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Re:

Posted: Tue Apr 07, 2015 12:18 pm
by oca
EdLee wrote:...
:black: 129 Exercise: what happens if B cuts at D14 now ?



Hi Edlee, thanks a lot for your comments !

here are my tries to cut at D14... that looks very nice but maybe I miss something and white can do better...


Posted: Tue Apr 07, 2015 12:32 pm
by EdLee
Hi oca,

Look at E10.

Re:

Posted: Wed Apr 08, 2015 5:15 am
by xed_over
EdLee wrote:Hi oca,

Look at E10.

why? and from which sequence?

oca's D14 cutting exercise started from move 131, instead of the suggested move 129. won't that make some difference with/out the H12/G12 exchange?

Re: OCA's log

Posted: Wed Apr 08, 2015 6:45 am
by Knotwilg
(BTW, I concur with Ed on most of his comments, so you can deal with my comments as efficiently as you want)

Game 1 Highlights:

- 39-40: both seem in no hurry to settle the hot upper left
- 68: opportunity to destroy Black
- 76: an exercise in global or local thinking (for me too)
- 102: how to win a won game, by Oca!



Game 2 Highlights:

- 19: Black can take the loot AND avoid White influence. On this occasion the costly mistake could even be game deciding. By 24 White is by no means behind
- 39: Nice discovery!!! But please do continue ...
- 58-76: too easy for White.
- 93: game deciding mistake
- 111: White was slack this time but the comeback is not enough


Re: OCA's log

Posted: Mon Apr 13, 2015 8:51 am
by oca
Thanks a lot for your comments Knotwilg !

Re: OCA's log

Posted: Mon Apr 13, 2015 8:58 am
by oca
For now, I spent most of the time I have for go on 9x9 games.
so not that much new to post... still played a new game that went fine for me, even if I missed that attack on the "should be" L+2 group in the bottom/left corner

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


Here :w2: is wrong I think (should be at 'b'), but :b3: should be at 'a' instead of the the position in the diagram.

Whole game ( :b1: is move 161 in the game)

Re: OCA's log

Posted: Wed Apr 15, 2015 3:30 am
by Knotwilg
Highlights:

41: killing an invasion (difficult)
43: reducing an invasion to the smallest size (easy)
66-82: read about small gaps at http://senseis.xmp.net/?SmallGap
87: reward your cutting strategy with a final surround & kill
163: how about that corner (since you asked for it)

All in all an easy and well deserved win by applying a natural strategy based on thickness and cut/surround


Re: OCA's log

Posted: Wed Apr 15, 2015 9:21 am
by oca
Thanks a lot Knotwilg :tmbup: ,

I will try to improve my playing reagarding to small gaps, I remember that Edlee allready mentioned that on some of my earlier games... I will try to replay the splitting sequence (66-82) against my self and see if I can do better...

Re: OCA's log

Posted: Wed Apr 15, 2015 12:32 pm
by mitsun
oca wrote:I will try to replay the splitting sequence (66-82) against my self and see if I can do better...
If you want a suggestion or hint:
At move 67, you came back to play the hanging connection at K9. This is a necessary and good move. It is also sente, since W will answer below to avoid being enclosed. Suppose you play this exchange a move earlier, without first pushing at J11. Now see how many more options you have above -- J12, J13, K12 for example are all more likely to enclose W than the game move J11, which forces W to squeeze out and escape. And if your reading says none of those moves actually work, then maybe consider head-butting the W stone at K15 or pushing through L17 to build extra strength before coming back to the primary attack.

To pursue the "squeezing through narrow gaps" idea a little more, suppose B plays something like K9 at move 65 and W decides the group below is safe, but the group above needs to avoid being enclosed. Then playing H12 looks like a reasonable and good move for W. After that, would B want to play J11? Surely that would be a slow and inefficient move after W already has a stone at H12. But with a different move order, this is what actually happened. Once your opponent successfully squeezes through the gap, your nearby stones are likely to end up on dame and become inefficient.

Re: OCA's log

Posted: Fri Apr 17, 2015 9:41 am
by oca
mitsun wrote: At move 67, you came back to play the hanging connection at K9.
... Suppose you play this exchange a move earlier...


I'm happy as I found this one before reading your comments... but then I got lost in a lot of variations... :lol:

http://www.lifein19x19.com/forum/download/file.php?id=5869


mitsun wrote:...But with a different move order, this is what actually happened.


Oh..., this kind of analysis when we place moves in a different order is really interesting... Is that what we call a Tewari analysis ?

Re: OCA's log

Posted: Sun May 03, 2015 1:28 am
by oca
Played two game last night. lost both games, with a very early resignation

I dont care that much losing games, as long as I do my best to understand why I lose the game.

Here is game #1

In that game, the experimental :w8: was the bad idea I think... I tried a table shape with :w14: but missed the attack at :b19: and then that was game over I think...




Here is game #2

Also some experimentation, at :b5: I wanted to try something else then the chinese / kobayashi opening

my attack at :b25: was too much, and white can then attack both of my groups... I wasn't strong enougth... I suppose my timing was completly wrong...


Any comments welcome

Re: OCA's log

Posted: Sun May 03, 2015 2:24 am
by Bki
On game 1, :w20: at H5 (followed by black G4, W-F4, black connect, white E5. Then if black cut at F3 you give atari at E3 and damage severely his corner.

Re: OCA's log

Posted: Sun May 03, 2015 5:49 am
by oca
Bki wrote:On game 1, :b20: at H5 (followed by black G4, W-F4, black connect, white E5. Then if black cut at F3 you give atari at E3 and damage severely his corner.


Thank you Bki, I played :w20: too fast, I was sure I can eat sthe stone like in a net, but missed that when he played H5, that would put my two stones in atari... very basic... but I still missed that :roll:

Re: OCA's log

Posted: Mon May 04, 2015 10:52 am
by mitsun
I would say you lost the second game because you played too many loose attacking and invading moves and never took the time to secure your positions with good thick defensive moves.

At the start, :b13: seems needlessly aggressive. Why jump into an area where you are already pincered and have no room to make a base? The right side is more open and larger. Letting W make a shimari here is not something you have to go to extreme measures to prevent.

The sequence to :b14: to :w20: left B with a glaring weakness at N2 -- if W plays there, B will have no base or eye-shape, while W will be making territory on both sides. W has already successfully punished the premature invasion. Instead of :b25:, which as you point out is an overplay, just defend calmly at N2 or M2. The game is still playable for B at this point.

:b53: is a very nice invasion, making use of the B thickness to the right, to get compensation for the loss on the side. The game is by no means lost yet. In fact, if you kill the corner, the game looks won -- try counting territories and see if you agree.

:b63: is again overly aggressive. Surely continuing the attack on the lower left corner to consolidate your gain there is much more important than starting an uncertain new fight in the center. After a surrounding move like F5, the W corner looks nearly dead. Even if W can live, playing here first guarantees sealing W in sente, for a very good local result. Or if you think W can live, attacking at G2 is an alternative, planning to drive W out, letting you naturally make side territory around C8. Either way B still has a good game.

Re: OCA's log

Posted: Tue May 05, 2015 11:27 am
by oca
Thanks a lot for your comments mitsun !

I play mostly on 9x9 these days, I wonder if that gave me some bad habits and if I became too aggressiv and maybe too ... "local thinking" on the 9x9 every thing is a battle...(or maybe not... but that's my perception from my level)