Asymmetrical AI advice: what am I missing?

Analyzing a recent game with katago I had trouble making proper sense of a piece of AI advice. In this situation, the AI really wants Black 23 to be H15 rather than B16 as in the actual game. Fair enough.

Interestingly though, when it is white’s turn, the AI recommendation is to play in the corner (or left side) rather than in the area around H15. For black, however, the AI continues to insist on H15 up until the corner sequence is played out.

03 Black 25

04 White 26

05 Black 27

Any thoughts about this asymmetry? Of course, when black is completely settled in the corner the H15 area is less important, but until then, why would it not be equally important for white to deprive black of this direction as for black to develop along it? How should I think?

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Sorry but you cut the numerotation on the left.

The positions are not symetric in themselves, because b adds a move. This added move even if it’s not the recommend one change things in the upper left so white may change the priority

Is the question why h15 big for black now, but after black plays b16 instead, why h15 or somewhere nearby isn’t the move for black?

Once black has spent a move in the corner to capture the 2 stones he is settled, so a white move there is just big, no life and death implications. So in expecting white to want to play h15 after black has got the corner it’s not actually so symmetric. The more symmetric position to consider would be if black tenukis to something gote like r6, then does white now want to play h15 or c7?


A related question: in the initial position, Black H15 was better than Black B16. However if Black tenukis, why is White B18 slightly better than White H15?
Capture d'écran 2023-10-11 232840

After playing out with AI, it seems that if White B18 then Black needs to defend with H15, however White can strike at the vital point H17 afterwards and Black is under pressure. Whereas if White H15 then Black can tenuki.


For one thing white b18 is a building move: makes territory and a base, whereas h15 is more a destroy black and make some centre power move. Because white can play b18 rather than b16 to capture c16, b18 is quite a few more points and by taking a liberty of c18 has some benefit on the top side such as makes g18 peep harder to resist e.g. if black h17 then white f18 cut immediately captures 4 stones thanks to taking b18 liberty.


Thanks, great explanation! And yes, after r6, h15 is the blue move for white.

Well my katago build actually still prefers h15 to b18, so at least it is consistent :slight_smile:
Thinking it might be that my katago network was old I downloaded a new one, but it still insists that h15 is the best move in the upper left corner.

Very often the proverb applies “your opponent’s key point is your own”, but like every proverb, it does not apply in all cases.