The Art of 9 × 9 Go

Superhuman Edition


We meant this book as a means of boosthing your 9 × 9 Go skill, a superhuman AI game review, showing the true meaning behind each move in the actual superhuman vs human 9 × 9 Go games. Attention will be paid to 9 × 9 Go principles, in a form suitable for novices who are already know Go rules and curious to know how super strong players think.

Top professional Go players and superhuman players alike used to play a lot. The proverbs say, "Lost your first 50 games as quickly as possible" and "A minute to learn, a lifetime to master.". We did. The principal author reached 2 dan within the first 10,000 games; the best practice at the time is noted in The Art of 9 × 9 Go: How to Beat Dan Players at GoQuest, which came out in 2009, when Go bots were still weaker than 9 dan professional Go players.

Then, once David J. Wu had written a great open-source AlphaZero-like Go playing program named KataGo, there was a KataGo engine verified by GoQuest user KataTest 9 dan (20b9_335 on RTX2060), the first and only invincible No. 1 top ranked player on the server (92 win 0 lost 1 draw). The KataTest's game records are no longer publicly available from the server, but 39 of them have been compiled and published in The Art of × 9 Go, Machine Learning Edition. At the time, one of the best ways of fast learning was by studying quality games the greatest players have played.

Nowadays, we can better study 9 × 9 Go with iOS application named "A Master of Go", of which the version with an old KataGo engine and a weaker neural network run on mobile device could reach No. 1 top ranked player on GoQuest on August 11, 2020. With this app, we could correctly predict all the next moves of KataTest in our experiment, and know how it thinks.

Principles of 9 × 9 Go noted in this book were learned from game analysis by A Master of Go, whose performance is arguably far beyond 9p or top superhuman of 9 × 9 Go.

A Master of Go
Go AI that reached No.1 top ranked player on GoQuest human 9 × 9 Go server and is the co-auther of this book.

Our book is not addressed to you if you already know common mistakes and the best solutions, or you already know what moves should be used in what situations and understand the following concepts:

  • Forms: Connecting, one-space jump, two-space jump, knight move, large-knight move, butterfly move, diagonal move, double dragon move, etc.
  • Basic movement: Attack (away, approach, and attach) and defend (joint, jump, and jerk).
  • Strategy: Global battle plan
  • Tactics: Local battle operations
  • The right moves the top 9 dan professional players and the superhuman AI have agreed
    • "Go Seigen"
    • "Cho Chikun"
    • "Yuki Satoshi"
    • "Cho Hunyun"
  • Move selection strategy
  • The right way to 9 × 9 Go

The coding of this e-book is not possible without great works of others. In particular, we thank David J. Wu for KataGo, Erin E. Sullivan for book layout, Jan Prokop for Go diagram (WGo.js), and Yuji Ichikawa for kind permission on the use of A Master of Go.

Monteo da Westi &
A Master of Go
World Go Academy