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I don't understand territory...
http://www.lifein19x19.com/viewtopic.php?f=11&t=10360
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Author:  Joelnelsonb [ Mon May 26, 2014 6:56 pm ]
Post subject:  I don't understand territory...

Hi! I'm brand new to go and I seem to be missing something about territory and area. Here's a game I played on my phone app. The app says white wins 49 to 4 but I don't see how. All the white stones appear to be dead and I (as black) surround territory. Help?



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Author:  Uberdude [ Mon May 26, 2014 7:11 pm ]
Post subject:  Re: I don't understand territory...

Hello and welcome! That game isn't finished so you can't score it yet: you need to wall off the black and white territories into separate areas.

There's a scoring section in this beginner tutorial: http://www.playgo.to/iwtg/en/

Author:  EdLee [ Mon May 26, 2014 8:07 pm ]
Post subject: 

Hi Joel, Welcome to Go. Diagrams are also very useful:
Click Here To Show Diagram Code
[go]$$
$$ -----------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ----------------------------------------[/go]

Author:  RobertJasiek [ Mon May 26, 2014 10:38 pm ]
Post subject:  Re: I don't understand territory...

Start with the "area" concept. AFA possible, create empty regions surrounded by exactly one player's stones. You do so by a) completing boundaries of your regions and b) approaching and removing all the opponent's stones inside your regions during the game's alternation. If you can't remove but your opponent removes your stones from a region, maybe it is indeed his:)

Author:  oca [ Mon May 26, 2014 11:02 pm ]
Post subject:  Re: I don't understand territory...

Hello,

like Edlee allready pointed out, go diagram are really a nice feature to show a game position.
Here is your game :
Click Here To Show Diagram Code
[go]$$B
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . . . , . . |
$$ | . . O O . O O X X |
$$ | X X X X X X X O O |
$$ | X O X . . . X O . |
$$ | . O X X O . O . X |
$$ | . O O O X . . O O |
$$ | . . . . . . . . . |
$$ +-------------------+[/go]


to edit go diagram, I use that tool, which is very handy :

http://hiddema.nl/diagrammer/

you then just need to copy the text and paste it in your post using [go] tags like this:
Code:

[go]$$B
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . . . , . . |
$$ | . . O O . O O X X |
$$ | X X X X X X X O O |
$$ | X O X . . . X O . |
$$ | . O X X O . O . X |
$$ | . O O O X . . O O |
$$ | . . . . . . . . . |
$$ +-------------------+[/go]

(or just click on the "Click Here to Show Diagram Code" just above, that will show the same...)

May I ask you what application do you use on your iphone ? Igowin ?

Author:  Inkwolf [ Tue May 27, 2014 7:19 am ]
Post subject:  Re: I don't understand territory...

Click Here To Show Diagram Code
[go]$$B
$$ +-------------------+
$$ | ? ? ? ? ? ? ? ? ? |
$$ | ? ? ? ? ? ? ? ? ? |
$$ | ? ? ? ? ? ? ? a . |
$$ | . . O O . W W Z Z |
$$ | X X X X X X X O O |
$$ | X O X . e . X O . |
$$ | b O X X O . O . B |
$$ | . O O O X d . O O |
$$ | c b c b . . . . . |
$$ +-------------------+[/go]


It's hard for a new player to tell when the game is finished, so if this helps you understand:
The upper side is still completely up for grabs. White has stones there, and though there are gaps in the line, white has plenty of room to make eyes if you do not succeed in stopping them.

If white plays at a, the two X-marked stones are in atari and trapped with no escape route. This pretty much ensures that the white group in the lower right will live, and connects it with the two marked white stones as well, so they will live. That means it is not going to be hard for white to take at least some of the upper side. (Actually, the lower right will most likely live as it is.)

Totally on their own, the lower left white stones can still live if white manages to play either the three b points, or the left b and the two c points, or the two outer b points and the corner c. Not very likely...

But that group is not on its own. If white plays at d, they not only ensure that the lower right side lives, by protecting cutting points and making a wider base for a second eye, but that also connects the lower left to the lower right, giving white the entire side.

The black stone marked with a circle is dead. You can't push to cut off the three white stones without putting yourself in atari.

With living white stones both above and below, your black shape is sandwiched in with no real territory. Playing at e will give you one eye, and the rest of your play will be a scramble to get the second eye you need to survive.

You haven't said whose turn it is, but I will assume you passed first, so white moves next. The game might possibly go something like this...

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


At this point you can see that things are not looking very good for black.

Author:  Joelnelsonb [ Tue May 27, 2014 7:22 am ]
Post subject:  Re: I don't understand territory...

I use two different apps: smartgo and one called "it igo net" by magnolia. For some reason the computer likes to pass really early and the app always says the computer wins but it's usually games like this one where white doesn't surround anything. This brings up another question: how do you decide which side of the board black is surrounding? Would it always be the smaller side?

Author:  Joelnelsonb [ Tue May 27, 2014 7:26 am ]
Post subject:  Re: I don't understand territory...

So basically the computers predicting how the game would play out if continued and scores it based on that? Is that how it really works? Can you just pass and say "I win because I'm in a better position"?

Author:  Inkwolf [ Tue May 27, 2014 7:32 am ]
Post subject:  Re: I don't understand territory...

Joelnelsonb wrote:
So basically the computers predicting how the game would play out if continued and scores it based on that? Is that how it really works? Can you just pass and say "I win because I'm in a better position"?


You can try, but generally, if the computer is behind and you pass when the game is not completely finished, the computer will take advantage of the chance to catch up with you and keep playing. :D

And the part you get to keep as your own is the part that the enemy can't survive in!

Author:  Uberdude [ Tue May 27, 2014 7:36 am ]
Post subject:  Re: I don't understand territory...

Play a computer that knows how to play Go and you won't be so confused. Or play a human. You can talk to them.

Author:  oca [ Tue May 27, 2014 7:40 am ]
Post subject:  Re: I don't understand territory...

I had exactly the same questions few month ago when I discovered the game...
The key point is that at some point in the game, everything is told and both player will "pass" (or one will resign) because there is nothing left to do that can change the issue of the game...

That's very difficult to see when we start learning the game... I remember that very well...

What helped me is the understanding of what is a living group of stones.
The first things to look at is the concept of "two eyes" and then what is called "seki" (but start with two eyes...)

two eyes means that a groups cannot be captured because the oppenent would then need to play two move in his turn...

in this picture none of the black groups can be eaten because they all have two eyes...

Image

Author:  Joelnelsonb [ Tue May 27, 2014 7:43 am ]
Post subject:  Re: I don't understand territory...

So suppose both players passed after the first move or within a couple moves - I know this isn't practical but who would take the game? Would it be a draw? I'm not understanding how you can "control" territory without actually surrounding it, just because you're in a position to. I've played chess my whole life so in my mind, it doesn't matter if you have the whole board in your favor; if you don't put the nail in the coffin then you don't win.

Author:  oca [ Tue May 27, 2014 8:01 am ]
Post subject:  Re: I don't understand territory...

Let's say a game went like this...
here black as more territory, if both player pass, black will win the game...
Click Here To Show Diagram Code
[go]$$B
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . . . , . . |
$$ | O O O O O O O O O |
$$ | X X X X X X X X X |
$$ | . . . . . . . . . |
$$ | . . , . . . , . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ +-------------------+[/go]


But what if [edit] black pass and [/edit] white plays :w1: ?

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


If black fail to stop the white invasion, that may lead to that position:

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


:wc: is move 11
:bc: is move 12
and here white just won the game... (but be sure black can resist more than that ;) )

Author:  Inkwolf [ Tue May 27, 2014 8:04 am ]
Post subject:  Re: I don't understand territory...

Oca is right to point out the matter of living groups. Also, if an area is big enough that you can pretty certainly make two eyes, and prevent the opponent from doing so, it's yours.

Life and death problems may help you understand! There are some tsumego phone apps, or you can try http://goproblems.com or http://gochild2009.appspot.com/ (You have to click through a few menu levels to find the actual problems on this site.)

One difference between Go and Chess is that Go is based on territory. In chess, only a good player can predict the winner based on where the pieces happen to be sitting. In Go, anyone can look at the board at any point and have a general idea of what territory seems like it is going to end up belonging to which side AT THAT MOMENT. Computer score estimators (and human ones) are very inaccurate because at any moment in a game, the tide may turn, a dead group may come back to life, a wall may be unexpectedly cut off and destroyed, a clever tesuji or bad mistake may kill a shape. But if a game is quit in the middle, the computer will score it based on a guesstimate of which stones control the most territory.

Pros often quit a game early because they can read ahead and know exactly how the endgame is going to finish up.(I find it frustrating to look at pro sgf files that seem to me to cut off before the game is over!) The computer doesn't have that skill. Like I said, if it considers itself ahead when you pass in an unfinished game, it may just quit and take the win. Or, depending on the program, it may just cheerfully go on demolishing you.

Author:  HermanHiddema [ Tue May 27, 2014 8:16 am ]
Post subject:  Re: I don't understand territory...

Joelnelsonb wrote:
So suppose both players passed after the first move or within a couple moves - I know this isn't practical but who would take the game? Would it be a draw? I'm not understanding how you can "control" territory without actually surrounding it, just because you're in a position to. I've played chess my whole life so in my mind, it doesn't matter if you have the whole board in your favor; if you don't put the nail in the coffin then you don't win.


In 99.99% of cases, territory is divided by agreement. The players agree on which groups are alive and which are dead, the dead groups are removed and added to prisoners, and in the resulting position, all territory is now fully surrounded by only one color. As soon as players are past the bare beginner level, they have generally learned to recognize life and death, and which parts of the board belong to who. To employ a chess analogy: as soon as players are past the bare beginner level, they can recognize mate and stalemate.

If the player cannot agree, then there are methods to resolve such disputes, where players can "prove" their claims about what it alive and what is dead.

If you pass early, both players can make claims as to which groups are alive and which are dead. If they agree, then they can score the game. If both have only played a few moves, then probably almost all points on the board are neutral, and white is therefore likely to win by the komi.

Author:  Uberdude [ Tue May 27, 2014 8:19 am ]
Post subject:  Re: I don't understand territory...

Joelnelsonb wrote:
So suppose both players passed after the first move or within a couple moves - I know this isn't practical but who would take the game? Would it be a draw?


It is possible to count such an unfinished position to get a score, but rather meaningless.

Joelnelsonb wrote:
I'm not understanding how you can "control" territory without actually surrounding it, just because you're in a position to.


You can't, you do have to surround it! Your computer program is wrong.

Joelnelsonb wrote:
I've played chess my whole life so in my mind, it doesn't matter if you have the whole board in your favor; if you don't put the nail in the coffin then you don't win.

There's not the same single goal of capturing the king in Go, so it is possible, but silly, to count an unfinished game. For example in your game the only surrounded territory is the marked bit on the right with the dead black stone inside:

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


That black stone can't escape or make 2 eyes so we call it dead, so white has 3 points of territory there plus one capture which is 4 points. No other area of the board is completely surrounded by only one player so it is all neutral, no one's points. So white would win this game by 4 points (plus any komi). But it's better to finish the game before passing and counting.

Author:  Inkwolf [ Tue May 27, 2014 8:28 am ]
Post subject:  Re: I don't understand territory...

One final note on the white shape in the lower right...if that shape was completely on its own surrounded by black, your black stone would have killed it by making it impossible to make a second eye. In that case, it would have become your territory, and the white stones would be dead. Like this.

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


But because white can make its second eye on the lower side, or by capturing the two black stones above, white is alive and the black stone inside is dead.

Click Here To Show Diagram Code
[go]$$B
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . . . , b b |
$$ | . . O O . O O X X |
$$ | X X X X X X X O O |
$$ | X O X . . . X O ? |
$$ | . O X X O . O ? X |
$$ | . O O O X . . O O |
$$ | . . . . . . . a ? |
$$ +-------------------+[/go]

Author:  Bill Spight [ Tue May 27, 2014 9:11 am ]
Post subject:  Re: I don't understand territory...

Uberdude wrote:
Joelnelsonb wrote:
So suppose both players passed after the first move or within a couple moves - I know this isn't practical but who would take the game? Would it be a draw?


It is possible to count such an unfinished position to get a score, but rather meaningless.

Joelnelsonb wrote:
I'm not understanding how you can "control" territory without actually surrounding it, just because you're in a position to.


You can't, you do have to surround it! Your computer program is wrong.


Ing rules use proximity scoring, where an empty point belongs to the nearest stone, or is neutral if the nearest stones are different colors. In practice it gives the same score as area scoring, except in very rare cases. But it does allow any board to be scored. (Which, I suspect, is why Ing included it.) :) By proximity scoring I get a 7 point win for White. ;)

But anyway, the computer program is indeed wrong.

Author:  EdLee [ Tue May 27, 2014 12:33 pm ]
Post subject: 

Joelnelsonb wrote:
I'm not understanding how you can "control" territory without actually surrounding it
Hi Joel, play, play, and play.

Experience is very helpful to you at this phase.
Direct personal experience.

Many others at your level also ask the same questions
as you do, and they also crave for more instructions, more theory,
and more tips as you do. It's all very natural.

Like a baby learning to walk, or an adult learning to swim, to bike, or to play golf for the first time, theory and tips are OK -- up to a point.
(In the case of babies learning to stand up or to walk, theory is completely useless.
Of course, all anologies have their limitations.)
At the end of the day, we must jump into the pool (and inhale a few mouthfuls
of water), get on the bike (and fall off a few times),
and try to just hit the golf ball (and miss, over 50%, on day one!)

Understanding from theory is one sphere;
understanding from actual combat is another.
It's an iterative process: the two provide a feedback loop
to each other. Learn some theory, test it in real games;
rinse and repeat.

Since you play chess, you already have an understanding
of the process.

You need direct personal experience. Lots of it.
Play bots. Play humans. 9x9, 13x13, all sizes OK.
Finish lots and lots of games.

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