Is the official solution to this problem incorrect?!
Problem diagram.
White's response to the marked play?
Source:
From Charles Matthews and Seong-June Kim's excellent preview on a book on shape.
Analysis: Myron Souris
Solution follows
(or click here to download SGF)
"Official solution"?
The official solution says, "White should play at 1 to give fewer points away."
Normally, attaching on the other side at 3 first would be about 2.5 points worse for White.
But in this position, what if Black 2 goes for the corner?!
Cutting off Black with 3 doesn't help.
The sequence through 6 is a disaster for White. Black lives in sente in the corner!
Maybe the "official solution" missed this resource for Black?
Does anyone see a better sequence for White here?
White variation.
The official solution says, "White 1 is the wrong order, though it works."
But given the previous diagram, this may actually be best move order here, because Black can no longer live in the corner!
The best that Black has seems to be to simply capture the White stone with 2.
Through 5, Black captures a stone in sente, but White keeps the corner.
Black variation.
Black 2 is an overplay. Now Black cannot live in the corner.
After White 9, Black dies.
Another Black variation.
Expanding eye space with Black 4 doesn't work either.
White 5 keeps Black to 1 eye.
This sequence shows that Black has nowhere to run and no way to make a 2nd eye at the top.
Ultimately, White has a "bent 4" shape in the corner to kill Black.
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