![]() StartingPoints Referenced by
|
RTG Problem 4 Attempts
BrianMarshall: Well, I guess I'll make an attempt.
To me, White 1 seems the best move at the vital point of Black. Even so, it seems black has the chance to live in ko.
After Black 8, doesn't this depend on the ko? unkx80: Nice try! Unfortunately the correct result is not ko. =)
Another attempt resulting in ko:
White invades fiercely...
But after White 13, Black can again live by winning the ko. White 11 at 12, while tempting (to me, at least), is worse. Black 2 at 1 gives Black unconditional life. Now an example of one failed attempt by White.
After Black 2, I think a and b are miai for life. unkx80: This statement is somewhat inaccurate. White 3 at b, Black 4 at a, and White 5 at c makes a ko. Brian: Ah, I see. Thank you for the correction.
Now Black can easily get two eyes and live. unkx80: If White 5 is played at 6, then Black dies. Also, what happens when Black 2 is played at 6? Brian: Hmm. If White 5 is at 6, then Black cannot split at 5, or he'll lose the marked stone. But blocking reduces the eye to three in a row, which White can kill. Ok, I see that now. But when Black 2 is at 6,
White can just extend with 3, preventing an eye in the corner. Black needs an eye on the left, so Black 4. Ah! White 5 kills, then, by threatening a White move at 6. Black 6 defends, but White 7 prevents the eye. Is this the correct answer this time? unkx80: What if Black 4 is played at 6? Brian: If Black 4 is played at 6, then White 5 played at 4 prevents an eye on the left. Bill: But then the result is seki. :-)
The situation after White 1. In my mind, for Black to form an eye at z he needs to occupy one set of: a-b-c-d, a-b-c-e, a-b-d-e, or b-c-d-e. Alternately, Black could attempt to form an eye at d. This would require points c-z-e. Since, at best, Black requires three of six points, White can prevent this. unkx80: I admit that this problem is not so easy, and this isn't the Beginner Exercises series. I shall drop one hint: the main line to the solution involves shortage of liberties. Good effort there! =)
Dieter: I have a feeling this is coming pretty close. Just another minute ...
In a real game I would have gone for ko, I'm afraid. :-( unkx80: Bingo. =)
Thanks for the hint, unkx80, I had been under the illusion that Black could connect at 9. ;-) This is a copy of the living page "RTG Problem 4 Attempts" at Sensei's Library. (C) the Authors, published under the OpenContent License V1.0. |