AlphaZero at the Candidates 2020

Before the first rest day, there were glimpses of how AlphaZero has revolutionized the chess world- Anish Giri and Fabiano Caruana in rounds 1 and 3 respectively showed some brilliant preparation based on sacrificing pawns for long term compensation, a strategy used by AlphaZero several times.

During rounds 3-6, there was more proof of how the silicon beast has took the world by storm, albeit in a different way. Caruana, Nepomniachtchi, Ding and Giri all used AlphaZero's now famous idea of tossing the h-pawn down the board.

Of course, this ambitious way of playing has been adopted by many players in the past, but there has certainly been a surge recently, with the main exponent being Magnus Carlsen himself.

Here's how it goes: In a seemingly innocuous position one player suddenly plays h4-h5 (or h5-h4 in Black's case) with the idea of not going for an attack down the h-file but instead closing it with h6! (h3!) thereby causing a lot of discomfort in the opponent's camp. There will be back rank problems, the fianchetto bishop won't find a safe square, and some weaknesses will be formed on the kingside. The downside, of course, is that the pawn might simply be too weak and captured at some point, it may be a bit slow, and the g4 (g5) square becomes weak.

Fabiano Caruana- Ian Nepomniachtchi; Round 4

In this typical Grunfeld position Caruana went for 16.h4! A fashionable trend, not exactly in this particular position, but in such type of structures. However, it seems like it gave Black the opportunity to exchange both rooks and simplify the position. But as the game shows, White has many ideas to fight for an advantage. After 16...Rxc1, 17.Rxc1-Rc8, 18.h5-Rxc1, 19.Qxc1-Qc8 the following position is reached:

Fabi played- you guessed it- 20.h6!-Bf8, 21.d5! even allowing the exchange of queens. What then, was the point of playing the pawn to h6 if we are not going to try and exploit the back rank? What are the chances of White getting an advantage in such a simplified position?

Well, of course there are chances. With a closer look, we can see that White's places are well co-ordinated but the same cannot be said for Black. For Black it's much more difficult to move his pawn majority on the queenside, and the h6 pawn acts as a thorn in his camp, making it much more difficult for Black's king to stride towards the center as the h7 pawn can be weak. Black also has his ideas, but White should be slightly better.

Nepomniachtchi instead went for 21...e6, and after 22.Nc3-Nc4, 23.Bxc4-Qxc4, 24.Qd2 White has some advantage which grew bigger as Black started making some mistakes. In the end, Caruana went went wrong and the game petered out into a draw.

Ding Liren- Anish Giri; Round 4

In the above position Giri went for 15...h5! Correctly understanding that White is statically better and Black should try to get counterplay before White completes his development. 16.Qxc6?! is too optimistic; after 16...Bf5! followed by Rfc8 Black has the initiative. Ding went for 16.Nc3-h4, 17.Ne2-Bd7, 18.Nf4. If 18.Nd4, Black can go 18...h3! 19.Bf3-Rfc8 with good play. In the game there followed 18...hxg3, 19.hxg3-Rfc8.

Black has almost equalized completely. Black couldn't play the pawn to h3 but the purpose is served; White's knight on f4 is not very well placed and after something like 20.Nd3-Qd6, 21.Nc5-Bg4, Black's bishop finds a good square. White's knight on c5 looks very strong but Black has enough counterplay. In the game Anish drew without much problems.

Ian Nepomniachtchi- Wang Hao; Round 5

The position seems more or less equal; equal material, and both players' pawn structure seem to be good. It is instructive to see how Nepomniachtchi manages to win this game with some energetic, powerful moves. 27.h6! White creates a weakness in Black's camp. 27...g6, 28.c4! From the other side! Objectively Black is fine, but he needs to play accurately to maintain the balance. 28...dxc4, 29.bxc4. (If 29...Nxc4? White wins after 30.Nxc4-Qxc4, 31.Qh2!) At this moment using prophylactic thinking Black can find 29...Nf7! Keeping an eye on the h6 pawn! 30.c5 (30.Qh2-Qd6 is the point)- Qd7, 31.Qh2-Qd8 and I don't see how to make progress with White.

Wang, however, went wrong with 29...Kg8?! and after 30.Qh2! he is already in trouble. 30...Kf7, 31.c5-Nb5, 32.Qb8 and this is a very critical moment. The strength of the h6 pawn is clearly starting to show!

The concrete way for Black to equalize here is 32...Nxd4!? 33.Qxb7-Qe7, 34.Qxa6-Qe4! and Black has big counterplay. But to find as well as evaluate this correctly isn't very easy, and the more human way is 32...Qe7! 33.Qh8-Ke6 and here Black has the escape square d7 for his king.. the position is unclear.

In the game was played 32...Qd7? and Nepo accurately took his chance with 33.Qh8-Ke6, 34.f4! and White has a decisive attack! Just the previous round Nepo had to face Caruana's unpleasant pawn on h6 and here he's already using the same idea.. these guys are quick to learn from their mistakes! You can see how White finished off things in the games list at the end of the article.

Ian Nepomniachtchi-Ding Liren; Round 6