Okjib hwal(Korean term for living without 2 complete eyes)

[ez4u]

Hi aeb, for this game doesn't B at M12 kill ?

Ed, imagine the group with all its outside liberties filled in. Is it, or any part of it, in atari?

[Bonobo]

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$$ . . O O O X X X O O O . .
$$ . O X X X . X . X X X O .
$$ . O X O O X X X O O X O .
$$ . O X O . O O O . O X O .
$$ . O X O O O O O O O X O .
$$ . O X X X X X X X X X O .
$$ . . O O O O O O O O O . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$ . . . . . . . . . . . . .
$$ . . . . . . . . . . . . .
$$ . . . . . O O O . . . . .
$$ . . O O O X X X O O O . .
$$ . O X X X . X . X X X O .
$$ . O X O O X X X O O X O .
$$ . O X O . O O O . O X O .
$$ . O X O O O O O O O X O .
$$ . O X X X X X X X X X O .
$$ . . O O O O O O O O O . .
$$ . . . . . . . . . . . . .[/go]

Just so that I understand: would the black group be called Okjib hwal?

Each eye is “false” if looked at isolated, but because the “tail” leading away from it meets the “false” eye on the other side, it is rendered “real”?

(and yeah, I realize I made some mistake with the diagram notation)

[macelee]

I was at a Go event in Beijing two days ago. After the evening, I, together with many pro and top amateur players, was sitting around dinner tables chatting and watching this game at the same time. It is truly amazing. Also other moves in the game, such as W82, B105 are quite interesting. I was very happy because I suggested the possibility of this unusual shape at move 118 and it only materialized at move 136.

BTW, it was a very interesting event - a bilateral match between China's Tsinghua University and Korea's Yonsei University. I was there as an alumni representative, winning two games. I met special guests Lee Sedol, Gu Li, Jiang Weijie and several other professional players.

[macelee]

$$ . . . . . . . . . . . . .
$$ . . . . . . . . . . . . .
$$ . . . . . O O O . . . . .
$$ . . O O O X X X O O O . .
$$ . O X X X . X . X X X O .
$$ . O X O O X X X O O X O .
$$ . O X O . O O O . O X O .
$$ . O X O O O O O O O X O .
$$ . O X X X X X X X X X O .
$$ . . O O O O O O O O O . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$ . . . . . . . . . . . . .
$$ . . . . . . . . . . . . .
$$ . . . . . O O O . . . . .
$$ . . O O O X X X O O O . .
$$ . O X X X . X . X X X O .
$$ . O X O O X X X O O X O .
$$ . O X O . O O O . O X O .
$$ . O X O O O O O O O X O .
$$ . O X X X X X X X X X O .
$$ . . O O O O O O O O O . .
$$ . . . . . . . . . . . . .[/go]

Just so that I understand: would the black group be called Okjib hwal?

Each eye is “false” if looked at isolated, but because the “tail” leading away from it meets the “false” eye on the other side, it is rendered “real”?

(and yeah, I realize I made some mistake with the diagram notation)

Yes, your example is an Okjib hwal.

[trout]

I was at a Go event in Beijing two days ago. After the evening, I, together with many pro and top amateur players, was sitting around dinner tables chatting and watching this game at the same time. It is truly amazing. Also other moves in the game, such as W82, B105 are quite interesting. I was very happy because I suggested the possibility of this unusual shape at move 118 and it only materialized at move 136.

BTW, it was a very interesting event - a bilateral match between China's Tsinghua University and Korea's Yonsei University. I was there as an alumni representative, winning two games. I met special guests Lee Sedol, Gu Li, Jiang Weijie and several other professional players.

Korea's Yonsei University is my Alma Mater(1965-1970). During last year, I was runner up in Go tournament.

[aeb]

I think that perhaps this is a case of talking about LARGE cases (many stone examples) where multiple groups none of which have two eyes on their own are alive because they mutually touch two separate eyes.

This Oza-snake is a case with a single group.
A 1-point eye can be (i) locally false, (ii) globally false, (iii) false.
Consider a single empty position surrounded by four White stones (fewer on an edge or in a corner). It is locally false when these four stones belong to more than one connected component if one restricts attention to the 3x3 square centered at the empty position. It is globally false when these four stones belong to more than one connected component on the board. It is false when some of these stones will be in atari when outside liberties are filled.
If there is only this single eye, your group is dead. Otherwise, a false 1-point eye is globally false and a globally false eye is locally false, but the converses do not hold: the Honinbo example given above has a globally false eye that is not false, and the Oza-snake has a locally false eye that is not globally false. A group with two non-false eyes is alive. Usually locally false eyes are false, but not in these snakes.

When we say "group" we most often mean a CONNECTED set of stones.

I have used "chain" (Dutch "keten") for a connected set of stones, and "group" for a loose aggregation of chains that might later live or die together.

[macelee]

Korea's Yonsei University is my Alma

Cool. I might visit there next year, assuming there's another match between the two universities.

[Uberdude]

I was at a Go event in Beijing two days ago. After the evening, I, together with many pro and top amateur players, was sitting around dinner tables chatting and watching this game at the same time. It is truly amazing. Also other moves in the game, such as W82, B105 are quite interesting. I was very happy because I suggested the possibility of this unusual shape at move 118 and it only materialized at move 136.

BTW, it was a very interesting event - a bilateral match between China's Tsinghua University and Korea's Yonsei University. I was there as an alumni representative, winning two games. I met special guests Lee Sedol, Gu Li, Jiang Weijie and several other professional players.

Someone else posted a nice picture of Gu and Lee from this event, maybe we can spy macelee in some of the other pictures in the linked news story?
http://www.lifein19x19.com/forum/viewto ... 10&t=13501

[macelee]

Someone else posted a nice picture of Gu and Lee from this event, maybe we can spy macelee in some of the other pictures in the linked news story?
http://www.lifein19x19.com/forum/viewto ... 10&t=13501

I do not appear in those photos. But I did get photos taken with Lee Sedol and Gu Li, and a few other professionals. They are both quite sweet persons, spending lots of time with fans. At dinner time, both circled around the dinner tables to drink with fans. Lee Sedol was particularly warm, we communicated via Lee Changho's elder brother who speaks Chinese very well.

[yoyoma]

Here is the sgf of the game:



I also found part of the broadcast on baduktv's youtube: https://www.youtube.com/watch?v=CXQU23Gv1SQ

The commentator brings up an interesting point: How is this situation handled during scoring? He considered it to be a seki, and therefore the points would not count. But I don't think it's a seki -- it's not sharing it's life with a white group. For a formal definition in Japanese rules sekis are defined as having dame which neither player can fill, and in this case the group will not have any dame left over at the end. I guess Korean rules would be similar.

[Kirby]

Someone else posted a nice picture of Gu and Lee from this event, maybe we can spy macelee in some of the other pictures in the linked news story?
http://www.lifein19x19.com/forum/viewto ... 10&t=13501

I do not appear in those photos. But I did get photos taken with Lee Sedol and Gu Li, and a few other professionals. They are both quite sweet persons, spending lots of time with fans. At dinner time, both circled around the dinner tables to drink with fans. Lee Sedol was particularly warm, we communicated via Lee Changho's elder brother who speaks Chinese very well.

I'd love to see photos if you're willing to share

[macelee]

I'd love to see photos if you're willing to share

Kirby please check your PM to see the macelee - Lee Sedol photo. As it is private I don't fancy the idea of posting it in a public forum. Other friends here please PM me to see the photo too.

Let me share a few more 'public' photos I took from the event.

Lee Sedol and Gu Li guessing the stones for their teams

IMG_3486.JPG (302.11 KiB) Viewed 6544 times

The Korean study room

IMG_3497.JPG (312.15 KiB) Viewed 6544 times

The Chinese study room

IMG_3499.JPG (210.18 KiB) Viewed 6544 times

[Kirby]

Thanks a lot, macelee!

I didn't mean to put you on the spot, but I was interested enough that I did anyway

You must have had a wonderful time! I'm so jealous!

[aeb]

I just noticed that the same phenomenon occurred in the final of the 28th Ryusei, 2019-09-23, Ueno Asami vs. Ichiriki Ryo. The double ko makes sure that Q8 will be an eye.