Illustration of Hou Yifan at the chessboard. This is not a real picture of her, and the board shown is not a position from a real game.
Let us start with a puzzle. Look at the position below. It is White's move. Black's bishop has just taken White's bishop on g3, so White is a piece down. But the black king, on g7, has a queen and two rooks beside it and not a single pawn that can shield it from the front, and White has a queen on f5 and two rooks. One check starts an attack that Black cannot stop. Which check is it? Keep it in mind: you will meet the answer in the game below.
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gWhite to move. Black's bishop has just taken a bishop on g3. White has a queen on f5, a rook on e8 and a rook on e1. Black's king is on g7, with a rook on f7, a rook on d7 and a queen on b6. One check starts an attack that wins the game. Which one?
The player with the white pieces was Hou Yifan, a 23-year-old from China. The player with Black was Fabiano Caruana, one of the strongest players in the world. In the rating list she was rated 2649 and he was rated 2817, a gap of 168 points. It was the first round of the GRENKE Chess Classic in Karlsruhe, Germany, in April 2017.
A Girl Who Liked the Pieces
Hou Yifan was born on 27 February 1994 in Xinghua, a city in Jiangsu province, in China. When she was small she was fascinated by the shapes of the chess pieces. When she was five she began to work with a coach, Tong Yuanming. In 2003, at the World Youth Championship in Halkidiki, Greece, she won the girls' under-10 title.
Youngest Again and Again
- In June 2007 she won the Chinese Women's Championship. She was 13, and she was the youngest champion China had ever had.
- In 2008, at 14, she became a grandmaster, the youngest woman ever to earn the title. That same year she reached the final of the Women's World Championship, the youngest finalist ever.
- In 2010 she won the Women's World Championship in Hatay, Turkey. She was 16, and she was the youngest Women's World Champion ever. The old mark belonged to Maia Chiburdanidze, who had won it in 1978 at 17.
- She defended the title in matches in 2011 against Humpy Koneru (5½ to 2½), in 2013 against Anna Ushenina (5½ to 1½) and in 2016 against Mariya Muzychuk (6 to 3). Over the three matches she won ten games and lost none.
- Her highest rating was 2686, in March 2015.
Chess was not her only school. In 2012 she began to study at Peking University, and later she studied at Oxford University as well.
The Game: Hou Yifan vs. Fabiano Caruana, GRENKE Chess Classic 2017
Hou Yifan 1-0 Fabiano Caruana GRENKE Chess Classic, Karlsruhe 2017 · Round 1 White: Hou Yifan · Black: Fabiano Caruana
A quiet opening
The game began as a Ruy Lopez, in the line called the Berlin Defence. Caruana took the pawn on e4 on move 4, and Hou took the pawn on e5 on move 6, so the pawns were even and the pieces came out one by one.
1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.Re1 Nd6 6.Nxe5 Be7 7.Bf1 O-O 8.d4 Nf5 9.Nf3 d5 10.c3 Bd6 11.Nbd2 Nce7 12.Qc2 c6 13.Bd3 g6 14.Nf1 f6 15.h3 Rf7 16.Bd2 Bd7 17.Re2 c5
For the first 16 moves our own Stockfish 17.1 run, at depth 22, kept the game within half a pawn of level. Black pushed several pawns forward, the pawns on g6 and f6 and then the pawn on c5, and 17...c5 is the first move our engine marks. It would have played 17...Ng7. After 17...c5 it had White better by about one and a quarter pawns.
Pawns that go forward cannot go back
18.dxc5 Bxc5 19.Bf4 Rc8 20.Rae1 g5
7
2efgPosition after 20...g5, with White to move. Black's pawn on g5 attacks the bishop on f4, and nothing guards the bishop. The black king has pawns on f6, g5 and h7 in front of it, and none of them can go back.
A pawn cannot step backward. Every move like 20...g5 leaves holes behind it, and a king that has lost its pawn cover is easier to attack. Black's pawn now attacked the bishop on f4, so Hou offered a trade, 21.Ng3 Nxg3 22.Bxg3, and the bishop was safe again.
22...a5 23.Qd2 a4 24.b4 axb3 25.axb3 Ng6 26.h4
egPosition after 26.h4, with Black to move. White's pawn on h4, queen on d2 and knight on f3 all attack the pawn on g5. Black's pawn on f6 is its only defender.
Hou's pawn on h4 attacked the pawn on g5. The pawn was attacked three times, by the pawn on h4, the queen on d2 and the knight on f3, and it was defended once, by the pawn on f6. Our engine had White better by about two pawns by this time.
26...gxh4 27.Nxh4 Nxh4 28.Bxh4 Qf8 29.Qf4 Bd6 30.Qd4 Rd8
egPosition after 30...Rd8, with White to move. White's queen on d4 and bishop on h4 both attack the pawn on f6, and Black's rook on f7 is the only defender.
Black took on h4 and the h-file was open. The trades left Hou's bishop on h4 and her queen on d4 pointing at the pawn on f6, which was attacked twice and defended once by the rook on f7. Our engine marks Hou's 29.Qf4 as a small slip, but its lead stayed above one and a quarter pawns. It also marks Caruana's 30...Rd8, and it would have played 30...Qg7. After 30...Rd8 it had White better by more than two and a half pawns.
The rook arrives
31.Re3 Bc8 32.b4 Kg7 33.Bb5 Bc7 34.Re8
egPosition after 34.Re8, with Black to move. White's rook has landed on e8, next to Black's queen on f8 and rook on d8. It is guarded by the rook on e1 and the bishop on b5, so Black cannot win it for free.
By move 33 our engine had White better by more than five pawns. Hou's rook jumped to e8, right in front of the black queen and rook. The rook was attacked twice, by the queen and the rook, and defended twice, by the rook on e1 and the bishop on b5, so Black could not simply take it for free. Black moved the queen instead.
34...Qd6 35.Bg3 Qb6 36.Qd3 Bd7 37.Bxd7 Rdxd7 38.Qf5 Bxg3
Now you have seen how the game reached the puzzle position at the top of the page. Black had just taken a bishop on g3.
The answer to the puzzle
39.Qg4+ Kh6 40.Qh3+
egPosition after 39...Kh6, with White to move. White's queen on g4 gave check and the black king went to h6. White's rooks on e1 and e8 are ready to join in, and 40.Qh3+ comes next.
The answer is 39.Qg4+, the queen check on the g-file. Our engine rates it more than ten pawns better for White. The next best moves it found, such as 39.R1e3, leave the game level, so it was the only winning move. Caruana's king stepped to h6, the queen checked again from h3, and our engine finds a forced checkmate from here. Caruana resigned after 40.Qh3+.
What to Learn from This Game
- Pawns that move forward leave holes. Caruana played ...g6, ...f6, ...c5 and ...g5. Each pawn move left something behind it to aim at, and in the end the black king had very little cover.
- Count the attackers and the defenders. The pawn on g5 was attacked three times and defended once. The pawn on f6 was attacked twice and defended once. When you attack more times than your opponent defends, something has to give.
- Open a line when the king's pawns have moved. After the trades on h4, White's bishop stood on h4 and aimed straight at the pawn on f6.
- A rook is safe when it is defended. The rook on e8 was attacked twice, but it was defended twice, so Black could not take it for nothing.
- Look at every check. When White was a bishop down on the board, the check 39.Qg4+ still won the game. Before you decide that a position is bad, look at every check and every capture.
Five More Games to Study
Every engine number below comes from our own Stockfish 17.1 run at depth 20.
- Gabriel Sargissian vs. Hou Yifan, Corus Group B, Wijk aan Zee 2008, Round 11 (0-1). Hou was 13. A Queen's Indian, and a long fight. Our engine had White better by about one and three quarters pawns after 15...f6, and then 16.f4 gave much of that back. The game became level in the endgame, and Hou won in 49 moves with two passed pawns on the c-file and d-file. Sargissian's 38.Kf3 is the move it marks.
- Hou Yifan vs. Anish Giri, Hans Suri Memorial, Biel 2014, Round 1 (1-0). A Sicilian, and a win in 28 moves against a player rated 121 points higher, 2750 against 2629. Our engine does not mark one huge error. Giri lost about half a pawn at a time, with 12...Ne5, 14...Bg4 and 16...Nxd5, and his 25...Qf6 was the biggest slip, at about nine tenths of a pawn.
- Hou Yifan vs. Anna Ushenina, Women's World Championship, Taizhou 2013, Round 7 (1-0). An English Attack against the Najdorf Sicilian, with a pawn storm on the kingside. The win made the match score 5½ to 1½. Our engine had Hou slowly better, and it marks Ushenina's 30...Qd4 and 38...Nf7.
- Hou Yifan vs. Mariya Muzychuk, Women's World Championship, Lviv 2016, Round 2 (1-0). A Ruy Lopez, and a win in 32 moves against a player rated 119 points lower. Our engine marks Muzychuk's 27...Bc5. After it Hou's rook took the pawn on d5, and her queen finished the game on e6 with check.
- Rafael Vaganian vs. Hou Yifan, Biel 2017, Round 8 (0-1). An Indian Game, and a win in 33 moves as Black, against a player rated 104 points lower. Vaganian's 20.b4 and 22.Qxg6 are the moves our engine marks. You can try the position after 20.b4 below.
A Position to Try
73fgVaganian vs. Hou, Biel 2017, after 20.b4. Black to move. White's queen on h5 attacks the knight on g6, and White's bishop on d4 aims at g7, next to the black king. Black's bishop on d5 looks at the pawn on g2. What would you play?
Hou played 20...Bxg2, and our engine's first choice at depth 22 is the same move. After 21.Kxg2 she took the bishop on d4 with 21...Qxd4, and the queen stood in the middle of the board.
A Champion Who Keeps Learning
Hou Yifan was Chinese champion at 13, a grandmaster at 14 and Women's World Champion at 16. She studied at two universities while she played. In the game above she used her pawns, her queen and her rooks together, one step at a time, and the last move was a check that no other move could match. When your opponent's pawns have moved forward, count what they are guarding, and then look for the line to open.