Kobayashi wins Judan titleFive years ago, Koichi Kobayashi
was the top go player in Japan. He had held the Kisei title for
eight straight years and the Meijin for seven. Only the Honinbo
title eluded him, but that one was held by his lifelong rival, Cho
Chikun.
Three times he challenged Cho for that title, but each time Cho
repelled Kobayashi's determined efforts and defended his title. Then
in 1994, Cho challenged for the Kisei title and Kobayashi's
eight-year reign came to an end. The following year, he also lost
his Meijin title to Masaki Takemiya. This was the beginning of a
long slump brought on, it is believed, by the sickness and eventual
death of his wife, Reiko, herself a famous go player.
Late last year, Kobayashi remarried and this seems to have
reinvigorated his game. At the end of last year, he won the
prestigious Tengen title and also won the right to challenge Cho for
the Kisei title. He also became the challenger for the Judan title,
the fourth most important Japanese title. In the Kisei title match,
Cho again proved his prowess by defeating Kobayashi 4-2. In
contrast, Kobayashi had an easy time defeating Naoto Hikosaka, the
Judan title holder, by winning three straight games in the
best-of-five title match.
This is not the first time that Kobayashi has held the Judan
title. In 1984, he defeated Masao Kato to take this title and held
it for three consecutive terms. But Kato came back as the challenger
three years later and dethroned him.
The fact that Hikosaka won the Judan title last year was a
surprise. At 37, he is certainly among the top Japanese players,
holding the rank of 9-dan, but he is not considered in the same
league as the top titleholders. Still, he had good results last
year, becaming the Judan challenger by beating Cho Chikun, then
going on to beat the great Masao Kato (who has won more than 40
titles) in the title match to take his first-ever title. He also did
very well in this year's Honinbo league, almost becaming the
challenger for the title. He ended with a top 5-2 record, but so did
another player, Cho Sonjin. In the playoff, Hikosaka lost to Cho.
Like Cho Chikun, Cho Sonjin was born in South Korea. He is 28
years old and came to Japan to study go when he was 12. He has won
two tournaments for young players, but this will be his first
challenge for a major title. No one gives him much of a chance
against Cho Chikun, but it would not be the first time an unheralded
player has upset the champion.
In an interview after the playoff with Hikosaka, Cho Sonjin said
he was overjoyed to have earned the honor to play the Honinbo in a
best-of-seven match and that he was determined to play some
beautiful games. The Honinbo title match will begin on May 12 and is
scheduled to continue through July.
The rule of ko
Since January, I have introduced four basic rules. They are:
Rule 1. The board is empty at the start of the game.
Rule 2. Black makes the first move, after which he and
White alternate.
Rule 3. A move consists of placing a stone of one's own
color on an empty intersection.
Rule 4. A stone or a solidly connected group of stones of
one color is captured and removed from the board when all the
interestions directly adjacent to it are occupied by the enemy.
By using these four rules, we have been able to explain many of
the tactics and strategies of go, but there is one more important
rule. This is the rule of ko, which is:
Rule 5. No stone may be played so as to re-create a former
board position.
This rule prevents
self-capturing moves. For example, White cannot play 1 in Diagram
1 because this stone will be immediately taken off the board and
the position is unchanged from the previous move.
Rule 5 also prevents endless cycles of capture and recapture, a
situation known as ko. The following six Diagrams illustrate this.
Diagram 2. It is
White's turn to play. His three stones on the lower edge are in
atari (threatened with capture), but so is the marked black stone.
Diagram 3. White rescues his three stones by capturing the
black stone with 1.
Diagram 4. Now the four
black stones in the lower left corner are in atari. However, the
marked white stone is also in atari.
Diagram 5. Black would like to capture with 2, but when
the white stone is taken off the board, the position is identical to
Diagram 2, which is prohibited by Rule 5. Therefore--
Diagram 6. Black has to
play on some other point. If he plays 2, for example, White can
capture four stones by playing at 3. But Black can now play 4, and
the five white stones in the upper right can no longer make eyes.
Although Black lost four stones in the lower left, the five white
stones and the territory Black gets around them by playing 4 is
bigger.
Diagram 7. Therefore, White must answer Black 2. He does
so by playing 3. But Black can now capture at 4. Note that the 2-3
exchange makes the board position different from Diagram 2. A
move like Black 2 is called a "ko threat."
Now White cannot immediately recapture Black 4, but must play a
"ko threat" such as 5. If Black answers White 5 by playing at "a,"
White can go back and capture 4. A ko situation such this will
continue for several moves until one side runs out of ko threats.
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