By the way, is the famous move Fujiwara-no-Sai immediately spots at a children's tournament in Hikaru no Go chapter 3. See Hikaru problem 1
Maybe this is a ridiculous variation but I couldn't help wondering what happens when Black takes that marvelous 1-2 point himself.
Anyone?
Nando: Well, I gave it a shot and couldn't find a way to unconditional life for White after in this diagram, my best result being ko.
JoelR: After working on this problem a couple of nights and missing some lines, I showed it to my boss, who is 3dan. He was able to finish it off. For now, I'll put the analysis at /Varation.
tasuki: Why exchange 3 for 4? It seems to me that this exchange doesn't help white at all and helps black quite a lot. Why not simply 3 at 5?
By the way Dieter, I totally agree with what you said at the bottom of the tsumego page. I figured a lot of variations starting with that diagram, and although I didn't succeed in solving the problem, I feel that I've learned quite a lot about shape and the special properties of the corner.
Gregory I agree that is a wrong play.
must be at
(R15) threatening the
point at Q14 if Black plays elsewhere.
However, Black may play quite differently from the main line, as follows.
See /Varation which shows how White survives if Black plays 6 at a.
Gregory The is the variation.
should go back to the mainline solution at the 1-2 point of S19.
JoelR: No, if at 'b', then
at 'c'. Since unlike the main line, Black does not have a stone at 'a', he can keep White from capturing three to make an eye.
White's next move seems difficult. But there is a lot of aji for White to exploit. Also, the door is open for White's three stones to escape at 'a'.
White gets a direct ko, and Black has to find the first threat.
Question from JoelR
What if B2@'a'? -JoelR
Incidentally, I almost had a solution where White didn't have to turn at , but
cooks it. Malcolm I don't understand this. "Nearly" had a solution?
If Black plays , White escapes at
, leaving Black dead in the corner, and with fewer liberties than White's surrounding stones, so White wins the capturing race.
tderz: I would like to introduce variations about the (un-)equivalency of this immideate . What will happen after black connects at a.
After a-f, g and h are miai in a sense that both times Black will be captured.
At first I thought that bG - wH, bI - wJ would be only ko, however Black is already taken off the board after wJ.
tderz: What did I miss , why could be inferior to a cut at b?
The conclusion for this problem: after White plays the first move in the solution (the cut at b34 (Audouard coordinates), then Black has a choice. Either let White live, or make a ko to kill White, in which Black risks the corner.
This page could do with a good edit!
Main line: HashimotoUtaro
Variations: Dieter, Malcolm