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Opening for analysis
http://www.lifein19x19.com/viewtopic.php?f=4&t=1093		 Page 1 of 1
Author:  Chew Terr [ Tue Jul 13, 2010 7:52 am ]
Post subject:  Opening for analysis
Haven't posted a game for analysis here for a while.


I won this game, so I won't ask for a full game review. However, I won it because my opponent created too many weak groups to look after, and bet too much on saving them. I feel that my opponent controlled the opening fairly handily, and by being less aggressive in midgame (such as playing 45 at M17 instead of creating a weak group) he could have reduced me fairly successfully and been ahead with his four corners and profit from attacking my weak eastern group. So the moves I would like suggestions or criticisms on are the first 44 or so.

For example, I wasn't sure how to handle the tenukis in the 3-3 invasion josekis. Nor did I know if there was a better way to treat the east. I would rather have a review of this sort of early-game stuff than a review of a game I've lost recently.

I play white. Thanks in advance for any comments.
Author:  amnal [ Tue Jul 13, 2010 8:37 am ]
Post subject:  Re: Opening for analysis
6: This gives your opponent a great move at R5 or R6 if he chooses to take it. It would be more normal to approach his 3-4 point to prevent a second shimari, though you don't have to.

By move 12, black has had his way a bit, but I think things are fine for white. Black thinks he can win with lazy two space extensions and the measly territory they give him, but he's wrong - black's opening lacks fighting spirit, IMO.

21: This seems to be one of the tenukis that confused you. You should note that by tenukiing, white gets B3 in sente, or black isn't very alive in the corner. White should probably play this straight away, leaving a shape with no weaknesses for black to attack, then play a big extension (D10 area seems obvious, but I would probably play C14 and claim white's thickness is overwhelming). White thereby gains a massive advantage from black's tenuki - black doesn't even need to tenuki, the B4 hane is sente for him!

27: This move is appallingly bad. You pincered, so you probably know why already.

30: Doesn't seem like an obvious move. It looks like it just tries to make territory from the thickness, though I think you intended it as a splitting attack. However, it gives black a good move at E11 (though he doesn't play it), which should give him easy sabaki - so there's no time to play a move which doesn't do much. I think E11 is a better move, keeping black on the run whilst preparing to make a large top moyo.

44: This move has good ideas behind it, but I think it leaves too much aji. Black gets C13, then can use D15 to start an attack which threatens to cut you up horribly. Playing normally is probably better, just extend.

45: Absolute rubbish. Black thinks he's better at sabaki than he actually is.

50: Oh no! You're right that there's aji here, but now is not the time (preventing this aji is a good reason to not play B11 earlier). Letting black get K15 will let him settle easily, and white will have nothing. black lets you off with his own hane, his corner group is probably fine without that.

Some odd stuff hapens now, like move 73 (terrible...what is it for?).



I won't review further, since you won. Basically you misused your thickness and left too much aji in your own positions. In the end, though, you correctly punished black's rubbish play.
Author:  Chew Terr [ Tue Jul 13, 2010 8:52 am ]
Post subject:  Re: Opening for analysis
Thanks, amnal. These were the sort of things I was hoping to hear input on. Yeah, my opponent's biggest problem was approaching too close to thickness.

As far as move 6 goes, I was mostly concerned that if I approached my opponent's corner, he would pincer, which would be an ideal extension from his top corner. Also I think I ought to approach more 3-4s straightaway like that because I am less comfortable with them.

With 44, I was obviously trying to prevent black from connecting underneath, so that I could attack (or get a sente move or two at least) against one or the other. So you think it's better to let him connect under than to leave aji in my position?

Thanks again!
Author:  ethanb [ Tue Jul 13, 2010 8:53 am ]
Post subject:  Re: Opening for analysis
EDIT: I had another comment here but confused the situation - ignore what it said if you read it.)

EDIT 2: Huh, looking again I had the situation entirely wrong in my head. Nothing seems to work the way I thought.

EDIT 3: Ok, I was right with the second half of my comment the first time. Sente endgame can be had at move 68, or ko if black responds incorrectly.
Author:  Magicwand [ Tue Jul 13, 2010 9:00 am ]
Post subject:  Re: Opening for analysis
22: lost your turn to save few point at bottom. no good. -17 points for this move.
30: this move have no purpose. it is not gaining any points nor attacking black group. waste of move. -10 points for this move.
34: why did you not atari?? -5 points for this move.
70: k15 is correct. knight jump you played is subpar -7 for this move.

there are many other moves i didnt like but...this will be enough for you to study.

you should have lost this game. he had plenty of chance to save all his stone then you are down about 30 points. bad game on you but lucky he was weak enough to kill his group.
Author:  Chew Terr [ Tue Jul 13, 2010 9:07 am ]
Post subject:  Re: Opening for analysis
Ethan, thanks. Is the point you were considering
G1
? It looks like that might be either seki or ko... Even ko/sente reduction would be better than the game though, right? But I guess it might be better for ko threats.
Author:  amnal [ Tue Jul 13, 2010 9:08 am ]
Post subject:  Re: Opening for analysis
Chew Terr wrote:
Thanks, amnal. These were the sort of things I was hoping to hear input on. Yeah, my opponent's biggest problem was approaching too close to thickness.

As far as move 6 goes, I was mostly concerned that if I approached my opponent's corner, he would pincer, which would be an ideal extension from his top corner. Also I think I ought to approach more 3-4s straightaway like that because I am less comfortable with them.

With 44, I was obviously trying to prevent black from connecting underneath, so that I could attack (or get a sente move or two at least) against one or the other. So you think it's better to let him connect under than to leave aji in my position?

Thanks again!


Letting your opponent get that pincer isn't as bad as it might seem - the fight isn't unreasonable for either player. Mostly white would play like this becuase the alternative, letting black get two shimaris, is equally poor when it comes to giving black good shapes.

You could play the two space low approach if you wanted to avoid a pincer, of course.

Your idea with 44 to avoid a connection is a strong one, but it's just too awkward here, with the D15 cut (I think). I feel that you can make a case for letting black connect, as he's on the first or second line, then try to make a large moyo by taking a big point.

You're right that it's painful though. I have tried to see if there is a way to get more out of the situation whilst keeping black disconnected. The obvious thing is to play D17 at C16, but I think the direction is too wrong for that to be allowable. I also wondered about the double hane, but that seems good for black too. Maybe the situation is just too poor to get a really good shape yourself - this would be down to your previous mistakes, so just fix them then this won't happen ;)
Author:  ethanb [ Tue Jul 13, 2010 9:09 am ]
Post subject:  Re: Opening for analysis
Chew Terr wrote:
Ethan, thanks. Is the point you were considering
G1
? It looks like that might be either seki or ko... Even ko/sente reduction would be better than the game though, right? But I guess it might be better for ko threats.


Yeah, that's the right one (after much editing of my previous post, jumping at ghosts... Need to learn not to open my mouth until I'm done looking at the position. :) )
Author:  Chew Terr [ Tue Jul 13, 2010 9:18 am ]
Post subject:  Re: Opening for analysis
Thanks guys, this is great stuff.

If nothing else, I hope to never play 30 again. =D

Magicwand: You're right about move 22. I thought that it would be my sente, which it kind of was, but it ended less well than if I had just taken something like D11 instead. Thanks, that would have been a huge help in-game.

Also MW: For 34, I didn't atari because I was sure my opponent would counter-atari on the outside and gain better shape to escape with. I guess if black can live anyways, I'm better off with the atari, forcing him to flee towards the center. I think I may have been trying too hard to kill. More than once I could have let my opponent force me to make a nice moyo in the top left, and I was too focused on killing to just peacefully accept the moyo.
Author:  mitsun [ Tue Jul 13, 2010 4:28 pm ]
Post subject:  Re: Opening for analysis
A few points not mentioned by others:

Move 14) seems like the wrong direction, failing to take advantage of the stone at K3. Note how unimportant K3 becomes in the position after move 20. If you block on the other side, B gets essentially the same corner territory, but K3 ends up as a nice extension from the W wall. (Move 22 tries to make something out of K3, but this is way too small, compounding the problem.)

Move 32) could just stand at D11 I think. The hane looks severe, but makes the position very complicated, giving B chances for sabaki. If you do hane, you must at least be prepared to atari next move and fight with all your strength. The simple stand leaves no cut aji for B to exploit and is actually a stronger attack I think. You got this right later at move 48 in a similar position.

Move 46) B has now created three weak groups, and you take time to defend your single slightly weak stone? You must attack! Your next 40 moves will all be larger than a potential B pincer of your lone stone.
Author:  Loons [ Wed Jul 14, 2010 4:00 am ]
Post subject:  Re: Opening for analysis
I'm going to just chime in about move 6 as well. In my mind, your 6 was very normal if black has a 4-4 point, not 3-4 point. My own reason for this is that you can tenuki, or play a super-far-away pincer from a 4-4 stone and still feel pretty good about it. Less so with 3-4 stones. If he pincers far away enough (3 space?) it starts to feel like he's 3-4 approached your 5-4 stone with some vague support on one side.

Also if his extension isn't so close the shimari, you can probably get a better result from a probe.
Author:  Bill Spight [ Wed Jul 14, 2010 7:57 am ]
Post subject:  Re: Opening for analysis
A few comments and variations. :)

No guarantees. ;)
Author:  Chew Terr [ Wed Jul 14, 2010 8:08 am ]
Post subject:  Re: Opening for analysis
Wow, thanks everybody! This is great stuff! Just have to start putting some of it into use in games...
Author:  Joaz Banbeck [ Wed Jul 14, 2010 10:05 am ]
Post subject:  Re: Opening for analysis
140: Why bother with K18? You can't kill his northern group now. M7 is huge.

142: You are ahead by a bunch. There is no need to allow him to create complications. Play B7. Then A7 and A8 are miai. This secures your big capture, and his chances on the west half of the board are exactly zero.

149: You are fortunate that he did not see A10 ( You can't play B7 - it puts you in atari ). Then he lives. This underscores the point about 142.
Author:  Chew Terr [ Wed Jul 14, 2010 11:45 am ]
Post subject:  Re: Opening for analysis
Joaz: Point taken about 142 and 149, I was cutting it a bit closer than was necessary.

For 140: Can I not kill? I thought 140 was sente, threatening H15? Can black live for sure if I get H15 after 140?

Edit: For 149 I assumed he would take the move you mentioned, and that I would only get to kill the two large tail pieces. You're right, I was more lucky than I deserved~.
Author:  Bill Spight [ Wed Jul 14, 2010 12:22 pm ]
Post subject:  Re: Opening for analysis
Joaz Banbeck wrote:
140: Why bother with K18? You can't kill his northern group now. M7 is huge.

142: You are ahead by a bunch. There is no need to allow him to create complications. Play B7. Then A7 and A8 are miai. This secures your big capture, and his chances on the west half of the board are exactly zero.

149: You are fortunate that he did not see A10 ( You can't play B7 - it puts you in atari ). Then he lives. This underscores the point about 142.


The problem is W144, which should be at B-07, capturing the A-07 stone. :)
Author:  Joaz Banbeck [ Wed Jul 14, 2010 2:45 pm ]
Post subject:  Re: Opening for analysis
Bill Spight wrote:

The problem is W144, which should be at B-07, capturing the A-07 stone. :)

Yes, B7 works then too. It seems to be the vital point for the position.

Chew Terr wrote:
For 140: Can I not kill? I thought 140 was sente, threatening H15? Can black live for sure if I get H15 after 140?


Ooops! :oops: :oops: You're right, it does kill.
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