BQM 225

  Difficulty: Expert   Keywords: MiddleGame, Tactics, Strategy, Question

Alex: It's been a while since I've posted a full board "best move?" problem from one of my games as a BQM, but I find the discussions that often ensue to be very beneficial, both to me, and to others.

Today at the club, I was playing Huang Yong, who is about 4 dan. I feel that he's a bit stronger than me, but he's modest, so we play even with nigiri. This time I had White with 6.5 komi.

White to play  

Alex: I felt Black got a better start, but then he let himself get heavy on the top side. I think he expected me to let him bully my top left corner enough that he could escape into the centre, but I felt it could be neglected as long as my attack was in full swing. I had just exchanged the marked stones, but was unsure how to continue. I tried hitting the shape point with a, aiming at a cut, but of course he answered at the circled point; my supposed kikashi just ended up pushing him towards my own weakness. I don't know why it didn't occur to me.

I'd like to hear some thoughts on where White should have played instead. I'll suggest b through e to get the discussion started, but everyone should feel free to propose their own moves if they see something better.

I'd also be curious to hear what people think about the position in general; clearly White is behind in territory, but is quite thick on the right side, while Black's weak group is heavy. If both players handle this attack well, who will be ahead?

tderz IMO, whoever can first exchange the peeping kikashis for shape points (black circle oe white d) gets some small advantage (because the other one cannot play these points anymore effectively).
I think of black circle, white f, Bg, Wh and cut black i (although one could hold everything after the initial black circle in reserve). Isn't white+circle + companion then very lonely?

Charles Matthews The white position looks too thin for a successful attack.

White's weaknesses  

Right now I would be concerned, as White, about being thin in the centre; and also about Black at a. W1 would be one way to deal with the centre.

IanDavis Yes I thought White looked a bit weak to start attacking. In the original diagram playing at the circled point was my initial choice, but I also wondered if White could jump to b to stabilise before an attack - gross error?

tderz: Forcing with W1 (Bb, Wc, Bd) means stabilising black's moyo. At the same time circle becomes/remains black's forcing move for shape.
Additionally I get interested in resisting with black e (might be crazy!)

Black resists - crazy idea?  

tderz: Perhaps W = circle now is the worst what white could do to black? Black reinforces with b and subsequently white likewise with c.
The eventual result is that the black+circle are weakened.

Charles The real strategic question is the lower right: see /lower right.

Alex: Alright, so let's rewind a bit. My error must have been earlier.

Moves 26-30  

Alex: Everything here looks normal enough to me. Maybe W6 is questionable - it's hard to build a moyo with Black so low and solid in the top right, but I wasn't sure what else to do. Anyway, after W8-W10, it looks fairly promising to me.

IanDavis: I found move 8 in combination with 6 questionable. Too gappy for my taste.

Bill: W6 - W10 look thin to me. And I agree that it's hard for White to build a good moyo on the top. Maybe it's time to invade Black's moyo on the left.

Moves 31-40  

Alex: B1 surprised me. I thought W4 was much too painful for Black to allow. B5 also seemed heavy, but I was kind of stuck for a reply. W6 makes rather awkward shape. The natural move would be a of course, but I didn't want to make B7 sente for him. He played it anyway. Should I have defended at a or b after all? Instead, I was worried about the cut at c, and came up with the sequence to W10 to fix it in sente, at the expense of giving myself an open skirt by forcing B9.

Andy: Between black+square and B1-B7 white has so much aji in the upper left corner that it seems to be white who lacks a base, not black. Accordingly, I like Dieter's suggestion below. When black reduces with B1, how about the usual W4 at x rather than W4 as in the game?

Bill: W4 and W6 reveal White's problems with thinness. Also, I think that W8 - B9 is not a good exchange for White. Maybe W8 is mochikomi. B9 offers Black somewhere to run if necessary, and minimizes any profit White might make on top from attacking Black there.

Charles /alternate shape

Moves 41-45  

Black has to defend at B1. W2 and W4 seemed good to me, for keeping him separated from the left side and aiming at a reduction of his moyo, but should I have held back more? W2 at a would be less thin, for instance, but wouldn't carry the threat of b.

Normally I'm pretty good at finding my own mistakes, but I must have gone wrong before the move in the original diagram, and don't know where.

kokiri it's not clear to me that the last few moves you make are coherent. playing W2, not a seems to be worrying more about the moyo on the left, and B3 does seem to expose the thinness of the white+circle W2 connection. To play W2, but then come back to play a defensive move to connect it seems almost unthinkable. On the other hand, to play a might encourage black to take profit on the bottom left, so i'm not really sure i like it. The conclusion I'd come to then, seems to be that playing W2 maybe should be followed up by driving further into the moyo. As an alternative, how about 2 at c, more directly threatening the top stones, and allowing you to jump further into the black sphere of influence on the left if black defends?

Bill: I suspect that the lower left corner was played out when the black+circle stones were in place. In that case, I think that white+square would have been better at z. The left side is the focus, not the bottom side.

Just for shape considerations I would like to sagari at y after B1, but that seems too passive. B3 is ideal, so I think I would play W3 instead of W2. I might even make a center moyo at some point.

(Later.) Hmmm. W3 has a problem with a Black peek at d. Not so good.

Alex: You're right about the lower left, and yes, that's good advice. Alternately, maybe I should have made a second approach before invading the corner to try to force him to block the wrong way.

Corner weakness

Defend and take territory  

Dieter: Using some basic concepts, I do not think that White is strong enough in the upper left to launch an attack with such a big stretch as the large knight's move. Moreover, Black is not exactlt weak either: he can exploit White's weak spot at a.

White is strong, maybe even too strong in the upper right and needs some territory to match Black's. I would play W1 to defend and make territory or b to defend with a one-space-jump/diagonal and threaten to erase Black's moyo OR attack Black's top.

Alex: Of everything I've heard, I like this idea the best. Even with the weak point at a, White's territory is not small. Not enough to match Black's moyo, of course, but White's thickness on the right side is worth a lot (overconcentrated, I agree, but very thick). White also has komi. I think if W1 here and Black defends his weak group, the game will be close.

much aji in White corner  

tderz: "Even with the weak point at a, White's territory is not small. "
This statement is a misconception, I think. IMO, esp. due to the weakness at a the san-san d should at least yield in ko - once Black's black+circle-group is safe.
I do not know now where to start first a or d.
For safety, W1 at e could be considered (if that makes a difference).

Alex: Okay, you're right. At first glance, I thought that the best Black could do after W1 was to connect out with a stone at a. Now that I've read out all the variations (I think), it seems that Black can get a ko no matter what White does. So, how about W1 at e instead? This page is so cluttered, I don't know where to put my diagrams, so how about I start BQM 225/Honte.

much aji in White corner  

tderz: After the exchange B2-W3, Black could continue with d or f, aways having white's weakness (Black g with 2 cutting points h and i) in mind.
How could white prevent at least a connection to black k?

much aji in White corner  

tderz: the blunt B4 just for studying here ...

much aji in White corner  

tderz: W1, W3 do not let Black succeed...

much aji in White corner  

tderz: (W2 perhaps also at d)
both players should have in mind that atari a induces black b-c (which however also weakens the black+circle).

A prerequisite is that the black+circle are safe.

much aji in White corner  

tderz: W42 above had several problems (too thin)
If the corner was safe (e.g. Wa in place), W1 here looks a little bit as an attack.

much aji in White corner  

tderz: strengthening the corner is perhaps a gote-no-sente type of good move?
How dangerous is now the black warikomi-cut at f?
Questions over questions ...

Charles Interesting what attracts the attention. Is Black f White g ever going to be a problem for White?

much aji in White corner  

tderz: Here is the cut at f (perhaps not a warikomi):
W3 at d B4=W3, W5 at k would be honte/good shape.

At least it displays the thinness of that particular corner.

honte/good shape  

tderz: No cut at f, black only reduced somewhat.

honte/good shape  

tderz: Black e above is sente (due to the invasion a).
(please note that black+square has been played/added here)

honte/good shape  

tderz: B9 above is not necessary, White loses in either case.
Moves as W2=a do not work, White comes 1 liberty short.

BQM 225 last edited by tderz on June 3, 2005 - 09:18
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