L19 Go Problem Championship: Round 3

Kirby · Post by **Kirby** » Fri Mar 03, 2017 12:04 am

Welcome to Round 3 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]$$Bc $$ ---------------- $$ | . . . . . O . . $$ | X O . . . O . . $$ | . X X X O . O . $$ | . O O O O . . . $$ | . . . . . . . .[/go]

Problem 2 (6 points)

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

Problem 3 (9 points)

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

Have fun!

gamesorry · Post by **gamesorry** » Fri Mar 03, 2017 12:50 am

1. Two eyes

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

2. Clamp

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

Variation: B3 might leave to a little more complicated variations, but still kills

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

Variation: Ko, B fails

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

Variation: B fails

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

3.

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

Variation:

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

Variation: after 3, a and b are miai

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

Variation: B fails - order matters

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

Variation: B fails

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

Variation: B fails

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

Kirby · Post by **Kirby** » Fri Mar 03, 2017 12:52 am

@gamesorry:

gamesorry · Post by **gamesorry** » Fri Mar 03, 2017 1:00 am

@Kirby

Kirby · Post by **Kirby** » Fri Mar 03, 2017 1:04 am

gamesorry wrote:@Kirby
Kirby wrote:@gamesorry:
Perfect. A little easy this week, I guess
Thanks I think problem 3 is easier than before because the best result is not a ko. But still, good problems!

@gamesorry:

EdLee · Post by **EdLee** » Fri Mar 03, 2017 3:42 am

2017 Round 3.1 (007)

Click Here To Show Diagram Code: [go]$$B :b5: tenuki, alive $$------------------ $$ | . 1 2 4 . O . . $$ | X O 3 . . O . . $$ | . X X X O O . . $$ | a O O O O . . . $$ | b . . . . . . . $$ | . . . . . . . .[/go]

Careful: Later, W has sente moves (a), (b).

2017 Round 3.2 (008)

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

Click Here To Show Diagram Code: [go]$$Wm8 (c), (d) miai: W seems dead this var $$ | . . . . . . . . . $$ | . . . X . . . . . $$ | . X X . X X . . . $$ | X X O O O X . . . $$ | O O 1 O . X . X . $$ | X X O O 2 . . . . $$ | . c . d . . . . . $$ ------------------[/go]

2017 Round 3.3 (009)

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

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

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

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

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

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

Kirby · Post by **Kirby** » Fri Mar 03, 2017 8:44 am

@EdLee

mongus · Post by **mongus** » Sat Mar 04, 2017 4:22 am

Problem 1

Problem 2

Shaddy · Post by **Shaddy** » Sat Mar 04, 2017 11:16 pm

Kirby · Post by **Kirby** » Sat Mar 04, 2017 11:21 pm

@mongus:

Kirby · Post by **Kirby** » Sat Mar 04, 2017 11:22 pm

@Shaddy:

mongus · Post by **mongus** » Mon Mar 06, 2017 11:44 am

@Kirby

Kirby · Post by **Kirby** » Tue Mar 07, 2017 3:08 pm

@mongus:

Kirby · Post by **Kirby** » Thu Mar 09, 2017 11:52 pm

Solutions and an updated leaderboard are given below.

Problem 1

Problem 2

Problem 3

Leaderboard

gamesorry - 54
Shaddy - 36
EdLee - 28
Schachus - 23
Lanrose - 16
jeromie - 13
dfan - 12
mongus - 4

Round 4 will be released shortly!

mongus · Post by **mongus** » Fri Mar 10, 2017 2:58 am

Many thanks for doing these. Great explanation of the solutions.

I have a lot of catching up to do!

Life In 19x19

L19 Go Problem Championship: Round 3

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