Author: Joachim Rang
Date: 06:33:19 08/31/05
Go up one level in this thread
On August 30, 2005 at 19:34:09, Marc Bourzutschky wrote: >On August 30, 2005 at 18:44:05, Dieter Buerssner wrote: > >>On August 29, 2005 at 14:01:31, Vincent Diepeveen wrote: >> >>>On August 29, 2005 at 10:45:38, Duncan Roberts wrote: >>> >>>>On August 29, 2005 at 03:29:12, Marc Bourzutschky wrote: >>>> >>>>>During the past 6 months Yakov Konoval and I have collaborated on efficient >>>>>algorithms to exactly solve 7-man endgames. Yakov has come up with a program >>>>>that contains every trick in the book, and then some. Many of the ideas are >>>>>refinements of those used by Johan de Koning in his path breaking FEG program. >>>>> >>>>>Our hardware is extremely basic, about US $3,000 worth of equipment: a single >>>>>3.6 GHZ PIV, with 4 GB RAM, two 250 GB IDE hard disks, running Windows XP. >>>>> >>>>>To put Yakov's programming skills in perspective, his program solves the >>>>>infamous 6-man krnknn endgame in just over one hour on that hardware. >>>> >>>>Great achievement. well done. >>>> >>>> >>>>how long would a dtm program have taken to solve the 6-man krnknn endgame on >>>>your machine. ? >>> >>>DTM requires much more than just a little bit overhead. >>> >>>Additional i feel there is no need for DTM. >>> >>>From the huge size that Marc shows for their DTZ egtb's, compressed still >>>a formidable 160GB for just a single EGTB, it is obvious IMHO that >>>win/draw/loss is just so so superior. >>> >>>of course in case of marc's egtbs there is only a 'win/no win' distinction >>>possible. They don't have a 'loss' component. >>> >>>That would reduce their EGTBs in win/no win format dramatical further! >>> >>>Yet at generation time, creating WDL is nearly the same effort like DTZ. >>>DTM is really a lot effort more, and if you ask me, just a bit overdone for >>>the big EGTBs. >> >>With a slight variation of the DTZ algorithm, you will be able to construct TBs >>that respect the 50 moves rule. This is obviously not possible, when you only >>use WDL. Marc did not tell details about the algorithm they used, yet. I guess >>RAM requirements at creation time would be the same. But perhaps RAM >>requirements is a non issue with the method used by them. >> >>Regards, >>Dieter > >Yes, 50-move rule is easy with a program that DTZ. However, at the moment I'm >hoping we might break that pesky 243 move krnknn record, so I don't want to >restrict the depth. So far we have come close with 226 moves. At the moment we >are actually limited to 254 moves because we use 1 byte per position, but I'm >sure we'll find a way around that when we need to! > >RAM for a general pawnless 7-man ending is a little under 3 GB. So far we have >only needed 1.5 GB, because we split krbnkrb into even and odd components on the >bishop's color. But it seems that we a special boot option we can use 3 GB even >on a 32 bit operating system, so it should not be a big issue. > >-Marc I don't see why you have to try tricks for a 32 bit OS. There are plenty of working 64 bit OS's so I think you can switch easily if needed. regards Joachim
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