European Go Journal: February 2022

artem.kachanovskyi · #1

This month Shin Jinseo 9p won the LG Cup, defeating Yang Dingxin 9p with a score of 2-0. In the February edition of the European Go Journal, you will find commentary on the second and deciding game of the final match between Shin and Yang.

Photo: Shin Jinseo 9p after winning the second game.

Subscribe on Patreon to receive future issues of the European Go Journal automatically: https://www.patreon.com/europeangojournal

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artem.kachanovskyi · #2

In the February edition of the European Go Journal, you will find an interview with Volodymyr Kachanovskyi - a go teacher and leader of a go school in Rivne, a city in the West of Ukraine.

Rivne's go school used to have up to 300 students and once was a home for such players as Andrii Kravets 1p, Artem Kachanovskyi 2p, and many other top Ukrainian players. Volodymyr also is Artem's father.

We talked with Volodymyr about the evolution of Rivne's go school, how the studying process is made, and much more.

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artem.kachanovskyi · #3

Updates on the European Go Journal will not be published here anymore - maybe only some really big news.

You can follow the news about the project on the other platforms:
https://www.facebook.com/europeangojournal
https://instagram.com/europeangojournal

Harleqin · #4

That's a pity, I don't use those at all.

karlsgo · #5

artem.kachanovskyi wrote:

Updates on the European Go Journal will not be published here anymore - maybe only some really big news.

And of course, you can read and subscribe here
https://eurogojournal.com/

Subscribe and support a Go project in Ukraine.

artem.kachanovskyi · #6

Harleqin wrote:

That's a pity, I don't use those at all.

If it's so, I will keep going here!

In the March edition of the European Go Journal, you will find an interview with Vsevolod Ovsiienko 4d.

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Vsevolod has just won the European Youth Go Championship (EYGC) in the "Under 16" age category, which took place this month in Prague. We talked with him about the tournament.

Besides, Vsevolod and his family have left Ukraine and are now in Portugal, so we asked him to share his first impressions of being a refugee.

In this month's issue of our magazine, you will also find commentary on Vsevolod's game against Yuze Xing 2d - the deciding battle of the EYGC.

Subscribe on Patreon to receive the future issues of our magazine automatically: https://www.patreon.com/europeangojournal

artem.kachanovskyi · #7

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I am excited to announce that the March edition of our magazine is now published and available for purchase on our website: https://eurogojournal.com/editions/march-2022/

Another good news: from now on, we accept a new payment method - PayPal. Feel free to contact us if you want to buy our magazine using it.

Highlights of the March 2022 edition:

- An article from Artem on the war between Russia and Ukraine, its historical context and impact on the European go scene
- An interview with Vsevolod Ovsiienko 4d on his recent European Championship Under 16 win, and first impressions of fleeing from Ukraine to the EU
- A review of the deciding game of the 26th LG Cup final match, played between Shin Jinseo 9p and Yang Dingxin 9p
- An interview with Volodymyr Kachanovskyi – Artem’s father and leader of Rivne Go School
- Karl Desfontaines’ article on implementing KataGo to try and solve possibly the hardest go problem in the world, including detailed commentary on the solution
- The latest of the Thirty-Six Stratagems presented by Dai Junfu 8d, Art & Photography and much more.

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Cassandra · #8

March 2022 Edition, page 45:

EGJ wrote:

Try to play it out and see what would be the difference if the exchange had not been made.

Click Here To Show Diagram Code: [go]$$Wm112 7 Main Semeai Liberties (12 = 112) $$ +---------------------------------------+ $$ | . . . . O . . . . . . . X . . . O X . | $$ | . . . X X O b X O O . X O X O . . O . | $$ | . . . X O X . O . . . X O . . O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O . a . | $$ | O O O O . X O O X X O O . O X . . 1 . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O . O X . O X O . X X O O O X O O | $$ | O O X O . X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White occupies the Guzumi Point at the right edge, instead of continuing the sequence in the upper left corner with a move at B.

Artem's kind challenge is about the implications of this deviation from KataGo's solution, where the Guzumi Exchange :b12:

, W A had NOT been played before. The answer is shown and explained in detail below.

For all those who would like to confirm their own result by following KataGo's wild jumps from one corner of the board to the next:
One example of KataGo's self-play games.

Click Here To Show Diagram Code: [go]$$Bm113 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . . . X . . . O X . | $$ | . . . X X O b X O O . X O X O . . O . | $$ | . . . X O X . O . . . X O a 2 O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X 1 X X O O . | $$ | . X . O O O X X X O . . X . X O . . . | $$ | O O O O . X O O X X O O . O X . . W . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O . O X . O X O . X X O O O X O O | $$ | O O X O 3 X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Michael Redmond's Kikashi in the Bamboo Joint is a tesuji, which only unfolds its effect in the "classical" line, where WHITE occupied the Guzumi Point :wc:

.
It forces White to choose between the solid connection :w14:

and the atari W A above.
:w14:

-- The solid connection is mandatory in this position, where White must not lose any tempo in the Main Semeai, despite is loses points compared to the atari.
The atari of W A would benefit White in the upper right territorially, but would also lose one tempo in the Main Semeai. Black would be able to play the large endgame move B B in the upper left, capturing all single White stones in this area.
:b15:

-- Black gives atari at White's two stones in the lower left.

Click Here To Show Diagram Code: [go]$$Wm116 7 MSL $$ +---------------------------------------+ $$ | . . 4 3 O 5 . . . . . . X . . . O X . | $$ | . . 6 X X O 1 X O O . X O X O . . O . | $$ | . . . X O X . O . . . X O . O O O . . | $$ | . X O , 8 7 . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | . X . O O O X X X O . . X . X O . . . | $$ | O O O O . X O O X X O O . O X . . O . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O a O X . O X O . X X O O O X O O | $$ | O O X O X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . b X O O O O O O X O X . O X | $$ | . X . . . . 2 O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues with the interrupted sequence in the upper left corner.
She is unable to connect her two stones with a move at W A, instead, as Black would answer with :b16:

again.

-- This descent to the bottom line is MANDATORY in the "classical" line, defending Black's territory in the lower left corner.
Mistakenly playing the "usual" block / atari at :b18:

would be one point worse for Black (White would continue with the hasami-tsuke W B in the lower left).
(Contrary, with the Guzumi Exchange played, this variation would NOT affect the outcome of the game.)
:w18:

-- White pushes at the upper edge, reducing Black's territory in the upper left in return.
:w22:

-- White gives atari at Black's single stone.
:b23:

-- Black captures, of course.

Click Here To Show Diagram Code: [go]$$Wm124 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . . . . . . X . . . O X . | $$ | . . X X X O O X O O . X O X O . . O . | $$ | . . . X . X . O . . . X O . O O O . . | $$ | . X O , X O . . . O . X . O O X 1 . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | . X . O O O X X X O . . X . X O . . . | $$ | O O O O . X O O X X O O . O X . . O . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O 2 O X . O X O . X X O O O X O O | $$ | O O X O X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues with the Main Semeai.
Connecting at :w25:

, instead, would be still a mistake.
:b25:

-- Black captures White's two stones in the lower left.

Click Here To Show Diagram Code: [go]$$Wm126 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . . . . . . X . . . O X . | $$ | . . X X X O O X O O 3 X O X O . . O . | $$ | . . . X . X . O . . 5 X O . O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | 2 X . O O O X X X O . . X . X O . . . | $$ | O O O O 4 X O O X X O O . O X . a O 1 | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O 6 X . . . X O O O O O O X O X . O X | $$ | . X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- The mutual occupation of opponent's liberties continues.
The placement of this move is a bit unusual, more often it is played at W A.

Click Here To Show Diagram Code: [go]$$Wm132 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . . . . . . X . . . O X . | $$ | . . X X X O O X O O O X O X O . . O . | $$ | . . . X . X . O . . O X O . O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X . O O O X X X O . . X . X O . . . | $$ | O O O O X X O O X X O O . O X . . O O | $$ | O X . X . X 3 O O X O . . . X X X X X | $$ | O X . X 4 1 2 O X X O . X X X X O O O | $$ | O O O X . X a O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O X X . . . X O O O O O O X O X . O X | $$ | . X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- KataGo likes this wedge in the left centre, but which is NOT really effective here.
The usual "calm" kikashi of W A, :b32:

would also do the job of preventing Black from getting any territory in the central area below in sente.
:b33:

-- Black must give atari from the outside.
:w34:

-- White's counter-atari is usually played at W A.
:b35:

-- As a matter of course, Black has to capture.

Click Here To Show Diagram Code: [go]$$Wm136 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . . . . 1 2 X . . . O X . | $$ | . . X X X O O X O O O X O X O . . O . | $$ | . . . X . X . O . . O X O . O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X 6 O O O X X X O . . X . X O . . . | $$ | O O O O X X O O X X O O 3 O X . . O O | $$ | O X . X . X O O O X O . . . X X X X X | $$ | O X 8 X X . X O X X O 5 X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O 7 X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O 4 . . O X . O X X X X X . O X X O X | $$ | O X X . . . X O O O O O O X O X . O X | $$ | . X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues with the Main Semeai.

Click Here To Show Diagram Code: [go]$$Wm144 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . 5 . . O X X . . . O X . | $$ | . . X X X O O X O O O X O X O . . O . | $$ | . . . X . X 4 O . . O X O . O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . . X . X O . . . | $$ | O O O O X X O O X X O O O O X . . O O | $$ | O X . X a X O O O X O . . . X X X X X | $$ | O X X X X 2 X O X X O O X X X X O O O | $$ | O O O X . X 1 O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X 3 O X X X X X . O X X O X | $$ | O X X . . 6 X O O O O O O X O X . O X | $$ | . X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White's atari erases Black's hopes on some points of territory below.
:b45:

-- Black's connection is mandatory.
He is unable to fight a ko after :w45:

, as White threatens to capture his three cutting stones above with W A.
:w46:

-- White plays her kikashi in the lower left corner.
:b47:

-- Black inserts a kikashi of his own at the upper edge in return.

Click Here To Show Diagram Code: [go]$$Wm150 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X . . . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X . X X O . . O X O . O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . . X . X O . . . | $$ | O O O O X X O O X X O O O O X 1 a O O | $$ | O X 2 X . X O O O X O . 5 . X X X X X | $$ | O X X X X X X O X X O O X X X X O O O | $$ | O O O X . X O O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X 6 O O X . . O X O . X O O O X X X O | $$ | 7 O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O X 3 O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X . O X X O X | $$ | O X X . . X X O O O O O O X O X . O X | $$ | 4 X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues with the Main Semeai.
Again, a move at W A would look less extraordinary.

Click Here To Show Diagram Code: [go]$$Bm157 7 MSL $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X 5 6 . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X . X X O . . O X O 8 O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . 4 X . X O . . . | $$ | O O O O X X O O X X O O O O X O 2 O O | $$ | O X X X . X O O O X O . O . X X X X X | $$ | O X X X X X X O X X O O X X X X O O O | $$ | O O O X . X O O X O O X X O O O O X . | $$ | 9 O O O X . . O X O . X O O O . X X X | $$ | 1 7 O O X . . O X O . X O O X X X O O | $$ | 3 . O O X . . O X O . X O O O X X X O | $$ | O O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O . O O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X 0 O X X O X | $$ | O X X . . X X O O O O O O X O X . O X | $$ | X X . . . . B O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Black plays the final oki into White's eye at the left edge.
:w66:

-- White captures the hanezeki's tail, choosing the Capture Variation.
Here, with Black's descent :bc:

in the lower left, the Semeai Variation would end two points worse for her.

Click Here To Show Diagram Code: [go]$$Bm167 Capture Variation $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X X O . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X . X X O . . O X O O O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O . . . | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X . X O O O . O . O . X X X X X | $$ | O X X X X X X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X O O | $$ | X . O O X . . O . O . X O O O X X X O | $$ | O O O X . X . O . O O X X O O O X O O | $$ | O O X . X X . O . O . O O X X X O O O | $$ | O X X X X . . O . O O O O X O X O O X | $$ | O X . . O X O O . . . . 1 O O X X O X | $$ | O X X . . X X O O O O O O X O X . O X | $$ | X X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Black recaptures four White stones.

Click Here To Show Diagram Code: [go]$$Wm168 Capture Variation $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X X O . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X . X X O . . O X O O O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O . . . | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X . X O O O . O . O . X X X X X | $$ | O X X X X X X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X O O | $$ | X . O O X . . O . O . X O O O X X X O | $$ | O O O X . X . O . O O X X O O O X O O | $$ | O O X . X X . O . O . O O X X X O O O | $$ | O X X X X . . O . O O O O X . X O O X | $$ | O X . . O X O O . . . . X 3 1 X X O X | $$ | O X X . . X X O O O O O O X . X 2 O X | $$ | X X . . . . X O . . . . O X X X 4 O 5 | $$ +---------------------------------------+[/go]

-- Joachim Meinhardt's Rediscovered Oki wins White the game.
:b69:

-- Black is forced to continue with the dissolving of the hanezeki.

Click Here To Show Diagram Code: [go]$$Bm173 Capture Variation $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X X O . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X . X X O . . O X O O O O O . . | $$ | . X O , X O . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O . . . | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X . X O O O . O . O . X X X X X | $$ | O X X X X X X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X O O | $$ | X . O O X . . O . O . X O O O X X X O | $$ | O O O X . X . O . O O X X O O O X O O | $$ | O O X . X X . O . O . O O X X X O O O | $$ | O X X X X . . O . O O O O X 4 X O O 3 | $$ | O X . . O X O O . . . 2 X O O X X O 1 | $$ | O X X . . X X O O O O O O X . X X O 5 | $$ | X X . . . . X O . . . . O X X X X O O | $$ +---------------------------------------+[/go]

-- Typical for AI, KataGo likes to play White's kikashi in the lower right "early".

Click Here To Show Diagram Code: [go]$$Wm178 Capture Variation $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X X O . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X 2 X X O . . O X O O O O O . . | $$ | . X O , X O 1 . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O . . . | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X . X O O O . O . O . X X X X X | $$ | O X X X X X X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X . . | $$ | X . O O X . . O . O . X O O O X X X . | $$ | O O O X . X . O . O O X X O O O X . . | $$ | O O X . X X . O . O . O O X X X . . . | $$ | O X X X X . . O . O O O O X O X . . X | $$ | O X . . O X O O . . . O . O O X X . X | $$ | O X X . . X X O O O O O O X . X X . X | $$ | X X . . . . X O . . . . O X X X X . . | $$ +---------------------------------------+[/go]

White has sente to return to the upper left, saving her single stone, also giving atari at Black's two stones above.
:b79:

Black connects.

Click Here To Show Diagram Code: [go]$$B White's gains, compared to KataGo's solution ( = 1 / = 2). $$ +---------------------------------------+ $$ | . . B O W O C O . . O X X X O . O X . | $$ | . . B X X O O . O O O X O X O . . O . | $$ | . . . X B X X O . . O X O O O O O . . | $$ | . X O , B O O C C O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O C C C | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X . X O O O . O . O . X X X X X | $$ | O X X X B X X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X . . | $$ | X . O O X . . O . O . X O O O X X X . | $$ | O O O X . X . O . O O X X O O O X . . | $$ | O O X . X X . O . O . O O X X X . . . | $$ | O X X X X . . O . O O O O X O X . . X | $$ | O X . . O X O O . . . O . O O X X . X | $$ | O X X . . X X O O O O O O X . X X . X | $$ | X X . . . . X O . . . . O X X X X . . | $$ +---------------------------------------+[/go]

White gained twelve points.

Click Here To Show Diagram Code: [go]$$B Black's gains, compared to KataGo's solution ( = 1 / = 2). $$ +---------------------------------------+ $$ | . . X O O O . O . . O X X X O . O X . | $$ | . . X X X O O . O O O X O X O . . O . | $$ | . . . X X X X O . . O X O O O O O . . | $$ | . X O , X O O . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O . . . O . O X . X O . . . | $$ | O O O O X X O O . . O O O O X O O O O | $$ | O X X X C X O O O . O . O . X X X X X | $$ | O X X X X B X O . . O O X X X X O O O | $$ | O O O X . X O O . O O X X O O O O X . | $$ | X O O O X . . O . O . X O O O . X X X | $$ | X X O O X . . O . O . X O O X X X . . | $$ | X . O O X . . O . O . X O O O X X X . | $$ | O O O X M X . O . O O X X O O O X . . | $$ | O O X M X X . O . O . O O X X X . . . | $$ | O X X X X . . O . O O O O X O X . . X | $$ | O X . . O X O O . . . O . O O X X . X | $$ | O X X . C X Z O O O O O O X . X X . X | $$ | X X . . C C X O . . . . O X X X X . . | $$ +---------------------------------------+[/go]

Black gained eleven points.

In total, Black lost one point by NOT playing the Guzumi Exchange.

This slight advantage of just one point may have been one of the reasons why KataGo only found my Guzumi on the very last day of its initial training in 2019.

For all others who would prefer an easy-to-follow confirmation and also like closed sequences in terms of content:
Manual choice of (already favoured) moves during analysis.

Click Here To Show Diagram Code: [go]$$Bm113 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . . . X . . . O X . | $$ | . . . X X O b X O O . X O X O . . O . | $$ | . . . X O X . O . . . X O a 2 O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X 1 X X O O . | $$ | . X . O O O X X X O . . X . X O . . . | $$ | O O O O . X O O X X O O . O X . . O . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O . O X . O X O . X X O O O X O O | $$ | O O X O 3 X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Michael Redmond's Kikashi in the Bamboo Joint is a tesuji, which only unfolds its effect in the "classical" line, where WHITE occupied the Guzumi Point :wc:

.
It forces White to choose between the solid connection :w14:

and the atari W A above.
:w14:

-- The solid connection is mandatory in this position, where White must not lose any tempo in the Main Semeai, despite is loses points compared to the atari.
The atari of W A would benefit White in the upper right territorially, but would also lose one tempo in the Main Semeai. Black would be able to play the large endgame move B B in the upper left, capturing all single White stones in this area.
:b15:

-- Black gives atari at White's two stones in the lower left.

Click Here To Show Diagram Code: [go]$$Wm116 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . . . X . . . O X . | $$ | . . . X X O a X O O . X O X O . . O . | $$ | . . . X O X . O . . . X O . O O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | . X . O O O X X X O . . X . X O . . . | $$ | O O O O . X O O X X O O . O X . 1 O . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O 2 O X . O X O . X X O O O X O O | $$ | O O X O X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues with the Main Semeai.
She is unable to connect her two stones with a move at :w17:

, instead, as Black would answer with B A in the upper left again.
:b17:

-- Black captures White's two stones in the lower left.
Please note that Black is par with the Punishment Semeai Liberty Level (= 7 Main Semeai Liberties for his large group in the upper right at White's decision point), and therefore has no choice but to follow White in the Main Semeai.

Click Here To Show Diagram Code: [go]$$Wm118 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . . . X . . . O X . | $$ | . . . X X O . X O O 5 X O X O . . O . | $$ | . . . X O X . O . . 9 X O . O O O . . | $$ | . X O , . . . . . O . X . O O X 3 . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | 4 X 0 O O O X X X O . . X . X O . . . | $$ | O O O O 2 X O O X X O O . O X 7 O O 1 | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O 8 . . O X . O X X X X X . O X X O X | $$ | O 6 X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- White continues to close all the holes into her territory in the upper right.
:b19:

-- Black does the same with the holes into his territory at the left side of the board.

Click Here To Show Diagram Code: [go]$$Wm128 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . 5 4 X 2 3 . O X . | $$ | . . . X X O . X O O O X O X O . . O . | $$ | . . . X O X . O . . O X O . O O O . . | $$ | . X O , . . . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . 7 X . X O . . . | $$ | O O O O X X O O X X O O 1 O X O O O O | $$ | O X 8 X . X . O O X O . . . X X X X X | $$ | O X 6 X . . . O X X O 9 X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X . O X X X X X . O X X O X | $$ | O X X . . . X O O O O O O X O X . O X | $$ | 0 X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Wm138 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . O X X X O . O X . | $$ | . . . X X O . X O O O X O X O . . O . | $$ | . . . X O X . O . . O X O . O O O . . | $$ | . X O , . . . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O . . . | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X . X . O O X O . 1 . X X X X X | $$ | O X X X . . . O X X O O X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X 2 O O X . . O X O . X O O O X X X O | $$ | 3 O O X . X . O X O . X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X . O X X X X X . O X X O X | $$ | O X X . . . X O O O O O O X O X . O X | $$ | X X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm141 7 MSL $$ +---------------------------------------+ $$ | . . . . O . . . . . O X X X O . O X . | $$ | . . . X X O . X O O O X O X O . . O . | $$ | . . . X O X . O . . O X O . O O O . . | $$ | . X O , . . . . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O . . . | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X . X . O O X O . O . X X X X X | $$ | O X X X . . . O X X O O X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | 5 O O O X . . O X O . X O O O . X X X | $$ | 1 3 O O X . . O X O . X O O X X X O O | $$ | . . O O X . . O X O . X O O O X X X O | $$ | O O O X . X . O X O 2 X X O O O X O O | $$ | O O X . X X . O X O X 4 O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O X . . O X . O X X X X X . O X X O X | $$ | O X X . . . X O O O O O O X O X . O X | $$ | X X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Black plays the final oki into White's eye at the left edge.

Click Here To Show Diagram Code: [go]$$Wm146 7 MSL $$ +---------------------------------------+ $$ | . . . 2 O . . . . . O X X X O . O X . | $$ | . . . X X O 1 X O O O X O X O . . O . | $$ | . . . X O X . O . . O X O . O O O . . | $$ | . X O , . . 8 . . O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O . . . | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X . X . O O X O . O . X X X X X | $$ | O X X X . . . O X X O O X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | . . O O X . . O X O . X O O O X X X O | $$ | O O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O . O O X X X O O O | $$ | O X X X X 0 . O X O O O O X O X O O X | $$ | O X . . O X 9 O X X X X X . O X X O X | $$ | O X X . 4 3 X O O O O O O X O X . O X | $$ | X X . . 6 5 7 O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- Now, the time is ripe to continue with the interrupted sequence in the upper left corner.
:b47:

-- Black defends his upper left corner territory, as "usual".
Descending to :b52:

at the lower edge, instead, would not affect the outcome of the game, but benefit White in the Semeai Variation unnecessarily.
:w48:

-- White's hasami-tsuke starts the reduction of Black's corner territory.
:b53:

-- Black plays tenuki, in order to defend in the upper left.
Connecting at :b54:

, instead, would be one point worse for him.

Click Here To Show Diagram Code: [go]$$Wm156 7 MSL $$ +---------------------------------------+ $$ | . . . X O 5 . . . . O X X X O . O X . | $$ | . . . X X O O X O O O X O X O . . O . | $$ | . . . X O X 1 O . . O X O . O O O . . | $$ | . X O , . 2 X 6 7 O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O . . . | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X . X . O O X O . O . X X X X X | $$ | O X X X . 4 . O X X O O X X X X O O O | $$ | O O O X . X 3 O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | 8 . O O X . . O X O . X O O O X X X O | $$ | O O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O . O O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X a O X X O X | $$ | O X X . X O . O O O O O O X O X . O X | $$ | X X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

-- KataGo likes to play this atari "early".
:w58:

-- White's "usual" bump in the left centre, played in sente, erases all Black hopes for creating an additional point of territory below.
:w60:

-- White connects her single stone at the upper edge.
:b61:

-- White lost one tempo in the Main Semeai by her previous move, so Black is able to push once into White's territory.
:w62:

-- White blocks, of course.
:b63:

-- Black plays the final atari in the nakade.
White will capture the hanezeki's tail next, so choosing the Capture Variation.

Click Here To Show Diagram Code: [go]$$B White's gains, compared to KataGo's solution ( = 1 / = 2). $$ +---------------------------------------+ $$ | . . . X O W C C . . O X X X O . O X . | $$ | . . . X X O O X O O O X O X O . . O . | $$ | . . . X O X O O . . O X O . O O O . . | $$ | . X O , . X X X O O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O C C C | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X . X . O O X O . O . X X X X X | $$ | O X X X . X . O X X O O X X X X O O O | $$ | O O O X . X O O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | O O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O . O O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X . O X X O X | $$ | O X X . X O . O O O O O O X O X . O X | $$ | X X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

White gained six points.

Click Here To Show Diagram Code: [go]$$B Black's gains, compared to KataGo's solution ( = 1 / = 2). $$ +---------------------------------------+ $$ | . . . X O O . . . . O X X X O . O X . | $$ | . . . X X O O X O O O X O X O . . O . | $$ | . . . X O X O O . . O X O . O O O . . | $$ | . X O , . X X X O O . X . O O X O . . | $$ | . . X X X X O O O . O X X X X X O O . | $$ | X X X O O O X X X O . O X . X O . . . | $$ | O O O O X X O O X X O O O O X O O O O | $$ | O X X X C X . O O X O . O . X X X X X | $$ | O X X X . X . O X X O O X X X X O O O | $$ | O O O X . X O O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | O O O X M X . O X O O X X O O O X O O | $$ | O O X M X X . O X O . O O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X . O X X O X | $$ | O X X . X O . O O O O O O X O X . O X | $$ | X X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Black gained five points.

In total, Black lost one point by NOT playing the Guzumi Exchange.

This slight advantage of just one point may have been one of the reasons why KataGo only found my Guzumi on the very last day of its initial training in 2019.

European Go Journal: February 2022

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