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We inserted Black's solid connection in the upper left manually, which followed one of Joachim's suggestions.

KataGo's favoured line of play, which is explained below, will largely follow Joachim's original ideas, AI-typical changes in the order of moves included of course.

Please also note that we played Michael Redmond's Kikashi in the Bamboo Joint (, ) later at this time.
For further details of our earlier analysis, please refer to the history of our investigations ...
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White must capture the nakade immediately, securing independent life for her group at the left.

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Black's throw-in creates a false eye for White's centre group, reducing its liberties by one.

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Black captures White's single stone in the right centre for an eye.

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White occupies the Guzumi Point, in order to prevent a second Black eye in this area.

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Black starts the creation of a ko-shape at the right edge.

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White ends in gote.

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Black attacks White's eye shape at the top, creating another false eye for her group.

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White's connection secures an eye for her group.

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Black reduces White's eye shape from the left.

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Black played from the right first (with ), so White's peep at the upper edge - which is sente - is mandatory for her success.

Please note that this peep was the move that KataGo searched for so long in its initial 2019 training.

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KataGo inserts this atari as a kikashi, ...

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... before connecting at the upper edge.

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White answers to Black's earlier move at the top, securing her own eye.

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Black creates a three-point eye.

Ko: ; ; ; ; ; ; ; ; ;

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In this line of Joachim's Ko-Semeai, White is forced to start the ko-fight at the right edge "early", in order to exhaust Black's ko-threats.

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Black's ko-threats at the left side of the board threaten to kill White's large group there, enforcing White to capture the hanezeki's tail, which would make Black's large group in the upper right alive.
However, Black should better play his ko-threat at in the hanezeki first.

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White answers Black's ko-threat from above.

However, a move at at the left edge would have been better for her.
Black would have had only two ko-threats in the nakade area, instead of four ko-threats here.

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White is able to utilise the filling of her false eye as a ko-threat.

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Black does not have any adequate ko-threat left, so he occupies a shared liberty.

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White connects the ko, so ending the ko-fight.

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Connecting the hanezeki's tail is Black's last hope in this semeai.

Please note that Black only got this far because White had donated him two additional ko-threats at the left with her technical mistake .

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White's oki is mandatory.

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Black's large group has one liberty too few.

Black cannot give atari at White's centre group with , as White would capture with .

Black's connected hanezeki group at the bottom is also dead. White could take it off the board, starting with .

White will win the game by a large margin.

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