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June 2003's Go Answer of the Month


Dia 1 - Where are A and X ?

Dia 1

This game is between two 9-dan professionals. The commentary for move 35 reads:
Black 35 was questioned after the game, it being suggested that A was the only move.
However, Black 33, aiming at X, is big, so I don't think it's a problem.

So where might 35' have been played (where is A) and at what point did 33 aim (where is X)?


16th Gosei Title Match: Game One, 1991.
White: Kobayashi Koichi, Gosei, 9p.
Black: Kobayashi Satoru, 9p.
Komi: 5 1/2 points.
Time: 5 hours each.
Result: White wins by 7 1/2 points.

A commentary by O Rissei, 9p, on this game may be found in Go World #67. In that article apparently the quote reads However, Black 35, aiming at X, is big, so the question posed may have been somewhat confused.


Review the situation

Black has the start of a moyo at top left, while all his other stones are stable. White has stable groups at bottom left, bottom right and top right. Stone 22 can be treated as aji. However the mid left stones (6,16,18) are attackable.

A must be a move that applies pressure to these three stones, the only question is how. Suggestions that have been made while discussing this at the club and elsewhere (3d to 13k players) include B thru H in Dia 2.

Dia 2 - B thru H.

Dia 2

B is an attempt to create a large moyo on the left in the expectation that white will answer on the right. However this weakens the top right black group.

C is too small / slow. D just chases the white group into the black moyo area. E is in the wrong part of the board.

F is trying to be too fancy by affecting the three mid left stones from a long distance - unlikely to be successful.

G and H look about right, enlarging the moyo in sente - else the three white stones come under severe attack. Dia 3 is one possible sequence.

Dia 3 - The stated "A" is 1 here (G).

Dia 3


As for X, aimed for by 35 or 33 or both. The only candidates were E or F to make a moyo at the bottom of the board and the correct answer X in Dia 4 which attacks the bottom left white group. That group will live, but it may be possible to make a large lower side out of the attack.

Dia 4 - "X" and the game continuation.

Dia 4

However, as the continuation in Dia 4 shows, White ignores the possibility of X and trashes the Black upper left moyo. In the game, Black never gets to attack at X since White reinforces first.


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