Author: Marc Bourzutschky
Date: 16:34:09 08/30/05
Go up one level in this thread
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
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.