Author: Ed Schröder
Date: 14:40:31 07/22/00
Go up one level in this thread
On July 22, 2000 at 15:42:30, blass uri wrote: >On July 22, 2000 at 15:32:26, Ed Schröder wrote: > >>On July 22, 2000 at 14:16:51, Andrew Dados wrote: >> >>>On July 22, 2000 at 14:11:20, Ed Schröder wrote: >>> >>>>On July 22, 2000 at 13:28:28, blass uri wrote: >>>> >>>>>Deeper blue had a positive evaluation before trading queens. >>>>> >>>>>The evaluation of Deeper blue was based on Deeper blue's logfile >>>>> >>>>>9(6) 3 T=46 34...Qxf1 >>>>>10(6) 2 T=130 34...Qxf1 >>>>>11(6) 2 T=168 34...Qxf1 >>>>> >>>>>The evaluation when deeper blue started to ponder (hash guess Rxf1) was >>>>> >>>>>7 (4) -30 >>>>>7 (6) -66 >>>>>8 (6) -50 >>>>>9 (6) -50 >>>>>10 (6) -50 >>>>>11 (6) -48 >>>>> >>>>>Deeper blue lost 0.5 pawn in the evaluation and the only reason that I can >>>>>explain it is that it is a root processor. >>>>> >>>>>I guess that something like this cannot happen to Deep Junior because it is >>>>>probably more knowledge based program. >>>>> >>>>>Uri >>>> >>>>The behavior you describe is quite normal. After a queen exchange in the >>>>next move often other more accurate tables are used which may cause such >>>>score differences. I do the same in Rebel. That doesn't make the program >>>>a root processor. A root processor is a program that totally (or to a >>>>great extend) relies on the evaluation on the root. If you read the IBM >>>>pages it is said DB has something similar (a short investigation at the >>>>root). That makes DB no root processor. >>>> >>>>Ed >>> >>>What you just said is pretty much confirmation of preprocessing to me: >>>'After a queen exchange in the next move often other more accurate tables are >>>used []'... >>>If it is done in the search - then no score differences should be seen; if it is >>>done at root then it is clear preprocessing... >>> >>>-Andrew- >> >>Yes such ticks are preprocessing. And it helps. But note that in Rebel >>only a few things are done this way not more than being < 0.5% of the >>total knowledge. That makes Rebel not a root processor and DB neither >>which was my reply to header of the subject. >> >>Ed > >I guess that I should use the words:Deep blue does some preprocessing Yes. And this is exactly what I understood from the IBM pages. If memory serves me well it is somewhere in the FAQ. >These are important news because the claim was that Deeper blue has more >knowledge than other programs and if Deeper blue does not know some things that >part of the other programs know(for example not to do preprocessing) then >it proves that Deeper blue's evaluation was not so good like Hyatt believed. > >They could do everything they wanted in hardware about the evaluation is wrong >because they could not avoid some preprocessing. Some pre-processing issues aren't necessarily bad. Sometimes you can fix some minor shortcomings of your eval in a very easy way without the need to rewrite your whole eval or to slow down your eval considerable. But all of this must be taken very carefully into account as I am not favor of pre-processing at all. Ed >Uri > >Uri
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.