:) Yeah, I was thinking of the bottom left corner. I did not read the whole game. So naturally thinking of it in the bottom left corner.
I had trouble with the same situation as well. And I agree with both of you that it is difficult to get it right without sacrificing speed. On Thu, Jan 13, 2011 at 10:32 AM, <[email protected]> wrote: > I know the source of the confusion now. The first example was "Bottom left > corner of 19x19 board" as Petr wrote it so the corner in the second example > must be the bottom right. If it is located in the lower left corner then all > you wrote made sense, but I am talking about the case where there is a > "1-approach liberty" whcih is only for the case where this pattern is > located in the lower right corner and is much hardwer to solve correctly. > > :) > > Magnus > > > Quoting fastgo <[email protected]>: > > I guess we are not talking about the same case or I may have misread the >> issue or the example. I was commenting on the second example. My take is >> that it is corner as Petr stated "Example is the other bottom corner of >> the >> same game:" >> >> O O . . . . >> O O X X X X >> . X O O X . >> . X O . O X >> . X O O . X >> >> I meant to say that if it is corner as the diagram shown, then the playout >> should almost always get it right. As the middle bottom white group has >> only >> 2 liberties left and the left black group has 3 liberties. Any attempt by >> the white group to take one liberty of the left black group will trigger >> black to immediately check its surroundings and kill the white group. >> >> Even in cases where the liberties of the 5 liberty group are played first >> by >> the white group, and when it goes down to 2 liberties, the black will >> check >> its surroundings and kill the bottom white group first. >> >> >> >> On Thu, Jan 13, 2011 at 9:42 AM, <[email protected]> wrote: >> >> Quoting Go Fast <[email protected]>: >>> >>> I do not see any difficult in handling the second example. >>> >>>> >>>> Whenever the white tries to take out one liberty of the corner X group, >>>> the >>>> 2-lib check should kick in and immediately put the bottom O group into >>>> atarai and it has no escape at all. >>>> >>>> >>> >>> Look. If white takes one liberty away from X that group has 4 liberties. >>> I >>> do not undestand what you mean with a two liberty rule. But I fear you >>> give >>> it magic properties it does not have and it sound you made a tactical >>> oversight from what you wrote. >>> >>> The atari is a self atari (X must connect the two X stones to the 5 Xes) >>> which means the two liberty white group has three liberties effectively. >>> And >>> since X needs to play an approach move and fill in a liberty X has >>> effectively less liberties. This is a lot of computations to do and if >>> you >>> do it everytime any group loses a liberty you have a huge impact on the >>> speed of the playouts. >>> >>> Capturing 2-liberty groups everytime a 5-liberty neighbor loses a liberty >>> is also not a solution to the problem it will just make a lot of >>> unneccessary moves and bias the playout in new weird ways, because most >>> such >>> situation are not a semeai with an eye and approach move. >>> >>> If this was trivial Petr and I would not independently struggle with the >>> same problem. >>> >>> Magnus >>> >>> >>> >>> On Thu, Jan 13, 2011 at 8:46 AM, <[email protected]> wrote: >>>> >>>> Quoting Petr Baudis <[email protected]>: >>>> >>>>> >>>>> >>>>> O O . . . . >>>>> >>>>>> O O X X X X >>>>>> . X O O X . >>>>>> . X O . O X >>>>>> . X O O . X >>>>>> >>>>>> >>>>>> Funny! This is exactly the kind of shape that I had to struggle with >>>>> in >>>>> Valkyria and which I cover in my other reply. >>>>> >>>>> Magnus >>>>> >>>>> >>>> >>> >>> _______________________________________________ >>> Computer-go mailing list >>> [email protected] >>> http://dvandva.org/cgi-bin/mailman/listinfo/computer-go >>> >>> >> > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go >
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