csmath: 4. ...g6
[unusual move, forcing the game out of any preparations. Aronian likes kingside fianchettos as black so this could have been expected!]
[new move in the position with offer of pawn sacrifice.]
[proper response, ignoring the b-pawn.]
[white insist on queenside initiative.]
11. Ba3!? c6!?
[x-ray move will be neutralized with b5.]
12. c5 Re8
13. e4?! Bg4
14. Qb3 Nd7
15. Nd2 Nc8
[this is a whole series of moves of white designed for space grab and countermoves by black. Black is avoiding any commitment.]
[Black has fully equalized and each side has one backward pawn that could well play into the ending.]
[weakening king's castling for no apparent reason.]
22. Bb3! Qxb3
23. c5 Rbc1!?
24. Rb8 Qa2?
[positional strike probably missed by MVL. Black dismantles white initiative on queenside leaving him with nothing but awkward placement of pieces. Refusing to recognize the disadvantages of his position MVL sacrifices pawn in hope for attack.]
[excellent move since now queen is shut out of the action.]
[of course 27. ...Qxb3? 28. Na7 and white loses material. 27. ...Qa1 does not look appealing but it was probably safer option defending the rook on d4 and knight on a4 after retakes.]
[forcing the exchange knights and obviously playing on queenside passers.
It is interesting that white invested so much energy on the queenside only to see black getting queenside initiative.]
[losing "tactical" move designed for attack on black castling. This cannot be considered a "blunder" but after the next move of black it is quite clear that obvious and natural move 32. Rcc7 was not only better move but also the only move.]
[and now it is obvious that 33. Rxe7? 34. Bxe7 leaves white with nothing but lost "ending".]
[the only practical chance since the game is lost for white so MVL tries to set up rook sacrifice on g6. Obviously this should be more than visible to Aronian and more importantly it will not work - see the comment after the next move.]
[Maybe not! Unbelievable! Aronian ignores it and throws the game away. This was winning:
34. Rxg6? fxg6
35. Qxg6 Kh8
36. Be4 b1Q+
37. Bxb1 Qd1+
and white is completely lost.]
[first of two unfortunate errors by MVL.
38. Qg6 (with the threat of mate) ...Bg7, 39. Be4 Rxh3, 40. Kg2 Rh6, 41. Qf5! and white wins easily.]
[39. Kh2 is safer as it moves king away from possible checks. Game now slowly moves to ending phase which is lost.]
Aronian makes grave mistake in won position but MVL misses the win and returns the favor. Two great tacticians making serious errors in a tactical game.