The thing is, some of white's gains on the left side costs white some turns or some liberties, but don't actually lose very much in the case that ultimately the semeai variation is chosen. If black spends those extra liberties pushing in the upper right, black improves the capture variation, but those moves *lose* points on the semeai variation.

So given that most of black's ability to balance white's gains comes at the cost of making one variation worse to improve the other, whereas some of white's gains just purely make one variation better without costing in the other, black starts to get squeezed in both variations.

A 50 per cent approach-move liberty

Did you ever wonder why the score difference between the Capture Variation and the Semeai Variation with KataGo's new ( & amateurish enhanced) solution is odd (W + 1 vs. Jigo), while this difference was even with Our Solution (B + 5 / B + 3), as well as decades ago?

...
With the Semeai Variation, however, due to Black's eye at O13 (and his connection at L6, and White's vanished eye in the centre at M12), White is able to approach at c AND d, only after connecting at the crossed board point before. This connection costs her one point of territory, but in the Semeai Variation only.

144 White's move should be in M11 instead of M12. its one point better for White in Semeai Variation.
so in both variations the result will be W + 1.

You credited some people with pointing out ideas. What about Katago, is it helping to analyze some of these ideas?

What about Katago, is it helping to analyze some of these ideas?

Thank you very much for your interest, and especially for your question about KataGo.

Indeed, most of our work was done manually. I used KataGo sometimes for confirming a new line, when I was very unsure about it. Dany once mentioned that KataGo has confirmed his usage of ko threats during his ko. Joachim did not have a suitable machine for running KataGo. But let me explain in more detail ...

The usage of KataGo was severly affected by the following aspects:

• Neither Joachim nor me own that powerful type of machine, which would be necessary to achieve an adequate amount of playouts in justifiable time. Please note that it would be necessary in most cases to analyse the same positition with different komi, in order to get the "optimal" suggestion by KataGo, also with a certain relationship to the (expected) final score. Our machines were simply much too slow / unsuitable for that purpose.
• KataGo 1.2, which was used to create the special IgoHatsuyoron120-network, calculates with Area Scoring only. This implies that KataGo 1.2 is unable to distinguish between (e.g.) "W+1" and "W+2" under Territory Scoring. But which would be necessary for a "really" reliable analysis of a problem that originated in Japan.
• As far as I know, KataGo does not use the (estimated) final score of a variation for prioritisation. Which is our parameter for ranking subvariations.
• Additionally, (I suppose that) KataGo does not use the final score of BOTH Main Variations as parameters for ranking moves / subvariations. ONE "sure" way to (e.g.) a win for White by two points will be enough. However, we would like to prioritise "W+2 / B+4" over "W+2 / W+2" at a branching point for Black's next move.

If one wanted to have an assistant for creating these "Why not play there?" moments (which I encountered during painting the diagrams, and which seems to be one of Joachim's talent when refuting lines of play in question), I think that the following requirements were needed:

• A technical environment that enables the creation of a reliable selection of candidate moves by KataGo in seconds, not in minutes.
• A (new?) special IgoHatsuyoron120-network that would be compatible with the newer versions of KataGo, which are able to also calculate using Territory Scoring.