For about a year now I’ve been reviewing Dosaku games every Sunday, chronologically. By now I’ve covered about 20 years’ worth of his game records.
In case you don’t know, Dosaku is one of very few people known as “go saints”. During his lifetime, he would give a two-stone handicap to other pros of the time. He invented the tool known as “tewari”, where one can explore the effectiveness of stones in a particular exchange by playing them in a different order and seeing if they all still make sense.
He’s also known for being one of the few pros that today’s pros would study, thought to be 12d or 13d by today’s ranks. And, most importantly, the AI confirms that Dosaku is indeed ridiculously strong, much more consistently strong than today’s top pros.
So… Dosaku’s Masterpiece. In 1684, Honinbo Dosaku played a game against Yasui Shunchi, and gave Shunchi a two-stone handicap. He ended up losing this game by only one point, which means he made up approximately 20 points over the course of the game. Dosaku’s play follows the AI-suggested strategy almost perfectly, and only has one or two moves that the AI considers suboptimal (which is to say, maybe they lose one point or two). Afterwards, Dosaku said of his opponent,
“He is a first-rate player and need feel no shame before the ancients. He is a rarity even by past standards. In this game there was no manoeuvre or moves of his that were not worthy of some praise.”
And the AI generally agrees with this statement as well; Shunchi made more mistakes than Dosaku (a few three-point mistakes, GASP!), but his play also generally follows AI suggestions, though his timing isn’t as good as Dosaku’s. In other words, this is a game between two top-tier players by today’s standards.
I will be going over this game specifically, with AI-assisted variations and counts, and explanations of the board position, direction of play, and why Dosaku may have chosen an idea over another. I will certainly not be the last person to go over this game, but I hope I’ll make it exciting and approachable for most!
Come one, come all, hang out, let’s dissect this game together!