: ( 648mk)
White chooses the push in the upper left corner as a ko threat.

We will explain below that neither , nor , in the upper right include a sufficient threat, which would enforce an immediate local reply by Black.

Please remember that we played of , in the left centre too early in 2019. Therefore, this exchange was still available as a ko threat for White. We will utilise the exchange of , at the lower edge as a replacement in the sequences below (if necessary).

Ko: ; ; ; ; ; ;

: (B 648qb)
Black uses this atari at the top as a ko threat.

KataGo (2021i) favours the connection in the right centre with just now, which implies that KataGo (2021i) wants to play this move as early as possible.

: (161 648qc)
White continues the ko fight with the forcing move in the upper left corner that had been developed by Dany.

However, KataGo (2020) found a way to generate an additional ko threat - the fourth one - in the upper left corner, which will benefit White decisively.

: (A 648qp)
White gives atari from inside the upper left corner.

Playing this atari from the outside, at instead, would be a grave mistake, resulting in a loss of one point overall.

: ( B 648qr)
Black continues with the ko fight by peeping in the right centre.

KataGo (2021i), however, ends the ko fight just now, keeping Black's final two territory-destroying moves in the upper right - which could be utilised as ko threats - in reserve.
This will result in Black winning the Semeai Variation, while not affecting the overall result of the game.

; :
Please understand these two moves as replacement for White's kikashi , in the centre, which had been played too early by us.

: ( B 648qs)
Black plays the push in the upper right corner as a ko threat.

However, this would have been the last moment to terminate the ko fight by connecting at in the right centre, achieving a win in the Semeai Variation.

: (C 648qt ; B 648qv ; F 648qx)
White peeps in the lower left centre.

Joachim found that Black could ignore any of White's moves , or , in the upper right.

In the very beginning, White could have inserted her kikashi of , in the lower left corner.
In this case, she would have a ko threat at , but which she must not utilise.

: ( 184 648qz)
Black defends his territory in the lower left corner.

He would gain two points in the Capture Variation, if he connected in the right centre, instead, but still be unable to affect the result of the Semeai Variation.

:
White must connect the ko - sooner or later.

: (184 648ra)
The Main Semeai continues.

Enlarging his territory in the right centre, instead, will not affect the final scores of the game any longer.

: (187 648rb)
You might wonder, whether White would be able to stop Black from playing the following one-point reduction move at by occupying this point herself.

Black is unable to connect at (this would cost him one liberty too many); therefore he is bound to realise his aim at the upper edge. If he did not succeed, White would benefit by one point in the Capture Variation.

:
Black plays 1/3 reductions.

:
After White's kikashi in the lower left corner, Black will have to capture at before the end of the game.

Capture Variation:

Compared to the superordinate variation, there are no changes.

White + 2 => White + 2

Semeai Variation:

Compared to the superordinate variation, there are no changes.

White + 2 => White + 2