[Computer-go] Semeai and ko
sheppardco at aol.com
Tue Apr 26 11:39:04 PDT 2011
Your research is quite astonishing.
I already suspected that I would not be able to manually create an expert
system that is also complete. I am now completely convinced.
Possibly an exhaustive approach can work, like Go Tools.
I will have to think it over.
From: computer-go-bounces at dvandva.org
[mailto:computer-go-bounces at dvandva.org] On Behalf Of Robert Jasiek
Sent: Tuesday, April 26, 2011 11:37 AM
To: computer-go at dvandva.org
Subject: Re: [Computer-go] Semeai and ko
On 26.04.2011 16:52, Brian Sheppard wrote:
> I have always found kos in semeais to be bewildering.
> I haven't come across any rules for how to count liberties when a ko is
You have identified the complexity correctly. I started to study semeais
with kos but after one month I postponed further study because I
realized that there are probably already hundreds of basic(!) cases. My
estimated research time for 2 group semeai without aji defects and
without non-trivial scoring prediction (but arbitrarily many dame, basic
nakade eyes, basic kos, approach moves) is between 3 and 24 months full
time work. It might be faster to write a program that does all the maths
proofs by itself... but writing what it shall find is already non-trivial.
Some of the major distinctions I have noticed so far are:
- topology of the semeai
- approach defects
- aji defects
- kos external for a particular group versus internal
- kos initially open or closed
- ordinary kos or flower-viewing kos, either with up to n approach moves
In other words, currently you do not have a realistic chance for a
reasonably complete expert system. Try to use other approaches to the
semeai with kos problem. E.g., identify equivalent intersections and
replace them by one virtual, multiple intersection. Then apply MC or
If your interest is all ko shapes rather than a strong program, read my
And please do not forget to share your findings! :)
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