A somewhat strange move that is not too dangerous.
1. d2d4  1... g8f6  2. c1f4  2... d7d5  3. e2e3  3... c8f5  4. f1d3 This opening was played several times during today's matches. 4... f5g6  5. h2h4 A rare plan—I found only two games by amateur players in my database. A transposition to a professional game will occur later on. In the other games, Grischuk played the more natural 5.Nf3. 5... e7e6  6. h4h5  6... g6d3  7. d1d3  7... b8d7  8. b1c3 [%c_highlight c2;keyPressed;none;opacity;0.8;square;c2;persistent;false,c3;keyPressed;none;opacity;0.8;square;c3;persistent;false] A curious square for the knight, since the more traditional laws of strategy don't recommend a knight in front of the c-pawn in queen's pawn structures. However, this rule has been broken for many years, and its validity is even more questionable in fast time controls. 8... f8d6  9. h5h6  9... g7g6  10. g1f3 Both players refuse to exchange bishops, proving once more that doubled pawns are not a weakness in many positions. If White captures, Black can make use of the half-open c-file, and the pawn on d6 will control the e5-square, taking it away from White's knight. In turn, if Black captures on f4, then White gains space and a robust pawn formation. 10... e8g8  11. e1c1  11... a7a6 [%c_arrow b7b5;keyPressed;none;from;b7;opacity;0.8;to;b5;persistent;false] Intending to advance the pawn to b5, starting counterplay on the queenside.