[computer-go] Monte Carlo challenge: ladders

[Christoph Birk]

On Thu, 2 Nov 2006, Peter Drake wrote:
> To those of you with Monte Carlo programs:
>
> .........
> ..ww.....
> .wBBw....
> ..wBBw...
> ...w.....
> .........
> ......B..
> .........
> .........
>
> I believe black's best move is to play in the center and escape via the 
> broken ladder.
>
> 1) Is this true? (This is a Go-playing question.)

yes.

> 2) Can your program find this move (and decide that it's not a good move if 
> the ladder-breaker is missing)?

yes.

> 3) If so, how many runs does it take?

about 10000 (ie. 1 second) using simple "guided" MC, ie. the winning move 
is more likely to be tried again (no UCT).
The program NO Go knowledge otherwise.

> 4) With fewer runs, what does the program do? If there is no ladder breaker, 
> does the program think the ladder works until it has read it to the end?

Plays 'random' bad move.
My program does not read (ladder or otherwise). It just finds 'E5'
easily because any other move ends in a sure loss.

Christoph