Whatever one says, chess is a sport. In a real tournament, apart from chess skills, extremely important are endurance, will power and luck. They (or lack of them) can change the course of events drastically. Who could think that unknown women's team from Kazakhstan can stop powerful China? But it happened. Who could imagine that skilled grandmaster Onischuk, who passed through fire and water, can possibly lose the rook endgame "two pawns against three on one side"? But it also happened.

Who would suspect Anna Muzychuk, the third women player of the World, in the ability to blunder a piece already on the 8th move of the game? But she did it!

That's Olympiad. High pressure and tiredness remove all barriers and make any events, even absolutely unpredictable, possible. So, 10th round became a day of big surprises.

The central match of the men's section finished very unpredictable. American grandmaster coped with all the difficulties and suddenly slipped on the flat space.

Ding,Liren (2695) - Onischuk,Alexander (2666)
China - USA

It seems that it is impossible to win such an endgame against experienced and classy grandmaster. Chinese player, considering the team spirit and hardly hoping for something, played till the end and suddenly succeeded!

55.g5!

Sasha thought for a long time and... found a way to make a mistake. Apparently he was so tired that did not control the situation at all. In such a situation one should play with a hand, not with head, which is in fact not working. Hands of a classy player automatically make natural and quite normal moves. But too clever and foggy head often can come up with something that can't even be true. That's what happened.

55...Rh1??

After 55...fxg5 56.Rd6+ Kf5 57.Rd5+ Kg6 any capture on g5 is fruitless. Here are the lines: 58.hxg5 (in case of 58.Rxg5+ Kh6 it is enough to glance on h4 pawn, which is weak, to estimate the position) 58...h4 59.f4 h3 60.Rd6+ Kf5 61.Rh6 Ra3+ - pawn on f4 goes, the fight is over.

Also does not lose 55...Ra6 56.f4 Kf5 57.Rd7 Ra3+ 58.Rd3 Ra6 59.Kf3 Ra5 and so on.

56.Rd6 Rxh4 57.f4!

Obviously, this move was a cold shower for the American grandmaster. It is easy to imagine his condition at the moment. It was a shock!

57...Rh1

In case of 57...Kf5 58.Rxf6+ Kg4 59.g6 Black was not in time to cope with white passed pawn.

58.Rxf6+ Kg7

Alas, black king did not manage to come to h5.

59.Rh6

Pawn on h5 cannot make a competition to white passed pawns.
59...Re1+
Passive defense did not help - 59...Kf7 60.Ke4 Kg7 61.Kf5 Rh2 62.Ra6 and so on.
60.Kf2 Rh1 61.Kg2 Rh4 62.Kf3 Rh1 63.Ke4!
With a little delay white king aims to f5.
63...h4 64.Kf5 h3 65.Kg4! h2 66.Kg3! 1–0

This is how China won the match and became the main contender for the gold, because its tie-breaks are higher than those of the rivals.

It was surprising, how hard was the victory for Russians, although the key win was conducted rapidly.

Karjakin,Sergey (2785) - Flores,Diego (2589)
Russia - Argentina

White is slightly better, but nothing screamed for a quick finale.
17...b5?
Too optimistic. He had to choose between two "evils":
Either 17...Bxb3 18.cxb3! Nd4 19.Bxd4 exd4 20.Nd5 Nxd5 21.exd5 h5 22.Bd3 with g2-g4.
Or 17...0–0 18.Nd5 Nxc2 19.Nxf6+ Qxf6 20.Qxf6 gxf6 21.Kxc2 Nd4+ 22.Kb1 Nxe2 23.Rxd6 and so on.
18.Nd5! Bxd5 19.exd5
Now the active knight on b4 becomes a victim in all the variations.
19...Nd4
Too boring is 19...Ne7 20.c3 or 19...Na5 20.c3.
20.Nxd4 exd4 21.Bxd4 Bxd4 [on 21...Rxc2 comes 22.a3] 22.Rxd4 Nxc2
In case of 22...Qa5 most accurate is 23.Re4+ Kf8 24.Qb3! Nxc2 25.Bd3 with the same outcome.
23.Rd2
After the step back of the knight to b4, the white queen's check on e4 decides. 1–0

Russians did not shine on the other boards. For example, Jakovenko conducted the game timidly and held it only with a big will power.

Armenian players, as it seems, found a second breathe. Their play in the match with Holland made a big impression.

Giri,Anish (2711) - Aronian,Levon (2816)
Netherlands - Armenia

Gaining space needs time and weakens the back ranks...
18...e5!
Levon skillfully uses White's development delay and the power of his own bishops.
19.d5
Otherwise black bishop goes to e6 with a tempo.
19...f5!
Artistically played, against all computer recommendations.
20.dxc6 e4
Black limits once strong elephant on g2 and gets a strong initiative for the pawn.
21.cxb7 Bxb7 22.c6 Ba6 23.Qb3
Apparently, stronger is 23.c7 Qe7 24.Qc6 e3 25.Nc3! (probably, Anish rejected this variation when he saw 25.fxe3 Qxe3+ 26.Kh1 Bb7!) 25...exf2+ 26.Kh1 (26.Kxf2? Bc5+) 26...Bxc3 27.Qxc3 Rac8 28.Qd2 Rxc7 29.Qxf2 Rxc1+ 30.Rxc1 Qb4 =+
23...Rc8 24.Nc3
This way or another the pawn on c6 is doomed. Not better is 24.Na3 Qb6.
24...Rxc6 25.Nd5 Bc5 26.Bf1

26...f4!
New powerful break.
27.Nxf4
If Anish could predict the future, he would play 27.Rxc5! Rxc5 28.Nxf4 (28.Bxa6 Qxd5) 28...Rc6 (28...Bxf1) 29.Bxa6 Rxa6 30.Qc4 with the chances to survive.
27...Bxf2+! 28.Kh1
Lost is 28.Kxf2 due to 28...Rxf4+ 29.gxf4 Qd2+ 30.Kg1 Rxc1 31.Rxc1 Qxc1 32.Qh3 e3 with inevitable e3-e2.
Apparently, a little more accurate was 28.Kg2 Rb6 29.Qd5!
28...Rb6! 29.Qc2
Here on 29.Qd5 unpleasant is 29...Bb7 30.Qxd8 Rxd8 (if the white king was on g2, the bishop on e2 would fall) 31.Rc2 g5 32.Ne2 e3+ 33.Bg2 Ba6! With the decisive advantage for Black.
29...e3
A very strong pawn on e3 paralyses White's forces.
30.Bg2 Qe8 31.Qc5 Rff6 32.Rc2 [32.Qxa5 e2!] 32...g5!
Getting rid of White's block, Black organizes a pawn to pass.
33.Nd5 [33.Ne2 Bd3!] 33...e2 34.Qxa5 e1Q+
Computer would play 34...Rbd6!, immediately finishing the game because impossible is 35.Nxf6? Rd1+.
35.Rxe1 Qxe1+ 36.Qxe1 Bxe1 37.Nxb6 Rxb6

There are no problems with converting of the extra piece.
38.Rc6 Rxc6 39.Bxc6 Kg7 40.Kg2 Kf6 41.Bf3 Ke5 42.h4 Bc8 43.hxg5 hxg5 44.Kf1 Bxg3 45.b4 Kd4 46.a5 Kc4 47.a6 Bb8 48.Bb7 0–1

Sokolov,Ivan (2696) - Akopian,Vladimir (2687) [D10]
Netherlands - Armenia

This extremely complicated game can be only watched from the side, without getting into details, enjoying the esthetics of the struggle.

19...Nxd4!
A good sac of the knight for three pawns.
20.exd4 Qxd4+ 21.Kg2 Qxf4 22.Qf2 Qxf2+ 23.Kxf2 Rac8 24.Ne2 Ne5 25.Ke3 b5 26.Rxc8 Rxc8 27.Rc1 Rxc1 28.Nxc1 Nc6 29.Bd6 Bd4+

30.Kd2?
Ivan for some reason decided that the opponent would necessarily capture on b2, and failed.
30...Bf2! 31.a4 bxa4 32.Bxa6 Bxh4 33.Bb5 Bxg5+ 34.Kd1 Na5 35.Nd3 Nc4 36.Bxc4 dxc4 37.Ne5 Bf6 38.Nxc4 g5 39.Kc2 Bd4 40.Kd3 Ba7 41.Nd2 Kg7 42.Ne4 g4 43.Nc3 h4 44.Ke2 Bd4 45.Nxa4

45...e5
The snowball of black pawns is approaching, and White's counter play is too slow.
46.Bc5 h3 47.Kf1 f5 48.Bxd4 exd4 49.Nc5 Kf6!
The fact that black king also takes part in the process makes a big impression.
50.Nd3 Kg5 51.b4 f4 52.b5 f3 53.Nf2 h2 54.Nh1 d3 55.Ke1 Kh4! 0–1
A brilliant chess performance! Bravo, Vladimir!

The outcome of the match Ukraine – Azerbaijan was decided by the obvious weakness of the latter on the second board.

Ponomariov,Ruslan (2734) - Safarli,Eltaj (2620)
Ukraine - Azerbaijan

After the suspicious opening, Eltaj stubbornly defended and almost balanced the game. But he slipped in the last moment.
24...Qd8?
Too passive. The weakness of the back rank is shown in the variation 24...Nf6 25.Rc8!.
That's why with the elimination method one can come to moves 24...h6 or 24...h5, which gave Black serious chances for the positive result.
25.Rc6! Qb8 26.Rxd6 Rxb3 27.Rxd7 Rxb2 28.Qd5!
Centre domination gives White serious advantage.
28...Rb1?!
More persistent is 28...h6 29.Rcc7 Qb3! 30.Qxb3 Rxb3 31.Ra7 Rb4 32.Rxa6 Rxe4 and so on.
29.Rxb1 Qxb1+ 30.Kg2 Qa1 31.a5 h6 32.Rd6!

With the fall of a6 pawn the intrigue is gone.
32...Rc8
It seems, Azeri player could not psychologically cope with the boring rook ending after 32...Qd4 33.Qxd4 exd4 34.Kf3.
33.Rxa6 Rc1
This is not a counter play, but a try to give a couple of checks before the end. 34.Ra8+ Kh7 35.Qxf7
White king shelters on g4 and covers with the pawn f3, black king is doomed. 1–0

The main sensation of the women's tournament in general, and we can judge of that yet, is the performance of the young team from Kazakhstan. Before unknown, these players demonstrate surprisingly solid play and score a lot.
In the match China - Kazakhstan the rating superiority of Chinese on all four boards summed up to, you won't believe, 1130 points! One could expect some result between 3,5-0,5 and 4-0. But in reality the fight was about equal and the final draw was absolutely natural.

Davletbayeva,Madina (2165) - Ding,Yixin (2424)
Kazakhstan - China

After unsuccessful opening the Chinese player heroically defended but could not confuse the opponent.
49.a5!
It is interesting to mention that this move was marked as a mistake on some sites with computer analyses. Apparently, computers got tired to the end of Olympiad, too!
49...bxa5
Recommended by computers 'escape' 49...f3 did not escape anything due to 50.Rf2!! exf2+ 51.Kxf2 Kd5, and here is a nice win: 52.c7! Nxc7 53.axb6 – there is no way to hold white pawn.
50.b6 f3 51.c7 Nf4
Black's counter play is serious, but White had an idea of blockade of black pawns.
52.Rf2!
Brilliant decision.
52...Nd3+ 53.Kf1 Nxf2 54.c8Q
The next moves can be explained only by the big grief of the Chinese.
54...Kd4 55.Qd7+ Kc5 56.b7 Ne4 57.b8Q Nd2+ 58.Qxd2 exd2 59.Qd8 1–0

The outcome of the match Russia – Armenia was decided when the bright break was conducted on the 4th board.

Pogonina,Natalija (2448) - Kursova,Maria (2338)
Russia - Armenia

The position of Black is quite solid, but the nerves of Maria are not made of iron. Natasha's next punch is aimed for them.
17.e5!! Ncxe5
The first alarm call. Played too cunning.
Natural and solid 17...Ndxe5 18.Nxe5, and any capture on e5 is good. Even 18...dxe5 19.Ne4 Rxd3! 20.Nxf6+ gxf6 21.Qg4+ Kh8 22.Qh4 Rxe3 23.Qxf6+ Kg8 24.Qg5+ Kh8 25.Qf6+ with perpetual check.
18.Nxe5 Bxe5?
Serious blunder, which is of course connected to miscalculation.The position could be held by 18...Nxe5 19.Ne4 (or 19.fxe6 Bxe6 20.Rxf6 gxf6 21.Ne4 Ng4!) 19...Bh4! 20.f6 (20.g3 exf5) 20...d5 21.Ng5 g6 22.Nxh7 Nxd3 23.cxd3 e5 and so on.
19.fxe6 Rxe6
19...fxe6 loses due to 20.Bxh7+ Kxh7 21.Qh5+ Kg8 22.Qf7+ Kh8 23.Rf3.
20.Bxh7+ Kf8
Prosaically lost is 20...Kxh7 21.Qh5+ Kg8 22.Qxf7+ Kh8 23.Qxe6.
21.Nd5 Qa5 [on 21...Qc6 decides 22.Be4] 22.c4 Rde8 23.Bf5 Kg8 24.Bxe6 Rxe6 25.Qf2
White has decisive material and positional advantage. Pogonina acted slowly and not accurately, but anyway managed to win.

When the Armenians saw the situation of their team-mate, they started to get nervous and made mistakes, that was used by Russians.

Tiredness as a decisive sport factor dictates the course of events at the whole Olympiad.
Even those who are famous for the calculation skills, sometimes miscalculate.

Rajlich,Iweta (2412) - Zhukova,Natalia (2442)
Poland - Ukraine

White's position is solid as a stone. The more surprising is what happened.
15.Rfd1?!
Who could think that this externally normal move would lead to problems?
15...Qb6! 16.Rab1
Not feeling the problem. 16.Rd2 Ne4 17.Rc2 Bf5 leaded to the unpleasant confrontation.
16.b3 would weaken the pawn structure - 16...Qa5 17.c4 Rad8 with the advantage for Black.
16...Bf5 17.Bd3 Bxd3 18.Rxd3 Qa6!
Double attack on d3 and a6. Black won the pawn and converted the game to the full point.

This game was decisive at Ukraine – Poland. This is how Ukrainians got a chance to fight for medals.

Another bright proof of a big role of physical endurance in chess was an iccident that happened with one of the best players in the world.

Cori Tello,Deysi Estela (2413) - Muzychuk,Anna (2606) [D97]
Peru - Slovenia

1.d4 Nf6 2.Nf3 g6 3.c4 Bg7 4.Nc3 d5 5.Qb3 dxc4 6.Qxc4 0–0 7.e4 Be6 8.d5

8...Bg4??
Unbelievable blunder. Normal is 8...Bc8! followed by the central break with c7-c6.
9.e5 Bxf3 10.exf6! exf6 11.gxf3
There is neither piece nor compensation. Black fought for 47 more moves, but lost.

The last round is ahead, it will put all the dots above i.