OCA's log

oca · Post by **oca** » Mon Aug 11, 2014 4:16 am

Thx Uberdude, so is that "summary" correct ? (for the sake of simplicity, black always start with hoshi, and white just played hoshi what ever black move is. But maybe that's just to simplistic...)

oca · Post by **oca** » Tue Aug 12, 2014 11:37 am

Hi,

Here are two games

In this one, I don't understand why white resigned :shock:

???

And in this one...

As always, any comments welcome...

oca · Post by **oca** » Thu Aug 21, 2014 3:28 am

Hi,

Here is a new game, that I finally won by a few points (thanks you komi ;-)

)... but I made so many mistakes...
I'm really not proud of that one... I played so bad that I really wanted to forgot that game as fast as possible, but I finally decided that would be better for me to really take time to do a self review and to comment as much things as possible. And Finally I really enjoyed doing that self-review.

So here is the game, with a tons of comments and variations...

Quick Summary :

73 - 77, lose my bottom/left corner
124 - 127, the "Bulky five" miss...
126 - OMG, what a miss
129 - 144, at least one I can kill...
153 - 169 so good so far... and big miss again at 170
191 - 210 got toothpasted... but got some territory in exchange...

Any comments very welcome !

Knotwilg · Post by **Knotwilg** » Thu Aug 21, 2014 6:14 am

I made an SL article about the corner shape:

http://senseis.xmp.net/?RectangularSixW ... nTheCorner

You will never miss the bulky five again, will you?

Good moves: 136, 180. Keep these in mind.

Black 223 what could he have done instead?
So, White 222, what could you have done instead?

Uberdude · Post by **Uberdude** » Thu Aug 21, 2014 6:22 am

oca wrote:Thx Uberdude, so is that "summary" correct ?

Yes

Marcus · Post by **Marcus** » Thu Aug 21, 2014 7:45 am

Knotwilg wrote:I made an SL article about the corner shape:

http://senseis.xmp.net/?RectangularSixW ... nTheCorner

I think you have a misread in your second "shortage of liberties" diagram. Black can still play:

Click Here To Show Diagram Code: [go]$$W Not so dead ... $$ ------------ $$ | . 3 X O . . $$ | 2 1 X O . . $$ | 5 6 X O . . $$ | b X X O . . $$ | 4 X O O . . $$ | a O . . . . $$ | . . O . . .[/go]

Knotwilg · Post by **Knotwilg** » Thu Aug 21, 2014 9:38 am

oca · Post by **oca** » Mon Aug 25, 2014 1:26 am

Knotwilg wrote:...
Black 223 what could he have done instead?
So, White 222, what could you have done instead?

Hi Knotwilg,
Thx for your comments, this is where I finally got to :

Knotwilg · Post by **Knotwilg** » Mon Aug 25, 2014 1:40 am

Great analysis!

oca · Post by **oca** » Thu Aug 28, 2014 3:26 am

Overall I start to win more often than I lose.
I was on a nice 8 wins in a row when this game bring me back to reality...

I'm not sure at which point did that game turned so bad for me...
Any comment welcome.

I commented a bit to nearly move 50.

Uberdude · Post by **Uberdude** » Thu Aug 28, 2014 4:04 am

s7 hane is a mistake, but that doesn't mean you should necessarily cut at r7 immediately (though I think it's probably ok). q2 to live first would be simple. Then you could cut, or just play a big move somewhere: if black takes gote to fix the cut you just tenuki again as black is being slow (Imagine he extended and you did q2 normal joseki, then end in sente to play a big move like top left corner knight's move, then black s7 turn now would be obviously slow and too early endgame move and you could play top left kosumi to complete the corner). p7 atari was good, actually better than double atari as it threatens q5 to capture the r5/6 stones which are the important cutting stones. q7 is not an important stone, capturing that was slow. Better to q2 to make the corner live. Can you see a better move for black 31? Hint: viewtopic.php?p=171661#p171661 . c9 must be c7 cut, this uses c5 and you will get an ok result. The game was ok for you until c5 died on a big scale.

Marcus · Post by **Marcus** » Thu Aug 28, 2014 4:33 am

I like leaving the aji from the s7 mistake for later, as it's often possible to reduce your opponent's territory later with the clamp at s8. Continuing at q2 and being patient can provide you with more options, depending on how your opponent plays.

Click Here To Show Diagram Code: [go]$$Wc Black needs to finish with 'a'\nbut has left a weakness at 'b' $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . b X . | $$ . . . . . . . X O . | $$ . . . . . . . X O . | $$ , . . . . . X O . . | $$ . . . . a . X O . . | $$ . . . . . 2 1 3 . . | $$ . . . . . . . . . . | $$ -------------------[/go]

If Black finishes the joseki as normal, you can clamp (now or later) at s8:

Click Here To Show Diagram Code: [go]$$Wc Black can't cut White off with\na descent to t7. Black cannot protect\nat both 'a' and 'b' $$ , . . . . . , . . . | $$ . . . . . . . . b . | $$ . . . . . . . 8 5 . | $$ . . . . . . 9 7 X 6 | $$ . . . . . . . X O . | $$ . . . . . . a X O . | $$ , . . . . . X O . . | $$ . . . . 4 . X O . . | $$ . . . . . 2 1 3 . . | $$ . . . . . . . . . . | $$ -------------------[/go]

Click Here To Show Diagram Code: [go]$$Wc Black is better off letting\nWhite just connect. White gets\na reduction. $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . . . . . 5 . | $$ . . . . . . . 6 X 7 | $$ . . . . . . . X O . | $$ . . . . . . . X O . | $$ , . . . . . X O . . | $$ . . . . 4 . X O . . | $$ . . . . . 2 1 3 . . | $$ . . . . . . . . . . | $$ -------------------[/go]

If Black decides that he needs to protect the r7 cut instead of finishing the joseki, you have another clamp you can use:

Click Here To Show Diagram Code: [go]$$Wc Black can't descend again. $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . 4 X . | $$ . . . . . . . X O . | $$ . . . . . . a X O . | $$ , . . . . 9 X O . . | $$ . . . . 8 7 X O . . | $$ . . . b 5 2 1 3 . . | $$ . . . . . 6 . . . . | $$ -------------------[/go]

Click Here To Show Diagram Code: [go]$$Wc Black must allow the connection. $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . 4 X . | $$ . . . . . . . X O . | $$ . . . . . . . X O . | $$ , . . . . . X O . . | $$ . . . . 6 8 X O . . | $$ . . . . 5 2 1 3 . . | $$ . . . . . 7 . . . . | $$ -------------------[/go]

Hope that gives you a few more ideas. :mrgreen:

Knotwilg · Post by **Knotwilg** » Thu Aug 28, 2014 4:37 am

is worthy of the "end of comments" remark, as the sequence starting at :b41:

went wrong for White and put Black in the lead. By :w118: the game is effecively over at our level.

The basic technique for :w42:

is to crosscut. White has the advantage of supporting stones. What follows is often a atari-connect sequence in which White gets the central influence and Black some side territory. Instead you block and let Black cut off your stone easily.

Then :w44:

suddenly remembers the lone stone and tries to save it, at the expense of a ponnuki for Black.
Next :w46:

decides to forget about the lone stone after all and strenghten the stones that are left.

This result is far inferior to the technique I referred to, where you get the upper hand in the local fight.

Other than that I second Uberdude's comments that the opening was well played. Myself I would always cut the premature hane, except if the central black influence would be overwhelming.

EDIT: looking back at this position, I'd cut at q5 with :w26:

oca · Post by **oca** » Thu Aug 28, 2014 11:43 am

Thank you all !!! your so helpfull :clap:

Uberdude wrote: Can you see a better move for black 31? Hint: viewtopic.php?p=171661#p171661 .

My best try is this one, where I didn't find any sequence to live for white playing :w34:

at either "a" or "b"

Click Here To Show Diagram Code: [go]$$Bcm31 $$ . . . , . . . | $$ . . . . . X . | $$ . . . O O X . | $$ . . O . O X . | $$ . . . O X O . | $$ . . . X X O . | $$ . . . X O . . | $$ . . . X O b . | $$ . . . 1 2 3 . | $$ . . . . a . . | $$ --------------+[/go]

but I'm still not 100% sure what happend in that case... I think I can live as white...

Click Here To Show Diagram Code: [go]$$Bcm31 $$ . . . , . . . | $$ . . . . . X . | $$ . . . O O X . | $$ . . O . O X . | $$ . . . O X O . | $$ . . . X X O . | $$ . . . X O . . | $$ . . . X O . . | $$ . . . 1 . 2 . | $$ . . . . . . . | $$ --------------+[/go]

Uberdude · Post by **Uberdude** » Thu Aug 28, 2014 11:58 am

33 is better at t6 then r1 hane. Remember the proverb "there is death in the hane": first try hanes from the outside to reduce the eyespace and then inside placements and then only if they don't work read inside moves first. How do you kill this one (Seems like sente seki to me)? Or at b looks like a ko.

Click Here To Show Diagram Code: [go]$$Bcm31 $$ . . . , . . . | $$ . . . . . X . | $$ . . . O O X . | $$ . . O . O X . | $$ . . . O X O . | $$ . . . X X O . | $$ . . . X O . . | $$ . . . X O b . | $$ . . . 1 2 3 . | $$ . . . . . 4 . | $$ --------------+[/go]

32 here is a nice idea, but how do you live after (or perhaps how do you kill, I find black's killing move harder to find than white's attempts to live):

Click Here To Show Diagram Code: [go]$$Bcm31 $$ . . . , . . . | $$ . . . . . X . | $$ . . . O O X . | $$ . . O . O X . | $$ . . . O X O 3 | $$ . . . X X O . | $$ . . . X O . . | $$ . . . X O . . | $$ . . . 1 . 2 . | $$ . . . . . . . | $$ --------------+[/go]

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