Life In 19x19

Posted: **Thu Mar 23, 2017 8:02 pm**

Since we started a bit late this week, I'll wait until about 24 hours from now to post solutions.

Posted: **Fri Mar 24, 2017 6:33 am**

Problem 3

Hard to even know where to start here. Maybe with the right incursions, we can limit White to a dead eye-space near the marked points?

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

The a and b points are jumping out at me.

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

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

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

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

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

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

Posted: **Fri Mar 24, 2017 6:44 pm**

Kirby wrote:@gamesorry:
For Problem 3, did you consider this?

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

Oops, I overlooked that.

So after 2 B has to play 3, but after W4B5, W has 6 and 8

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

Therefore, to prevent 6 and 8, B need to consider something like:

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

B still needs to be careful: B3 fails

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

Therefore, B3 should:

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

(Please deduct at least half of the points even if this is correct.)

Posted: **Fri Mar 24, 2017 11:13 pm**

Solutions and updated leader board are given below.

Problem 1

Problem 2

Problem 3

Leaderboard

gamesorry - 82
Shaddy - 49
Schachus - 43
EdLee - 38
dfan - 25
Lanrose - 16
hyperpape - 15
jeromie - 13
mongus - 10

Posted: **Fri Mar 24, 2017 11:51 pm**

Ah, I excluded the correct answer in the beginning due to the following W2:

Click Here To Show Diagram Code: [go]$$Bc $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . X X X X . . . $$ | . . . . X O O O O X X . $$ | . . . X . 1 . . . O X . $$ | . X . X O . O 2 . O X . $$ | . X . . X a b . O . X . $$ | . . X . . . c . O O X . $$ ------------------------[/go]

a and b obviously do not work, but actually c works. However, playing c first doesn't work. Nice problem!

Posted: **Sat Mar 25, 2017 8:42 am**

That C1 stone is nice

But yeah, I think the 3rd problem here was pretty tricky. The next couple of rounds should be a bit easier.

It's hard to find the ideal difficulty for each problem, so I usually try to mix it up (sometimes easier, sometimes harder).

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