Problem 30 in "Life and Death: Intermediate Level Problems"

EricBackus · Post by **EricBackus** » Sat Aug 20, 2011 10:23 pm

Here is the problem:

Click Here To Show Diagram Code: [go]$$c Problem 30: Is White dead or alive? $$ ------------------- $$ . . . . O . . . . | $$ . . . X X O O 1 . | $$ . . . . . X O . . | $$ . . . . X . O O . | $$ . . . . . X O X . | $$ . . . . . X X X . | $$ . . . . . . . . . | $$ . . . . . . . . . |[/go]

The book says:

However, can't black do this?

What am I missing?

Redundant · Post by **Redundant** » Sat Aug 20, 2011 10:33 pm

Mef · Post by **Mef** » Sun Aug 21, 2011 4:11 am

Just for further study -- A related position

EricBackus · Post by **EricBackus** » Sun Aug 21, 2011 10:09 am

Redundant wrote:
$$c Problem 30: Ko?
$$ -------------------
$$ . . . . O . . 4 . |
$$ . . . X X O O X 2 |
$$ . . . . . X O . 3 |
$$ . . . . X . O O . |
$$ . . . . . X O X . |
$$ . . . . . X X X . |
$$ . . . . . . . . . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code
[go]$$c Problem 30: Ko? $$ ------------------- $$ . . . . O . . 4 . | $$ . . . X X O O X 2 | $$ . . . . . X O . 3 | $$ . . . . X . O O . | $$ . . . . . X O X . | $$ . . . . . X X X . | $$ . . . . . . . . . | $$ . . . . . . . . . |[/go]

$$c Problem 30: Ko?
$$ -------------------
$$ . . . . O . 7 4 5 |
$$ . . . X X O O X . |
$$ . . . . . X O 6 3 |
$$ . . . . X . O O . |
$$ . . . . . X O X . |
$$ . . . . . X X X . |
$$ . . . . . . . . . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code
[go]$$c Problem 30: Ko? $$ ------------------- $$ . . . . O . 7 4 5 | $$ . . . X X O O X . | $$ . . . . . X O 6 3 | $$ . . . . X . O O . | $$ . . . . . X O X . | $$ . . . . . X X X . | $$ . . . . . . . . . | $$ . . . . . . . . . |[/go]

$$c Problem 30: Ko?
$$ -------------------
$$ . . . . O . 7 . 5 |
$$ . . . X X O O X . |
$$ . . . . . X O 6 3 |
$$ . . . . X . O O 8 |
$$ . . . . . X O X . |
$$ . . . . . X X X . |
$$ . . . . . . . . . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code
[go]$$c Problem 30: Ko? $$ ------------------- $$ . . . . O . 7 . 5 | $$ . . . X X O O X . | $$ . . . . . X O 6 3 | $$ . . . . X . O O 8 | $$ . . . . . X O X . | $$ . . . . . X X X . | $$ . . . . . . . . . | $$ . . . . . . . . . |[/go]

White lives in double ko.

This all stems from my deciding that I want to understand the L+1 and L+2 groups better. As always seems to be the case in go, there is an awful lot going on if you look at it thoroughly. I keep thinking I should be able to get to where these shapes are like bulky five, where I just "know" the right answer and don't need to read. But I've got a long way to go.

Mef · Post by **Mef** » Sun Aug 21, 2011 11:36 am

EricBackus wrote:This all stems from my deciding that I want to understand the L+1 and L+2 groups better. As always seems to be the case in go, there is an awful lot going on if you look at it thoroughly. I keep thinking I should be able to get to where these shapes are like bulky five, where I just "know" the right answer and don't need to read. But I've got a long way to go.

Not to promote shortcuts, or using memorized answers to avoid actually reading out positions but you can kinda think of it this way --

Remember the L group is dead (regardless of sente)...then thinking about what that implies...

Presumably, if you add 1 stone to it (L+1, or J group), now it lives or dies by sente....

Which means presumably, if you added 2 stones to it (L+2, or J+1) it should live even if your opponent has sente....

Of course hanes for black or descents for white can make it all the more tricky...

Life In 19x19

Problem 30 in "Life and Death: Intermediate Level Problems"

Problem 30 in "Life and Death: Intermediate Level Problems"

Re: Problem 30 in "Life and Death: Intermediate Level Proble

Re: Problem 30 in "Life and Death: Intermediate Level Proble

Re: Problem 30 in "Life and Death: Intermediate Level Proble

Re: Problem 30 in "Life and Death: Intermediate Level Proble