Life In 19x19

Peekaboo!

It's nice to know that putting as much effort into a game as Uberdude does, actually pays off (judging by his OGS rating!).

Let's just be aware that nothing has happened in the last TWO WEEKS(!) except following the joseki most frequently played in this position by the pros. For all the "deep analysis", the Dude could have used one trigger to reach this position back on January 8th!

I find that a large number of my mistakes occur when I talk myself out of the common/known/frequent move/sequence due to some circumstance that doesn't really apply. Uberdude has managed to talk himself *into* the common sequence. I regard that as a fairly significant accomplishment!

According to dailyjoseki.com, this is the most common followup:

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[go]$$Bcm21 Prisoners:
$$ ---------------------------------------
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . 2 . . . . . . . . . . . . |
$$ | . . X O O . O 1 . . . . . . . . . . . |
$$ | . . . X . O X . 3 . . . . . . . . . . |
$$ | . . . O O O X . O , . . . . . , . . . |
$$ | . . . O X X . X . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

So now it's big decision time. Do I play on the left, or on the bottom side? The former means I get a group on both sides of white's lower left corner, but then white will also get a group on the lower side, splitting the board up, a mutual destruction style. If I play on the bottom side white will probably play on the left and I will build a nice bottom side (works nicely with q3), and white a nice left side (works nicely with d16), mutual creation. I think both options are probably fine and it is more a matter of style than correctness which one to play. My inclination in this position is to build rather than destroy (if I was white then destruction would appeal more as it makes komi relatively bigger), but let's look at some possible continuations.

Below black builds the lower side, and white the left. Instead of shimari at q5 I could also consider the larger scale but looser low/high Chinese shape at a/b. c also remains as a big influence and boundary of 2 moyos point. If black can push and white extends then black will be happy to make that sente exchange, but maybe white ignores or hanes, I will have to read and think about timings more for that move. White 26 is thick but maybe he won't go there yet but approach the lower right. Black then hopes to get sente to play at c8 and the forcing moves there help black build a group on the left side.

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[go]$$Bcm21 Building
$$ ---------------------------------------
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . b a . . |
$$ | . . 6 . . . . . . . . . . . . . . . . |
$$ | . . 4 X . . 2 c . . . . . . . . . . . |
$$ | . . X O O . O 1 . . . . . . . . . . . |
$$ | . . . X . O X . 3 . . . . . . 7 . . . |
$$ | . . . O O O X . O , 5 . . . . , . . . |
$$ | . . . O X X . X . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Even though above seems to make a nice shape, black still has some shape weakness there at j3 as after j3 if white plays h2 black can't block at g2 or else white gets a huge ko or cuts at h5. Of course maybe black can allow the cut and still try to kill everything so I'll read a bit of that but it feels likely white can get something. If black answers j3 at h2 it is solid but really quite painfully submissive, similarly answering h2 hane safely at g3 to avoid the ko/cut.

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[go]$$Bcm21 Shape weakness, a and b miai
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . 2 . . . . . . . . . . . . |
$$ | . . X O O . O 1 . . . . . . . . . . . |
$$ | . . . X . O X a 3 . . . . . . . . . . |
$$ | . . . O O O X 8 O , 5 . . . . , . . . |
$$ | . . . O X X b X 4 . . . . . . X . . . |
$$ | . . . . . . 7 6 . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

But if white plays j3 after the trade in the first diagram, black can safely block to the right side with 27 (l3 would be most solid, but m3 also seems to kill and is bigger) as although answering h2 at g3 is painful the position is sufficiently settled that black can be sure of killing white.

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[go]$$Bcm21 Can play painful moves when killing
$$ ---------------------------------------
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 X . . 2 c . . . . . . . . . . . |
$$ | . . X O O . O 1 . . . . . . . . . . . |
$$ | . . . X . O X . 3 . . . . . . . . . . |
$$ | . . . O O O X . O , 5 . . . . , . . . |
$$ | . . . O X X 9 X 6 . . 7 . . . X . . . |
$$ | . . . . . . . 8 . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

So, how about playing on the left first? The move I first learnt in this position is the hanging connection at c8. Lee Changho and Cho Hun-hyeon played this opening many times in the 90s (but lower right a 4-4). In fact I remember when I first came across this shape my first thought was solid connection at c5, afterall that means if white cuts at c7 black can capture it. But c5 is rather heavy as white can attack the whole group at d9. d5 was just a kikashi stone to induce h3, black shouldn't hang on to it. Indeed if after the c8 connection white plays c5 to capture the stone (and make eyes, the hanging connection does have a latent threat against the white corner) black is not sad at all: he plays atari at b5 (which helps black's eyeshape) and could then defend at b7 or tenuki (and fight a ko if white cuts). Seeing as black played on the left, it is natural for white to play on the bottom side and attack the black group there. White could play 22 at h6 which is a nice thick extension, but black answers by sliding to k2 and is low but safe and in good shape. Black has to come out with the empty triangle and white keeps up the attack at k5 and develops his group. 27 is again a rather painful shape to run. White might then play something like 8 to extend and strengthen his group. If you remember a while ago I mentioned the difference a 3-4 makes in this corner to white settling on the side. This is the sort of position I meant. If black has a 4-4 in the lower right then a white move like o3 combines an extension with the standard corner approach. However, here white's n4 is an approach to the 3-4 stone from the wrong side. When I say wrong it doesn't mean it is a bad move, but that, just locally considering the 3-4 stone, white should approach from the r5 side to stop black making a shimari. To approach from the wrong side like this entails a local loss of territory. You do see that sort of outside approach move in the Chinese opening, that's because the Chinese r9 stone cramps an approach, but here the side is open. So black can be happy to answer with the shimari. And white's base still isn't secure yet, he might want to play o3 soon.

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[go]$$Bcm21 Destroying
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . . . X . . 6 . 7 . . . . . . . . . . |
$$ | . . X O O . O 5 . 4 . . . . . . . . . |
$$ | . . . X . O X 3 . . . . . . . 9 . . . |
$$ | . . . O O O X . O , . . 8 . . , . . . |
$$ | . . . O X X . X 2 . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Another choice for white is to make the checking extension at c10 against black's hanging connection to attack black (with or without the j3-h5 exchange first). This is a powerful move combined with the peep at b7.

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[go]$$Bcm21 More aggressive from white
$$ ---------------------------------------
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 8 . . . . . . . . . . . . . . . |
$$ | . . 4 5 9 . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . 6 7 X . . . . . . . . . . . . . . . |
$$ | . . X O O . O . . . . . . . . . . . . |
$$ | . . . X . O X 3 . . . . . . . . . . . |
$$ | . . . O O O X . O , . . . . . , . . . |
$$ | . . . O X X . X 2 . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Black develops his group but is rather squashed. Notice how black uses the f7 peep to move out, and thus it would be a bad idea to exchange h6 for g7 if black then plans to play c8. Possibly because of the uncomfortableness of black's position I have seen c8 played more lightly at c9, and in that game black did make the h6-g7 exchange first.

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[go]$$Wcm30 More aggressive from white contd.
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . O X X . . . . , . . . . . , . . . |
$$ | . . 1 2 . . . . . . . . . . . . . . . |
$$ | . . X . 6 8 . . . . . . . . . . . . . |
$$ | . O X X 5 4 7 . . . . . . . . . . . . |
$$ | . . X O O 9 O . . . . . . . . . . . . |
$$ | . . . X . O X X 0 . . . . . . . . . . |
$$ | . . . O O O X . O , . . . . . , . . . |
$$ | . . . O X X . X O . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I could go on drawing diagrams until the cows come home, but anyway I've decided that while these variations are interesting and fun, I'm going to play more simply and build the bottom side.

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[go]$$Bcm21 illluck vs. Celebrir
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . O . X . O . X . . X . . |
$$ | . X O , . . . . . , . . O O X , . . . |
$$ | . O 3 . . . . . . X . . . . X . . . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . , . . . |
$$ | . . . . . X . . . . X . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Had some issues with posting this reply, but apparently a reboot made it work.

Perhaps something as below? The normal sequence is 29 at a, but that's ridiculous in this case.

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[go]$$Bcm21 illluck vs. Celebrir
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 4 6 . O . . O . X . O . X . . X . . |
$$ | 8 X O 5 . . . . . , . . O O X , . . . |
$$ | . O 3 . . . . . . X . . . . X . . . . |
$$ | . 7 9 . . . . . . . . . O . . . . . . |
$$ | . . . . a . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . , . . . |
$$ | . . . . . X . . . . X . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Next move of your game in the wrong thread ? Oo If yes you cann assume I play B17

So depending on holding White with Komi or Black you would go for mutual destruction or mutual building, did I get you right? If yes, I would find it very interesting - never heard of this approach.

I wouldn't necessarily go for mutual destruction as white, but it would be a factor in favour of it. The thinking is if black gets 100 points on the board and white a bit, say 10%, less so 90, then komi is not enough to win. But if white splits the board into lots of small territories and black gets 50 points, and white again 10% less so 45, then now komi is relatively bigger so means white wins.

This is why if I am white and my opponent plays diagonal opening I will often play 3-3 as my 2nd corner as it grabs the territory and being diagonal it is hard to make big moyos so I will play to split the board up and make komi count for more.

Is the argument with the % really working ? I think my moyo games are as often decided by a few points like my games with small groups. I still try to think "This move (/wall) gets me x more points than him" in moyo games.

It's not a bullet-proof argument, and indeed the fact komi is a fixed amount rather than a percentage does suggest black's advantage from going first is a fixed amount, but I believe it has some merit. In a moyo game the moves are likely to be larger swings as the boundaries of large moyos are decided, so as black goes first his [sl=tedomari]tedomari[/sl] can be bigger. I certainly find a mistake in direction in a moyo game could easily be a 20 point loss, whereas in a plonking-small-groups-around-on-the-third-line game a mistake in direction is smaller.

See viewtopic.php?p=89658#p89658 for my thinking.