: ( 221)
White gives atari at Black's stone below.

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Black solidifies his formation in the upper left centre.

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White is forced to connect her stones, also giving atari at Black's nakade.

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Black sacrifices another stone.

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White captures in the lower left.

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Black is forced to connect below, defending his lower left corner.

: (97 222ab ;  A 222an ; C 222ge)
White plays the tsuke of Yamada Shinji "early".

A detailed explanation of its variations after a "late" start of the endgame will be given later ( 222fw).

White might consider following the "classical" line of play, by choosing the atari at . She would become one point better than in Our Solution, but still remain one point behind the alternative subvariation.

In order to punish Black's delay with the guzumi, it is best for White to occupy the guzumi point herself, before attacking Black's upper left corner. Black will counter with the kikashi of Michael Redmond in the bamboo joint, but in the end White will be two points better than in Our Solution.

If White wanted to pre-empt this kikashi, she could play the peep of at the upper edge first. However, she would provide Black with the chance of playing the guzumi, therewith returning to the score level of Our Solution again.

: (97 222gf)
White crosscuts immediately, as favoured by KataGo.

Please note that this crosscut must not be played in the case of a "late" endgame ( 222fx).

Drawing back to , instead, would be too slow, as Black's upper left corner is not threatened enough by this move.
White would still be as good as in the solution, but she could have done better, following KataGo's suggestion.

However, pre-empting the Guzumi Exchange just now will allow us to include a detailed analysis of the variation tree for Yamada's tsuke in the upper left corner in the classical line of play into this update of our website.

: ( D 222iu)
Having a special idea from Joachim in mind, Black gives atari at White's stone at the upper edge.

After a long analysis, it was quite surprising to us that giving atari at , instead, did not produce a better overall result either - a correct continuation of both sides provided.

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White gives atari at Black's stone at the third line.

Giving atari at Black's other stone at the second line, with from the corner, would be a grave mistake.

: (A 222iz)
White's immediate connection is a simple line of play.

It is not necessary for White to complicate the issue by extending into Black's corner with a move at .

: ( A 222jc)
Black has to defend his corner, and he gives atari at White's single stone there.

However, as we now know, Black's atari in the corner is in danger of becoming a lost move. It would be better for Black to play at , instead.

: ( B 222kb ;  105 222kz ;  C 222mw)
At the beginning of our investigations, we favoured White's immediate connection in the corner. However, as it turned out later, this approach was not correct.

Please note that this move does not lose a tempo in the Main Semeai, as it creates an approach-move liberty for her group at the left side in the corner, due to Black's weaknesses at and .

White's single stone in the upper left corner is not that important. White's best option here is to occupy the guzumi-point with . White should take this chance just now, as she will become limited in her choices after she connected her single stone in the upper left and five of her stones were in atari thereafter.

Connecting at would also be preferable, compared to the connection at , as Black would be unable to play his following throw-in.

If White only wanted to frustrate Black's intention of entering Joachim's Ko-Semeai, she could play the peep of at the upper edge just now. However, she would do not better overall than in the solution.

: ( B 222mx)
Black has a special idea in mind when he chooses this throw-in that reduces White's eye space at the top.

However, it would be better for him to play the guzumi, instead.

: ( B 222my ;  C 222na)
White captures.

However, as two moves earlier, White's best option here would be to stop Black from playing the guzumi.

Similar, if White only wanted to frustrate Black's intention of entering Joachim's Ko-Semeai, she could play the peep of at the upper edge just now. However, this move would result in a loss of one point, compared to the alternative subvariation.

: ( 110 222nb)
With Joachim's special idea in mind, Black gives atari at White's five stones in the upper right corner. Black hopes that White will connect her stones, so losing a decisive liberty at the top.

However, connecting is not mandatory for White, so Black should have played the guzumi again.

: ( 110 222ns ;  A 222nw)
White connects her five stones, so falling into the trap that has been set up by Black. She just reduced the number of her centre group's liberties unnecessarily.

As with her two previous moves, White should have taken the guzumi point from Black.

Playing the peep of at the upper edge would also destroy Black's intention of getting into Joachim's Ko-Semeai. However, this move would result in a loss of one point, compared to the alternative subvariation.

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Black wants to fight Joachim's Ko-Semeai, and so captures White's single stone in the right centre.

As a matter of course, Black could have kept the game countable by playing the guzumi - at the last possible moment now.

Concerning the Main Semeai, Black has only six liberties left after this move. As he does not intend to choose this line of play, we will stop colouring the edges of the board here.

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Black's throw-in creates an additional cutting point in the centre.

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Black reduces White's group to only one eye.

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Black connects at the upper edge, because he is unable to fight a ko at the upper edge alone.

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White's hane makes it more difficult for Black to approach White's group at the upper edge.

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Black creates the ko shape in the centre.

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Black is unable to give atari at directly.

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White continues with occupying Black's outside liberties.

Capturing the ko in the upper right "early" does not help here, as White does not have the time to connect this ko thereafter.

: (143 222op)
White still continues with occupying Black's liberties.

Under Japanese Rules, White might consider capturing the hanezeki's tail just now - quite contrary to the "original" Joachim's Ko-Semeai.

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The moment has come when Black has to connect the hanezeki's tail.

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White starts a series of alternating ko captures.

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We have reachted the repetition of the position six moves before.

Neither side can stop capturing in this triple-ko.
If White had not captured with , Black would connect there, and win the remaining double-ko, because the ko capture at would be an atari at White's centre group.
The same is true with Black . If White connected at this point, she would win the remaining double-ko, as the ko capture in the centre would become atari at Black's group at the right.

Therefore, under Japanese Rules ...

The game will end with "no result".

Please note that under Chinese Rules (also used by KataGo 1.2) White would win the game by a large margin.
Black's ko capture at is prohibited under these rules, so stopping the triple-ko cycle.

By playing elsewhere, either side could release this ban.

However, Black has only one valid ko threat with , while White is favoured by six valid ko threats (, , , , , ), and so will start the last triple-ko cycle for capturing Black's large group at the right.