opening book?

[flok]

Does Go have something like an opening book?
In what format is it?

If not: is there a standard way of hashing a Go board? (independent of the dimensions?)

[Rémi Coulom]

The only standardised format for Go is SGF.

I am not aware of a standard way of hashing a Go board.

Here is the 9x9 opening book I computed with Crazy Stone:
https://www.crazy-sensei.com/book/go_9x9/

It handles transpositions into symmetries or rotations of the board. For this I needed a hash code that produces the same value for all 8 transformations of the board.

Some people tried clever ways to make hash codes that are invariant with board transformation:
https://www.mail-archive.com/computer-g ... 17519.html

But it is not clear whether this actually works. What I do is I compute the 8 Zobrist hash codes, compute S = sum of all hash codes, and pick the hash code h_i that minimizes h_i + S. This + S trick is to ensure uniform distribution of codes. Maybe using S as the hash code would work as well.

[flok]

Would it make sense for my tournament software to start with a few randomly placed stones for both sides? In case neither of the players has a way of randomizing and would play the same game over and over again?

[Rémi Coulom]

Starting from varied positions is important. Two games should be played from each starting position (swapping colors). If you maximize territory, then completely random positions are OK. Otherwise, if you maximize the probability of winning, then you should try to somehow select positions that are balanced.