Lesson 113: Eternal Life (2)
By Nam Chi-hyung
After I wrote the last lesson on eternal life, Setsuo Morino, a Japanese 9-dan professional Baduk player, paid me a visit. He showed me a Baduk diagram and wanted me to solve the problem.
According to him, the problem was made by one of his pupils, Hoshinobu Hatanaka, who is now a 1-dan professional player in the Kansai Baduk Association of Japan. This young genius made the problem when he was a mere student.
Diagram 1
This is the problem I got from Mr. Morino.
Of course, there are many excellent life and death problems invented by Korean professional players. However, there is a reason why I'm introducing this problem here.
This problem is precisely about `eternal life.' Although the problem is pretty hard to solve even for strong amateurs, I hope you will be able to appreciate the depth of the game in the attempt. Let's look at the problem.
It is Black's turn and its mission is to not lose the game. As you see, most of the borderlines are settled except on the right side. White's territory on the left is bigger than Black's territory on the upper side and the lower right corner by one point. Furthermore, the two groups of White and Black on the right side are not completely alive.
Because Black has a smaller territory than White, it is not enough for Black to make a dual-life situation on the right side. Also, he doesn't have any ko threats even if he succeeds in creating a ko. Then, what else can Black do?
I hope you remember that when there is an eternal life, and if neither player gives up the situation, the game is considered a draw. By now, you should have guessed the answer. Yes, Black has to make an eternal life on the right side in order not to lose the game.
Diagram 2
The process for making an eternal life is quite difficult. The sequence from 1 to 7 is its first step. With any other move, such as if Black plays 2 instead of 1, or 4 instead of 3, the Black group cannot escape death.
Diagram 3
After Black captures the two white stones with 7 in Dia.2, White 1 here is mandatory to prevent Black from making two eyes. If Black captures it with A, the situation will turn into a ko. However, as mentioned above, Black does not have any ko threats. Maybe the situation looks to be disastrous for Black, but in fact he has a brilliant move at 2.
Diagram 4
Black anticipated White capturing the five stones with 1. However, Black also can capture White by cutting at 2. This is a skill called 'cut-back.' Now, the tables are turned. White has no choice but to enlarge the victim with 3. If he plays A instead of 3, the entire white group will die.
Diagram 5
After Black's capture of the three white stones in Dia.4, White again throws in at 1. If Black captures it with 3, then White 2 will kill the black group.
Therefore, the sequence up to Black 4 is compulsory. Now, did you notice that the final situation of this diagram is the same as the one in Dia.3?
If not, please add one move of White at 1 again, and one move of Black at A. Do you see the repetition? Perhaps this eternal life has the longest repeating term that I have ever seen.
The writer is a baduk professor at Myongji University and a professional player of the game.