Book review: Game Changer - my Book Of The Year!

Book review: Game Changer - my Book Of The Year!

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At the end of January New In Chess published the long-awaited book Game Changer by Matthew Sadler and Natasha Regan. In the book the authors explain the science behind AlphaZero through interviews with the developers of AlphaZero at Google Deepmind. Furthermore, they analyze the unique playing strategies of AlphaZero based on 2350 games played between AlphaZero and Stockfish in the beginning of 2018.

Matthew Sadler recorded a separate video series analyzing the world chess championship games using AlphaZero. This analysis is not part of this book. Moreover, there is a Youtube Game Changer channel in which Regan and Sadler analyze games between AlphaZero and Stockfish that are NOT in the book.This video series focuses more on Openings while the book focuses more on Chess Strategies involving piece mobility and kings attack.

During the Tata Steel Chess Tournament Magnus Carlsen commented on the release of the book (skip to 1 minute 25 seconds in the interview below to hear Magnus' opinion):

Position after 18.Qd3. Black could have continued 18…. f5. Carlsen chose 18... Qc8

Magnus Carlsen commented after his draw against Teimour Radjabov in round 11 of the Tata Steel Chess Tournament on the book Game Changer: "I found the book quite inspirational. I was thinking at several points during the game: How would AlphaZero have approached this? I thought AlphaZero would have played f5, f4 and then very slowly try to go g6 and h5." The best humor always contains some truth! Yes, AlphaZero likes the initiative, attack the king and indeed takes it's time to cover weaknesses in his own position first before launching the final attack.

This book is clearly a labor of love. It is a fascinating read for players at all levels. Sadler and Regan have done an outstanding job in explaining the science behind AlphaZero, the style of AlphaZero’s play and the uniqueness of AlphaZero.


  • Paperback Amazon US (list: $24.95; currently: $16.34)
  • Kindle: $13.99 electronic book
  • Forward Chess: $19.99 (on sale currently for $16.99) electronic format with the possibility to replay games alongside the text (see the picture below)
  • Chessable: $24.95 (on sale currently for $17.99): to read the book and  solve AlphaZero quizzes

I recommend for this book the electronic format of Forward Chess. It is a great benefit to be able to play through all the beautiful games while reading the text side by side. Below is a picture of the book on Forward Chess. Forward Chess books can be read on iOS, Android, MacOS and Windows.

The book (416 pages) is split into 5 parts: 1. AlphaZero’s history, 2. Inside the box 3. Themes of AlphaZero’s play, 4. AlphaZero’s opening choices 5. Conclusion.

The first and second part are very interesting because of the access that Sadler and Regan had to the Deepmind team. After the initial publication in December 2017, there were many questions about AlphaZero left unanswered. The Leela Chess Zero development team, the public engine that was based on AlphaZero, researched many issues themselves and could not just rely on the scientific papers of Google Deepmind. The recent publications have helped the Leela Chess Zero team finetune the Leela Chess Zero engine. Leela Chess Zero is currently battling Stockfish 10 in the TCEC season 14 final and is holding her own with both engines winning 6 games after 40 games total.

The first part includes a chapter called ZeroZeroZero in which Sadler analyses positions which the three leading engines Stockfish, Komodo and Houdini consider equal (0.0). The chapter highlights how differently AlphaZero evaluates these positions. In the ‘Python Squeeze’ AlphaZero slowly builds up a kings attack and then transforms one advantage (kings attack) into another (piece activity) and goes on to win the game based on the latter.   

Part 3 ‘Themes in AlpaZero’s play’ explains how AlphaZero plays based on the themes Piece Mobility and Attacking the king. The authors draw comparisons between the best human players, like Anand, Kasparov and Carlsen, and AlphaZero. Every theme is introduced in a very systematic way including elements like Purpose, Prerequisites, Risks, Unique implementation by AlphaZero. This makes it very easy to read and to understand AlphaZero’s unique approach to chess. This part of the book comprises of 220 pages and is thus the main part of the book.

Part 4 describes AlphaZero’s opening choices and how they developed while AlphaZero was learning. AlphaZero likes to play the Berlin against 1.e4. With White AlphaZero often opened the game with 1.d4 or 1.Nf3. The chapter also describes AlphaZero’s unique strategy to deal with the Carlsbad pawn structure.

In Part 5 Conclusion, the authors convey what they learned from AlphaZero. The most important learnings  according to the authors are: the opening choices, new opening strategies where AlphaZero shows a clear plan and other engines are stuck at 0.00, a re-evaluation of compensation and the initiative and new attacking techniques and strategies around piece mobility.

Karpov and Mazukewitsch distinguish the following 7 criteria for assessing a position and for the development of a plan:

1. Material balance
2. Direct threats
3. Position of both kings (safety)
4. Pawn structure including Strong and Weak Squares
5. Activity and coordination of the pieces
6. Control of the centre and space
7. Control of open lines and diagonals

My conclusion from reading the book is that AlphaZero has a deeper understanding of the interaction of these elements and specifically how these elements evolve over time. As an example, AlphaZero likes to push Harry the h-pawn to create weaknesses in the enemy camp. Mortals would be afraid that the h-pawn might become a weakness over time and that pushing it would waste too much time.

Conclusion: 5 out 5 starts highly recommended

 A final thought: for AlphaZero to be a real Game Changer, the engine should be made available by Google Deepmind going forward. I appreciate that they have other research priorities but for the chess community it would be great if the chess engine would be publicly available and new discoveries about the game of chess can continue to be made. If there are technically constraints then Deepmind could give access to the top 1000 grandmasters or make the AlphaZero code available to the Leela Chess Zero team. Would it not be great to see what we can learn about chess with AlphaZero in the hands of players like Magnus Carlsen? The true symbiosis between man and machine fitting with the vision of Kasparov.  

Ben Johnson, from the Perpetual Chess Podcast, interviewed both authors in episode 112. You can listen to this hour long interview here: Episode 112 - Game Changer The authors also discuss their 2016 book Chess for Life, one of my favorite books.

Matthew Sadler (1974) is a Grandmaster who twice won the British Championship and was awarded an individual Gold Medal at the 1996 Olympiad. Matthew Sadler is rated 2691 and one of the 50 strongest players in the world. Natasha Regan is a Women’s International Master from England who achieved a degree in mathematics from Cambridge University. Matthew Sadler and Natasha Regan won the English Chess Federation 2016 Book of the Award for their book Chess for Life.