[Computer-go] Alphago and solving Go

Brian Sheppard sheppardco at aol.com
Sun Aug 6 07:42:46 PDT 2017

```Yes, AlphaGo is brute force.

No it is impossible to solve Go.

Perfect play looks a lot like AlphaGo in that you would not be able to tell the difference. But I think that AlphaGo still has 0% win rate against perfect play.

My own best guess is that top humans make about 12 errors per game. This is estimated based on the win rate of top pros in head-to-head games. The calculation starts by assuming that Go is a win at 6.5 komi for either Black (more likely) or White, so a perfect player would win 100% for Black. Actual championship caliber players win 51% to 52% for Black. In 9-dan play overall, I think the rate is 53% to 54% for Black. Then you can estimate how many errors each player has to make to bring about such a result. E.g., If players made only one error on average, then Black would win the vast majority of games, so they must make more errors. I came up with 12 errors per game, but you can reasonably get other numbers based on your model.

Best,

Brian

From: Computer-go [mailto:computer-go-bounces at computer-go.org] On Behalf Of Cai Gengyang
Sent: Sunday, August 6, 2017 9:49 AM
To: computer-go at computer-go.org
Subject: [Computer-go] Alphago and solving Go

Is Alphago brute force search?

Is it possible to solve Go for 19x19 ?

And what does perfect play in Go look like?

How far are current top pros from perfect play?

Gengyang

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