It is currently Thu Mar 28, 2024 11:03 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 10 posts ] 
Author Message
Offline
 Post subject: Why can't you just do this?
Post #1 Posted: Thu Mar 10, 2016 7:50 pm 
Beginner

Posts: 2
Liked others: 0
Was liked: 0
Why can't black just go where I put the black circle and take out the whites with the red X's?


Attachments:
Untitled.png
Untitled.png [ 168.82 KiB | Viewed 5197 times ]
Top
 Profile  
 
Offline
 Post subject:
Post #2 Posted: Thu Mar 10, 2016 8:15 pm 
Honinbo
User avatar

Posts: 8859
Location: Santa Barbara, CA
Liked others: 349
Was liked: 2076
GD Posts: 312
The three :wx: stones still have 2 liberties -- at (x) and (y):
Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . 1 O . . . . . .
$$ | x P X . . . . . .
$$ | y P P X . . . . .
$$ | . X X O O . . . .
$$ | . X O X . O . . .
$$ | . . . X . . . . .
$$ | . . . . . . . . .[/go]

In addition, W can capture the :bc: stone with :w2: ...
Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . 1 O . . . . . .
$$ | . P B 2 . . . . .
$$ | . P P X . . . . .
$$ | . X X O O . . . .
$$ | . X O X . O . . .
$$ | . . . X . . . . .
$$ | . . . . . . . . .[/go]
...Resulting in this situation:
Click Here To Show Diagram Code
[go]$$B Captured: :bc:
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . 1 O . . . . . .
$$ | . O . 2 . . . . .
$$ | . O O X . . . . .
$$ | . X X O O . . . .
$$ | . X O X . O . . .
$$ | . . . X . . . . .
$$ | . . . . . . . . .[/go]

The situation is completely different if everything is shifted one line toward the edge --
Here, the 3 :wx: stones have only 1 liberty left, at (z):
Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | z O . . . . . . .
$$ | P X . . . . . . .
$$ | P P X . . . . . .
$$ | X X O O . . . . .
$$ | X O X . O . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .[/go]
This time, :b1: removes the last liberty (z);
Black captures and removes the 3 :wx: stones...
Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | 1 O . . . . . . .
$$ | P X . . . . . . .
$$ | P P X . . . . . .
$$ | X X O O . . . . .
$$ | X O X . O . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .[/go]
...Resulting in this situation:
Click Here To Show Diagram Code
[go]$$B Captured: :wx: :wx: :wx:
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | 1 O . . . . . . .
$$ | . X . . . . . . .
$$ | . . X . . . . . .
$$ | X X O O . . . . .
$$ | X O X . O . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .[/go]

Make sure you clearly see and count every liberty. :)


This post by EdLee was liked by: Nyanjilla
Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #3 Posted: Thu Mar 10, 2016 11:12 pm 
Judan

Posts: 6087
Liked others: 0
Was liked: 786
The edge of the board is part of the grid and so provides liberties.

Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #4 Posted: Fri Mar 11, 2016 2:18 am 
Dies with sente

Posts: 96
Liked others: 0
Was liked: 14
Others have already answered this, but more simply I think as a beginner you forget that the first line of the grid on which you can make legal moves is actually the edge of the grid.

Top
 Profile  
 
Offline
 Post subject:
Post #5 Posted: Fri Mar 11, 2016 4:00 am 
Honinbo
User avatar

Posts: 8859
Location: Santa Barbara, CA
Liked others: 349
Was liked: 2076
GD Posts: 312
Hi longshanks, good guess. :) And possibly have to do with chess.

Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #6 Posted: Fri Mar 11, 2016 6:05 am 
Oza

Posts: 2180
Location: ʍoquıɐɹ ǝɥʇ ɹǝʌo 'ǝɹǝɥʍǝɯos
Liked others: 237
Was liked: 662
Rank: AGA 5d
GD Posts: 4312
Online playing schedule: Every tenth February 29th from 20:00-20:01 (if time permits)
asdf is the name of a troll who frequently is seen on KGS in the ECR. I suspect this is not a genuine question.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #7 Posted: Fri Mar 11, 2016 7:21 am 
Beginner

Posts: 2
Liked others: 0
Was liked: 0
Thanks ed & others. I didn't realise you could play on the edge! It was killing me tryin to watch AlphaGo vs Lee Sedol. Another thing I found interesting was the programming decision to have Alpha go for the higher probability of winning over getting more points, i.e. if a move will give 90% chance of winning by 2 points, it will be preferred over an %80 chance of winning by 12 points. I get they really want to prove themselves by winning, but i think from an evaluation standpoint, it's better to find a more even balance towards obtaining points. You could evaluate much better how good alpha is by having games where he wins by alot, rather than winning by a little everytime.

Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #8 Posted: Fri Mar 11, 2016 8:28 am 
Tengen

Posts: 4380
Location: North Carolina
Liked others: 499
Was liked: 733
Rank: AGA 3k
GD Posts: 65
OGS: Hyperpape 4k
DrStraw wrote:
asdf is the name of a troll who frequently is seen on KGS in the ECR. I suspect this is not a genuine question.
asdf isn't a particularly unique username, unlike DrStraw or hyperpape, where you assume it's the same person across multiple forums. One of my high school friends was "asdfinator" on some service 15 years ago because "asdf" was taken (and neither of them were the KGS troll, as far as I can tell).

In this case, I think it would be better to not accuse someone of being a troll until there's more reason.

_________________
Occupy Babel!


This post by hyperpape was liked by: Uberdude
Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #9 Posted: Fri Mar 11, 2016 8:44 am 
Lives with ko
User avatar

Posts: 145
Liked others: 82
Was liked: 65
Rank: KGS 3k and falling
DrStraw wrote:
asdf is the name of a troll who frequently is seen on KGS in the ECR. I suspect this is not a genuine question.


This person has far better English than the user of that name on KGS. It is a fairly common mash-the-keyboard type of name from a qwerty board.

One thing I find difficult when teaching beginners is looking at a position as a beginner does. To me it seems so obvious that that black move couldn't possibly work, but I've met similar questions before.

Top
 Profile  
 
Offline
 Post subject: Re: Why can't you just do this?
Post #10 Posted: Fri Mar 11, 2016 9:13 am 
Judan

Posts: 6725
Location: Cambridge, UK
Liked others: 436
Was liked: 3719
Rank: UK 4 dan
KGS: Uberdude 4d
OGS: Uberdude 7d
asdf: Also something to think about is if black could have captured those 3 stones like you thought with the edge not being liberties, white could also have captured three black stones further down (same column, row 18 in your picture) for sometime before. Looking at a position from the point of view of both players is important to avoid blind spots.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group