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Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 11:27 am
by PeterPeter
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
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 11:29 am
by jts
http://www.lifein19x19.com/forum/download/file.php?id=2114
Posted: Thu Oct 04, 2012 12:18 pm
by EdLee
A little homework for you: study the upper right corner's life-and-death of your B group.
(;CA[utf-8]GM[1]FF[4]AB[cg][gc]AP[glGo:1.4]SZ[9]ST[1]PB[Human]PW[Igo for windows]
KM[0]HA[2]RE[B+6.0]MULTIGOGM[0]
;W[gf];B[eg];W[dc];B[ce];W[ef];B[df];W[fb];B[gg];W[hf]
(;B[hd]C[See var.];W[fc];B[cc];W[cb]
(;B[cd]C[See var.];W[bb];B[gb];W[he];B[gd];W[fe]LB[gc:a]C[Locally, the B (a) corner is dead shape for B -- verify for yourself.]
;B[ee]
(;W[fd]C[See var.];B[ff]
(;W[ga]C[See var.];B[ha]
(;W[fa]C[See var.]
(;B[hb]C[This is still dead shape for B -- verify for yourself -- see var.]
(;W[hg]C[See var.]
(;B[ib]C[Now B is alive, yes but see also var.];W[ae];B[be];W[ad];B[bd];W[ag];B[bg]
;W[af];B[bf];W[ac];B[bc];W[bh];B[ch];W[gh];B[fg];W[ih];B[bi];W[ah];B[ed];W[ec];B[fh]
;W[da];B[gi];W[ge];B[hh];W[id];B[ic];W[ie];B[hi];W[dd];B[de];W[ab];B[ii];W[ig];B[tt]
;W[ai];B[ci];W[tt];B[tt])
(;B[ic]))
(;W[ic]C[Locally, B is still dead shape -- verify for yourself.]))
(;B[ib]C[This is alive for B -- verify for yourself.]))
(;W[ib]C[Locally, B is dead shape -- verify for yourself.]))
(;W[ge]C[If W simple connects here, the B corner is unconditionally dead -- verify for yourself.]))
(;W[ff]))
(;B[bc]))
(;B[ff]))
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 12:52 pm
by Coyote
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[9]HA[2]KM[0.00]
PW[Igo for windows]PB[Human]AB[gc][cg]RE[B+6.00]
;W[gf]
;B[eg]C[A good response to White claiming a 3-4 point is the knight jump away?]
;W[dc]
;B[ce]
;W[ef]
;B[df]C[Reason: puts pressure on the White stone, and strengthens Black's grip on the LL corner.]
;W[fb]
;B[gg]C[Claims that corner, and the bottom of the board.]
;W[hf]
;B[hd]C[I wanted to protect my g7 stone, but I feel this was the wrong move (too small).]
;W[fc]
;B[cc]
;W[cb]
;B[cd]
;W[bb]
;B[gb]C[Securing that corner.]
;W[he]
;B[gd]C[Is this connection needed at this point?]
;W[fe]
;B[ee]
;W[fd]
;B[ff]
;W[ga]
;B[ha]
;W[fa]
(;B[hb]
;W[hg]
(;B[ib]C[This group is isolated, and I think this move guarantees 2 eyes.]
;W[ae]C[This was unexpected. I thought that most of the left side was mine. I ended up losing it all. How should I have replied to this?]
;B[be]
;W[ad]
;B[bd]
;W[ag]
(;B[bg]
;W[af]
(;B[bf]
;W[ac]
(;B[bc]
;W[bh]
;B[ch]
;W[gh]
;B[fg]
;W[ih]
;B[bi]
;W[ah]
;B[ed]
;W[ec]
;B[fh]C[This seemed to be the biggest endgame move.]
;W[da]
;B[gi]
;W[ge]
;B[hh]
;W[id]
;B[ic]
;W[ie]
;B[hi]
;W[dd]
;B[de]
;W[ab]
;B[ii]
;W[ig]
;B[]
;W[ai]
;B[ci]
;W[]
;B[]C[])
(;B[bh]))
(;B[bh]
;W[bf]
(;B[cf])
(;B[ac]
;W[bc]
;B[ah]
;W[ab]
;B[cf]
;W[ac]C[Even better
])))
(;B[ac]
(;W[af]
;B[bc]C[White will struggle here. There's no room for eyes and even if black plays very passively he'll still be far ahead in liberties.]
;W[bh]
;B[ch]
(;W[bf]
;B[cf])
(;W[cf]
;B[bf]
;W[bg]
;B[bi]))
(;W[bc]
;B[af])
(;W[ab]
;B[bc]
;W[bf]
;B[bg]
;W[bh]
;B[cf]
;W[ch]
;B[af])))
(;B[ic]C[Here is better. Still two eyes but takes away j6 for white. Since you don't have a stone on j8 you're up one point.]))
(;B[ib]C[This secures your group in one move.]
(;W[hc]
;B[ic]
;W[id]
;B[hb])
(;W[ic]
;B[id]
(;W[hb]
;B[hc])
(;W[hc]
;B[hb]))
(;W[id]
;B[ic]
(;W[hc]
;B[hb])
(;W[hb]
;B[hc]))))
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 1:18 pm
by PeterPeter
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?
Posted: Thu Oct 04, 2012 2:26 pm
by EdLee
Peter, after
, your corner already looks super unhappy.
Re:
Posted: Thu Oct 04, 2012 2:53 pm
by PeterPeter
EdLee wrote:Peter, after
, your corner already looks super unhappy.
That early?
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?
Re: Re:
Posted: Thu Oct 04, 2012 3:44 pm
by xed_over
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)
Re: Re:
Posted: Thu Oct 04, 2012 4:24 pm
by mitsun
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.
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 9:06 pm
by PeterPeter
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?
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 9:27 pm
by jts
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.
Re: Please review beginnerâs 9x9 game
Posted: Thu Oct 04, 2012 9:48 pm
by Phelan
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:
"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.
$$B 2 corners for each
$$ -------------------
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . O . . . X . . |
$$ | . . . . . . . . . |
$$ | . . . . , . . . . |
$$ | . . . . . . . . . |
$$ | . . X . . . O . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ -------------------
- Click Here To Show Diagram Code
[go]$$B 2 corners for each
$$ -------------------
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . O . . . X . . |
$$ | . . . . . . . . . |
$$ | . . . . , . . . . |
$$ | . . . . . . . . . |
$$ | . . X . . . O . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ -------------------[/go]
vs
$$B 3 corners for black
$$ -------------------
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . X . . . X . . |
$$ | . . . . . . . . . |
$$ | . . . . , . . . . |
$$ | . . . . . . . . . |
$$ | . . X . . . O . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ -------------------
- 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.
Re: Please review beginnerâs 9x9 game
Posted: Fri Oct 05, 2012 7:54 am
by CnP
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?
Re: Please review beginnerâs 9x9 game
Posted: Fri Oct 05, 2012 8:20 am
by PeterPeter
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.
Re: Please review beginnerâs 9x9 game
Posted: Fri Oct 05, 2012 10:12 am
by xed_over
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