Re: [gnugo-devel] Extremely bad mistake

[SP LEE]

> 
> A part of the solution is probably to make break_chain3_moves() more
> ambitious. I know Paul has started on this. Do you have any results to
> report?
> 
> /Gunnar
> 

I found the root of the problem. However, I can't provide a patch because I'm 
not familiar with the program structures yet.

In the reading process, attack and defend is carried out virtually and it seems 
the actual board position is unchanged. However when gnugo checks if A16 is a 
suicide move, it doesn't know there is already a stone at A18 and gets the 
conclusion A16 is a suicide move. This in turn makes the defence of C19 failed 
on the attack of A18. 

I think when checking suicide moves, gnugo must take into account of any 
virtual moves already played.

SP Lee