L19 Go Problem Championship: Round 4

[Kirby]

For problem 2, did you consider this move?

$$B
$$ ------------------
$$ . . . X . . . . . |
$$ . . . X O . . 1 2 |
$$ . . . X O X O O . |
$$ . . X . O O X O X |
$$ . . . X X X X X . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B
$$ ------------------
$$ . . . X . . . . . |
$$ . . . X O . . 1 2 |
$$ . . . X O X O O . |
$$ . . X . O O X O X |
$$ . . . X X X X X . |
$$ . . . . . . . . . |[/go]

Not sure, but it transposes, right?

$$B
$$ ------------------
$$ . . . X . . . 5 . |
$$ . . . X O 4 3 1 2 |
$$ . . . X O X O O . |
$$ . . X . O O X O X |
$$ . . . X X X X X . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B
$$ ------------------
$$ . . . X . . . 5 . |
$$ . . . X O 4 3 1 2 |
$$ . . . X O X O O . |
$$ . . X . O O X O X |
$$ . . . X X X X X . |
$$ . . . . . . . . . |[/go]

@hyperpape:

Is white alive or dead?

[Kirby]

Problem 3:

Two moves jump out at me. I thought both failed, but now I'm unsure about the second. I'll have to review my attempt when I have more time.

$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . , O . O X . ,
$$ | . X O . O b . X . .
$$ | . X O . . a . . X .
$$ | . . . . O . . . X .
$$ ---------------------

Click Here To Show Diagram Code

[go]$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . , O . O X . ,
$$ | . X O . O b . X . .
$$ | . X O . . a . . X .
$$ | . . . . O . . . X .
$$ ---------------------[/go]

$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . , O . O X . ,
$$ | . X O . O 4 3 X . .
$$ | . X O . 6 1 2 . X .
$$ | . . . . O . 5 . X .
$$ ---------------------

Click Here To Show Diagram Code

[go]$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . , O . O X . ,
$$ | . X O . O 4 3 X . .
$$ | . X O . 6 1 2 . X .
$$ | . . . . O . 5 . X .
$$ ---------------------[/go]

$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . 0 O . O X . ,
$$ | . X O . O 1 2 X . .
$$ | . X O . 8 3 4 . X .
$$ | . . 9 7 O 6 5 . X .
$$ ---------------------

Click Here To Show Diagram Code

[go]$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . 0 O . O X . ,
$$ | . X O . O 1 2 X . .
$$ | . X O . 8 3 4 . X .
$$ | . . 9 7 O 6 5 . X .
$$ ---------------------[/go]

@hyperpape:

You are pretty close.

Did you consider this?

$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . . O . O X . ,
$$ | . X O . O 1 2 X . .
$$ | . X O . . 3 4 . X .
$$ | . . . 7 O 6 5 8 X .
$$ ---------------------

Click Here To Show Diagram Code

[go]$$B
$$ | . . . . . . . . . .
$$ | . . . . X X X X . .
$$ | . . X X O O O X . .
$$ | . X . . O . O X . ,
$$ | . X O . O 1 2 X . .
$$ | . X O . . 3 4 . X .
$$ | . . . 7 O 6 5 8 X .
$$ ---------------------[/go]

[Kirby]

Solutions and the next round will be postponed until this weekend. I had some personal business today to attend to.

[mongus]

Cool, maybe I can get one in just in time!

I can only find a solution that ends in Ko. Anything else baffles me!

$$B
$$ ------------------
$$ . . . . . X . 5 4 |
$$ . . . O X . X O 3 |
$$ . . O . O X X 1 2 |
$$ . . . O O , O O . |
$$ . . . . . O . . . |
$$ . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B
$$ ------------------
$$ . . . . . X . 5 4 |
$$ . . . O X . X O 3 |
$$ . . O . O X X 1 2 |
$$ . . . O O , O O . |
$$ . . . . . O . . . |
$$ . . . . . . . . . |[/go]

[Kirby]

@mongus:

Looks good!

[Kirby]

Solutions will be posted in around 8~9 hours.

[Kirby]

Solutions and updated leader board are given below.

Problem 1


Problem 2


Problem 3


Leaderboard

1. gamesorry - 72
2. Shaddy - 49
3. EdLee, Schachus - 33
4. Lanrose, dfan - 16
5. jeromie - 13
6. mongus - 7
7. hyperpape - 5

[mongus]

I really need to work on my problem solving ability. I instantly discounted the correct solution to problem 2 when I tried to solve it, thinking that would never work...

[Kirby]

I really need to work on my problem solving ability. I instantly discounted the correct solution to problem 2 when I tried to solve it, thinking that would never work...

Yeah, that can be tricky.

One way you might have gotten to the solution in problem 2 would be to try T18 first. Then you see that it almost works, but doesn't quite work, since white can capture at Q18. So after you try changing the order, maybe try Q18 first so white cannot play there.

It works with some problems, but not others. Just have to keep trying until something works, I guess.

[mongus]

I think a big problem is I focus too much on capturing individual stones rather than on eye space. I thought Q18 was a pointless move because White could just capture those two stones rather than just one.