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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #81 Posted: Mon Jan 11, 2021 10:34 am 
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"Classical" way of play => Black's weakness in the upper left (contd.)

Black has to passively back away (II).

Click Here To Show Diagram Code
[go]$$Wcm108
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | . . . . X O O . O O . X O X O . . O . |
$$ | . . . X O X X O . . . X O . O O O . . |
$$ | O X O , . X O . . O . X . O O X . . . |
$$ | . 4 X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:b11: connects immediately, seeling the lock at the left side.

Click Here To Show Diagram Code
[go]$$Wcm112
$$ +---------------------------------------+
$$ | . . . . a X . O . . . . X . . . O X . |
$$ | . . . 1 X O O . O O . X O X O . . O . |
$$ | . . . X O X X O . . . X O . O O O . . |
$$ | O X O , 2 X O . . O . X . O O X . . . |
$$ | . X X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

But White remembers the dud at the right, and gives atari with :w12:.

It is best for Black to capture with :b13:.
Connecting at a, instead, might turn the entire corner into a seki.

Click Here To Show Diagram Code
[go]$$Wcm112
$$ +---------------------------------------+
$$ | . 6 5 . 7 X 9 O . . . . X . . . O X . |
$$ | . 4 3 O X O O . O O . X O X O . . O . |
$$ | . . . X 8 X X O . . . X O . O O O . . |
$$ | O X O , X X O . . O . X . O O X . . . |
$$ | . X X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:w14: extends into the corner.

Blocking at :b15: is Black's only choice to prevent a seki in the corner.

:w16: prepares creating a ko shape at the upper edge.

It is best for Black to connect with :b19:, as he will be unable to win a ko fight in this corner.

Click Here To Show Diagram Code
[go]$$Wcm120
$$ +---------------------------------------+
$$ | . X O 4 O 3 O O . . . . X . . . O X . |
$$ | . X O O X O O . O O . X O X O . . O . |
$$ | . . 2 X X X X O . . . X O . O O O . . |
$$ | O X O , X X O . . O . X . O O X . . . |
$$ | . X X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 . . a X O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

After :b23:, the upper left corner is settled.
White will continue with a in the lower left corner.

Compared to the superordinate variation above, Black gained one point in the upper left corner, but White did not lose a tempo in the Main Semeai there.
The net effect is zero, so White will win this variation by FOUR points, too.

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The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #82 Posted: Mon Jan 11, 2021 11:57 am 
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"Classical" way of play => Black's weakness in the upper left (contd.)

Black gives atari at the left edge.

Click Here To Show Diagram Code
[go]$$Wcm108
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | . . . . X O O . O O . X O X O . . O . |
$$ | a . . X O X X O . . . X O . O O O . . |
$$ | O X O , . X O . . O . X . O O X . . . |
$$ | 4 . X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:b11: gives atari from the outside.

You will easily realise that starting with the inside atari at a results in a change in the order of moves with the sequence shown below.

Click Here To Show Diagram Code
[go]$$Wcm108
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | . . . . X O O . O O . X O X O . . O . |
$$ | 6 5 . X O X X O . . . X O . O O O . . |
$$ | O X O , . X O . . O . X . O O X . . . |
$$ | X . X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:w12: gives counter-atari in the corner.

Black has to capture with :b13:.

Click Here To Show Diagram Code
[go]$$Wcm108
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | 7 . 8 a X O O . O O . X O X O . . O . |
$$ | X O . X O X X O . . . X O . O O O . . |
$$ | 9 X O , . X O . . O . X . O O X . . . |
$$ | X 0 X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:w14: gives another atari in the corner.

Black has to defend his cutting point at a with :b15:.

:w16: captures the first ko.

:b17: connects the second one, as Black cannot afford to fight any ko in this corner, due to White's unbeatable ko threats in the hanezeki.

Click Here To Show Diagram Code
[go]$$Wcm118
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . c . O X . |
$$ | O . X . X O O . O O 1 X O X O . . O . |
$$ | . O . X O X X O . . . X O b O O O . . |
$$ | O X O , a X O . . O . X . O O X . . . |
$$ | X X X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 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 has created a shortage of liberties for Black's upper left corner, and so will keep Black down at par with the Punishment Semeai Liberty Level.

Please note that Black is unable to remove his shortage of liberties by capturing at a, because this move would lose him a very decisive tempo in the Main Semeai.
Quite similar, White must not mistakenly play at b or c at the right (which usually would be answered by Black to avoid losing points), because Black would tenuki here to a in the upper left corner, making the game countable.

Click Here To Show Diagram Code
[go]$$Bcm151
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | O . X . X O O . O O O X O X O . . O . |
$$ | 5 O . X O X X O . . . X O . O O O . . |
$$ | O X O 4 . X O . . O . X 2 O O X . . . |
$$ | X X X X X X O O O . O X X X X X O O . |
$$ | 1 X 3 O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | O X X X X . . O X O O O O X O X O O X |
$$ | O . . . O X . O X X X X X 6 O X X O X |
$$ | O . X . . . X O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

Black will occupy White's liberties in the upper left last.
Please note that I did not adjust the diagram, just assume that this sequence is played earlier.

:w54: is atari, also threatening a snap-back, so Black has to capture the ko at the left edge with :b55:.
White uses the capture of the hanezeki's tail as a ko threat.

Click Here To Show Diagram Code
[go]$$Bcm157
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | O . X . X O O . O O O X O X O . . O . |
$$ | X O . X O X X O . . . X O . O O O . . |
$$ | 2 X O O a X O . . O . X O O O X . . . |
$$ | X X X X X X O O O . O X X X X X O O . |
$$ | X X X O O O . . . O . . X . X O . . . |
$$ | O O O O . X O O . . O O . O X . O O . |
$$ | O X . X . X . O O . O . . . X X X X X |
$$ | O X . X . . . O . . O . X X X X . O O |
$$ | X O O X . X . O . O O X X O O O O . . |
$$ | X X O O X . . O . O . X O O O . X X X |
$$ | X X . O X . . O . O . X O O X X X O O |
$$ | X X O O X . . O . O . X O . O . X X O |
$$ | X O O X . X . O . O . X X O O O X O O |
$$ | X O X . X X . O . O X . O X X X O O O |
$$ | O X X X X . . O . O O O O X O X O O X |
$$ | O . . . O X . O . . . . 1 O O X X O X |
$$ | O . X . . . X O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

Black has to recapture with :b57:, if he wants that his right side survives.

:w58: recaptures the ko in the upper left, and there is nothing Black can do to stop White from killing his upper left corner by capturing at a with her next move.
White will win the game by a large margin.

_________________
The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #83 Posted: Mon Jan 11, 2021 2:37 pm 
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"Classical" way of play => Black's weakness in the upper left (contd.)

Black descends to the left edge.

Click Here To Show Diagram Code
[go]$$Wcm108
$$ +---------------------------------------+
$$ | . . . . . X . O . . . . X . . . O X . |
$$ | . . . . X O O . O O . X O X O . . O . |
$$ | . . . X O X X O . . . X O . O O O . . |
$$ | O X O , . X O . . O . X . O O X . . . |
$$ | . . X X X X O O O . O X X X X X O O . |
$$ | 4 X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:b11: descends to the left edge, also intending to maximise the corner territory.

Click Here To Show Diagram Code
[go]$$Wcm112
$$ +---------------------------------------+
$$ | . . . . 5 X . O . . . . X . . . O X . |
$$ | . . 4 3 X O O . O O . X O X O . . O . |
$$ | . 1 . X O X X O . . . X O . O O O . . |
$$ | O X O , a X O . . O . X . O O X . . . |
$$ | . 2 X X X X O O O . O X X X X X O O . |
$$ | X X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

First, White gives atari with :w12:, forcing Black to connect at :b13:.

Thereafter, White :w14: cuts at the top, also giving atari.

Black has to give counter-atari with :b15:.
Capturing with a, or connecting at 116, instead, would result in a real desaster in the corner.

:w16: captures Black's stone in the corner, so gaining a massive profit from reducing Black's top left corner.

Click Here To Show Diagram Code
[go]$$Wcm112
$$ +---------------------------------------+
$$ | . . . . O X . O . . . . X . . . O X . |
$$ | . 6 X O . O O . O O . X O X O . . O . |
$$ | . O . X O X X O . . . X O . O O O . . |
$$ | O X O , . X O . . O . X . O O X . . . |
$$ | . X X X X X O O O . O X X X X X O O . |
$$ | X X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 . . a X O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

:b17: is necessary to bring Black's corner to life.

White will continue with the usual endgame in the lower left, starting with a.

White will win the game by about 12 points.

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The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #84 Posted: Tue Jan 12, 2021 12:57 am 
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"Classical" way of play => Black's weakness in the upper left (contd.)

KataGo does not want to follow Yamada's original sequence any longer!

When painting the diagrams for my postings for LifeIn19x19, I suddenly had the strange feeling that something was wrong.
Finally, I found out: In my draft for the update of our website, I had used another order of moves than had been originally shown by Yamada Shinji to us.
And now, with KataGo's new net, it does not want at all to follow that line of play...

Click Here To Show Diagram Code
[go]$$Wcm98
$$ +---------------------------------------+
$$ | . . . . c b . . . . . . X . . . O X . |
$$ | . . . . 4 3 5 X O O . X O X O . . O . |
$$ | . . . . . X a O . . . X O . O O O . . |
$$ | . 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 |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O 2 O X . O X O . X X O O O X O O |
$$ | X O X O X X . O X O X . O X X X O O O |
$$ | 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]

(Again, :w98: for :b99: is inserted for simplicity.)

After White's draw-back to :w2:, KataGo's new net does not seem to consider Yamada's move at a any longer for Black.
Instead, KataGo favours the immediate hane at b, and the descent to c, with the latter getting the upper hand over time.

Click Here To Show Diagram Code
[go]$$Wcm98
$$ +---------------------------------------+
$$ | . . . . . 8 . a . . . . X . . . O X . |
$$ | . . . . X O O X O O . X O X O . . O . |
$$ | . . . 9 7 X 6 O . . . X O . O O O . . |
$$ | . 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 . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

If we let Black play the "original" :b3:, White will still cut at :w4:, but after Black's atari with :b5:, she does NOT capture at a!
KataGo's new net draws back to :w6:, instead. sacrificing White's two stones at the upper edge.

Click Here To Show Diagram Code
[go]$$Wcm106
$$ +---------------------------------------+
$$ | . . . . . X 2 . . . . . X . . . O X . |
$$ | . . 4 6 X O O X O O . X O X O . . O . |
$$ | . 3 5 O O X X O . . . X O . O O O . . |
$$ | . 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 . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

Black :b7: takes White's two stones off the board. I suppose that this has to be done anyway -- sooner or later.

:w8: blocks in the corner, whereafter Black attacks White's shape from above.

Click Here To Show Diagram Code
[go]$$Wcm112
$$ +---------------------------------------+
$$ | . . . . . X X . . . . . X . . . O X . |
$$ | 7 6 X X X . . X O O . X O X O . . O . |
$$ | . O O O O X X O . . . X O . O O O . . |
$$ | 1 X O , 5 3 4 . . O . X . O O X . . . |
$$ | . 2 X X X X O O O . O X X X X X O O . |
$$ | . X . O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

White's atari at :w12: has to be answered by the connection of :b13:.

Now, the time is ripe to cut Black apart with :w14: at the right.

Black continues in the corner with :b17:
Jumping to 118, instead, would not lead to a better result for him.

Click Here To Show Diagram Code
[go]$$Wcm118
$$ +---------------------------------------+
$$ | . . . . . X X . . . . . X . . . O X . |
$$ | O X X X X . . X O O . X O X O . . O . |
$$ | 5 O O O O X X O . 8 . X O . O O O . . |
$$ | O X O a O O X 2 6 O . X . O O X . . . |
$$ | 4 X X X X X O O O 7 O X X X X X O O . |
$$ | 3 X 9 O O O X X X O . . X . X O . . . |
$$ | O O O O . X O O X X O O . O X . O O . |
$$ | O X . X . X . O O X O . . . X X X X X |
$$ | O X . X . . . O X X O . X X X X . O O |
$$ | X O O X . X . O X O O X X O O O O . . |
$$ | X X O O X . . O X O . X O O O . X X X |
$$ | X X . O X . . O X O . X O O X X X O O |
$$ | X X O O X . . O X O . X O . O . X X O |
$$ | X O O X . X . O X O . X X O O O X O O |
$$ | X O X . X X . O X O X . O X X X O O O |
$$ | 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 O O O O O O X O X . O X |
$$ | . X . . . . . O . . . . O X X X . O . |
$$ +---------------------------------------+[/go]

It is best for Black now to push with :b19: at the top.

As a matter of course, he could capture White's stones in the upper left corner with B a, W 122, B 121.
However, he would be forced to really take White's group at the left off the board, enabling White to win the Punishment Semeai at the right.

:w20: captures Black's partial group in the upper left, while Black starts capturing White's top with :b25:.

This exchange favours White, who will win the game by about 15 points.
Please note that the hanezeki will remain untouched here, as both large groups live independently.

_________________
The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)


Last edited by Cassandra on Thu Jan 14, 2021 9:46 am, edited 1 time in total.

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #85 Posted: Tue Jan 12, 2021 6:10 am 
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Is there any hint of when this network will be available for download? I'd very much like to play with it.

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #86 Posted: Tue Jan 12, 2021 8:09 am 
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hakuseki wrote:
Is there any hint of when this network will be available for download? I'd very much like to play with it.

According to Friday9i's current schedule, he intends to train his new network for additional three months, at least, before a potential publication.

I have the feeling that he is currently extremely concerned about (probably somewhat unusual) "white spots" in the variation tree of the problem, which KataGo has not yet sufficiently explored / analysed during training. If I understood that issue correct, he is still on the way do develop some kind of tool, which should help a lot to overcome that problem.

To give you a recent example:
As far as I remember (disclaimer: my memory can be deceptive; probably there had been no need to go there any deeper), Lightvector's net did not have any problems with the original line of play after Yamada's tsuke in the upper left.
Probably, Friday9i's new net dislikes this order of moves now, because it had (additionally) analysed subvariations after Joachim's (yet unpubished; this is part of the draft I mentioned above) trial to "punish" KataGo's immediate crosscut (no Black guzumi played before) during training. In my understanding, the resulting positions have significant similarities, especially with regard to the hidden weaknesses in Black's corner.

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The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #87 Posted: Tue Jan 12, 2021 8:18 am 
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"Classical" way of play => Black's weakness in the upper left (contd.)

KataGo does not want to follow Yamada's original sequence any longer!

I feel that I have to add this posting to make clear that Yamada Shinji 6p must not be blamed for the abovementioned impact of KataGo's analysis.

When he, together with his study group, worked out his improvement over the "classical" atari, he had been asked only, if he could be so very kind to validate the correctness of the guzumi.

At that time, the endgame at the left side of the board was still played "late", i.e. after the dissolving of the hanezeki, i.e. after the occupation of White's liberties in the upper left.
Once that border of Black's upper left corner is settled, KataGo's new finding is NOT applicable any longer!

It was Prof. Jeong, who told us later that it would be technically correct to start that endgame early.
Therefore, it were some poor amateurs, who overlooked the hidden weaknesses of Black's upper left corner, when transposing Yamada's sequence to an earlier moment in the game.

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The really most difficult Go problem ever: http://igohatsuyoron120.de/index.htm
Igo Hatsuyoron #120 (still unresolved by professionals, maybe solved by four amateurs)

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 Post subject: Re: KataGo @ Igo Hatsuyoron 120
Post #88 Posted: Tue Jan 12, 2021 9:00 am 
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hakuseki wrote:
Is there any hint of when this network will be available for download? I'd very much like to play with it.

Hi
As said by Cassandra, I effectively intend to release the new net once the training is finished, in a few months. It already is very significantly stronger than g146 : -): it beats it from starting position even if 50x less visits, as it improved its understanding and knows how to squeeze a bit more profit. From a panel of thousands of random Igo Hatsuyoron positions, with only 25 visits, it manages to beat g146 with 100 visits, with an about 40 Elo performance (from about same Elo 2 months ago), so it still improves quite healthily. I'm also developing a small python tool to automate exploration of board positions (using KataGo's analysis engine), which will hopefully help wide exploration of the problem, and possibly help it to discover unexpected moves : -). We'll see in the coming weeks if we get some interesting results from this additional exploration.
Thanks to Cassandra for its panel of Igo positions (very precious for training), and big thank you to lightvector for precious advice to launch the run with adequate training parameters : -)


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