Life In 19x19

Posted: **Sun May 14, 2017 10:55 pm**

Welcome to Round 13 of the L19 Go Problem Championship.

All problems are black to play. As usual, provide your solutions either via hide tags, or direct private message to me.

Problem 1 (3 points)

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

Problem 2 (6 points)

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

Problem 3 (9 points)

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

Have fun!

Posted: **Mon May 15, 2017 2:24 am**

Click Here To Show Diagram Code: [go]$$B (a), (b) miai kill $$ ------------- $$ | . a 1 b X . $$ | O O X O X . $$ | . O O O X . $$ | . X . X X . $$ | . X . . . . $$ | . . . X . . $$ | . . . . . .[/go]

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

Click Here To Show Diagram Code: [go]$$Bm11 $$ ----------------------- $$ . 7 6 9 . . . . . . . | $$ . 5 4 1 . . . . . . . | $$ . 3 2 O X X O . X O . | $$ . , X O O O X 8 X O . | $$ . . . X X O O X X O . | $$ . . . . . X O X O . . | $$ . . . . . . X O O . . | $$ . . . . . . X . . . . | $$ . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$Wm20 $$ ----------------------- $$ . X O X . . . . . . . | $$ . X O X . . 2 . . . . | $$ . X O O X X O . X O . | $$ . , X O O O 1 O X O . | $$ . . . X X O O X X O . | $$ . . . . . X O X O . . | $$ . . . . . . X O O . . | $$ . . . . . . X . . . . | $$ . . . . . . . . . . . |[/go]

If W captures

any time instead of {

..

},
then B simply squeezes.

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

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

Posted: **Mon May 15, 2017 9:29 am**

@EdLee:

Posted: **Mon May 15, 2017 10:10 am**

Problem 1

Problem 2

Posted: **Mon May 15, 2017 10:16 am**

Problem 1 (3 points)

Problem 2 (6 points)

As usual, problem 3 requires more thinking time.

Posted: **Mon May 15, 2017 10:29 am**

@hyperpape:

Posted: **Mon May 15, 2017 10:29 am**

@jeromie:

Posted: **Tue May 16, 2017 1:16 pm**

Posted: **Tue May 16, 2017 1:51 pm**

@Shaddy

Posted: **Tue May 16, 2017 5:55 pm**

Posted: **Tue May 16, 2017 9:07 pm**

@Shaddy:

Posted: **Tue May 16, 2017 9:25 pm**

Kirby wrote:@Shaddy:
Is necessary?

Posted: **Tue May 16, 2017 9:47 pm**

I should clarify for Problem 3: You don't need to save all the stones, necessarily. You just need to live.

Posted: **Tue May 16, 2017 11:40 pm**

1. After

, a and b miai

Click Here To Show Diagram Code: [go]$$Bc $$ ------------ $$ | . b 1 a X . $$ | O O X O X . $$ | . O O O X . $$ | . X . X X . $$ | . X . . . . $$ | . . . . . .[/go]

2. Ladder

Click Here To Show Diagram Code: [go]$$Bc, j = 1 $$ ---------------------- $$ g f i . . . . . . . . | $$ e d a . . k . . . . . | $$ c b 0 7 5 O . X O . . | $$ . X 8 6 4 1 h X O . . | $$ . . 9 3 2 O X X O . . | $$ . . . . X O X O . . . | $$ . . . . . X O O . . . | $$ . . . . . X . . . . . | $$ . . . . . . . . . . . |[/go]

3. Intuitions:

Click Here To Show Diagram Code: [go]$$Bc $$ | . . . . . . . . $$ | . O . O . . . . $$ | . . O X O . . . $$ | O O X . . O . . $$ | X X e , X O . . $$ | . a O f . O . . $$ | X c d X . . O . $$ | . b . . . O . . $$ -----------------[/go]

a: B fails

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

b: B fails

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

c: B fails

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

d: B fails

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

e:

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

Variation:

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

f: B fails

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

Looks like e is the solution

Posted: **Wed May 17, 2017 2:12 am**

Hi Kirby,

Nice of you to clarify.
( Though it seems to be a standard, implied condition in all Go problems I've seen.
E.g. Round 12, problem 2: B needs not save

. )

Life In 19x19

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