[computer-go] Congratulations to GNU and to MoGoBot19!

[Rémi Coulom]

Nick Wedd wrote:
>  - the winners of last Sundays tournament on KGS.  My report is at
> http://www.weddslist.com/kgs/past/27/index.html.  I expect people will 
> soon report the many misprints in it, as usual  :)
> 
> Nick

Hi,

Thanks Nick for your report.

Here is what I found after analyzing the blunder of Crazy Stone against 
MogoBot19. In fact, the capture at F18 was not pruned. But White 
extension at F18 after Black L10 was. The reason is that F18 is a Ko shape.

The urgency of shapes was learnt from game records that contain many Ko 
fights. The consequence is that capturing in a Ko shape had a very high 
urgency, whereas extending in a Ko shape had a very low urgency. So 
black thought white would never extend to F18 before being captured.

I now have added Ko-related features to Crazy Stone pattern-learning 
algorithm. Crazy Stone now makes the difference between a Ko extension 
and a non-Ko extension in the shape at F18, and plays much better thanks 
to this additional knowledge.

Rémi