British Go Journal No. 66.  November 1985. Page 24.
Richard Granville analyses the answers of our panel of experts to the competition in our last issue.
BGJ had a summary of replies for each problem listed here. It has been split to put each summary with the relevant problem. The original article used coordinates (such as K10) for most of this article. It has been altered to use marked up diagrams for the EBGJ.
You might wish to open a second window beside the first one to view Dia X1 whilst reading the text in the first window.
Marks for various white moves.
Diagram 1 |
When I discussed the idea of the BGJ competition with Matthew Macfadyen, he said that panelists would sometimes overlook moves that were chosen by other people. This has certainly happened here, since none of the panelists even mentioned the move which I played.
Diagram X1 |
Macfadyen: "The impressive feature of this position is Black's moyo (territorial framework) on the left. Normally there are three ways of handling a moyo.:
a) Invade it directly. The only sensible way to do this seems to be to pull out the cutting stones in the upper left. Unfortunately, White's corner is weak (B & C are sente for black), so Black will be able to play at G and white will have little chance to counter-attack.
b) Push it down from the edge. the obvious way to do this is K. I find it hard to refute K unambiguously, but it feels like the wrong area - the black marked stone becomes well placed and, although White may not want to play D immediately, he should be preparing to do so soon.
c) Make some of your own territory so that the moyo needs to get bigger. There is a perfect move at E for doing this. As well as making a huge corner almost secure, it builds thickness towards Black's moyo.
Other moves such as Q, N or J seem irrelevant, though they are all large. E is really the only move."
Brian Chandler almost agrees:
"Before reading 'Attack and Defense' I favoured E on the grounds that it was too precipitate to do anything witht he two white stones in the top left. On the other hand, the black stone still has some life in it, and E is rather slow."
Brian goes on to consider, but then reject, playing at F, and concludes that is the pivotal stone, preferring Q to M in reply to it.
There is strong support for Matthew's second option:
Rickard: "The white group in the top left seems to be alive, but the black hane and connection at A is sente. The white hane at B and connection is is also pretty much sente, but it might strengthen Black's moyo too much.
Considering the rest of the board first, I would play the sequence in Dia 2 which leaves a large sente endgame sequence starting at I. Black's left side becomes rather large but this seems better than allowing L. Given that I am going to strengthen Black's moyo, the double sente seems worthwhile, so my first move would be B."
Diagram 2 |
Shepperson agrees, but prefers N to the solid move at 7 in Dia 2.
Manning also wants to play the double sente point at B, and then to follow in the lower right, planning to reduce the moyo with H later. Roads on the other hand prefers to start immediately with H, treating the two cutting stones as aji only.
Diagram 3 |
In the actual game I played the sacrfice sequence in Dia 3, so as to make shape in the centre. Later I was able to invade the lower left side. (Ed - this seems playable, but a bit illogical, since the main attraction of saving the cutting stones is to prepare a counter-attack on Black's upper group.)
The answer to problem 3 can be found on page 25 .