Re: [Computer-go] Seki frequencies

[Ingo Althöfer]

Hi Petri,

your comment was covered already by te moe general comments
of Robert Jasiek and THomas Wolf.

Thanks nevertheless.

Ingo.
 
 

Gesendet: Montag, 18. Januar 2016 um 12:13 Uhr
Von: "Petri Pitkanen" <petri.t.pitka...@gmail.com>
An: computer-go <computer-go@computer-go.org>
Betreff: Re: [Computer-go] Seki frequencies

"Seki means a constellation on the go board with twoliving neighboring groups: 
one by Black, the other one
by White. Each of the groups has only one eye"
 Why would you need an eye for seki?
http://senseis.xmp.net/?Seki
Shared liberties is good enough and quite typical in my limited experience
 
Petri

 ___ Computer-go mailing list 
Computer-go@computer-go.org 
http://computer-go.org/mailman/listinfo/computer-go[http://computer-go.org/mailman/listinfo/computer-go]
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Robert Jasiek]

On 18.01.2016 15:58, "Ingo Althöfer" wrote:

understand the development of the fight during the running game.


Simply speaking, there is a relation between a) captures / avoiding 
captures and thus controlled regions of the board and b) score peaks. 
This is so for ordinary captures, ordinary unsettled life / death, 
maintained / broken territory regions and sekis. Correct plays or 
mistakes result in regions controlled by certain players. Peaks tell you 
where such position-local changes in scores occur and you can call these 
regions "potential fighting regions". Once you know where they are, a 
second step might do a functionally abbreviated reading (To defend or 
not to defend this region / string?) for these big decisions together to 
find potentially good strategic decision-making for the "large" scale 
decisions.


This is not the same as my go player term "fighting region" (simply 
speaking, a local set of unsettled groups with its near empty 
surrounding intersections, details see the book Fighting Fundamentals), 
and it is also not the same as what a go player understands as a 
"fight", which includes such things as "attack a group for the same of 
making an additional 1 point in sente during this particular sequence". 
With histograms, you see nothing like this in the near future, I'd guess.


Define 'fight'! (As you understand it for your study purpose.)

--
robert jasiek
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Robert Jasiek]

On 18.01.2016 08:47, "Ingo Althöfer" wrote:

My main motivation for thinking about Seki was/is the question
if it is possible to recognize upcoming Seki situations in the
histograms of an MCTS bot


As you have understood now, seki detection is not only a shape / 
topology question but mainly is about stability due to disadvantageous 
value changes both locally and globally (e.g. ko threat played in a seki 
as a means of offering a local sacrifice). In terms of histograms, you 
might identify the number of local value extrema e.g. for the whole 
board position's score. Is seki much different from ordinary life and 
death? Why care if anything is a seki? Maybe it is sufficient to study 
histograms of final global scores and detect at which tree branches 
peaks arise. (Or do likewise for subpositions.)


--
robert jasiek
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Petri Pitkanen]

*"Seki means a constellation on the go board with two*

*living neighboring groups: one by Black, the other oneby White. Each of
the groups has only one eye"*

Why would you need an eye for seki?
http://senseis.xmp.net/?Seki
Shared liberties is good enough and quite typical in my limited experience

Petri

>
>
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Ingo Althöfer]

Hi Robert,

thanks for your new (again) interesting comments. 

Perhaps it would be interesting to perform some experiements
with a "CrazyRobert" team sooner or later ("Crazy" stand for
CrazyStone, the computer part) - in the spirit of the CrazyManja
experiments in 2015.

I will contact you by private mail in this respect.

> ...
> Define 'fight'! (As you understand it for your study purpose.)

At the moment I can only define "interesting fight":
that is when the histograms look interesting (for instance like
in the seki sequence).

Ingo.
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Nick Wedd]

There are some exotic sekis on this page by Denis Feldman:
http://denisfeldmann.fr/bestiary3.htm#p2

Nick

On 17 January 2016 at 16:04, Thomas Wolf  wrote:

> Hi,
>
> On Sun, 17 Jan 2016, "Ingo Althöfer" wrote:
>
> Hi Robert,
>>
>> thanks for the whole bunch of very intersting information.
>>
>> Seki has AT LEAST two groups
>>>
>>
>>
>> Sekis can have various different shapes ...
>>> ... stable anti-sekis (stable because other anti-sekis exist elsewhere
>>> on the board).
>>>
>>
>> Can you give an example for anti-seki?
>>
>> Listing the possible configurations is a demanding open research field.
>>>
>>
>> Perhaps you and someone like Thomas Wolf (with his life-and-dath
>> background) would be "the right" people for this question.
>>
>>
>
> I have an (unpublished) talk about sekis online:
> http://lie.math.brocku.ca/twolf/papers/sekitalk2.pdf
>
> I am grateful for any references about literatur on seki and any examples
> of
> strange, exotic seki.
>
> Thomas
> ___
> Computer-go mailing list
> Computer-go@computer-go.org
> http://computer-go.org/mailman/listinfo/computer-go
>



-- 
Nick Wedd  mapr...@gmail.com
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Ingo Althöfer]

Hi Robert,

thanks for the whole bunch of very intersting information.

> Seki has AT LEAST two groups 


> Sekis can have various different shapes ...
> ... stable anti-sekis (stable because other anti-sekis exist elsewhere on the 
> board). 

Can you give an example for anti-seki?

> Listing the possible configurations is a demanding open research field.

Perhaps you and someone like Thomas Wolf (with his life-and-dath background) 
would 
be "the right" people for this question.

 
> > My question: How frequent are Seki constellations?
> 
> This very greatly depends on which player population is observed. On 
> KGS, sekis are frequent. Among Japanese professionals (for which I 
> counted sekis for an unrepresentative sample from the second half of the 
> 20th century), sekis occur only once in ca. every 70th game. I think 
> sekis are not so scarce among Chinese and Korean professionals.

Very interesting.

> Apparently long playing time combined with great playing strength avoids 
> sekis. Short thinking time with relatively great playing strength 
> (amateur dans on KGS) seeks seki as a reasonable compromise in 
> unreasonable fights.

Hmm. Would strong go bots also fall in this category?

QUESTION to MCTS programmers:
How do the frequencies of Seki in playouts and in MCTS-based
games relate?

Ingo.
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Robert Jasiek]

On 17.01.2016 12:19, "Ingo Althöfer" wrote:

Can you give an example for anti-seki?


One black string and one white string share exactly one liberty and do 
not have any other liberty. Copy & paste the same but invert colours 
elsewhere on the board. The shortest perfect play is to pass.


It can also be more complicated: use pendulum kos.

Asymmetric sets of subpositions is an interesting study field for 
algebraists, says Charles Matthews.



Listing the possible configurations is a demanding open research field.

Perhaps you and someone like Thomas Wolf (with his life-and-dath background) 
would
be "the right" people for this question.


Actually for non-ko sekis there are specialists such as Bill Taylor, 
Harry Fearnley, Ger Hungerink, Denis Feldmann and others whose name I do 
not recall now. Given enough time, Wolf and I might also do related 
research and Wolf would have suitable programs to use but I have - for 
me - more urgent tasks, such as continuing research on ordinary semeais.



Would strong go bots also fall in this category?


I do not know because I have seen too few games played by them.

--
robert jasiek
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Thomas Wolf]

Hi,

On Sun, 17 Jan 2016, "Ingo Althöfer" wrote:


Hi Robert,

thanks for the whole bunch of very intersting information.

Seki has AT LEAST two groups 




Sekis can have various different shapes ...
... stable anti-sekis (stable because other anti-sekis exist elsewhere on the board). 


Can you give an example for anti-seki?


Listing the possible configurations is a demanding open research field.


Perhaps you and someone like Thomas Wolf (with his life-and-dath background) would 
be "the right" people for this question.





I have an (unpublished) talk about sekis online:
http://lie.math.brocku.ca/twolf/papers/sekitalk2.pdf

I am grateful for any references about literatur on seki and any examples of
strange, exotic seki.

Thomas___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go

Re: [Computer-go] Seki frequencies

[Robert Jasiek]

On 17.01.2016 05:33, "Ingo Althöfer" wrote:

Seki means a constellation on the go board with two
living neighboring groups: one by Black, the other one
by White. Each of the groups has only one eye. And
they share a joint liberty.


Seki has AT LEAST two groups. Sekis can have various different shapes 
incl. such with unreducable three shared inside liberties per pair of 
groups, major strings having only 1 liberty (hane seki), or multiple 
kos. Do not overlook the stable anti-sekis (stable because other 
anti-sekis exist elsewhere on the board). Listing the possible 
configurations is a demanding open research field.



My question: How frequent are Seki constellations?


This very greatly depends on which player population is observed. On 
KGS, sekis are frequent. Among Japanese professionals (for which I 
counted sekis for an unrepresentative sample from the second half of the 
20th century), sekis occur only once in ca. every 70th game. I think 
sekis are not so scarce among Chinese and Korean professionals. 
Apparently long playing time combined with great playing strength avoids 
sekis. Short thinking time with relatively great playing strength 
(amateur dans on KGS) seeks seki as a reasonable compromise in 
unreasonable fights.


***

If you want to study seki configurations, the best is to do theoretical 
research. If you want many ordinary sekis in actual games, take KGS samples.


--
robert jasiek
___
Computer-go mailing list
Computer-go@computer-go.org
http://computer-go.org/mailman/listinfo/computer-go