How Alpha Zero Won Against Stockfish in Game 40

Much has been written about Alpha Zero, the most amazing artificial intelligence technology by Google’s company, Deepmind. I mentioned in one of my posts that I used to play chess and this inspired me to analyze the game especially for intermediate players.

I used to play against chess computers before and almost all of them chose to play open or tactical positions. Surprisingly, Alpha Zero is a positional player in the style of former World Champion Anatoly Karpov.

According to the news, Alpha Zero has no human input except for the rules of the games. It has mastered Chess by playing against itself. Now, you may ask if a chess player can master chess by playing against himself. I think it is difficult for human to master this game by just playing against himself. This program is different from other chess engines and this is a great achievement in the field of technology.

Now let us analyze how this program plays in game 40 wherein Alpha Zero won against one of the best chess engines in the world, if not the best, Stockfish.

The opening is a Ruy Lopez, Berlin Defense and after sixteen moves, the position below has been reached.

Position after 16…b6

At a glance you will notice that White (Stockfish) has the better position because of its superior mobility, but it can not capitalize on this advantage because Black (Alpha Zero) has no weak points. Usually as an intermediate player, once you achieved an advantage in mobility, try to convert this into an attack against the King or against any weak points. In case your opponent has no weak points just like in the position above, then you will have to wait for him to make a mistake or a bad move.

Here, I would like to add that White can achieved a much better position if he did not maneuver his Queen’s Bishop to g3. This is not a good square for this Bishop if he intended to exert pressure on Black’s King’s Pawn because Black has already overprotected his King’s Pawn at e5 even at the expense of immobilizing his King’s Bishop.

It is interesting to note that Alpha Zero intentionally made his King’s Bishop at d6 a “problem child” because it only served as a Pawn at this point. Stockfish did not exploit this weakness by retaining his Queen’s Bishop to control its original diagonal (c1-h6) but instead chose to put his active Queen’s Bishop into an inactive spot (g3) thus, making the two bishops almost equal in mobility.

After 24 Bg3, the position below has been reached.

The next move of Alpha Zero is quite surprising. An average player would try here f5 but instead Black replied …Rfe7. What is the point of moving a rook in f7 if Black has no intention of the breakthrough move f5? Is it a waiting move? Perhaps Black evaluated that f5 will open the game in the center and this could be dangerous to his King.

After 35 h4, the position below has been reached.

At this point, Alpha Zero realized that his King’s bishop has been immobilized for a long time. Usually, an average player will plant a Knight at f4 via g6 after locking the pawn via pawn move g4. But instead Black gave way for his King’s Bishop to join the battle.

It is interesting to note that at this point Alpha Zero had already studied the endgame possibilities. White’s pawn at c4 and e4 are weaknesses in the endgame and that is the reason why it preserved the Knight by not posting it at f4. Black’s King Bishop will not be useful for that endgame plan so that is why Black will try to force an exchange of this piece.

After 40…Bh6, the position below has been reached.

At this point you will notice that Alpha Zero had made some amazing maneuvers. The Knight at e7 went to d6 via c8 and the King’s Bishop went to h6 via f8. Black really planned the endgame possibilities. He threatened to eliminate the White’s Knight at e3 that protects the pawn at c4 and at the same time his Black’s Knight exert pressure on White’s pawn at c4 and e4.

After 57 Nxb3, the rooks have been exchanged and the position below has been reached.

Now let us pause for a while and analyze the resulting position. At first glance an average player would evaluate the position as better for White because his King is safe whereas Black’s King is somewhat in danger after marching to the base of his pawns. To eliminate this weakness, Alpha Zero will try to exchange Queens and will try to exploit the weakness of White’s pawn at c4 and e4.

White’s plan here is to penetrate the King on the Queen’s side because there is no entry point at the King’s side. He plans to move the Queen to a4 with the possibility of a Queen side attack with the aid of his Knight. Black prevented this plan by moving his Bishop to a4 and moving his King to e7.

A series of moves forced the exchange of Queens because White can not simultaneously defend his weak pawns at c4 and e4. Three pieces are attacking from Black but only two are defending from White because the Bishop at g3 which covers the King, can not join the battle.

The position below has been reached after the exchange of Queens.

Position after 63…Bxg4

Stockfish can not avoid to lose his pawns…the rest is technique.

Based on this game, we can learn some techniques on how to win a game especially against a very strong chess engine. Alpha Zero played a very instructive game here with some amazing positional moves.

We can now summarize how Alpha Zero won against Stockfish in this particular game:

  1. Take note of some weaknesses in the opening. In this case, White’s pawn at c4 and e4 are good targets in the endgame.
  2. Try to force exchange of major pieces to avoid counter-play and try to preserve the necessary minor pieces in case you have a favorable endgame like Black.
  1. If you have an inactive piece, try to find ways to maneuver it in a better position. In this particular game, Alpha Zero found a clever way to maneuver his bishop and knight to better squares.
  2. Exploit the absence of your opponents piece in the battle. In this game, Stockfish’ Queen’s Bishop did not join the battle because it only guards the King into a possible attack.

I hope you have some fun in your chess games.

Featured image: pixabay

Game source: deepmind

Chess diagram: chessx

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