Please review beginnerâs 9x9 game

PeterPeter · Post by **PeterPeter** » Thu Oct 04, 2012 11:27 am

Hey guys

This is a simple game that I put reasonable thought into, and one of the first where I actually felt I understood quite a bit of what was going on, but still think I could have done a lot of things better. My comments are in the sgf.

Thanks

jts · Post by **jts** » Thu Oct 04, 2012 11:29 am

EdLee · Post by **EdLee** » Thu Oct 04, 2012 12:18 pm

A little homework for you: study the upper right corner's life-and-death of your B group.

Coyote · Post by **Coyote** » Thu Oct 04, 2012 12:52 pm

PeterPeter · Post by **PeterPeter** » Thu Oct 04, 2012 1:18 pm

Thanks.

What would you say was the first move (either White or Black) that condemned the upper right group to death, assuming White had played perfectly after that move?

EdLee · Post by **EdLee** » Thu Oct 04, 2012 2:26 pm

Peter, after :b10:

, your corner already looks super unhappy.

PeterPeter · Post by **PeterPeter** » Thu Oct 04, 2012 2:53 pm

EdLee wrote:Peter, after , your corner already looks super unhappy.

That early? :shock:

I would never see a problem that far off.

What is the clue in the position that trouble is coming? The White stone on f8? The wall of White stones on line 4? The bad placing of my h6 move?

xed_over · Post by **xed_over** » Thu Oct 04, 2012 3:44 pm

PeterPeter wrote:What is the clue in the position that trouble is coming?

not enough eye-space

http://senseis.xmp.net/?SmallestGroupWithTwoEyes

(and almost cut off from any other living group)

mitsun · Post by **mitsun** » Thu Oct 04, 2012 4:24 pm

PeterPeter wrote:
EdLee wrote:Peter, after , your corner already looks super unhappy.

That early? I would never see a problem that far off....

Note that this is not necessarily a problem. It becomes a problem if you do not see that it will be difficult to live, but you try anyway and fail. If you see that living is difficult, then there is a simple solution -- give up that stone, but force W to capture it on a small scale. Try playing out some games from move 10, where you deliberately decide to sacrifice that stone.

PeterPeter · Post by **PeterPeter** » Thu Oct 04, 2012 9:06 pm

I think I see it: after move 9 there is theoretically enough space in that corner to make eyes, but the problem is that White is strong in that quarter of the board while Black is weak, so White can too easily disrupt that space?

Instead of playing h6 for move 10, it would be better to recognise that g7 is now probably dead, and play somewhere more valuable like c7?

EDIT: Thinking about it, I thought 3-3 corners were usually safe? Is it the White stone on f8 that causes the problems?

jts · Post by **jts** » Thu Oct 04, 2012 9:27 pm

PeterPeter wrote:I think I see it: after move 9 there is theoretically enough space in that corner to make eyes, but the problem is that White is strong in that quarter of the board while Black is weak, so White can too easily disrupt that space?

Instead of playing h6 for move 10, it would be better to recognise that g7 is now probably dead, and play somewhere more valuable like c7?

EDIT: Thinking about it, I thought 3-3 corners were usually safe? Is it the White stone on f8 that causes the problems?

Every time an opponent adds another stone in the vicinity of your corner stone (whether it's a 3-3, 3-4, 4-4 stone, or whatever) he makes it harder for it to live. The basic things you can do, once you have a corner stone, are; (i) extend down one of the two sides; (ii) block off the corner, in one of two directions; (iii) move out towards the center. Conversely, your opponent can preempt you by occupying the sides, undercutting the corner, and fencing you in.

If your opponent has a 4-4 stone and you invade at 3-3, you can (usually) live. But if he has a 4-4 stone, you invade, he blocks, and then you play elsewhere, he can easily kill your invasion stone. Every move you ignore not only weakens your stone, but makes it more painful to save it.

Phelan · Post by **Phelan** » Thu Oct 04, 2012 9:48 pm

PeterPeter wrote:EDIT: Thinking about it, I thought 3-3 corners were usually safe? Is it the White stone on f8 that causes the problems?

Yes, but

was also a problem. It means that if you play from G7 to the right, it won't threaten much.

F8 is an approach on your corner stone. When that happens, either you feel that that the corner is still safe even if the opponent gets another stone close and play elsewhere that you feel is better, or you play something in response. Here, I think a response was necessary. G8 seems a good response.

As for something that hasn't been mentioned, as far as I see:
:b2:

"A good response to White claiming a 3-4 point is the knight jump away?"
I think a better approach to that corner would be F7. This might change on a bigger board, since with more space around, the knight jump is probably better.

However, there was an empty corner free. Usually, getting an empty corner is better than approaching an already occupied corner. Getting 3 corners in a 9x9 like this would be a very big advantage. (Note: In a 19x19 it isn't so clear)
Also, if you get the 3rd empty corner, your stones are better connected. I'm not sure how visual you are in Go, but if you look at the board with and without the extra corner, you should see the difference.

Click Here To Show Diagram Code: [go]$$B 2 corners for each $$ ------------------- $$ | . . . . . . . . . | $$ | . . . . . . . . . | $$ | . . O . . . X . . | $$ | . . . . . . . . . | $$ | . . . . , . . . . | $$ | . . . . . . . . . | $$ | . . X . . . O . . | $$ | . . . . . . . . . | $$ | . . . . . . . . . | $$ -------------------[/go]

vs

Click Here To Show Diagram Code: [go]$$B 3 corners for black $$ ------------------- $$ | . . . . . . . . . | $$ | . . . . . . . . . | $$ | . . X . . . X . . | $$ | . . . . . . . . . | $$ | . . . . , . . . . | $$ | . . . . . . . . . | $$ | . . X . . . O . . | $$ | . . . . . . . . . | $$ | . . . . . . . . . | $$ -------------------[/go]

So, in a 9x9 game, unless the opponent approached one of your stones, get the 3rd corner.

CnP · Post by **CnP** » Fri Oct 05, 2012 7:54 am

Regarding white 29, this is the monkey jump move http://senseis.xmp.net/?MonkeyJump. There's even a book just about the correct response http://senseis.xmp.net/?MonkeyJumpWorkshop.

Also, no-one's mentioned yet but that top right dead group is a well known standard dead shape: (L-group) http://senseis.xmp.net/?LGroup It's discussed in Elementary Go series Life and Death btw.

edit: White 25 is a mistake isn't it?

PeterPeter · Post by **PeterPeter** » Fri Oct 05, 2012 8:20 am

CnP wrote:Regarding white 29, this is the monkey jump move http://senseis.xmp.net/?MonkeyJump. There's even a book just about the correct response http://senseis.xmp.net/?MonkeyJumpWorkshop.

That's useful. On further analysis I had concluded that it was better to ignore it, as there were useful moves to be made elsewhere, and I lost my naive battle to defend that side of the board anyway.

CnP wrote:Also, no-one's mentioned yet but that top right dead group is a well known standard dead shape: (L-group) http://senseis.xmp.net/?LGroup It's discussed in Elementary Go series Life and Death btw.

I will try to remember that, as it looks like a common shape.

xed_over · Post by **xed_over** » Fri Oct 05, 2012 10:12 am

CnP wrote:Also, no-one's mentioned yet but that top right dead group is a well known standard dead shape: (L-group) http://senseis.xmp.net/?LGroup It's discussed in Elementary Go series Life and Death btw.

that's the homework EdLee wanted him to do

Life In 19x19

Please review beginnerâs 9x9 game

Please review beginnerâs 9x9 game

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