So i have been doing this collection, and I wonder if the problem seki solution is acceptable to the attacker. I tried this problem so many variation, and the best variation is seki for the attacker.
I'm pretty sure black can kill. There's a black 1 that you have not considered. It's a forcing move. Actually black 1 was not the difficult move to find, but black 3 was a little unusual.
$$B $$ ----------------- $$ | . 3 X O O 5 X . $$ | O O 1 4 . O X . $$ | X O 2 O O X . . $$ | X X X X X X . . $$ | . . . . . . . . $$ | . . . . . . . .
[go]$$B $$ ----------------- $$ | . 3 X O O 5 X . $$ | O O 1 4 . O X . $$ | X O 2 O O X . . $$ | X X X X X X . . $$ | . . . . . . . . $$ | . . . . . . . .[/go]
Variation
$$B $$ --------------- $$ | . 3 X O O 4 X . $$ | O O 1 5 a O X . $$ | X O 2 O O X . . $$ | X X X X X X . . $$ | . . . . . . . . $$ | . . . . . . . .
[go]$$B $$ --------------- $$ | . 3 X O O 4 X . $$ | O O 1 5 a O X . $$ | X O 2 O O X . . $$ | X X X X X X . . $$ | . . . . . . . . $$ | . . . . . . . .[/go]
Not seki obviously since a kills
Edit: Ooops, even this is seki. There was a white 4 that I didn't consider.
Re: Cho Chikun intermediate
Posted: Sat Jul 07, 2012 2:42 am
by tchan001
Best solution in this position is seki. Verified with Gotools which says that the position with black to move is alive.
Re: Cho Chikun intermediate
Posted: Sun Jul 08, 2012 5:52 am
by LokBuddha
Yes I also believe it to be seki. I know the problem seem to set out as the throw in standard to destroy eye hence the kill, but the unexpected best response by white is as seen as my solution.
I happen to be around 3-4 dan on KGS, and I have been doing Cho chikun set. I finished the elementary, now doing the intermediate. IMHO, the whole set probably is harder than Gokyo Shumyo since you have to figure out the best possible play for both side without knowledge of seki or Ko solution since you have no idea what to expect.
It goes like this
To live problem 1. Unconditional live 2. Seki 3. Ko to live
To kill problem 1. Unconditional kill 2. Ko to kill 3. Seki Needless to say, number 1 is what you strive to do, if not then the next best variation should be number 2. The worst is number 3.And of course there is the number 4 (not listed) which is the wrong solution variations that you also should read out to reinforce the other numbers that actually accomplish something. sometimes you go in backward order, from number 4 to 1, just to make sure you solve the problem completely.
Gokyo at least categorized in a way that you know the answer you should look for is a ko or not.
And it took me 9 hours + to finish the elementary....Checking out all sort of variation. I am having severe pain at some problem in the intermediate.