game, Svane took on d6, and found some counterplay to equalize.
[title "Svane, Rasmus (2542) vs. Ragger, Markus (2695) Bundesliga 2015"]
1.Nf3 c5 2.c4 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g3 Qb6 7.Nb3 Ne5 8.e4 Bb4 9.Qe2 d6 10.f4 Nc6 11.Be3 Bxc3+ 12.bxc3 Qc7 13.Bg2 e5 14.c5 b6 15.cxd6 Qxd6 16.O-O O-O 17.Rfd1 Qe7 18.f5 Qa3 19.Bc1 Qa4 20.Bg5 Ba6 21.Qe3 Rfd8 22.Bxf6 gxf6 23.Qh6 Rxd1+ 24.Rxd1 Qxa2 25.Qxf6 Qxb3 26.Qg5+ Kh8 27.Qf6+ Kg8 28.Qg5+ Kh8 29.Qf6+ Kg8 ½-½
In summary, it's really hard to give a definite answer. However, I tend to agree with @Allure that taking in
b6 was a good alternative. At least it's probably not worse than taking in
d6 since after
14.c5, the move
14..b6! gave Black a very good position.