- Click Here To Show Diagram Code
[go]$$Bcm13
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . b . . . . . . . . . . . . . |
$$ | . . . O . . . . . 1 . . . . . X . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . X . . . . . a . . . |
$$ | . . . O . . O . . , . . . . . , . . . |
$$ | . . . O . X . . O . X . . . . X . . . |
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$$ ---------------------------------------[/go]
I think this position is an excellent example of why go is so hard!
It is so easy to use conventional advice and come up with a Black move at A, just like the bots. For example, we could point out that 13 is not urgent because there are two big points left on the sides and Black will always get one of them as miai, so he should give priority to protecting his investment in the lower right. On one view, A can even therefore be regarded as a tedomari. We can also rely on conventional advice to tell us that the correct time to erase a moyo is one move before it is complete. From that it follows that by playing 13 at the top, and not A, Black is just playing into White's hands.
It is also easy to use one of the various patented methods pros offer. One such here is to divide the board horizontally through the centre line. What that shows us is that the position at the top of the board is equal, but at the bottom of the board Black has a much more expansive position. White has already lapsed into some overconcentration and Black has good forcing moves to make that even worse. It therefore looks good for Black to play A so that he doesn't fall into the same sort of stunted shape as White.
It is furthermore easy to rely on AI, with all the bots telling us that A is best. But they don't tell us why, and despite the surface manifestation of unity, they are just as cussedly opinionated as the humans. For example, Elf says 13 is an 11% win-rate drop, but my Leela gives 4%. But if we say that the precise numbers don't matter, it's the principle of lower side versus upper side, then why does my Leela give almost the same score for B as it does for A? At first sight, B has much, much more affinity (upper side) with 13 than it has with A. (B has in fact been played once in the GoGoD database, and 13 twice - no other games exist).
It may be that in the AI "consciousness" the split is not actually between upper side and lower side (which is my sense of what humans see first if we go by the extant games and my own experience), or moyo completion versus moyo erasure, but is rather simply side versus centre: A and B are both corner moves and we do know bots lurrrrve the corners.
Then, of course, we should consider psychology and style. Was Yi Se-tol playing the man or the board, or was he just being Yi Se-tol?
It is MUCH, MUCH easier to understand Brexit politics, or even Sheldon's string theory.