1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8f6  4. d2d3  4... f8c5  5. b5a4 A mysterious move, played by several strong grandmasters, including the ultimate boss, Magnus Carlsen. The idea isn't simple to understand. I suppose White is anticipating the move a6, but I also don't know why it matters if Black plays this move anyway or what the big advantage is in preventing it. In any case, this is yet another of the many attempts to surprise Berlin Defense players. 5... d7d6  6. e1g1  6... e8g8  7. c2c3  7... c6e7 The typical knight maneuver to g6. 8. c1e3 I've found just one game in my database with this move, and it dates back to 1895. There's a reason for this: it makes Black's life easy. 8... c5e3  9. f2e3  9... e7g6  10. b1d2  10... c7c6  11. d1e1  11... d6d5 Black has achieved good control of the center and has a comfortable position. 12. e4d5  12... c6d5  13. a4b3  13... a7a5 I like this move, inducing White to put the pawn on a4. The inclusion of a5-a4 helps Black in several ways: the bishop on b3 is less safe, the pawn on a4 can be attacked, and Black can use the a6-square for a rook lift. 14. a2a4  14... c8d7  15. d3d4  15... d8e7  16. h2h3 It's important to control the g4-square so the black knight cannot use it. 16... a8e8 The beginning of an interesting plan, and it's important for its implementation that this rook and not the other is placed on e8. 17. e1f2  17... e5d4 This is the idea behind the previous move. Black wants to capture and play Ne4. The rook on f8 is important to protect the f-pawn. 18. e3d4  18... f6e4  19. f2e3 A solid choice. 19... e7d6  20. d2e4  20... e8e4  21. e3g5 The queen is badly placed here. 21... d7c6  22. a1e1  22... h7h6  23. g5d2  23... b7b5 Opening the game on the queenside and activating the bishop. 24. a4b5  24... c6b5  25. f1f2  25... e4e1  26. f3e1  26... f8e8  27. b3c2 White managed to escape the worst, but her position is still a bit uncomfortable. 27... g6h4 Not so dangerous for White as it seems. 28. e1d3  28... h4g6 Nobody likes going back and forth with the pieces, so it's clear that something went wrong with Black's strategy. 29. d3c5 The knight goes forward, a natural instinct. I wonder whether this is better than the humble return to e1, repeating the position. After the knight's capture on g6, the white knight can go to f3 or c2, fulfilling its defensive functions. 29... d6g3 