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Review my game, 7-8k
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Author:  Alexfrog [ Tue May 26, 2015 9:43 pm ]
Post subject:  Review my game, 7-8k
I posted one before but I hadn't played much yet and was underrated, so people said I should play more and get a close game or loss.

This one was very close. It seems that about 7-8k is probably correct for me right now.

I know of some mistakes I made in this one, but maybe you guys can point out some I haven't seen.

I am white.




Some thoughts:
* My move 20 is horrible. On move 18 I thought I had the ladder, and then on move 20 I read it again and thought "Oh crap, I don't have the ladder, that was bad", and made a mistake, because actually I did have the ladder. That was a huge loss. So I know I need to practice ladders. :)

* For the moves in the 70s, how should I have played out this joseki? I think I couldve done better than I did. I am thinking that my move 76 was a big mistake?

* In the move 90-110 range I feel that I shouldve been able to kill my opponent's group, but instead he got out. What did I do wrong here?

Thanks!
Author:  Shenoute [ Wed May 27, 2015 12:12 am ]
Post subject:  Re: Review my game, 7-8k
I'm not sure about the ladder you mentioned but why not use :w20: to connect under? Sure, connecting on the 2nd line is not exactly big in itself but here it means connecting your weak group and still being able to aim at putting pressure on b's group later.

And why :w24: ?
- you are adding stones to your already alive corner (and even in terms of points it was not so big at that moment)
- it hurts your three stones
- it enables black to link up his weak group

Taking the sequence as a whole : before :w16: both players had a group that needed to run; after :b27:, w still has a weak group while b got rid of his. Because of this, I 'm not sure playing :w28: was needed. These three stones are much weaker than before because b has become strong everywhere around. So w is just giving b a target. Maybe you should leave them as they are. As I see it, getting them out or connecting them was interesting as long as this also meant keeping b weak on the left. Once his group is connected, suddenly the stones are only worth 6 points and adding :w28: doesn't do much to b.

Rob van Zeijst has some nice words about these two aspects (securing weak groups but also estimating if they are worth saving) in 501 Opening problems:
Quote:
The most important lesson to learn about opening strategy is avoid being burdened by weak groups. If you have a weak group, you are immediately at a disadvantage because your opponent can make profit by attacking it, so it is "urgent" that such a group be secured as quickly as possible. Remember the go proverb: "Play urgent points before big points!" I have worked a system (…) to quantify the value of weak groups. A weak group without eye is worth minus 20 points; a weak group with only one eye is worth minus 10 points. (…) when you have the choice of running away with a weak stone or of sacrificing it, you can appraise both strategies quantitively using this system.
Author:  Xom [ Mon Jun 08, 2015 6:03 pm ]
Post subject:  Re: Review my game, 7-8k
Hi Alexfrog, nice to see you here. I'm a fan of your analyses in games other than Go.

I'm not that much stronger than you but I commented what I could:


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Author:  Joaz Banbeck [ Tue Jun 09, 2015 12:02 am ]
Post subject:  Re: Review my game, 7-8k
If you play 50 at A5, how does he live?
Author:  ez4u [ Tue Jun 09, 2015 4:38 am ]
Post subject:  Re: Review my game, 7-8k
Joaz Banbeck wrote:
If you play 50 at A5, how does he live?

White looks too thin to me right now...
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O O O . . . . . , . . . . . , O . . |
$$ | . X X O 5 . . . . . . . . . . . . . . |
$$ | . . X X O 4 . . . . . . . . . . . . . |
$$ | X . . . 2 6 O . . . O . . . . . . . . |
$$ | . X X X 3 . O X . . . . . . . . . . . |
$$ | 1 X O X . . O X . . O . . . . . . . . |
$$ | . O O O . O X X X , O X X . . X . . . |
$$ | . . . . . O O X . . O X . . . . . . . |
$$ | . . . . . . O O X X X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

However, that means that there are all kinds of outside plays that would threaten to kill Black. For example, playing 1 at 4, solidly connecting White, looks like sente against the Black group.
Author:  perceval [ Tue Jun 09, 2015 5:59 am ]
Post subject:  Re: Review my game, 7-8k
Maybe its interesting to know the moves that seem like mistakes to someone your own level; so i ll just mention what jumped to my eyes; already mentionned before

:w20: needs to be at H2 to connect the weak group. Just avoiding weak groups and hunting the ones form my opponents i how i win most of my games against 7-8k. It also how i lose most of them when i fail to do it

:w24: it doesn't connect, so it only strengthen black. The refutation is the most obvious B reply, so that mistake can be avoided

:w67: at our level, I see this joseki mistake more often than the correct answer (!!), probably because it often goes unpunished like here :D ! knowing the refutation :study: (see Xom comments) will net you a ton of big corners against 7-8k
Author:  ez4u [ Tue Jun 09, 2015 6:02 am ]
Post subject:  Re: Review my game, 7-8k
A few thoughts...

I think it is fair to say that normally we think about cutting a 2-space jump with the high move at 1 below rather than 'a' as played. Did you consider this and reject it, or not really think about it?
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . X . . . . . . . . . . . |
$$ | . . . . . . . 1 . . O . . . . . . . . |
$$ | . . . O . . . a . , O X X . . X . . . |
$$ | . . . . . O . X . . O X . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


I would like to suggest that 50 (below) was a worse move than 20! :-) The play at 20 stemmed from a reading error. Although Shenoute is right that connecting under would have been much better, we've all panicked from time to time when we've made a mistake. However, 50 betrayed a very poor assessment of the overall situation. This is harder to fix than ladder reading.

First we should realize that the marked White stones are strong. They form a good, solid shape. In addition, Black's small group on the left is not completely alive so it is difficult to imagine that the White stones will be cut off (OK, this actually requires a careful assessment of the life and death situation on the left but no way should White be imagining that the marked stones are in danger). So the question arises how should White use those stones?

Another feature of this position is that fundamentally White can invade a large knight shimari like that in the upper left and live. If you check Sensei's Library, you can find info on that shape and related invasions.

So White needs to think about how to continue. Two things that White should not want to do: protect strong stones that do not need protection and prompt Black to protect the upper left shimari. White 50 manages to do both. :-) The exchange up to 54 makes Black's corner safe and White's left side over-concentrated.

To my eye White probably wants to calmly enclose the upper right at 'a' instead of 50. It is the biggest point left IMHO (bigger in fact than either of the connections at 58 and 62 played in the game ;-) ).
Click Here To Show Diagram Code
[go]$$Wcm50
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . . . a . . . . . |
$$ | . . X 4 . . . . . , . . . . . O . . . |
$$ | . . 2 1 . . . . . . . . . . . . . . . |
$$ | . . 3 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . W W W . . . . . , . . . . . , O . . |
$$ | . X X W . . . . . . . . . . . . . . . |
$$ | . . X X W . . . . . . . . . . . . . . |
$$ | X . . . . . O . . . O . . . . . . . . |
$$ | . X X X . . O X . . . . . . . . . . . |
$$ | . X O X . . O X . . O . . . . . . . . |
$$ | . O O O . O X X X , O X X . . X . . . |
$$ | . . . . . O O X . . O X . . . . . . . |
$$ | . . . . . . O O X X X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Of course 66 should have been in the other direction at R16.

At 76, just connect solidly. The marked stone below protects the cut at 'a' and means that Black can not resist here... Black will have to live in the corner and White will get to attack the two Black stones to the left anyway. There is a connection at 'b' remaining for White.
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . . . . . . . . . . . . b . 1 O X . |
$$ | . . . . . X . . . . . O . X . O X 4 . |
$$ | . . X X . . . . . , . . . . . O X . 5 |
$$ | . . X O . . . . . . . . . X . . O X 9 |
$$ | . . O O . . . . . . . . . . 2 . O X . |
$$ | . . . . . . . . . . . . . . . . O 6 8 |
$$ | . O . . . . . . . . . . . . . . a 7 . |
$$ | O . . . . . . . . . . . . . . . . . . |
$$ | X O O O . . . . . , . . . . . , W . . |
$$ | X X X O . . . . . . . . . . . . . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | X . . . . . O . . . O . . . . . . . . |
$$ | . X X X . . O X . . . . . . . . . . . |
$$ | X X O X . . O X . . O . . . . . . . . |
$$ | X O O O . O X X X , O X X . . X . . . |
$$ | O O . . . O O X . . O X . . . . . . . |
$$ | . . . . . . O O X X X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Whether White could have captured Black after White 90 is beside the point. White did a very nice job of building territory while attacking Black through 156. White added territory at the top, in the center, and on the right, playing in a very consistent fashion. Having a nice feeling for this is more valuable than being a little better at finding a killing play.
Author:  Alexfrog [ Fri Jun 26, 2015 4:34 pm ]
Post subject:  Re: Review my game, 7-8k
Thanks everyone for the excellent comments, I will study them! :)
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