Konstantin Sakaev,
grandmaster

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!?

Rather rare move, very sharp and risky. The main way is 9. Bd3 Nxd2 10. Kxd2 c5 .

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.

If 12. O-O immediately, then 12...Nxd3 13. cxd3 Bd7 ( 13...h5 14. Qh3 ).

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.

Preventing 15...Bb5 .

This natural move, probably, is a mistake. If 15...b5 , then strong is 16. Ba5!

Another possible way - 17. f4 g6 18. Qh3 with the following 19. g4 and 20. f5 , or 19. Be1 , 20. Nf3 and 21. Bh4 .

Threatening is 20. Bxh6 .

The idea to carry out c7-c5 is wrong. Necessary was 20...a5 and then b6-b5-b4 , developing counterplay. To open any line is good for White.

22...c4 23. dxc4 dxc4!? deserved attention.

The only move, 26. Qxf7 threated.

Better was 27. Rf6! gxh4 28. Rg4 Qf8 29. Rxh4 h5 30. Qe2 Nc3 31. Qf3 and 32. Rxh5 with mating attack.

In the case of 28. Qg4 unpleasant is 28...Nc3 .

Stronger was 29. Kh2 with mating attack, for example, 29...Qc3 30. Qg4 Qxe5 31. Rxf7! with a win.

Once more 33. Kh2 with the further mating attack was better.

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.