O Rissei, 9dan (W) - Kato Masao, 9 dan, 1998-02-19a
After
Elf estimates
White's winrate as 89% with 59.6k playouts. White, O Rissei, won by 1½ pts.
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[go]$$Bcm23 White is ahead
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . 2 a X O . . . . . . |
$$ | . . . O . . . . 4 1 O O X O O , O O . |
$$ | . . . . . . . . . 5 3 . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Black's bad shape, the empty triangle on the bottom side, is a clue. However, Kato, who was no slouch, had just played to create it. Perhaps he thought that
would connect at
a. If so, he was right, O Rissei did play
at
a. Elf disagrees. It regards
as a blunder, costing 19%.
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[go]$$Wcm28 Elf's mainline variation for
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 3 . . . . . 9 . X . . . . . |
$$ | . . X , 4 O . . . , . . . . . , X . . |
$$ | . . . . . 5 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 8 . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 2 . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . 6 O . X O . . . . . . |
$$ | . 7 . O . . . . O X O O X O O , O O . |
$$ | . . . . . . . . . X X . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
is big, enlarging White's right side moyo. Instead of replying to
White turns to the top side, making a three stone wall. Next, the cut at
is big.
is interesting, avoiding an extension towards the right, which would not have a good follow-up to its right.
approaches the top right enclosure. It may also be considered as an extension from the three stone White wall. OC, the bots do not care about the human rules for such extensions.
Earlier in the game
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[go]$$Wcm14 loses 13% versus a
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , 1 . a O O , O . . |
$$ | . . . . . . . . . . . . X X . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf regards
as a mistake, preferring the simple and strong push at
a.
- Click Here To Show Diagram Code
[go]$$Wcm14 Elf's mainline variation for
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 3 . . . . . . . X . . . . . |
$$ | . . X , 4 O . . . , . . . . . , X . . |
$$ | . . . . . 5 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 0 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 6 8 . . . . . . . . . . . . . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . O . 9 . . . , . . 1 O O , O . . |
$$ | . . . . . . . . . . . 2 X X . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
After
White turns to the top left corner, making the three stone wall. White replies to
with a kick and jump. The fact that
is high suggests that White is looking to attack
and
.
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[go]$$Wcm24 Elf's mainline variation for , continued
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X O . . . . . . 2 X . . . . . |
$$ | . . X , X O . . . , 3 . 1 . . , X . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 5 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . B B . . . . . . . . . . . . . . . |
$$ | . 7 O . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . O O O , O . . |
$$ | . . 6 . . . . . . . . X X X . . . . . |
$$ | . . . . 4 . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
plays the Go Seigen/AI shoulder blow against the top right enclosure.
takes advantage of White's high posture in the bottom left corner to play a submarine attack.
and
play a counterattack against the
stones.
The actual game continues.
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[go]$$Wcm20 Mutual misunderstanding
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X O . . . . . . |
$$ | . . . O . . . . . , O 1 X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . 2 . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf estimates that
loses 15½% to par.
returns the favor, losing 17½%. This kind of exchange of nearly equal mistakes suggests a shared misunderstanding of the position.
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[go]$$Wcm20 Elf's mainline variation for
$$ ---------------------------------------
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 1 . . . . . . |
$$ | . . . . . . . . . 4 2 B O . . . . . . |
$$ | . . . O . . . . 3 5 W 6 X O O , O O . |
$$ | . . . . . 7 . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
stands instead of cutting off the
stone. OC, cutting off the
stone shows fighting spirit, and is consistent with
(
). Not to cut off the
stone suggests that
was a mistake. Elf would agree.
and
push along the fifth line, forming a center facing wall, before connecting with
.
jumps along the fourth line and then:w24: connects. In effect, Black has forced White to "crawl" along the fourth line. According to traditional go wisdom, that is ill advised. However, the bots ofter prefer to make center facing walls on the fifth line in exchange for the opponent's edge facing walls on the fourth line. The bots have a lot to teach us about center oriented play.
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[go]$$Bcm27 Elf's mainline variation for , II
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . 7 X . . |
$$ | . . . . . . . . . . . . . . 2 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . 4 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 5 . 3 . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . X X X O . . . . . . |
$$ | . . . O . . . . O O O X X O O , O O . |
$$ | . . . . . O . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
approaches White's small moyo on the right side. The resulting sequence illustrates Elf's light, flexible play.
on the 5-5 threatens to cut off
or to invade the Black enclosure.
invades the White moyo. OC, Black's fifth line wall offers support for this invasion.
separates
and
, attacking both.
jumps out into the center and then
defends the White territory. Finally,
defends the Black position in the top right.
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[go]$$Wcm34 Elf's mainline variation for , III
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 1 . . . . . . . X . . . . . |
$$ | . . X , 2 O . . . 4 . . . . . X X . . |
$$ | . . . . 8 3 . . . . . . . . O . . . . |
$$ | . . . 7 9 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 5 X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . 6 . . . . O . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . X X X O . . . . . . |
$$ | . . . O . . . . O O O X X O O , O O . |
$$ | . . . . . O . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
builds the three stones wall on the top side. Then
attacks it while extending on the side.
bolsters White's position in the top right and then
defends his invasion.
takes the double keima, then
and
push and cut, and the opening fight continues.
Next we look at Elf's variation for
in the actual game
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[go]$$Bcm21 Elf's mainline variation for
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 6 5 7 . . . . . |
$$ | . . . . . . . . . 9 . 1 2 . 8 . . . . |
$$ | . . . . . . . . . 3 . X O . . . . . . |
$$ | . . . O . . . . . 4 W W X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
The stand,
, looks right and left, taking aim at the
stones and at White's weakness in the bottom right.
threatens the one and then
threatens the other.
is a strong riposte, cutting Black in two.
- Click Here To Show Diagram Code
[go]$$Wcm30 Elf's mainline variation for , continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . O X X . . . . . |
$$ | . . . . . . . . . X . X O . O . . . . |
$$ | . . . . . . . . . X . X O . . . . . . |
$$ | . . . O . . . . . O O O X O O 3 O O . |
$$ | . . . . . . . . . . . 5 X X 6 . X 2 . |
$$ | . . . . . . . . . . . 1 4 . a X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
turns to attacking the Black corner.
shores up a White weakness and threatens to play at
a.
and
secure the Black group.
Back to the game.
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[go]$$Wcm22 Overplay
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 1 . . . . . . |
$$ | . . . . . . . . . . . X O . . . . . . |
$$ | . . . O . . . . . 2 O O X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
may be a tesuji. but Elf indicates that it is an overplay, losing 13½% to par.
- Click Here To Show Diagram Code
[go]$$Bcm23 Elf's mainline variation for
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 6 . . . . . 0 . X . . . . . |
$$ | . . X , 7 O . . . , . . . . . , X . . |
$$ | . . . . . 8 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . .9. . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 5 . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . O . . . . . . |
$$ | . 4 . . . . . . . . . B O . . . . . . |
$$ | . . . O . . . . . . O O X O O , O O . |
$$ | . . . . . . . . . 1 . . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
is a solid play, but gote. The checking extension,
, is big.
approaches the bottom left corner. White replies with the footsweep,
, as
hinders White's development on the bottom side.
is an interesting play, threatening to save
, as well as to invade the right side. White now turns to develop the top side, as we have seen above.
Back to the game.
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[go]$$Wcm24 Blunder
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . 1 . X O . . . . . . |
$$ | . . . O . . . . 3 X W W X O O , O O . |
$$ | . . . . . . . . . 4 2 . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
threatens the
stones, but it is a blunder. According to Elf it loses 30%.
- Click Here To Show Diagram Code
[go]$$Bcm25 Elf's mainline variation for
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 8 . . . . . . . X . . . . . |
$$ | . . X , 9 O . . . , . . . . . , X . . |
$$ | . . . . . 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . B . . . . . . . O . . . . . . |
$$ | . . . . . . . . 4 O . X O . . . . . . |
$$ | . 5 . O . . . 6 1 X O O X O O , O O . |
$$ | . . . . . . . . . a . . X X . . X . . |
$$ | . . . . . . . . 7 . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
=
is typical when Black does not need to play at
a. In this position, White does not answer
in the corner, but pushes in the center. After the now rare slide,
, White plays the hane,
, and
protects, forming a table shape. Next, White forms a three stones wall on the top side. Then
jumps into the center.
Attack and Kill Kato blundered on the bottom side with a strong local attack, accepting bad shape in the process. He probably assumed that O Rissei would save his two stones, which he did, making his own blunder. We warn beginners against overvaluing a few stones. It just goes to show that even 9 dans can sometimes make kyu level plays.