We can use math to shed some light on the topic: * Assume that doubling the speed of a machine increases the rank of a program by 100 ELO, as Don has previously concluded.
* Then we have the following table of approximate costs, which comes from the equation y = 100 * 2^x cost -> lost ELO ---------------- 1% -> 1.5 ELO 2% -> 3.0 ELO 3% -> 4.5 ELO 4% -> 6.0 ELO 5% -> 7.5 ELO 6% -> 9.0 ELO 10% -> 15.0 ELO * In my program (which implements undo), the cost of for suicide detection is around 1%, which means it would lose 1.5 ELO points. * If I wanted to know whether it was worth it, I would want to measure the ELO benefit by making better decisions concerning suicide. It is a small but real amount, probably at least 1 ELO (using my finger in the breeze). * Thus the issue of whether you detect suicide may be a complete wash. * On the other hand detecting superko costs more like 6% or so, which costs 9 or more ELO. So a benefit of 1 ELO for doing superko right may not be worth the cost. Conclusions * The effect of suicide detection is *very* small in the scheme of things, and is probably not worth arguing over. Superko is also small, but might be worth a tiny amount of effort. * Some kind of study to measuring the ELO cost of bad suicide and ko decisions would be useful. * I plan to detect both suicide and superko on principle, confident that it doesn't make much difference. Michael Wing Don Dailey <[EMAIL PROTECTED]> said: > > There are two reasons to consider suicide and its detection.. > > > > 1) Some rule sets allow suicide. In such a rule set a suicide can > > be the best move because it can be a huge ko threat. > > > > 2) As David Fotland has pointed out many times, when competing > > under rules that allow suicide, some programs will do one just to > > see if your program refuses to play when you detect its suicide. > But there are very few arguments for putting suicide in the play-outs. > You can still design your program to accept and even play suicide > without putting these moves in the play-outs. > > The play-outs are imperfect by nature - they try to take a statistical > sample of many possible ways the game might proceed. The path to > improve the quality of this statistical sample is to not play moves that > represent very UNLIKELY continuations. Adding these moves randomly to > the play-outs doesn't improve it's ability to statically measure the > likely outcome. > > For instance since is "legal" to resign, we could randomly include this > possibility in the play-outs, but it would not increase the resolving > power of the play-outs. > > Moving into 1 point eyes is also legal, but virtually all Monte Carlo > programs forbid this as it's well known to be incredibly stupid in the > vast majority of cases. But in some rare cases it is actually good - > but we still would not want to add it to our play-outs. > > Because of the 1 point eye rule, suicide in the play-outs probably isn't > THAT bad. You are probably only suiciding a group that is already > dead - but you are weakening the play-outs. It may be worth it if you > get enough speed in return. > > In my program I am always looking for an excuse to veto moves that are > obviously bad. If I had such an obvious class of position like > suicide, I would jump on the opportunity to remove them from the play-outs! > > - Don > > > > > > > > Cheers, > > David > > > > > > > > On 16, Jan 2008, at 5:52 AM, Don Dailey wrote: > > > >> I think suicide is insane myself. But I think the reason programs > >> might use it is only for a speedup - it's faster with some > >> implementations to allow suicide even though it makes the games longer. > >> > >> Of course you are right about point B. If suicide is illegal in the > >> actual game, there can be no point in allowing it in the play-outs. > >> It's almost certainly wrong to allow it in the play-outs even if you are > >> playing by suicide rules - a lot of work has gone into finding good > >> moves in the play-outs and this would be one of the prime candidates for > >> removal! > >> > >> - Don > >> > >> > >> Jacques Basaldúa wrote: > >>> Gian-Carlo Pascutto wrote: > >>> > >>>> Multi-stone suicide is allowed, single stone not. > >>> > >>> I hadn't even considered suicide.(It would be a major change for me, > >>> as neither my Gui nor my board system allow such moves.) > >>> > >>> The question is Why do you do it? > >>> > >>> a. Just in case you wanted the entire program to support suicide go > >>> > >>> or > >>> > >>> b. Because that has some advantage as a random playout. > >>> > >>> If it was b, can anyone explain why suicide is a better evaluation for > >>> a normal (non suicide) game. > >>> > >>> Jacques. > >>> > >>> > >>> _______________________________________________ > >>> computer-go mailing list > >>> computer-go@computer-go.org > >>> http://www.computer-go.org/mailman/listinfo/computer-go/ > >>> > >> _______________________________________________ > >> computer-go mailing list > >> computer-go@computer-go.org > >> http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > _______________________________________________ > > computer-go mailing list > > computer-go@computer-go.org > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > -- _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
