I think AMAF is a feature not a bug. It's only a matter of how judiciously it's applied.
Also, almost any evaluation feature in a game playing program is a bug - meaning it is an imperfect approximation of what you really want. Of course it could turn out that AMAF got them in trouble in this game. The Mogo team will probably analyze the reason for the problem. But as long as they are playing strong professional players they are going to have something to debug and analyze! - Don On Mon, 2008-09-22 at 06:06 -0700, terry mcintyre wrote: > Consider this as tentative, since I heard it about 3rd-hand, but I believe > the number of processors used to have been 3000. > > > Congratulations to the Mogo team; good luck improving your program to deal > with the ladder and life-and-death issues. > > Looking forward to further information! > > I have always wondered if AMAF is a feature or a bug. There are many > situations where the order of moves is crucial; A before B wins, B before A > loses; ladders are a classic example where the ordering of moves is utterly > important. AMAF seems to assume that order doesn't matter. Of course, there > are many other positions where this assumption is true; that is why it > sometimes yields an improvement in processing speed, but it seems risky. > > Ladders are also a classic case where two patterns can look very similar, but > be very different. When you capture a ladder, you are in a very good > position. But if the stones under attack have just one extra liberty, the > position may "look like" a ladder, but your target will escape, and your > stones will be full of cutting points; the proper evaluation for that > position would be much harsher. More generally, whenever I see a Monte Carlo > program lose, it is usually a semeai where being one liberty behind or one > ahead makes all the difference. We call these "capturing races" in English > for a reason; being ahead or behind by one liberty matters a great deal. To > make life interesting, there are "loose ladder" constructs where an extra > liberty does not help the fleeing stones; they still get corraled and > captured. > > These corner cases are tough, but many games hinge on correctly reading out > the exact consequences of life-and-death struggles. > > Terry McIntyre <[EMAIL PROTECTED]> > > > "Go is very hard. The more I learn about it, the less I know." -Jie Li, 9 dan > > > On Mon, 2008-09-22 at 13:59 +0200, Magnus Persson wrote: > > > Quoting Mark Boon : > > > > > > > Playing out that fake ladder in the first game meant an instant loss. > > > > Surprising. And embarassing. Any information on the number of > > > > processors used? > > > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/
signature.asc
Description: This is a digitally signed message part
_______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
