On Dec 19, 2007 9:40 AM, Heikki Levanto <[EMAIL PROTECTED]> wrote: > On Wed, Dec 19, 2007 at 12:21:18AM -0500, Chris Fant wrote: > > I just witnessed CrazyStone defend a fairly long ladder, resulting in > > a dead 17-stone block. Why not use a ladder reader at the root of the > > UCT tree to prevent provably bad ladder moves from being considered? > > I don't know for sure, but I suspect that even if it means that it would not > play out a bad ladder, the UCT would still see it as a desirable thing, and > direct the game towards one - and then not play it.
Still better than actually playing it out. Another idea I had was to do a tactical analysis of a block whenever the UCT node has been hit X number of times. When the move is provably pointless (e.g. adding to a dead block), prevent that line from continuing to be explored. If X is large enough and the tactical analysis is restricted enough, hopefully it won't significantly affect the overall speed. And it has the nice trait that it can be used not only at the root but at any level in the tree. > Plus, it is not quite trivial to recognize a bad ladder - some times it pays > off to extend a stone that is in atari, and then sacrifice two stones. Some > nakade shapes also require sacrificing more than one stone... But this was the trivial kind and it cost the game. _______________________________________________ computer-go mailing list [email protected] http://www.computer-go.org/mailman/listinfo/computer-go/
