Light sabaki invasion

Numsgil · Post by **Numsgil** » Mon Jan 09, 2012 4:24 pm

I'm looking for some general advice beyond just this specific position, but I figure if I don't have a specific example people will complain

Suppose you have this game below. It feels a bit artificial, but it's not entirely unreasonable (I just sort of plonked stones down. At least the move counts are consistent (I hope)

)

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

Let's say white wants to invade black's right side (instead of trying to harass the black group on the left, say), and let's say he wants to do it by attaching to black's single stone (leaving aside whether this is good timing, the best way to invade, and other issues like that).

I have two questions: how do you decide which direction to attach, and how do you decide whether to cross cut or double hane assuming black hanes back?

Some examples:

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . . . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . 3 . . . | $$ . . . . 2 1 . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . X . . . | $$ . . O . . . . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . . . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . 3 X . . | $$ . . . . 2 1 . . | $$ . . . . . . . . | $$ . . . . X . . . | $$ . . O . . . . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

In games when I try this sort of light invasion/sabaki, it either works out really well and I live on the side or I get absolutely destroyed and torn to pieces. I think a lot of the problem comes from the fact that the direction I attach and whether I cross cut or double hane is chosen pretty randomly. If I can read something out I'll do that, but usually the position needs judgement more than reading, and I don't really have a good inuitive grasp of this sort of thing yet.

So are there any helpful guidelines? If I have a line of sight to some white influence I'll attach in that direction, but otherwise I feel like I'm poking around in the dark.

Bill Spight · Post by **Bill Spight** » Mon Jan 09, 2012 4:36 pm

Helpful guidelines:

1) Do not invade too deeply. (Jowa's advice.)

2) Do not try to save everything. Offer some stones up for sacrifice. (See Kitani's games for some amazing invasions.

)

jts · Post by **jts** » Mon Jan 09, 2012 5:08 pm

Why attach, though? (Non-rhetorical question.)

My sense is that attaching works in two different contexts. First, as a probe: (i) you attach, (ii) he commits himself to a specific strategy, (iii) you now invade/reduce in a way that is awkward for him, given how he has committed. Second, as a 50% solution: (i) you invade, (ii) he attacks the invasion severely, (iii) you attach, (iv) unless he wants to sacrifice the attached stone, he must hane, giving you forcing moves and developing a light shape towards the center.

What I'm getting at is that most of the positions (with which I'm familiar) where you need to decide whether to double-hane up, to double-hane under, or to cross-cut are positions where the stones involved are all light, forcing moves designed to be sacrificed in order to help a pre-existing invasion/weak group live gracefully. So the question doesn't make a lot of sense to me. You should choose one of those options by reading out which way helps the original stones the most, but why bother with any of them if there are no stones to save?

Shaddy · Post by **Shaddy** » Mon Jan 09, 2012 5:18 pm

You have to read. It's kind of a copout answer, but I think it's really the only way to go when you want to do something as tactical as a deep invasion and have success.

Numsgil · Post by **Numsgil** » Mon Jan 09, 2012 5:37 pm

I don't mind reading, but it always feels like six of one, half a dozen of the other.

amnal · Post by **amnal** » Mon Jan 09, 2012 5:44 pm

For this example, two immediate questions present themself to me.

First, black's most territorially powerful defence is probably the following. So the first question to ask yourself is, is this good enough for white?

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . . . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . 3 4 6 . | $$ . . . . 2 1 5 . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . X . . . | $$ . . O . . . . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

Having asked that question, here's another one. Is this good enough for white?

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . . . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . B X . . | $$ . . . . . W . . | $$ . . . . . 9 . . | $$ . . . . 3 4 6 . | $$ . . . . 2 1 5 . | $$ . . . . . X 7 . | $$ . . . . . 8 . . | $$ . . . . . . . . | $$ . . . . X . . . | $$ . . O . . . . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

In this case, white has made a separate probe, trading for the marked stones. This makes things much more difficult for black if he tries this way, as white has stronger shape.

This illustrates how extremely position dependent this stuff is. You simply have to read this variation every time...or, after a while, develop a feel for what needs to be where for it to work.

Now, second question...if black decides he can't play so strongly and so tries something else:

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . a . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . 3 5 7 . | $$ . . . . 2 1 4 . | $$ . . . . 6 X 8 . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . X . . . | $$ . . O . . . . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

Black decides it's too risky to claim the territory is enough, and just plays the simplest solid way instead. Is this good enough? Where can white run to? Is there anything white can lean on? White can also think about the possibility of moves like a, and probably play them earlier.

These two shapes usually seem like the harshest to me, though that's not to say they're automatically harsh - they're just terrible for black under some circumstances. But in any case, this means that they're the first two things to think about. If they're both okay for you, your hane is looking good and may merit further thought. If one of them isn't okay for you, think harder.

I tend to have similar thought processes about the other shapes, perhaps you will find the idea useful. This particular hane doesn't actually seem very good normally, as it's often better to just extend and make good shape on the side.

Kirby · Post by **Kirby** » Mon Jan 09, 2012 6:09 pm

Numsgil wrote:I don't mind reading, but it always feels like six of one, half a dozen of the other.

You dont have to read every combo. Read the things you think might actually happen.

Numsgil · Post by **Numsgil** » Mon Jan 09, 2012 6:20 pm

A lot of the problem comes from my not really knowing how much I should expect from a given position. That comes with experience, no doubt.

As way of example, is this sort of thing reasonable for white to aim for? When I was maybe a stone weaker I'd probably accept this, but now I think it's not good for white because of 8 and 10 (and, you know the overwhelming thickness black gets).

Click Here To Show Diagram Code: [go]$$Wc $$ ----------------- $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . X . . . . | $$ . . . . X . . . | $$ . . . . . . . . | $$ . . . . . X . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ . . . . O X X . | $$ . . . 2 X O O 6 | $$ . . . . 1 X 4 . | $$ . . . . . 3 5 . | $$ . . . . 7 . . . | $$ . . . 8 X 9 . . | $$ . . O . . 0 . . | $$ . . . . X . . . | $$ . . O . X . . . | $$ . . . . . . . . | $$ . . . . . . . . | $$ ----------------[/go]

ChrisH · Post by **ChrisH** » Mon Jan 09, 2012 6:27 pm

Black's position is so solid that invading will just get you attacked and won't leave anything to look forward to. It would be better to just reduce lightly and develop the center. In this game white can also attack black's two stone group on the left hand side. Working out where how to invade is difficult because you shouldn't invade here.

Kirby · Post by **Kirby** » Mon Jan 09, 2012 6:35 pm

ChrisH wrote:Black's position is so solid that invading will just get you attacked and won't leave anything to look forward to. It would be better to just reduce lightly and develop the center. In this game white can also attack black's two stone group on the left hand side. Working out where how to invade is difficult because you shouldn't invade here.

I dunno, I kind of like the idea of invading. The area seems large enough, and it will take away many black points.

You make a good point about the left side, though. Maybe it's good to first pressure the left, then invade after.

Post by **Joaz Banbeck** » Mon Jan 09, 2012 10:32 pm

Numsgil wrote:... how do you decide which direction to attach...?
...

Hmmm... there is some serious dan level horsepower in the posts above mine, but nobody has actually addressed the question of direction.

Shaddy gave you part of the correct answer:

Shaddy wrote:You have to read. It's kind of a copout answer, but I think it's really the only way to go when you want to do something as tactical as a deep invasion and have success.

Numsgil wrote:I don't mind reading, but it always feels like six of one, half a dozen of the other.

Your reaction to his answer is quite natural. You can read, but the variations that you read seem equivalent, for you don't know what you are trying to achieve. There is an issue of direction here. Shaddy probably knows it, and uses it to evaluate the variations that he reads, but he has become so used to doing it that he isn't consciously aware that he does it. That is why it feels like a copout. His answer is not wrong, just incomplete. We need to be explicit about direction.

Before addressing that, let's back up a bit and consider the nature of an attachment, and the theory of why it works.
As the proverb states, 'attach to strong stones, not to weak ones'. When you attach to a stone, the opponent adds one nearby, you add one, he adds another, etc, and both sides get stronger. Making your group stronger is good for you of course, but making his group stronger is not...unless it already is strong. Then making his strong stone stronger costs you almost nothing. His strength gets overconcentrated and thus is wasted.

So you attach to a strong stone, you fight, and you get stronger efficiently, he gets stronger inefficiently. To make this happen, you must ensure that his strong stones are close to each other, and as far as possible from you.

Let's look at some examples. ( These diagrams are a bit contrived and simplistic, but they illustrate the idea, even if they are not perfect in the particulars. ) Maybe we can infer a direction from them.

We'll start with a situation not too different from your example, just a bit stylized:

Click Here To Show Diagram Code: [go]$$W $$ . . . . . . . . . . . | $$ . . . . . . . . X . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . B . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . X X X X X X . | $$ . . . . . O O O O O . | $$ . . . O . . . . . . . | $$ . . . . . . . . . . . | $$ ---------------------[/go]

Suppose we want to attach to the marked stone. It is not a bad target for an attachment, for it is strong, being backed up by the wall to the south.

Let's first try attaching inside:

Click Here To Show Diagram Code: [go]$$W $$ . . . . . . . . . . . | $$ . . . . . . . . X . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . a . . | $$ . . . . . . . . . . . | $$ . . . . . . . 2 X . . | $$ . . . . . 6 4 3 1 . . | $$ . . . . 8 7 5 . . . . | $$ . . . . . . . . . . . | $$ . . . . . . . . . . . | $$ . . . . X X X X X X . | $$ . . . . . O O O O O . | $$ . . . O . . . . . . . | $$ . . . . . . . . . . . | $$ ---------------------[/go]

This is not looking good. We're probably going to die here. Even worse, because of his new strength, invading at 'a' can be dangerous.

Let's try attaching outside:

Click Here To Show Diagram Code: [go]$$W $$ . . . . . . . . . . . | $$ . . . . . . . . X . . | $$ . . . . . . . . . b . | $$ . . . . . c . 7 9 a . | $$ . . . . . . 5 6 8 . . | $$ . . . . . . 4 3 1 0 . | $$ . . . . . . . 2 X ? ? | $$ . . . . . . . ? ? ? ? | $$ . . . . . . . ? ? ? ? | $$ . . . . . . . ? ? ? ? | $$ . . . . . . . ? ? ? . | $$ . . . . X X X X X X . | $$ . . . . . O O O O O . | $$ . . . O . . . . . . . | $$ . . . . . . . . . . . | $$ ---------------------[/go]

We have a successful invasion here. Not only that, but we are getting some strength facing northward, and after playing something like 'a' or 'b', we now have a group that is stronger than the triangled stone up top, and we may be able to attack it. Or we can just run with 'c'.
Black, on the other hand, is over concentrated. He gets territory in the shaded area, but he has spent a lot of stones to do it, and is overconcentrated.

From these two contrasting examples, we can infer a rule for direction.Attach so that his newly built strength will be close to his pre-existing strength, and your newly built strength will be further away from it.

Numsgil wrote:...how do you decide whether to cross cut or double hane assuming black hanes back?
...

Ok, now it's time to invoke Shaddy's answer: you read. But now you know what direction you are going, so you will be able to evaluate the results of your reading.

Now that we have a theory, let's try to apply it to the example that you gave.

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . X . . . . X . . X . . . . | $$ | . . . . . . . . . X . . . . . X . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , a . . | $$ | . . . . . . . . . . . . . . . . # . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . O . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . B . . . | $$ | . . . . . . . . . . . . . O . . . . . | $$ | . . . O . . . . . O . . . . . B . . . | $$ | . . . . O . . O . . . . . O . B . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The squared stone is moderately strong, for it has three friends to the south. If we attach, theory says that we want to end up on the outside, at 'a', away from his strength..

I find reading terribly boring, so it is time for my copout. :lol:

You know what you result you want, so just read accurately to get it. As Bill says, you may want to sacrifice a stone or two...I leave the details up to you.

Uberdude · Post by **Uberdude** » Tue Jan 10, 2012 1:32 pm

Proverbs are all just shortcuts to avoid reading, and for positions like this reading truly is king. But if you replay pro games you will develop your feeling of the sort of tactics to use.

In your position if you want to build a group in the r11 area you want to attach at r13 and r10. So first do the one which is more likely to get an extend rather than hane as an answer as that's easier to tenuki to the other attachment. Which one is this? probably r9 as it is weaker (q6 is further away from it than q16 is from r14) and therefore if black hanes and you counter hane and immediate local fighting erupts you are less likely to instantly die. So unlike the usual proverb of attach to the stronger stone here I'm saying attach to the weaker! That's because they are both pretty strong. And reading is king. These ideas are not ones I have learned as proverbs and am just making up now. It could all be wrong, reading is king.

Numsgil · Post by **Numsgil** » Tue Jan 10, 2012 3:15 pm

Uberdude wrote:Proverbs are all just shortcuts to avoid reading, and for positions like this reading truly is king.

I think rather proverbs help formulate a plan (hypothesis), and reading shows if it'll work or not (experimentation). Sort of like a scientific method (hypothesis before experiment).

If you're at a point where you can form plans ex nihilo, you don't need proverbs.

Kirby · Post by **Kirby** » Tue Jan 10, 2012 3:19 pm

Numsgil wrote:
Uberdude wrote:Proverbs are all just shortcuts to avoid reading, and for positions like this reading truly is king.

I think rather proverbs help formulate a plan (hypothesis), and reading shows if it'll work or not (experimentation). Sort of like a scientific method (hypothesis before experiment).

If you're at a point where you can form plans ex nihilo, you don't need proverbs.

That's probably a good analogy. Maybe it is less limiting when you get to the point where you can make your own hypotheses from experience, independently of proverbs...

MMaestro · Post by **MMaestro** » Wed Jan 11, 2012 2:38 pm

Invasions may be successful here...but I think any invasion will help give black more thickness and ruin your center. Especially the E7 stone. Instead I would attack the left side from the center to build influence, which will help invade the top if you need to or reduce the right side. In reducing the right side I'd expect black to counter attack which would naturally let you also reduce a bit more of his potential there, otherwise you can probably build up the center if he just backs off for territory which would work nicely with the aforementioned thickness from attacking the left.

Life In 19x19

Light sabaki invasion

Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion

Re: Light sabaki invasion