Hou,Y (2509) - Vitugov,N (2604) [B42]
Aeroflot Open 2007 Moscow (1), 14.02.2007
[Analysis by Albertan,Rybka 2.2, Hiarcs 10]

WGM Hou Yifan of China is now the second-highest rated girl in the World,the third highest woman in China,the 18th highest-rated player in China and the 637 highest-rated player in the world. (In terms of girls she is second in rating only Humpy Koneru has a rating higher than Yifan). In this game Yifan plays 20 year old GM Nikita Vitugov of the Republic o fRussia.Vitugov is the 29th highest rated player in the Republic of Russia, and the 132nd highest rated player in the world.When he was a junior he was one of the strongest junior players in the Repubic if Russia.Vitugov was the runner up to Zaven Andriasian in the 2006 World Junior Chess Championship. Opening:Sicilian Defense:Kan variation ECO:B42

1.e4 c5

The Sicilian Defense.

2.Nf3 e6

Allowing for rapid development of the kingside,and also influencing the key d5-square.

3.d4 cxd4 4.Nxd4 a6

This move is characteristic of the Kan variation of the Sicilian Defense.

5.Bd3

This move defines the variation of the Kan,for obvious reasons it is called the 5.Bd3 variation.The bishop now protects her e--pawn.

5...Bc5

Attacking his knight,winning a tempo unless she now plays 6.Nb3. I recall that Judit Polgar played this continuation, in a game, and in the annotations for the game, the GM gave an unfavorable impression of this variation for Black. According to my chessbase program opening book,the Elo performance of this move is 2447 ( the rating a player would have achieved in a fictitious tournament playing the move in all her or his games.) In recent top level chess, the likes of Kramnik,Ivanchuk,Svidler, and Topalov have used this variation for Black. [ Analysis:The main continuation is: 5...Nf6 and play most often continues: 6.0-0 Qc7 7.Qe2 d6 8.c4 g6 9.Nc3 Bg7 10.Rd1 0-0 11.Nf3 Nc6 12.h3 Nd7] Returning to the moves played in the game,she next played:

6.Nb3

The main continuation,winning a tempo. Perhaps this is why the GM who analyzed the game involving Polgar I mentioned,dislikes this 5....Bc5, as Black is forced to lose a tempo in the opening.

6...Be7
The lost tempo. [ Analysis:(a)According to my database, it is more popular for Black to play 6...Ba7 which gives the bishop more activity than it has on e7.; (b)Black has also used the move 6...Bb6 in this position.] The game continued with her playing:

7.0-0 The main continuation for White.

7...d6

The most popular continuation for Black,creating a "little pawn center" . Now his formation resembles the Scheveningen variation of the Sicilian Defense.

8.c4

The most popular continuation,clamping down on the center.By playing this move she prevents him from gaining queenside counterplay with 8...b5. His next move was:

8...Nf6

Behind in the development of his minor pieces,he tries to catch up to her.This is the most popular continuation for Black in this position.

9.Nc3

A move almost always played by White in this position,continuing with the development of her minor pieces.

9...Nbd7

Developing another minor piece, which increases his influence on the e5 and c5-squares. [ Analysis:The main line of this variation continues: 9...b6 10.f4 Nbd7 11.Qe2 Qc7 12.Bd2 Bb7 13.Rae1 Rd8 14.Rf3 Nc5] Returning to the game,which continued with her playing:

10.f4

The most popular move in this position,gaining space on the kingside, intending to move her queen to f3 to connect her rooks.

10...b6

This pawn advance is the most popular move for Black in this position in my database.He increases his influence on the c5 square. This pawn advance also allows him to fianchetto his bishop to b7.

She completes the development of her minor pieces.

11...Bb7

He also does the same,creating a double-attack against her weak e-pawn (which ties down her knight and bishop to defend this pawn). Now we see that he decision to advance her f-pawn to f4 has denied her the chance to support her e-pawn with f3.

12.Qf3

Connecting her rooks,she intends to move the queen to h3.

12...Qc7

By playing this move he gains more influence over the e5 square and facilates the connection of his rooks once he castles.

13.Rae1 [ Analysis:In my database the move 13.Qh3 has also been tried in this position by White.]

13...g6

He spends a tempo to gain more influence over the f5-square.In addition this move prepares the advance of his h-pawn to h5. [ Analysis:Black has also played the move 13...0-0 in this position.] The game continued with her playing:

14.Qh3

This move prepares the advance of her f-pawn to f5.

14...h5!?

Loosening the pawn structure in front of his king.This pawn advance allows him to move his knight to g4 in the future.

15.Nd1N

She plays a new move in this position. Prior to this game,the only move which had been played was 15.Qg3. Her idea is to use this square to transfer the knight to f2. [ Analysis:The move 15.Qg3 was played in the game: Markzon,G (2326) - Kriventsov,S (2438) [B42] USA-ch Seattle (8), 09.01.2003 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Bd3 Bc5 6.Nb3 Be7 7.c4 d6 8.0-0 Nf6 9.Nc3 Nbd7 10.f4 Qc7 11.Qf3 b6 12.Bd2 Bb7 13.Rae1 g6 14.Qh3 h5 15.Qg3 h4 16.Qh3 0-0-0 17.Nd4 Kb8 18.b4 e5 19.Nd5 Nxd5 20.exd5 Bf8 21.Nb3 Bg7 22.a4 exf4 23.Re7 Rhf8 24.Rxf4 b5 25.axb5 axb5 26.Na5 Bh6 27.Qxh4 Bxf4 28.Bxf4 Qb6+ 29.Be3 Qc7 30.Qd4 Rde8 31.Rxe8+ Rxe8 32.Bf4 bxc4 33.Bxc4 Ne5 34.Bb5 Re7 35.Be3 Ba8 36.h3 f6 37.Kh2 g5 38.Bf2 f5 39.Nc6+ Nxc6 40.dxc6 Bxc6 41.Bxc6 Qxc6 42.b5 Qc7 43.b6 Qd7 44.Qf6 Re2 45.Qd4 Qe7 46.Kg1 Ra2 47.Qc3 f4 48.Qc4 Ra1+ 49.Kh2 Ra5 50.Bd4 Rf5 51.Qc6 Rf7 52.b7 Qd7 53.Qb6 Qxb7 54.Qd8+ Qc8 55.Qb6+ Ka8 56.Qa5+ Kb8 57.Qb6+ Ka8 58.Qa5+ Kb8 1/2-1/2 ]

He is willing to sacrifice a pawn, (however in reality a combination involving the capture of a pawn after 16.cxb5 axb5 17.Bxb5? would be a mistake due to 17...Qb6+ ) ie.the pawn would be poisoned). This pawn advance creates the threat of 16....bxc4 winning a pawn and a tempo. [ Analysis:(a)Rybka 2.2: 15...0-0-0 16.Nf2 Kb8 17.a4 a5 18.Nd4 Qc5 19.Nb3 Qc7 =; (b)Hiarcs 10: 15...Nc5 16.Nxc5 dxc5 17.Bc3 Rg8 18.Be5 Qd8 19.Nf2 Nd7 ] Returning to the moves played in the game, for her next move the WGM played:

16.Ba5

Attacking his queen winning a tempo. [ Analysis:Hiarcs 10: 16.cxb5 axb5 17.Nc3 ( Taking the pawn would be a mistake: 17.Bxb5? Qb6+ 18.Be3 Qxb5 19.Nc3 Qb4 20.f5 gxf5 21.exf5 e5 ) 17...b4 18.Nb5 Qb6+ 19.Be3 Qd8 20.Bd4 0-0 =; Analysis:Rybka 2.2: 16.Ba5 Qb8 17.Bc3 bxc4 18.Bxc4 Qc7 19.Bd3 0-0 20.f5 Ne5 21.fxg6 fxg6 22.Qxe6+ Kg7 with some compensation for the pawn.] The game continued with GM
Vitugov playing:

16...Qb8
The lost tempo. [ Analysis:Hiarcs 10: 16...Qc6 17.Ne3 0-0 18.Bb4 Nc5 19.Bxc5 dxc5 20.Na5 Qc7 21.Nxb7 bxc4 22.Bxc4 Qxb7 ]. The next move of the game was:

17.Bc3
Spending a tempo to recentralize her bishop.

The game continued with GM Vitugov making the following move:

17...b4!?

GM Vitiugov offers her a pawn sacrifice. Rybka 2.2 evaluates this position as =. [ Analysis:Rybka 2.2 and Hiarcs 10: 17...bxc4 18.Bxc4 Qc7 19.Bd3 0-0 ( 19...Nc5 20.Nxc5 Qxc5+ 21.Kh1 Rc8 22.Nf2 Qb6 23.a4 a5 =) 20.f5 Ne5 21.fxg6 fxg6 22.Qxe6+ Kg7 ] Yifan decided to accept his gift:

18.Bxb4

Momentarily going up a pawn in material. [ Analysis:(a)Rybka 2.2: 18.Bd2 Qc7 19.f5 Ne5 20.fxe6 fxe6 21.Nf2 Nfg4 22.Nxg4 Nxg4 23.Be2 Kd7 ; (b)Hiarcs 10: 18.Bxb4 Bxe4 19.Bc3 Bxd3 20.Qxd3 Qb6+ 21.Nf2 Rc8 22.Nd4 Rg8 23.Nxe6!? fxe6 24.Rxe6 Kf7 25.Rfe1 Rge8 With sufficient compensation for the pawn] For his next move in the game Vitiugov played:

18...Bxe4

Immediately regaining his pawn.Now her bishop on b4 is enprise so such must spend a tempo to move it or protect it.

19.Bc3

The lost tempo. [ Analysis: 19.Bxe4 Nxe4 20.Rxe4 ( 20.Ba5 Qa7+ 21.Kh1 Ndf6 22.Qd3 d5 23.cxd5 exd5 24.Ne3 h4 ) 20...Qxb4 =] Vitiugov now continued the game by playing:

19...Bxd3

He decides to simplify the position.

20.Qxd3 h4

Preventing her from playing g2-g3 unless she wants to allow the opening of the h-file (which would be extremely dangerous for her). Rybka 2.2 gave a poor evaluation to this move ( ). [ Analysis:(a)Rybka 2.2: 20...0-0 21.Ne3 Qb6 22.Qc2 Rfe8 23.Re2 Rac8 24.Bd4 Qc7 25.Qd2 e5 26.Bc3 Ne4 =; (b)Hiarcs 10: 20...Qb7 21.Nd2 0-0 22.Bd4 Nc5 23.Qc3 Ncd7 24.f5 e5 25.Qd3 Kh7 26.Nf3 Ng4 =] The game continued with her playing:

21.Nf2

Placing more influence against the h3 square.By playing the knight to f2 she prevents him from playing ...h3.

[ Analysis:Rybka 2.2: 21.Nd4 Qb6 22.Nf2 Kf8 23.b4 Re8 24.Nxe6+!? fxe6 25.Rxe6 h3 26.Rfe1 Kf7 27.gxh3 Rhg8 ] The next move of the game was:

21...Rh5

By playing the rook to h5 Vitiugov prepares the advance ...d5 or the advance ....e5. [ Analysis:(a)Both Rybka and Hiarcs gave better evaluations to other moves:Rybka 2.2: 21...Qb6 22.Nd4 Nc5 23.Qe3 Qb7 24.Nf3 Rc8 25.Re2 Ncd7 26.Qd3 Qc7 27.Rc2 Rh5 =; (b)Hiarcs 10: 21...Qb7 22.Na5 Qb6 23.Qh3 Rh5 24.b4 Kf8 25.Qd3 Rf5 26.Qd2 Qc7 27.Ne4 Nxe4 28.Rxe4 Kg8 =] Returning to the moves played in the game which continued with her playing:

22.Nd4

Now Yifan threatens to play the exchange sacrifice 23.Nxe6!? which would yield her the advantage. [Analysis:Hiarcs 10 and Rybka 2.2: 22.Nd4 Kf8 23.Nh3 ( Analysis:Rybka 2.2: 23.Nc6 Qc7 24.Nxe7 Kxe7 25.Nh3 d5 26.Rc1 dxc4 27.Bb4+ Ke8 28.Rxc4 Qb6+ 29.Nf2 Rd8 =) 23...Nc5 24.Qf3 Qb7 25.Qxb7 Nxb7 26.f5 gxf5 27.Nf4 Rh6 28.Nfxe6+!? fxe6 29.Nxe6+ Kf7 30.Nd4 Rh5 31.Nxf5 Bd8 With sufficient compensation for the pawn.] Going back to the moves played in the Yifan-Vitiugov game, Vitiugov next played:

22...Nc5

Attacking her queen winning a tempo. [ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 22...Kf8 with a possible continuation being: (a)Rybka 2.2: 23.Nc6 ( (b)Hiarcs 10: 23.Qe2 Qe8 24.b4 Rc8 25.Bb2 Nb6 26.Nxe6+!? !? 26...fxe6 27.Qxe6 Nfd7 28.f5 gxf5 29.Ng4 Qf7 30.Nh6 !? 30...Qxe6 31.Rxe6 Rxc4 32.Nxf5 Rxf5 33.Rxf5+ Ke8 =) 23...Qe8 24.b4 Rc8 25.Nxe7 Qxe7 26.Nh3 a5 27.a3 Rf5 28.Ng5 Nh5 ]

The lost tempo. [ Analysis:Rybka 2.2: 23.Qc2 Kf8 24.b4 Ncd7 25.Rxe6!? Qc8 ( 25...fxe6? ?? 26.Qxg6 Bd8 27.Nxe6+ Ke7 ) 26.Re2 Qxc4 27.Nc6!? !? 27...Qxc6 28.Bxf6 Qxc2 29.Bxe7+ Ke8 30.Rxc2 Kxe7 ] The next move made by Vitiugov was:

23...Qb7?

This mistake will cost him a pawn.
[Analysis:(a)Rybka 2.2:Better is: 23...Kf8 with a possible continuation being: 24.b4 Ncd7 25.Rxe6 !? 25...Qc8 ( 25...fxe6 ? 26.Qxg6 Bd8 27.Nxe6+ Ke7 28.Re1 threatening: 29.Qg7+ Ke8 30.Nc7# ) ; (b)Hiarcs 10:Better is: 23...a5 24.Nxe6 ! 24...Nxe6 ( Worse is: 24...fxe6?? ? 25.Qxg6+ Kd7 26.Bxf6 Qe8 27.Qg7 Rf5 28.Bxh4 ) 25.Bxf6 Bxf6 26.Rxe6+ !? 26...fxe6 27.Qxg6+ Kd7 ] Going back to the game, it continued with the two players making these moves:

24.b4 h3

Creating the game-ending threat of ....Qxg2# [ Analysis: (a)If he had tried to save his knight then after: 24...Ncd7 ? 25.Nxe6 ! 25...fxe6 26.Qxg6+ Kd8 27.Bxf6 Nxf6 28.Rxe6 h3 29.Ne4 Qa7+ 30.c5 She would have a decisive advantage.; (b)Analysis:Hiarcs 10: 24...Rc8 25.f5 gxf5 ( Worse would be trying to save the knight: 25...Ncd7? as after: 26.fxe6 Ne5 27.exf7+ Kxf7 28.Ne4 Qd7 because now she could play 29.Rxf6+ ! and after: 29...Bxf6 30.Rf1 Ng4 31.h3 d5 32.hxg4 dxe4 33.gxh5 ) 26.bxc5 Rxc5 27.Qe2 Re5 28.Qd3 Rc5 29.Nh3 Ne4 And he would not have suffcient compensation for the pawn.]

25.Nxh3

Now his knight on c5 is enprise so he must spend a tempo to move it. [Analysis:Rybka 2.2 and Hiarcs 10:Better is: 25.gxh3 with a possible continuation being: 25... 25...Ncd7 ( Hiarcs 10: 25...Qc8 26.Ba1 Ncd7 27.Rxe6 ! 27...Nb6 ( 27...fxe6 ?? 28.Qxg6+ Kd8 ( 28...Kf8 29.Nxe6#) 29.Nxe6#) 28.Re2 Ng8 29.Rc1 Rb8 ) 26.Nxe6 !? 26...fxe6 27.Qxg6+ Kd8 28.Bxf6 Nxf6 29.Rxe6 Rh8 ] Going back to the moves played in the game, for his next move the Russian GM played:

25...Nce4

The lost tempo.

Threating 27.Nxe4.

[ Analysis:Hiarcs 10 gave a better evaluation to the temporary sacrifice: 26.Nxe6 with a possible continuation being: 26... 26...fxe6 27.Bxf6 Nxf6 28.Rxe6 Kf7 29.Rfe1 Bd8 30.Ng5+ Kg7 31.Rxd6 Qxb4 32.Qd1 Qc5+ 33.Kh1 Qf2 34.Rxd8 ] His next move in the game was:

26...d5

He spends a tempo to overprotect his knight. [ Analysis:Rybka 2.2:Better is: 26...Nxc3 27.Qxc3 Qb6 28.Qd3 Kf8 29.Rb1 ( Analysis:Hiarcs 10: 29.Ngxe6+ !? 29...fxe6 30.Rxe6 Ng8 31.f5 gxf5 32.Rxf5+ Rxf5 33.Qxf5+ Bf6 34.Rxf6+ Nxf6 35.Qxf6+ ) 29...Rd8] The game continued with the Chinese WGM playing:

27.c5

She gains a protected-passed pawn.
[Analysis:Rybka 2.2:Better is: 27.a3 Nxg5 28.fxg5 Ne4 29.Bb2 Bxg5 30.g3 Rc8 ]

His next move of the game was:

27...Kf8?!

[ Analysis:Rybka 2.2:Better is: 27...Nxg5 28.fxg5 Ne4 29.h3 a5 30.c6 Qc7 31.Rxe4 !? 31...dxe4 32.Qxe4 Rxh3 !? 33.gxh3 Qg3+ 34.Qg2 Qxc3 35.Nb5 Qe3+ ] Returning to the moves played in the game, which continued with these moves:

28.a3 Kg8

He intends to move his knight back to h7. [ Analysis:(a)Rybka 2.2:Better is: 28...Rd8 with a possible continuation being: 29.Ndf3 Nxc3 30.Qxc3 Ne4 31.Qd3 Bxg5 32.Nxg5 Rd7 33.Nxe4 dxe4 34.Qxe4 Qxe4 35.Rxe4 Ke7 ; (b)Hiarcs 10:Better is: 28...Qc8 with a possible continuation being: 29.Bb2 a5 30.Ndf3 axb4 31.axb4 Rb8 32.Bxf6 Nxf6 33.Rxe6 ! 33...Qe8 34.Re2 Rxb4 ] She next made the following move:

29.Ndf3

Overprotecting his other knight and threatening to win a pawn by playing the combination:30.Bxf6 Bxf6 31.Nxe4 dxe4 32.Qxe4

Vitiugov next played the capture

29...Nxc3

Ending her pressure against his other knight. The following moves were now made by the two players:

30.Qxc3 Nh7

He offers to exchange pieces to simply his defensive task. [ Analysis:Rybka 2.2:Better is: 30...a5 with a possible continuation being: 31.Ne5 axb4 32.axb4 Ne4 33.Nxe4 dxe4 34.Re3 Rb8 35.Rb1 Qb5 ] Returning to the moves played in the game, Hou Yifan continued play by making the capture:

31.Nxh7

She eliminates a key defensive piece. [ Analysis:Hiarcs 10:Gave a better evaluation to: 31.g4 with a possible continuation being: 31...Rh6 32.Ne5 Nxg5 33.fxg5 Rh7 34.Qe3 d4 35.Qf4 a5 36.c6 Qb8 37.Re2 Qb5 ]

31...Rxh7

[ Worse is: 31...Kxh7 32.g4 Rh6 33.Re3 Qc7 34.g5 Rh5 35.Ne5 Kg8 36.Rff3 Rd8 ] The next move of the game was:

32.Qd4

[ Analysis:(a)Hiarcs 10:Better is: 32.Ng5 with a possible continuation being: 32... 32...Rh5 33.Nxe6 !? 33...fxe6 34.Rxe6 Kh7 ( Worse is: 34...Kf7 35.Rfe1 Bh4 36.g3 Qc8 37.Qe3 Bd8 38.Rd6 threatening:39.Qe8+ Kg7 40.Qxg6+ Kf8 41.Re8# ) 35.f5 gxf5; (b)Rybka 2.2:Better is: 32.Rc1 with a possible continuation being: 32... 32...a5 33.Rb1 Rh5 34.Rfd1 axb4 35.axb4 Qb8 36.g3 Ra4 37.c6 Qc7 ]

GM Vitugov continued the game by playing:

32...Rh5

Preventing her from playing Qe5.
[ Analysis:Rybka 2.2:Better is: 32...a5 with a possible continuation being: 33.Rb1 axb4 34.axb4 Ra4 35.Rfc1 Rh5 36.c6 Qc7 ]

33.h3

She creates luft for her king.
[ Analysis:Rybka 2.2: Gave a better evaluation to 33.g4 with a possible continuation being: 33...Rh6 34.Rc1 Rc8 35.Qe3 Kg7 36.Ne5 Rh4 37.c6 Qc7 38.h3 f6 39.Nf3 Rxh3 40.Qxe6 Qxf4 41.Qxe7+ Kh6 ] The next move played by him was:

33...Bf8

He intends to redeploy the bishop to g7. [ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 33...a5 34.Rb1 ( Hiarcs 10: 34.Qc3 Rc8 35.Re3 Rd8 36.Rc1 axb4 37.Qxb4 ( Not as effective is: 37.axb4?! d4 38.Nxd4 Bf6 39.Rd3 Rhd5 ) ) 34...Qb5 35.Rfc1 Rc8 36.Rc3 Bd8 37.Rcb3 Bc7]

For her next move in the game she played:

34.Qd3

Now she creates the threat of 35.Rxe6 ie:35... Rf5 36.Rb6 Qc7 37.g4 Rxf4 38.Qxd5 Kg7 [ Analysis:(a)Rybka 2.2: 34.Ne5 Bg7 35.Re3 Rc8 36.Rfe1 Qb5 37.Rc3 Bf6 38.g4 Rh4 39.Rec1 Bd8 ; (b)Hiarcs 10: 34.Qd3 Bg7 35.Ne5 Rc8 36.g4 Rh6 37.Rf2 Rh4 38.Kg2 Qb5 ] GM Vitugov next played the following move:

34...Bg7

[ Analysis:Hiarcs 10:The program gave a better evaluation to the move 34...Rh8 with a possible continuation being: 35.Rc1 Qc7 36.Ne5 Bg7 37.Qe3 Rh4 38.Rcd1 Rd8 ]

The next move made by her was:

35.Nd4

Intending Nb3 [ Analysis:Rybka 2.2 and Hiarcs 10:gave a better evaluation to the move 35.Ne5 with a possible continuation being: 35...(a)Rybka 2.2: 35...Rd8 ( (b)Hiarcs 10: 35...Qc7 ) 36.Qd4 Rc8 37.Qe3 a5 38.g4 Rh4 39.Rb1 d4 40.Qg3 ( 40.Qxd4? Bxe5 ( 40...Rxh3 With compensation for the pawn,) 41.fxe5 Rxh3 42.Qf4 axb4 43.axb4 Ra8 with compensation for the pawn.) ] Play in the game continued with Vitugov playing:

35...Rh4 ?!

[ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 35...a5 36.Rb1 axb4 37.axb4 Rh4 38.Qd2 ( Hiarcs 10: 38.Ne2 Rc8 39.Rfe1 e5 !? 40.Qf3 ( Less effective is: 40.fxe5 Rxb4 41.Nf4 Rb8 42.Rxb4 Qxb4 43.Qe3 Bh6 44.Rf1 Re8 ) 40...e4) ] Returning to the moves played in the game,which continued with her playing:

36.Kh1

She spends a tempo to take her king off the g1-a7 diagonal. [ Analysis:(a)Hiarcs 10: 36.Nxe6! !? 36...fxe6 37.Rxe6 Rh6 38.Rxg6 Rxg6 39.Qxg6 a5 40.c6 Qb6+ 41.Kh2 axb4 42.axb4 Qxb4 43.Qe6+ Kh8 44.Qxd5 ; (b)Rybka 2.2: 36.Rd1 a5 37.Rb1 axb4 38.axb4 Qa6 39.Qe3 Qc4 40.Nc6 Ra2 41.Qg3 Rh5 ]

Vitugov now continued the game by playing:

36...Qc7

Double-attacking her f-pawn winning a tempo. [ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 36...a5 with a possible continuation being: (a)Rybka 2.2: 37.Qg3 ( (b)Hiarcs 10: 37.Rb1 axb4 38.axb4 Qc7 39.Qd2 Bf6 40.Rf3 Kf8 41.g4 e5 42.Qf2 exf4 ) 37...Rh5 38.Qc3 Rh4 39.Qd2 axb4 40.axb4 Qb8 41.Kh2 Ra4 42.Rb1 Rxf4 !? 43.Rxf4 g5 44.Nc6 Qc7 45.Ne7+ !? 45...Kh8 ( 45...Qxe7 ?! 46.Rg4 Be5+ 47.Kg1 f6 48.h4 Qh7 ) ]

Hou Yifan next played:

37.Qe3

This move represents the lost tempo.
[Analysis:(a)Rybka 2.2:gave a better evaluation to: 37.Qd2 with a possible continuation being: 37...a5 38.Rf3 axb4 39.axb4 Qb8 40.g4 Ra4 41.Rb1 Qa7 42.Qc3 Ra2 With some compensation for the pawn.; (b)Hiarcs 10: 37.Qg3 Rh6 38.Qc3 Rh8 39.Rd1 Rb8 40.g4 a5 With insufficient compensation for the pawn.]

37...Bf6

Intending to move the bishop to d8.
[ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 37...a5 with a possible continuation being: 38.Qg3 ( (b)Hiarcs 10: 38.Nb5 Qd7 39.Nd6 axb4 40.axb4 Rd8 41.Rb1 Bf6 42.Qg3 Rh5 43.Qd3 Ra8 With insufficient compensation for the pawn.) 38...Bf6 39.Qf2 axb4 40.axb4 Ra4 41.Rb1 Qa7 with some compensation for the pawn,] The next move of the game was:

38.Nb3

Possibly short of time,she appears to play a waiting move (as the knight returns to d4 on move 40). [ Analysis:(a)Rybka 2.2:Better is: 38.Qd2 with a possible continuation being: 38...a5 39.Kh2 Rh5 40.Kg1 Rh4 41.Rf3 axb4 42.axb4 Ra4 43.Rb1 Qc8 ; (b)Hiarcs 10: 38.Rd1 Rd8 39.g4 a5 40.Rd3 Rh7 41.Kg1 Rb8 42.Rb3 axb4 43.axb4 Ra8 with some compensation for the pawn.]

The next move of the game was:

38...Kg7

He vacates the eighth rank with his queen, so that he can play his rook to h8 in the immediate future. [ Analysis:Rybka 2.2 and Hiarcs 10:Better is: 38...Rd8 with a possible continuation being: 39.Rd1 Rh5 ( Hiarcs 10: 39...Kg7 40.Kg1 Rhh8 41.Rf3 Rb8 42.Qd3 Rhc8 43.g4 Kh7 ) ] Going back to the game, it continued with her playing:

39.Qd2

Attacking Vitiugov's d-pawn which prevents him from playing ...e5 She intends to play the knight maneuver Nd4-f3-e5 in the immediate future.

[ Analysis:Hiarcs 10: 39.Rf3 Rah8 40.Rd1 Rc8 41.g4 Rhh8 42.f5 exf5 43.gxf5 Rce8 44.Qd3 g5 ]

Vitugov now continued the game by playing:

39...Qd7

Overprotecting his e-pawn and intending to move the queen to a4 in the near future, in order to attack her a-pawn. [ Analysis:Rybka 2.2: Better is: 39...d4 !? with a possible continuation being: 40.Na5 Rd8 41.Nc4 Rh5 42.Qd3 Qd7 43.Kg1 Kg8 ]

Ho Yifan next made this move:

40.Nd4

[ Analysis:Rybka 2.2 and Hiarcs 10:Both programs gave a better evaluation to the move 40.Rf3 with a possible continuation being: (a)Rybka 2.2: 40... 40...d4 ( (b)Hiarcs 10: 40...Rah8 41.Kg1 Qa4 42.Nd4 a5 43.Ref1 Rc8 44.Rc1 Rb8 ) 41.Na5 Rah8 42.Kg1 Rd8 43.Nc4 Kg8 44.Qd3 Qd5 ] The next move of the game was:

40...Rah8

Creating the threat of 41...e5 and if her knight were to move then he would play: 42...Rxf4 equalizing material.

[Analysis:(a)Rybka 2.2:Better is: 40...Qa4 with a possible continuation being: 41.Rf3 a5 42.Kh2 axb4 43.axb4 Rhh8 44.Rd1 Rhb8 45.Rb3 Rc8 ; (b)Hiarcs 10:Better is: 40...g5 with a possible continuation being: 41.Nxe6+ !? 41...fxe6 42.fxg5 Be7 43.Qe2 Bxg5 44.Qe5+ Kg6 45.Qxe6+ Qxe6 46.Rxe6+ Kg7 ]

41.Nf3

Attacking his rook winning a tempo.
[Analysis:(a)Hiarcs 10: 41.Nf3 R4h5 42.Ne5 Qa4 43.Rf3 Rh4 44.Kg1 Qe8 ; (b)Rybka 2.2: 41.Kg1 Rc8 42.Nf3 Rh5 43.Ne5 Qb5 44.Qe3 Rb8 45.Qc3 Rc8 ] His next move of the game was:

41...R4h5

The lost tempo. [ Analysis:Rybka 2.2: 41...R4h5 42.Ne5 Qb5 43.Ng4 Rf5 44.Nxf6 Rxf6 45.Rc1 Rc8 ; (b)Hiarcs 10: 41...R4h7 42.Ne5 Qe7 43.Ng4 Rh4 44.Kg1 R8h5 45.Nxf6 Qxf6 46.c6 Rh8 47.Rc1 Ra8 ]

The game continued with her playing:

42.Ne5

Attacking his queen,threatening him with the loss of a tempo, unless he plays 42...Bxe5 or 42...Qa4. [ Analysis:Rybka 2.2: 42.Ne5 Qb5 43.Ng4 Rf5 44.Rf3 a5 45.Rc1 e5 46.c6 e4 47.Rf2 axb4 48.axb4 Rc8 ] His next move was:

42...Qa4

Attacking her undefended a-pawn winning a tempo. [ Analysis:(a)Rybka 2.2: 42...Qb5 43.Ng4 Rf5 44.Rc1 Rc8 45.Rf3 a5 46.Kh2 Be7 47.Qb2+ Kh7 48.Qd4 Rh5 49.Ne5 axb4 50.axb4 Kg8 ; (b)Hiarcs 10: 42...Qa4 43.Rf3 Kg8 44.Rc1 Qe8 45.Qd3 Bxe5 46.fxe5 Qc6 ( Worse is: 46...Rxe5 47.Qxa6 ) ] The game continued, with her next move being:

43.Rf3

This move represents the lost tempo.

43...Rb8

Creating the threat of 44...a5 followed by 45.....axb4 and 46..Q or Rxb4 equalizing material. [ Analysis:(a)Rybka 2.2: 43...a5 44.Ng4 Be7 45.Qc3+ Kh7 46.Ne5 Rf5 47.g4 Rf6 48.f5 !? 48...axb4 49.axb4 Rb8 50.Nxf7 ! 50...Qxb4 51.fxg6+ Rxg6 52.Qxb4 Rxb4 ]

Hou Yifan now played the following move:

44.Ng4

Threatening his bishop.
[ Analysis:(a)Hiarcs 10: 44.Ng4 Bh4 45.Qd4+ Kg8 46.Nf6+ Bxf6 47.Qxf6 Re8 48.Re5 Rh7 49.Rg3 Qd7 50.f5 ! 50...Qe7 51.Qxe7 Rxe7 52.fxg6 fxg6 53.Rxg6+ Kf7 ] The next move in the game was:

44...Bd8

Losing a tempo.
[ Analysis:Rybka 2.2:Better is 44...Bh4 45.Qd4+ Kg8 46.Rc1 Rc8 47.Qd3 Qb5 48.g3 Be7 49.Kg2 Kf8 ] The game continued with her playing:

45.Qd4+

Winning another tempo.

45...Kf8 ?

The lost tempo. [ Analysis:Rybka 2.2:Better is: 45...Kg8 with a possible continuation being: 46.f5 gxf5 47.Rg3 !? 47...fxg4 48.Qxg4+ Rg5 49.Qf4 Rc8 50.Rxg5+ Bxg5 51.Qxg5+ Kf8 ] The next move played in the game by her was:

46.Rc1

Threatening 47.c6 48.c7. [ Analysis: Hiarcs 10::Better is: 46.f5 ! 46...gxf5 47.Nh6 Rxh6 48.Qf4 Kg7 49.Qxb8 Bh4 50.Rc1 Bg5 ]

Vitiugov now continued the game by playing:

46...Rc8

47.Ne5

By playing the knight to e5 she now threatens to play her pawn to c6.

47...Qb5

[ Analysis:(a)Rybka 2.2: 47...Qb5 48.c6 Rc7 49.Rc5 Qe2 50.Kg1 Qe1+ 51.Rf1 Qe2 52.Rcc1 Qb5 53.Rf3 Be7 54.Nd7+ Kg8 ; (b)Hiarcs 10: 47...Rc7 48.c6 Kg8 49.Qc5 Rh8 50.Qd6 Kh7 51.g4 Qb5 52.Rd3 Qb6 53.Nd7 Qf2 54.Rcd1 ( 54.Nf6+? Kg7 55.g5 Qb2 56.Re1 Rc8 57.Ng4 Bc7 58.Qe7 Rhe8 59.Qf6+ Qxf6 60.gxf6+ Kf8 ) 54...Qe2 ]
The next moves in the game were:

48.c6 Rc7

Blockading her passed pawn.

49.Nd7+

Winning a tempo.

49...Kg8
50.Qb6

Now she threatens Nf6+ which would win the exchange. [ Analysis:Rybka 2.2: 50.Rfc3 with a possible continuation being: 50... 50...Be7 51.Qd1 d4 52.Qxd4 Rd5 53.Nf6+ Bxf6 54.Qxf6 Qe2 55.Kh2 Qf2 56.h4 Qb6 57.R1c2 Kf8 58.Rc4 Kg8 59.Qc3 Qb8 60.Rc5 Qd8 61.g3 Rd3 62.Qb2 Rd1 63.Qe5 Qd3 64.Rf2 Rc8 65.c7 Qxa3 66.Qe4 Qa4 67.Rfc2 Qd7 68.Qb7 Rd2+ 69.Rxd2 Qxd2+ 70.Kh3 Qd7 71.Qc6 Qd3 ]

The game concluded with him playing:

50...d4?

He misses the fact that she can play the check 51.Nf6+