Pogonina vs Chess.com Move 26.
Well there is some to add here but I also refer to the commentary to move 25.
http://www.chess.com/votechess/game.html?id=14051
The Chess.com community voted 25. ... Qd7. A main defensive idea is to expose the vulnarability of the white pawn a5 which can be executed by Rcc5-Qc7-Bd8. Thus Qd7, regrouping the troops. That scheme is not to be taken lightly, although combining the guard of the unhappy pawn with general motifs and counter attacks might be the best option. Weak spots in Black's set up are b7, d6 and f7. The only real weakness White has are a5 and a somewhat passive Be2. Main candidates for White are:
26.Be2 is a way of relocate and put the bishop to work. If White queue up on the b-file and Black defends with Rb8, the bishop threatens Bxa6 because the black rook is hanging. From c4 it will put pressure on a6 and f7. From d5 it will aim at b7 and f7. It will stop Rc7-c5-b5.
26.Rb4 obviously aims at b7 simultaneously defending e4. From b6 it cross-eyes b7/d6 and blocks Black's view of a5. Frees the Queen.
26.Qb3 defends Ra4, puts pressure on b7, aims for f7 and controls c4.
26.g3 would fill the aim of air to the king and less squares for the black bishop. It hampers the communication between the wings and may be a good move later. I see no immediate need.
26.Rd5 directly blocks d6 and defends a5. It also blocks a light squared route a2-f7.
From what I can deduce above, 26.Rb4 is the move that does the most for White. So I would put my money on 26.Rb4.
Hey! What about the a-pawn?
Ok, 26. ... Rc5 27.Rb6 Rc6 (Rxa5 28.Rbxd6 [27.Qb3 Rb8 28.Be2 (28.Rb6 Rxa5 29.Rbxd6 Qb5 30.Qxb5 Rxb5 31.b4 Be7 =) ... Rxa5])
It doesnt look easy really. White has a small edge but it isn't enough to be satisfying and it looks as Black can achieve material equality. Positionally, there is a wide spectrum. I really would not like to speculate too far ahead and save some energy for the position to arise in a couple of moves. Maybe this is a critical position, more even than the choice between Rac8 or Rfc8.
Looking at dsarkar's 26.Rb4 Rc6 I judge it not to be a promising line for Black since the a-pawn will be swopped for the b-pawn and the ensuing pawn structure is a nice one for White. 26. ... Rc5 looks like a stronger choice. Rd5 and Be2 are weaker responses, in my view.