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 Post subject: Dealing with tengen openings
Post #1 Posted: Mon Jul 11, 2016 5:35 pm 
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Recently, I played a game (as White) that opened as follows:

Click Here To Show Diagram Code
[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 5 . . . . . , . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . 1 . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 , . . . . . , . . . . . 2 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


I couldn't figure out what to do to keep Black from getting a big moyo. I tried approaching 5 from the top, but Black wound up with most of the left side, winning when he killed my invasion. Black also had a large amount of territory in the upper right; even if my group on the left side had lived I probably would have lost badly. Now, obviously in this particular game I could have played 4 at 5 to prevent Black from getting that big moyo. To be honest, though, I've never been comfortable with diagonal fusekis either. Besides, what happens if Black opens like this:

Click Here To Show Diagram Code
[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 3 . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . 1 . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 2 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


The two remaining 4-4 points are miai, and Black gets his moyo.

I suppose the other option is to approach Black's corner with White 4 and let Black wind up with three of the four corners (especially in a game where Black opens in two different corners as opposed to a center opening), but that doesn't seem good either.

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Post #2 Posted: Mon Jul 11, 2016 5:38 pm 
Honinbo
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Related thread.
Similar issues; that one went on a few more moves, to about :b7: . Post 6.

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 Post subject: Re: Dealing with tengen openings
Post #3 Posted: Mon Jul 11, 2016 8:19 pm 
Oza
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IMHO, these openings are never that threatening. Immediately one big question becomes, is Black's tengen stone a good play. Naturally it all depends on subsequent play but every opening is like that.

Probably the the first thematic reply is simply splitting the top. Black did not play there so what if White does? White has miai extensions to the left and the right. How does Black make full use of the tengen stone here? Admittedly this is a rather negative strategy for White though.
Click Here To Show Diagram Code
[go]$$Bcm5
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 2 . . . . . . . . . |
$$ | . . . 1 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . B . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


What about extending up the right side? This is based on the asymmetric position on the bottom. Black's natural approach in the lower left is around e4, which does not fit with the tengen stone and top left star point, so we pick the right. What does Black do here? If Black plays at the top, White plays on the left side. If Black plays on the left side, White splits the top.
Click Here To Show Diagram Code
[go]$$Bcm5
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . B . . . . . 2 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


So finally what if White just ignores Black's play and continues at the bottom? If Black approaches the lower right and White says, "Go ahead, build your framework!" Is Black's stone better placed on tengen than on the upper side?
Click Here To Show Diagram Code
[go]$$Bcm5
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . B . . . . . 5 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . 4 . O . . . |
$$ | . . . . . . . . 2 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

_________________
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21


This post by ez4u was liked by: jeromie
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 Post subject: Re: Dealing with tengen openings
Post #4 Posted: Tue Jul 12, 2016 1:15 pm 
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Ed:

I went over the game again, and found a glaring error on for White 72:

Click Here To Show Diagram Code
[go]$$Wc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . . X O . . O . X . . . . . . . . . |
$$ | . . X , O . . O . , . . . . . X . . . |
$$ | . . . . . X X O . X X . . X . . X . . |
$$ | . . . X . X O O . O . . . . . O O . . |
$$ | . . . . . X O . . O . X . . . . . . . |
$$ | . . X X . . X O O . O X . . . . . . . |
$$ | . . O O O . . X X . O . . . . O . . . |
$$ | . . . , . . . . . X X X . . . , . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . X . . . . . . . . . . . . . |
$$ | . O . . . . . . . . . . . . . . . . . |
$$ | . X X . X . O . . . . . . . . . O . . |
$$ | . . . . . . . . X . . . . O . . . . . |
$$ | . . O , . X . O X , . . . . . O O . . |
$$ | . . . . O O . O O X X . . X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]


I should have played at either E7 or F7, but instead played A6, trying to get an eye on the side. :oops: I spent a good half hour trying to figure out what would happen if I had played at F7 or E7, but I still can't figure it out:

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

No matter what I tried, I kept finding variations where Black gets to kill some of the white stones above and live, or Black gets the corner. Either way is disaster for White. D4 seems to be a good response to E7, too.

More importantly, I posted because I seem to fall behind regardless of what fuseki my opponent chooses. Whether it's a tengen opening or something more common like the Chinese, my opponents keep getting big moyos that I have to try to invade, which never goes well. I don't want to keep falling behind right from the beginning of the game!

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 Post subject: Re: Dealing with tengen openings
Post #5 Posted: Wed Jul 13, 2016 11:14 am 
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If you post the game up to this point, we might be able to provide some guidance on the opening. At this point, the opening is over and B looks far ahead on territory. W probably has to try something a bit unreasonable, like killing the lower left group or invading and living in the upper right corner.

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Post #6 Posted: Wed Jul 13, 2016 11:49 am 
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Quote:
I don't want to keep falling behind right from the beginning of the game!
Hi Fedya,
An objective statiscal analysis is helpful.
Suppose we study a number of your games (say, 100) where you felt this was happening.
We find out what percentage of those games your assessment was correct.
We then figure out what were the biggest problems.
Maybe you were correct 100% (unlikely); maybe 0% (also unlikely).
The reality is somewhere in between -- but is it closer to 0% or 100% ?
My guess is the majority of the cases the biggest problems were not in the opening, but later.
But one way to find out is an objective study.

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 Post subject: Re: Dealing with tengen openings
Post #7 Posted: Wed Jul 13, 2016 1:39 pm 
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mitsun wrote:
If you post the game up to this point, we might be able to provide some guidance on the opening. At this point, the opening is over and B looks far ahead on territory. W probably has to try something a bit unreasonable, like killing the lower left group or invading and living in the upper right corner.

There are, of course, a whole bunch of variations because I was trying things out, some of which are clearly lousy.


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 Post subject: Re: Dealing with tengen openings
Post #8 Posted: Wed Jul 13, 2016 3:02 pm 
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A few notes on the game:

:w6: isn't inherently bad, but as a follow up, consider the basic joseki that runs C16, E16, D14, C17, B17, D17, B15, and then an extension by white. You may want to make it a bit narrow because of tengen. :w8: is problematic, looking for influence where the tengen stone is already nullifying it, and not helping the group.

:b9: is a weird direction. Black is trying to make something directly. Nothing wrong with a corner enclosure, I think, or you could even tenuki.

:w14: Black bullied white in the top left a bit to get a corner and good influence. This stems from the mistake of H16 and now white feels behind. Starting a fight here, though, is what black wants. Tengen is meant to support fighting and crazy extensions. Don't just play into it, with another weak group on the board. You could instead consider L17, slow but solid, or an approach at O17, which might invite a pincer (maybe dangerous), or maybe just grab the right side.

:w20: Black has overconcentrated himself a bit here, so maybe just support the top group, knowing that you can connect under with B6 any time. You could also play to preserve the connection with E8, since a black move there would cut it off in sente.

:w22: feels too passive. Maybe attach on top at K16? It's a tough spot. After the followup, white's group is heavy and under attack while not doing much.

:w34: What's wrong with the 3-3?

:w36: If you're going to play :w34: you can't come back and defend here. Black just got the corner in sente while white got no compensation.

:w38: if you had the 3-3, this or J3 especially would be a good way to pressure black's group. As it is, it's pretty lackluster... just a two space extension.

:w40: Yes, locally.

At this point, also, look at the board. Black has two solid corners to white's one, and black's stones are almost all connected and working together. White, on the other hand, has 3-4 groups in various states of weakness. There are a few things that led to this: Lack of joseki knowledge leading to poor local results in the UL and LR, starting fights unnecessarily, and ignoring weak groups so black can play a splitting attack.

Finally, :w70: is a huge mistake. Up to this point, white could have played B6 to connect underneath (look up the tesuji if you don't know it). Once white plays here, it invites black to cut white in two and a poor result is inevitable.

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 Post subject: Re: Dealing with tengen openings
Post #9 Posted: Wed Jul 13, 2016 8:14 pm 
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You are meekly answering too many of your opponents "forcing" moves. Do you have a feeling for when this is happening? I will try to point out a few places in this game.

First however :w8: is not joseki, because it is too easy for B to make W over-concentrated after this move. For example, B could play E17 immediately, and W has no good answer. B accomplished something similar with the D17-E17 exchange, which leaves the H16 stone slightly misplaced. Were you a bit concerned with the W position after :w12:?

This is not an opening problem, as you managed to develop in the direction you intended, breaking up the B top position. It is more a problem of efficiency. The cure for this problem is joseki study. But continue with the opening from this point to see a bigger problem.

Looking at the top W group now, is there any remaining weakness? Do you see a good attacking point for B? You should anticipate that B has a good approach at K17, undermining the base of this group. There are three options to deal with this:

1) Extend around L17 before B approaches. Good!
2) Plan to resist somehow when B approaches. Good!
3) Plan to defend meekly when B approaches. Unacceptable!

You ended up answering K17 submissively at H17 in the game. This exchange is profitable for B and should be completely unacceptable for W. If you believe the B approach requires such a submissive defense, then preemptively extending to make a base should be very high priority.

Moving on a little further, the result through :w16: was good. Again you achieved your strategic goal of breaking up the left side, making a decent base for your stones while B jumped into the center. No problem with opening strategy here.

The next example of letting your opponent push you around was :b36:. This was a big move for B, taking corner territory and making a base for his group. Do your really have to answer this move locally? That just adds insult to injury, making his move sente, and giving you an inefficient over-concentrated shape. It would be much larger, and a much more positive attitude, to make your own large play elsewhere. Approaching the upper right corner, or even invading the 3-3 point, would be huge. B would probably answer all your moves there.

How about turning the tables on B and getting him to play submissive moves while you take profit? It should be possible to do precisely that by attacking the two weak B stones in the lower left. In the best scenario, you would secure the C8 group, and take territory around G3, while forcing the B stones to flee through the center, all the while keeping sente, to eventually play first in the upper right corner! That would be a great middle game strategy.

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 Post subject: Re: Dealing with tengen openings
Post #10 Posted: Thu Jul 14, 2016 12:38 pm 
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Quote:
:w6: isn't inherently bad, but as a follow up, consider the basic joseki that runs C16, E16, D14, C17, B17, D17, B15, and then an extension by white. You may want to make it a bit narrow because of tengen.

Yes, I know that joseki, but one of my (many) weaknesses is not understanding which joseki is the right one in a given situation. There's also not knowing what to do when one's opponent plays a move that isn't a joseki move, and then trying to figure out from first principles what to do.

Quote:
B accomplished something similar with the D17-E17 exchange, which leaves the H16 stone slightly misplaced. Were you a bit concerned with the W position after :w12:?

Not at the time, no. It was only at about :w24: that things started looking not quite right.

And all this time I thought :w34: and :w36: were good moves, keeping me from getting stuck with a tiny territory in the corner. :oops:

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Post #11 Posted: Thu Jul 14, 2016 4:01 pm 
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:w34: is a good move, just as good at R3. In fact it is fairly common for W to defer both of these moves until later, treating them as miai. So if B takes the corner with R3, W extends to R9 to make a base, while if B approaches at R8, W takes R3 to make a base.

The problem is that you answered R3 by blocking at R4, which is a really small move. Small moves are sometimes necessary to live or avoid attack, but you already have R6 and R9 on the board, so your group is safe and strong, with no need for additional defense.

R3 is a big territorial gain for B. R4 in response only stops B from making an additional relatively small gain. You cannot go around the board everywhere letting your opponent make profitable exchanges like this. When B plays R3, instead of worrying about how to limit further damage, you should look for places where you can make a similarly large gain (or inflict similarly large damage) yourself.


This post by mitsun was liked by: Bill Spight
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