Opening/middlegame problem from my game

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 8:06 am

Here's a position from a recent OGS game of mine where I (black) had a really tough job deciding where to play.

Click Here To Show Diagram Code: [go]$$Bc Black to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . . . . . | $$ | . . X O X O . . . . . . . O . . . . . | $$ | . X O O O . O . . O . . . . . X . . . | $$ | . . X O O O . . . . . . . . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . . . . | $$ | . O O O X . . . . . . . . . . X . . . | $$ | X X X . X . . . X X . . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Where would you play and why? What sequence would you expect to follow? I've put my thoughts and the game in a hidden below.

P.S For those fancy people who like to count to decide what to do, white has 6 captures to black's 1, komi is 6.5

There is nothing urgent now (the last area of play was the lower side and both black and white have settled their groups there now, saving the 4 stones on the left is just endgame (though quite big as it has a follow-up at b9, and as they cut the stones above it increases the aji of saving e13 and the b12 move).

So one idea was try to make some centre territory, e.g.

Click Here To Show Diagram Code: [go]$$Bc Centre dreams $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . . . . . | $$ | . . X O X O . . . . . . . O . . . . . | $$ | . X O O O . O . . O . . . . . X . . . | $$ | . . X O O O . . . . . . . . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O 8 6 . . . . . . . . . . . . . | $$ | . . . . 7 5 . 9 . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . . . . | $$ | . O O O X . . . . . . 3 . . . X . . . | $$ | X X X . X . . . X X 1 2 4 . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

However, there are a few problems with this. For starters black can't assume

is sente, white may tenuki to come in to the centre around g10. If black continues at m5 and n5 he builds some infleunce over the right side, but that area is wide open to white could just invade and live easily and black would feel like he spent 2 gotes on dame (almost, there is still chance to make a few centre points). Similarly

is not really sente.

So that left the last big open areas: the right side and top right corner. A long time ago in the opening black played the q14 high move in answer to o17 approach, white answered at k16 and black didn't continue on the right side, so white r12 can be an invasion with attacking potential on that shape (though black would answer at r10 and build a few extra points on the side).

If I want to play on the side, q11 is a common continuation in that shape, but I didn't like white taking the top right corner. I pretty much have to block on the right side to stop q11 becoming dame, but once white has the corner it is harder for me to do something with the m17 gap (though white is open at g18 so the top side can be reduced there) and I didn't see an obviously good move to continue with. it seems like white has got tedomari, and the right side might not even be my points yet with the r8 aji.

Click Here To Show Diagram Code: [go]$$Bc I didn't like going for the side. What next? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . 4 8 6 . | $$ | . . X O X O . . . . . . . O . 3 2 7 . | $$ | . X O O O . O . . O . . . . . X 5 . . | $$ | . . X O O O . . . . . . . . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . . . . | $$ | . O O O X . . . . . . . . . . X . . . | $$ | X X X . X . . . X X . . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

If not the side, how about the corner, coming down to q18. This makes the corner my territory which is always big, and makes the invasion at m17 easier if white ignores. If white jumps to o15 I wouldn't bother invading, just get the nice sente yose at o18 and with g18 too the top isn't very big for white (so I didn't think he would o15). If white answers at p18 to try to prevent the o18 yose it is already a good exchange for black to prevent white entering at 3-3 and I could tenuki, and there is still the m17 gap or black could play to solidify the corner and white's top. As q18 gets the corner it threatens to play q11 or similar on the side and turn the corner plus side into a big territory, so it is natural for white to then invade the side. One expected continuation is as below. Having played q18, I felt I needed to block at r14 to protect my corner investment (allowing s15 slide in sente for r15 is too painful) rather than pincer at r10, but then q14 looks a bit misplaced and would be better as a one point jump to a (though iron pillar does have the advantage white can't attach at s14. Maybe

could also be at b. This key thing that made me choose this (and this was in fact the game continuation) was black ends with sente and has an obviously good move to play with it: the m17 invasion. I lost some potential points on the right side, but I get them back at the top.

Click Here To Show Diagram Code: [go]$$Bc Take the corner, give the side, take the top $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . 1 . . . | $$ | . . X O X O . . . . . 7 . O . . . . . | $$ | . X O O O . O . . O . . . . . X . . . | $$ | . . X O O O . . . . . . . . . . . . . | $$ | . . X X O O . . . . . . . . a X 3 . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . 6 . 2 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . 4 b . | $$ | . O O O X . . . . . . . . . . X . 5 . | $$ | X X X . X . . . X X . . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Another idea I considered was starting at n15 to grow the right side on a large scale. If white defends the top black is probably happy as it's open at g18, but then what? The right side is so wide open that if you grow it again with a move like a or b then white comes in and it seems like you have to kill it to make sense of the moyo moves, but a kill seems unlikely.

Click Here To Show Diagram Code: [go]$$Bc Right side moyo? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . . . . . | $$ | . . X O X O . . . . . . . O . . . . . | $$ | . X O O O . O . . O . 2 . . . X . . . | $$ | . . X O O O . . . . . . 1 . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . a . . . . . . | $$ | . O O O X . . . . . . . . . . X . . . | $$ | X X X . X . . . X X b . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Here's the full game:

Alguien · Post by **Alguien** » Mon Jan 28, 2013 8:31 am

just for reference of how badly a sdk can play, without reading the hidden text I'd have played M17.

shapenaji · Post by **shapenaji** » Mon Jan 28, 2013 8:37 am

Q18, makes miai of endgame reductions on top, stabilizes the right side.

White is then behind on territory without any obvious way to make more.

EDIT:

Bill Spight · Post by **Bill Spight** » Mon Jan 28, 2013 10:21 am

Click Here To Show Diagram Code: [go]$$Bc Black to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . a . . . | $$ | . . X O X O . . . . . . . O . . . . . | $$ | . X O O O . O . . O . . . . . X . . . | $$ | . . X O O O . . . . . . 1 . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . b . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . . . . | $$ | . O O O X . . . . . . . . . . X . . . | $$ | X X X . X . . . X X . . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Without much hesitation I would choose

as lying on the frontier of frameworks. Next I would expect an invasion by White on the right side.

could help in the ensuing fight.

Edit: How might it help? First, it strengthens Black's two stones in the top right. Second, it might cut off an avenue of escape if White runs into the center. Third, if Black encloses White on the right side, it is well placed to make a central framework.

It is interesting that at this stage of play there are big fuseki moves in the top right quadrant. IMO Black has a commanding lead. A Black play at "b" would say I have won, and it is hard to argue with that, and that would be my third choice. My second choice would be "a", securing the corner and aiming to invade the top side.

Edit: If White responds to

then "a" would not threaten much, and I would secure the right side, thank you very much.

As a practical matter, I would advise people to play their own game. Unless they are prone to losing won games, OC.

jts · Post by **jts** » Mon Jan 28, 2013 10:54 am

I guess before I peek at the hidden I should commit to Q18 - I spent a long time looking for ways to justify a move on the left but eventually it came down to Q18 vs. R12. I decided Q18 was preferred because R17 is an invasion from which B cannot hope to get compensation (in terms of invading at M17 after Wr17), due to W's thickness.

However, having seen Bill's move, it looks much better.

Edit: I'm surprised D6 got played so quickly (and even before B12.) This was a move on the left that I spent at least a minute daydreaming about, and then sheepishly decided was bad in every way (doesn't threaten the group above, doesn't threaten the group below, doesn't help defend the center). Thoughts?

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 11:31 am

@shapenaji:

shapenaji wrote:Ooh, you picked mine, though I don't think I would have had the fortitude to hold back and make an iron pillar when he approaches the corner from the right side.

Yeah, it feels a tad slow, but I really dislike giving the slide as profit/eyes in sente (and however you answer it at r15/s16/r16 white has some annoying aji and yose). The pincer at r10 is very big too but there is still the r8 aji.

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 11:34 am

Bill Spight wrote: It is interesting that at this stage of play there are big fuseki moves in the top right quadrant.

Yes, I wasn't sure whether to call this an opening or middlegame problem

: in terms of move number we are in the middlegame, but in the top right quadrant it is still the opening.

Bill Spight wrote:
Edit: If White responds to then "a" would not threaten much, and I would secure the right side, thank you very much.

Where? That was what I couldn't decide on. If q11 then my thought was the n15 m16 exchange could be an aji keshi as you lose the m17 invasion (but open at g18 so maybe we don't care). Or something grander? Would you then plan on killing an invasion of the right?

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 11:55 am

jts wrote: but eventually it came down to Q18 vs. R12.

Black r12? White r12 is a move, but I would never dream of playing it as black. If white had a position below and I wanted to close a territory then I might play black r11.

jts wrote: Edit: I'm surprised D6 got played so quickly (and even before B12.) This was a move on the left that I spent at least a minute daydreaming about, and then sheepishly decided was bad in every way (doesn't threaten the group above, doesn't threaten the group below, doesn't help defend the center). Thoughts?

Did you take into account the follow-up tesuji at b9 when evaluating d6? B12 is 10 points. D6 is 18 points if black gets b9, 13 if white gets it, i.e. 15.5 points.

Magicwand · Post by **Magicwand** » Mon Jan 28, 2013 12:13 pm

D6 without any hesitation
It is too big not to save that stones...
also..black is ahead already..make simple moves to simplify the board.
white can not earn points enough to turn this game around.

Bill Spight · Post by **Bill Spight** » Mon Jan 28, 2013 1:25 pm

Uberdude wrote:
Bill Spight wrote: It is interesting that at this stage of play there are big fuseki moves in the top right quadrant.
Yes, I wasn't sure whether to call this an opening or middlegame problem : in terms of move number we are in the middlegame, but in the top right quadrant it is still the opening.

Bill Spight wrote:
Edit: If White responds to then "a" would not threaten much, and I would secure the right side, thank you very much.
Where? That was what I couldn't decide on. If q11 then my thought was the n15 m16 exchange could be an aji keshi as you lose the m17 invasion (but open at g18 so maybe we don't care). Or something grander? Would you then plan on killing an invasion of the right?

My thought was R-11. Q-11 may be a bit better, but R-11 makes for easier play, I think (at least for me

). I can imagine Dosaku or Go Seigen playing N-07 to invite an invasion, but I am not that good.

I think that N-15 restricts White's possibilities more than Q-18, and opens up possibilities for Black. If White lets me play it with sente, so much the better. I would view that as kikasare for White, not ajikeshi for Black.

jts · Post by **jts** » Mon Jan 28, 2013 2:18 pm

Uberdude wrote:
jts wrote: but eventually it came down to Q18 vs. R12.
Black r12? White r12 is a move, but I would never dream of playing it as black. If white had a position below and I wanted to close a territory then I might play black r11.

jts wrote: Edit: I'm surprised D6 got played so quickly (and even before B12.) This was a move on the left that I spent at least a minute daydreaming about, and then sheepishly decided was bad in every way (doesn't threaten the group above, doesn't threaten the group below, doesn't help defend the center). Thoughts?
Did you take into account the follow-up tesuji at b9 when evaluating d6? B12 is 10 points. D6 is 18 points if black gets b9, 13 if white gets it, i.e. 15.5 points.

Yeah, I meant R11. Sometimes I think that 11 is the center row, not sure why. But I take it you still think r11 is weak, locally? I see the possibility of W invading at R17 and W invading at R12 as both being big moves, which you seem to agree with; and Q18 and R11 seem to be the most natural ways to make a W invasion bad.

I guess I didn't realize that the B9 follow-up is quite so big, just in terms of points alone. I was thinking 5 pts plus another 5 pts in follow-up, although that's clearly way off. So I thought I could only justify D6 if it made B12 sente, or something like that. May I ask how big H2 is (at 163)?

logan · Post by **logan** » Mon Jan 28, 2013 3:14 pm

Magicwand wrote:D6 without any hesitation
It is too big not to save that stones...
also..black is ahead already..make simple moves to simplify the board.
white can not earn points enough to turn this game around.

ditto, it also allows for some pretty nasty followups, such as b11.

The only problem which could lead me otherwise is that the followups rely on accentuating the e13 stone, but since White will play into the center anyway covering e13, then the usefulness of Black's plans in this area can be naturally reduced by White.

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 5:13 pm

logan wrote:
Magicwand wrote:D6 without any hesitation
It is too big not to save that stones...
also..black is ahead already..make simple moves to simplify the board.
white can not earn points enough to turn this game around.
ditto, it also allows for some pretty nasty followups, such as b11.

The only problem which could lead me otherwise is that the followups rely on accentuating the e13 stone, but since White will play into the center anyway covering e13, then the usefulness of Black's plans in this area can be naturally reduced by White.

Wow, a 15 point yose in the opening seems too small to me. It is true it has some aims so it is not pure yose, but nothing devastating.

I don't see how b11 is nasty. As logan says white may answer d6 in the centre (g10 area) which is a move he wanted to play anyway, subduing e13 and also threatening to make quite a sizeable centre territory. And even if white tenukis d6 and then black plays b11, just answer at b13 (which is worth a few points) forcing black b9 connection and then net e13.

Magicwand wrote:black is ahead already..make simple moves to simplify the board.

Playing simple moves when ahead I certainly agree with, but taking a big yose is not what I would call a simplifying move. If any black group is going to get in trouble in this position it is q14. Therefore if I want to simplify a winning position I would play to settle it. Taking the money at d6 would give white sente to start fighting on the right side and then the game could get complicated.

Also, in terms of points, isn't r17 invasion (assuming black blocks at r16 after q17) bigger than 15 points?

Dusk Eagle · Post by **Dusk Eagle** » Mon Jan 28, 2013 5:24 pm

Click Here To Show Diagram Code: [go]$$Bc Black to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . X X . . . . . . . . . . . . . . | $$ | . . X O X O . . . . . . . O . . . . . | $$ | . X O O O . O . . O . 2 . . . X . . . | $$ | . . X O O O . . . . . . 1 . . . . . . | $$ | . . X X O O . . . . . . . . . X . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 3 . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . O X . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . . . . . . . | $$ | . O O O X . . . . . . . . . . X . . . | $$ | X X X . X . . . X X . . . . . . X . . | $$ | O O X O . . . . X O O . . . . X O . . | $$ | O . O , O X . O X O X . . . . , . . . | $$ | . O O O X . X X O . O O . . . X . . . | $$ | . . O . X . . . O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I would play like this (if white let me

). But I'm never very confident about what the right way to play is in situations like this.

Uberdude · Post by **Uberdude** » Mon Jan 28, 2013 5:51 pm

jts wrote:May I ask how big H2 is (at 163)?

It's actually quite hard to count as it is not clear what white's best move there is (turn or small monkey jump) and whether black should answer or ignore those. It's also spare eyes for the black group. Something like 6-8 points, possibly even reverse sente. But I counted a11 and f19 are bigger which is why I played them first.

Life In 19x19

Opening/middlegame problem from my game

Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game

Re: Opening/middlegame problem from my game