Konstantin Sakaev,

1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. Bg5 Bb4
This is the MacCutheon variantion, rarely used now. It seems that the most unpleasant line for Black is 5. e5 h6 6. Bh4!? (an uncommon continuation, as well as all the variant with 4...Bb4 ) 6...g5 7. Bg3 Ne4 8. Nge2 c5 9. Qd3!? 5. e5 h6 6. Bd2 Bxc3 7. bxc3 Ne4 8. Qg4 Kf8 9. Be3
Rather rare move, very sharp and risky. The main way is 9. Bd3 Nxd2 10. Kxd2 c5 . 9...Nxc3 10. Bd3 Nc6 11. Nf3!?
A questionable decision, no wonder that Svidler spent a long time while thinking about this move. The alternative was 11. a3 , avoiding a trade of the bishop d3 , but it would have lost an important tempo. 11...Nb4 12. Bd2
If
12.
White can't play 14. Nh4? (necessary is 14. Bd2 Na4 with the same position as in the game), for after 14...h5! 15. Qh3 g5! Black wins a piece. 12...Nxd3+ 13. cxd3 Na4 14.Preventing 15...Bb5 . 15...b6?! This natural move, probably, is a mistake. If 15...b5 , then strong is 16. Ba5! 16. Nh4 Qe8 17. Rfe1Another possible way  17. f4 g6 18. Qh3 with the following 19. g4 and 20. f5 , or 19. Be1 , 20. Nf3 and 21. Bh4 . 17...Kg8 18. Re3 Rh7 19. Rg3Threatening is 20. Bxh6 . 19...Kh8 20. Re120...Rc8?!
The idea to carry out
22...c4 23. dxc4 dxc4!? deserved attention. 23. Qxd4 Rc2 24. Qf4 Rxa2 25. h325...Rxd2 The only move, 26. Qxf7 threated. 26. Qxd2 g527. Qb4?! Better was 27. Rf6! gxh4 28. Rg4 Qf8 29. Rxh4 h5 30. Qe2 Nc3 31. Qf3 and 32. Rxh5 with mating attack. 27...a5 28. Qd4In the case of 28. Qg4 unpleasant is 28...Nc3 . 28...Qc8 29. Re3Stronger was 29. Kh2 with mating attack, for example, 29...Qc3 30. Qg4 Qxe5 31. Rxf7! with a win. 29...Qc3 30. Qg4 d4 31. Re4 Nc5 32. Rxd4 a433. Nf3 Once more 33. Kh2 with the further mating attack was better. 33...Qc1+ 34. Kh2 h5 35. Qxg5 Qxg5 36. Nxg5 Rg7 37. Rd6 Rxg5 38. Rxg5 a3 39. d439...a2? 39...Nb3 was better, though after 40. Rxb6 ( 40. Rxd7 a2 41. Ra7 Na5 ) 40...a2 41. Ra7 a1=Q 42. Rxa1 Nxa1 43. Rxh5 White must gradually win. After 39...a2 Black had no chances, his position is lost. 40. dxc5 a1=Q 41. Rxd7 Qc1 42. Rxh5+ Kg7 43. Rh4 bxc544. g3 Kf8 45. Rf4 Ke8 46. Rfxf7 1:0 
Next game, annotated by K.Sakaev  
Previous game, annotated by K.Sakaev 