Author: Antonio Dieguez
Date: 14:43:41 01/21/02
Go up one level in this thread
On January 21, 2002 at 17:28:11, Antonio Dieguez wrote: >On January 21, 2002 at 17:18:03, Bas Hamstra wrote: > >>On January 21, 2002 at 16:47:09, Antonio Dieguez wrote: >> >>>On January 21, 2002 at 16:30:22, Bas Hamstra wrote: >>> >>>>On January 21, 2002 at 15:56:59, Antonio Dieguez wrote: >>>> >>>>>>It should matter in quiet positions, right? >>>>> >>>>>Well, It should matter depending on how often the pv changes, so may be more in >>>>>unquiet positions. >>>>> >>>>>>Well, here is data, opening >>>>>>position: >>>>>> >>>>>>Rootwindow <-inf, inf> takes 2404K nodes >>>>>>Rootwindow <-50, 50> takes 2420K nodes >>>>>> >>>>>>...to complete 10 ply. >>>>> >>>>>strange, I don't know the logic there, i would have guessed a bigger >>>>>difference. please don't be angry but if that is what I would get in amyan >>>>>regularly I would be sure it has a bug or I made a mistake in the experiment. >>>> >>>>It is possible of course, but I don't think so. It just don't seem to buy me a >>>>lot. As far as I know it has never been proven anyway. Plus (based on only a >>>>couple of tests) I simply don't see it here. >>> >>>but search with alpha+1,beta is better if beta is not infinite. I don't think >>>that using pvs changes that much, the results of your tests, if have done well, >>>are counterintuitive. >> >>Yes. I am not claiming it is better of course. It just happened in this >>position. But it is interesting to figure out how this can happen in *any* >>position. One thing I can think of is that you lose bound info. > >ok but it shouldn't matter much when using a conservative window, except in big >fail low or fail high. > >>>>>>Convince me with data :-) Should be no big deal to do this little test for >>>>>your engine? Difference? Other position is also fine. >>>>> >>>>>I'm not using much pvs inside the three as it does not help me, may be other >>>>>person may do that quicker. >>>>>Be well... >>>> >>>>Do you use straight alphabeta? PVS might be a tiny bit more efficient. At least >>>>that is what everybody says. But the difference is small IMO. >>>hyatt says that for him, the difference between alphabeta with aspiration and >>>pvs is only 10%, for me is near zero. >> >>Well that is a number that does not seem unrealistic to me. Only slightly >>better. On the other hand not having a rootwindow spairs you the trouble of >>having fail-low's. After which you have no hashmove, *bang*. What's better >>overall remains a question for me. > >"After wich you have no hashmove" >you mean the hash moves of positions inside that tree? they don't have to be >deleted by the fail low... altough yes possibly if the thing is failing low may >be some of them were not so good but they are there. ok ok the tree can be much different, so many positions with still big depth may not have hash moves, right. best wishes again... me.
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