Life In 19x19

The self-play training of my KataGo 28-block network has revealed some new moves for White within the Main Semeai.
These are presented and explained in detail at ...

News From the Main Semeai World ...

Cassandra wrote: Thu Mar 12, 2026 4:26 amPreparatory work for the corresponding update of the IH120 website is underway, but it will take more than a while...

Initial content has been uploaded:

The Non-Main-Semeai Solutions

在中国古代死活题中，强调的是题中最精彩的变化或容易忽略的陷阱，而不是唯一的解答。
In ancient Chinese life-and-death problems, the emphasis is on the most brilliant variations or the easily overlooked traps within the problem, rather than on a single solution. (by DeepL)
This is also true for Inoue Dôsetsu Inseki's Igo Hatsuyôron 120 ...

During the formation of the Nakade

Even after completing the Crosscut-Sequence, non-Main-Semeai solutions are still possible. Black will already have played one or two moves that temporarily cut the white groups on the left edge for the potential formation of the Nakade.

Black may already have ...

Just before the end of the Crosscut-Sequence

The next opportunity for non-Main-Semeai solutions comes immediately before the final exchange to complete the Crosscut-Sequence in the upper left centre.

Black may already have reduced White's territory in the upper right corner to varying degrees ...

After the completion of the Hanezeki

The second phase of generating non-Main-Semeai solutions begins immediately after the completion of the Hanezeki, i.e. when the tail length is two stones. It ends when the tail begins to move upwards.

Black may already have reduced White's territory in the ...

During the formation of the Hanezeki

The first opportunities to deviate towards a non-Main-Semeai solution arise in the initial phase of the formation of the Hanezeki, i.e. as long as the outer blockade is not yet complete.
Black may already have inserted the first exchange for reducing White's ...

Almost a year has passed since the last status report. In the course of further network training during this time, additional non-Main Semeai variations were found, so I decided to split the update to improve clarity.

Preparatory work for the corresponding update of the IH120 website is underway ...

The other non-Main-Semeai variations

The other non-Main-Semeai variations still have a long way to go before consolidation, as the board is much emptier / more open and there are therefore many more variations to investigate.

8 generations of the 28b-net after #59 ...

dany wrote:So in any case Main-Semeai will be choosen not non-Main-Semeai variations

Really?
The further course of the Main Semeai does NOT match the historical meaning of the title of the problem given by Inoue Dôsetsu Inseki.

Sorry for playing the noob.
Some trivial help below ...

$$Bm135
$$ +---------------------------------------+
$$ | . . . . X . X O . . . O . O . . O X . |
$$ | . . X 8 . X O . O O O X O . O . . O . |
$$ | . X O O X X . O . . . X O O . O O . . |
$$ | . X O X O X X 9 0 O . X . O O X . . . |
$$ | X ...

The other non-Main-Semeai variations

The other non-Main-Semeai variations still have a long way to go before consolidation, as the board is much emptier / more open and there are therefore many more variations to investigate.


046048_F2J3

$$B ...

082_E15
Both side's option for returning to the Main Semeai

In this non-Main-Semeai Variation, both sides may cooperate to return to the Main Semeai.

$$Bm83
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . X . . . O X . |
$$ | . . 9 . . . . X O O . X O X O . . O ...

082_E15

$$Bm75
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . # . . . O X . |
$$ | . . . . . . . X O O . X O # @ . . O . |
$$ | . . . . . X . O . . . X @ . . W O . . |
$$ | . X O , . . . . . O . X . O O B . . . |
$$ | . . X X Q X 2 O O . O X X . X X O O . |
$$ | . X ...

084_E15

$$Bm77
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . # . . . O X . |
$$ | . . . . . . . X O O . X O @ W @ . O . |
$$ | . . . . . X . O . . . X # @ . # O . . |
$$ | . X O , . . . . . O . X . O O B . . . |
$$ | . . X X Q X 2 O O . O X X . X X O O . |
$$ | . X ...