the merits of this move

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cherryhill
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the merits of this move

Post by cherryhill »

i am watching what is a really informative youtube lecture on the double hane by starstorm3 and several times he ends his a variation with the marked black move instead of the triangle move but doesn't go into detail as to why. but when i see that i get nervous because i then see white making the triangle move and splitting the two black groups and i dont know how you would follow up white playing the triangle move and escaping without ruining any of the thickness you've made.


Click Here To Show Diagram Code
[go]$$c This is a label for the diagram.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . T . X # . . . . . . |
$$ | . . . . . . . . . . O X O . . X . . . |
$$ | . . . . . . . . . X X O O . . . . . . |
$$ | . . . X . . . . . X O . . O . X . . . |
$$ | . . . . . . . . . X O . . O X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Re: the merits of this move

Post by tomukaze »

What is the purpose of splitting the two black groups? Are either of them weak?
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Re: the merits of this move

Post by cherryhill »

with my skill they would be lol
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Re: the merits of this move

Post by tomukaze »

I suppose the way I see it, if white splits by playing the triangled move they would only be creating a weak group for themselves whilst the black groups are relatively stronger than that group.
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Re: the merits of this move

Post by golem7 »

yes, if white plays the triangled move, the one who has to escape is white, not black. his stones will be weak and a burden for the rest of the game. such a splitting attack is only sensible if white can attack either of blacks groups.
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Re: the merits of this move

Post by cherryhill »

here is another example of the same move but to me both black groups don't seem strong at all if white escapes. especially the bottom one

Click Here To Show Diagram Code
[go]$$c This is a label for the diagram.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X X X . . |
$$ | . . . , . . . . . , . . . O X O O . . |
$$ | . . . . . . . . . . . . X X O . . . . |
$$ | . . . . . . . . . . . . X O O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Re: the merits of this move

Post by Boidhre »

You need more stones on the board for analysing this kind of situation, and indeed most except for corner life and death sequences. The status of the top right and bottom left corners is important here.

On that board the bottom one is fine on Black's move and White is too weak to attack it yet so it's unlikely White can remove Black's base on the bottom unless they can strengthen whilst attacking the right.
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Re: the merits of this move

Post by xed_over »

cherryhill wrote: but when i see that i get nervous because i then see white making the triangle move and splitting the two black groups and i dont know how you would follow up white playing the triangle move and escaping without ruining any of the thickness you've made.

cherryhill, you ask interesting questions.

For me, I think the short answer is that the white stones would be very weak, floating in the middle without any base (or room to make eye shape), surrounded on either side by two strong black groups that can keep getting stronger while chasing the white group out into the center still looking to live somehow.

Lets take a look at your 2nd example

Click Here To Show Diagram Code
[go]$$c White is on the run.
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . . . . Q . X X X . . |
$$ . , . 1 . O X O O . . |
$$ . . . . X X O . . . . |
$$ . . . . X O O . . . . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]


Now suppose black black responds to White's triangled move with :b1:

Black now has two strong walls facing either side that can live easily, and if white ignores this move, will be caught in a ladder.

Click Here To Show Diagram Code
[go]$$c Caught in ladder.
$$ . . . . . . . . . . . |
$$ . . . M . . . . . . . |
$$ . M C C 3 . . . . . . |
$$ . . M C O 1 X X X . . |
$$ . , . X 2 O X O O . . |
$$ . . . . X X O . . . . |
$$ . . . . X O O . . . . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]



And regardless of where white responds, black can continue to chase and harass for a while, making himself even stronger in the process.

White would have been better off not trying to rescue the "cutting" stone in the first place.
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Re: the merits of this move

Post by ez4u »

There is a saying in Japanese (which of course I can't remember exactly :blackeye: ) to the effect that "If there's no blood, you're not cut". Similarly a couple of years ago Rob van Zeijst explained to me a taxonomy of cuts that he was working on for one of his books. He went progressively from the best cuts (dividing your opponent into two weak groups) to the worst cuts (dividing your opponent into two strong groups = no cut at all). In the original example as long as Black can ensure strong stones on either side, there is no cutting stone, only a target.
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Re: the merits of this move

Post by Phoenix »

cherryhill wrote:[...]i dont know how you would follow up white playing the triangle move and escaping without ruining any of the thickness you've made.


What's the point of thickness if you're not going to use it to chase a weak group around? :D

If White pulls his horribly damaged stone out, he's only helping you validate your thickness. You'll gain and he'll stagnate or die. It's a sure-fire way to lose!
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Re: the merits of this move

Post by jts »

ez4u wrote:There is a saying in Japanese (which of course I can't remember exactly :blackeye: ) to the effect that "If there's no blood, you're not cut". Similarly a couple of years ago Rob van Zeijst explained to me a taxonomy of cuts that he was working on for one of his books. He went progressively from the best cuts (dividing your opponent into two weak groups) to the worst cuts (dividing your opponent into two strong groups = no cut at all). In the original example as long as Black can ensure strong stones on either side, there is no cutting stone, only a target.


I'm not sure if it's van Zeijst or another strong European player who writes books, but I've read something to the effect that you should treat a group as worth -10 points for every eye it owes. So when you cut a group in two, you can estimate the value of the cut (assuming you're not planning to sac the cutting stones immediately) by comparing how many eyes the initial group owed to (how many eyes the two cut groups owe, minus how many eyes the cutting stones owe).
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Re: the merits of this move

Post by Sverre »

jts wrote:I'm not sure if it's van Zeijst or another strong European player who writes books, but I've read something to the effect that you should treat a group as worth -10 points for every eye it owes. So when you cut a group in two, you can estimate the value of the cut (assuming you're not planning to sac the cutting stones immediately) by comparing how many eyes the initial group owed to (how many eyes the two cut groups owe, minus how many eyes the cutting stones owe).


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Re: the merits of this move

Post by Bantari »

Hi cherryhill,

I actually understand your uneasiness about not capturing the stone firmly. I think it stems from several factors, among those:
1. You play games against (much) stronger players who punish you for leaving the door open like that, and
2. You still lack the experience to know what you can do when White starts funky business with the single stone, and
3. Because of the above, you tend to exaggerate the weakness of your groups while often overlooking the weakness of opponent's groups.

Having said the above, there is some potential left in the White cutting stone, and there are situations in which capturing it firmly is preferable. So, the issue is that of recognizing when the White stone is dangerous and needs to get captured, and when it can be left alone for now.

To be able to make this decision you have to imagine your opponent will move the stone out, and then compare the potential weaknesses of all stones. Who will be in more trouble? I know, I know - you always think it will be *you* in trouble, but you have to get past this idea to get stronger, even if it will lose you games initially. Maybe try to think of the position as one you are observing rather than one you are playing...

The bottom line, and what other people are saying here, is that in a vast majority of the cases the White cutting stone, if activated, will be much weaker than either of the surrounding Black groups, so most likely it will be in much bigger trouble. For this reason, it might be actually to your advantage to have it move, so instead of one half-dead stone, you will have a more substantial target for your attack. Even if you never kill this stone in the end, attacking a running group like that might have game-changing advantages for you if played right.

So, we have two important concepts in the above:
Concept #1. Comparative strength of stones - if you have several weak groups fighting, the important thing is often not that they are all weak, but which ones are the weakest.
Concept #2. Look at opponent stones also as targets for attack, not only as nasty little things that try to do you harm.

To glue it together, and make the decision possible, there is also a third concept necessary here:
Concept #3. Look at the overall whole-board position. In particular - if there are any stones already on the board which can substantially affect the evaluation of who is weak and who is strong. For example: are there already White stones nearby which will make White cutting stone stronger or your weak groups weaker, and stuff like that.

To reiterate Concept #3: As one of my teachers told me when I was a beginner, you can never become strong if your nose is too close to the board. ;)

PS>
A few final comments.

- Thinking of the Concept #1, a situation like that can be looked at in two ways, generally. When faced with a potential of a cut or activation of cutting stone like that, you can either capture the stone which removes the problem, or make your surrounding stones stronger. The latter makes it less lucrative for the opponent to cut and in addition, it usually gives you more strength globally rather than just locally capturing a stone. I think this exactly is what the move you asked about does. It tells the opponent: see how strong I am around here, you ould just be asking for trouble to try anything funny.

- I have often seen weak(er) players worrying too much about things like cutting and connecting. It seems like a funny thing to say, but I think it is actually a stepping stone to understand a few things here. Cuts should only be executed when they make sense - when they actually cause or can cause trouble. So, cutting two strong or even already alive groups is often a waste of a move. Also a waste of move is to try to connect two living groups. Why bother? A cutting or connecting move should aim at changing the situation in your favor, not at giving the opponent another free move elsewhere.

- Same goes for capturing or saving stones. Are the stones to capture/save important enough to invest a move in order to capture/save them?

- And finally, lets compare the two possible ways of playing visually:

Click Here To Show Diagram Code
[go]$$B1
$$ . . . . . . . . . . . |
$$ . . 3 . . . . . . . . |
$$ . 2 . X 1 . . . . . . |
$$ . . O X O . . X . . . |
$$ . X X O O . . . . . . |
$$ . X O . . O . X . . . |
$$ . X O . . O X . . . . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ -----------------------[/go]


Click Here To Show Diagram Code
[go]$$B1
$$ . . . . . . . . . . . |
$$ . . . . 4 . . . . . . |
$$ . 1 3 X 2 . . . . . . |
$$ . . O X O . . X . . . |
$$ . X X O O . . . . . . |
$$ . X O . . O . X . . . |
$$ . X O . . O X . . . . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ -----------------------[/go]


By far the majority of strong(er) player would prefer the second position as white to the first, unless there is some substantial White support nearby on the board. If you imagine yourself as White in this situation - which looks better for you? If it is the first position, rest assured that you are not correct. ;)
- Bantari
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WARNING: This post might contain Opinions!!
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Re: the merits of this move

Post by snorri »

You always have to look at the board from the other player's perspective. That white stone may have aji later, and maybe at some point netting it will be the honte move. Or maybe will never be a threat. We don't know yet. But if I were white, I would be thinking, after black's turn: "I don't have time for this. My group doesn't have two eyes yet!" Even if white is not showing this fear, you must learn to smell it. Or at least read it out, which should be better.

Go is a game of negative reinforcement. Maybe, as Bantari says, you've been punished in the past for leaving some aji too long, so there's a tendency to swing 180 degrees and try removing all problems right away. But go isn't that simple, because that just makes it too easy on the opponent.

I sympathize. I keep reading Yuan Zhou's book Master Play: The Fighting Styles of Kato Masao & Seo Bong Soo. In it, he shows just how precise an attacker must be, because to get into an attacking position in the first place, they often have to leave some weakness elsewhere, and then there is the possibility of counter-attack. It feels so good to keep a dragon under pressure or even kill it, but it requires enormous accuracy. If you slip a little, almost any crude move seems to work for the defender, and that can be demoralizing.
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Re: the merits of this move

Post by Bill Spight »

It may be counterintuitive that the turn facing the center is big. Especially since there is a saying that there is no territory in the center. ;) But it is, as a rule, as big as a corner enclosure. Bantari's diagrams show why it is especially big in this instance.

There is another saying, Don't sweat the small stuff. And in this case the White orphan is small stuff. After the turn, if it runs, it will come under attack instead of leading or preparing an attack itself.
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