: ( 58ap)
White captures Black's stone in the lower left.

:
It is best for Black to block immediately.

: (104 58bc)
White gives atari at Black's nakade stones.

She has another valid option for doing so.

: (103 58by)
Black gives atari at White's two stones in the lower left as early as possible.

Alternatively, he might consider defending his weaknesses in the left centre just now.

: ( A 58cs)
White connects her two stones immediately.

This early connection - which is not mandatory at all - is the game-deciding mistake.

White must never ever connect her two stones, as long as the position in the upper left corner is still open.
White should simply play the crosscut of just now - capturing the nakade before seems to be a matter of taste - and play this connection after Black's (correct) reply in the upper left corner.

: (B 58ct)
Black defends his potential territory in the left centre.

Choosing the defensive move of , instead, would be a grave mistake after White's previous connection in the lower left.

:
White captures the nakade.

:
KataGo seems to like inserting the wedge in the left centre in-between.

Please note that Black has already strengthened his formation in the left centre. Therefore, this wedge does not make a difference, compared to KataGo's bad-shape move in this area.

:
White crosscuts at the top, returning to the unfinished position there.

:
White has already connected her two stones in the lower left (with ), so Black chooses the atari at the outside, punishing White for her earlier mistake.

:
White has to give counter-atari at the fourth line.

:
Black must capture immediately.

:
White connects in the corner.

:
This hane is Black's best choice.

:
White leads her corner stones into the open.

:
White has to connect Black's atari immediately.

Her connection with in the lower left lost some tempi in the Main Semeai, so Black would be able to capture her five stones without affecting the Main Semeai, if she did without.

:
Black erases a potential White ko threat.

:
White's block at the top is a valid reply, but somewhat unusual.

Her "standard" answer would have been at .

:
Black is able to play the large descent to the lower edge, defending his territory in the lower left corner.

:
White continues in the left centre.

: ( 129 58cx)
White plays KataGo's bad-shape move in the left centre.

This move was the second "false positive" in this subvariation (I analysed from back to front), after I had found the mistake in my continuation after the first one below.

Nevertheless, White would benefit in the Semeai Varaition, if she connected her single stone in the right centre, instead.

:
White's previous move is gote locally, so Black takes the opportunity to capture White's single stone in the right centre.

:
White attaches in the left centre, in order to erase Black's potential point of territory above.

: ( 135 58cz ; 143 58db)


This move was the first candidate for a potential mistake in this subvariation, as it reminded me of a comparable analysis of one of Joachim's Ko-Semeai, where he found out that this push was not a valid ko-threat.

But after a closer inspection of the alternative continuation I had to admit that I was too hasty in the very beginning. The status of this move changed to "false positive".

Nevertheless, White should not let capture her stone in the left centre. She would benefit in the Semeai Variation

:
Black captures White's stone in the left centre.

:
Black is par with the Punishment Semeai Liberty Level, so White simply continues with the Main Semeai.

:
Black has to play a protective move in the corner before approaching White's liberty at .

; :
White might also play this exchange after her decision point.

Black must not play any reduction.

Before the end of the game, Black will have to connect at .

Capture Variation:

Compared to the superordinate variation, ...

• White's cumulated gain in the upper left corner is five points.
• White got an additional point of territory at the upper edge.
• White destroyed one point of Black's territory in the left centre.
• Black captured an additional White stone in this area, so gaining two points.
• Black destroyed one point of White's territory in the right centre.
• Black's cumulated gain in the lower left corner is five points.
• Black did not capture White's two stones in the lower left, so losing three points.

In total, White gained three points.

Black + 2 => White + 1

Semeai Variation:

Compared to the superordinate variation, ...

• White's cumulated gain in the upper left corner is five points.
• White got an additional point of territory at the upper edge.
• White destroyed one point of Black's territory in the left centre.
• Black captured an additional White stone in this area, so gaining two points.
• Black destroyed one point of White's territory in the right centre.
• Black captured three White stones more at the left, so gaining six points.
• White captured one Black stone more in the upper right, so gaining two points.

In total, White lost five points.

Black + 2 => Black + 7