Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Why dont engines support the egtb format that Chessmaster uses?

Author: Vincent Diepeveen

Date: 09:20:01 04/02/04

Go up one level in this thread


On April 02, 2004 at 11:46:32, Eugene Nalimov wrote:

>Vincent, I did not gave you permission to use *my* code in your convertor, or I
>am missing something?

Are you planning to sue me?

Who says i have a special convertor by the way?

Why wouldn't it be an option in an engine of mine?

Note i always found your claims ridicioulous. Really sick microsoft way of doing
things.

Your first releases of your egtb code there was no copyright claim anywhere of
you. It was released for the public.

Then later "for commercial usage" one needed permission.

By the way my commercial diep version will not have a byte of
your code of course.

It makes my executable 1.5MB bigger to start with which is unacceptable for
possible cdrom release.

>Thanks,
>Eugene
>
>On April 02, 2004 at 11:15:56, Vincent Diepeveen wrote:
>
>>On April 01, 2004 at 22:30:27, Eugene Nalimov wrote:
>>
>>>On April 01, 2004 at 21:38:22, Marc Bourzutschky wrote:
>>>
>>>>On April 01, 2004 at 21:30:23, Eugene Nalimov wrote:
>>>>
>>>>>On April 01, 2004 at 21:15:05, Marc Bourzutschky wrote:
>>>>>
>>>>>>On April 01, 2004 at 20:36:32, Eugene Nalimov wrote:
>>>>>>
>>>>>>>On April 01, 2004 at 20:03:20, Marc Bourzutschky wrote:
>>>>>>>
>>>>>>>>On April 01, 2004 at 17:59:38, Eugene Nalimov wrote:
>>>>>>>>
>>>>>>>>>On April 01, 2004 at 15:16:34, Marc Bourzutschky wrote:
>>>>>>>>>
>>>>>>>>>>The Chessmaster format is indeed better
>>>>>>>>>
>>>>>>>>>What does it mean "better"? :-)
>>>>>>>>>
>>>>>>>>>It stores less information, thus compresses better.
>>>>>>>>>
>>>>>>>>
>>>>>>>>No, it stores the same information, just in two different files.  Those files
>>>>>>>>together are still somewhat smaller than the Kadatch compressed ones...
>>>>>>>
>>>>>>>AFAIK it doesn't stores non-wins for side to move. Is it so? That alone should
>>>>>>>result in the better compression.
>>>>>>>
>>>>>>
>>>>>>It stores complete information, just distributed differently.  For example, the
>>>>>>equivalent of the Nalimov krpkr in FEG is the set of krpkr and krkrp.  Each
>>>>>>stores only wins for the side to move, but between the two you get the exact
>>>>>>same win/loss/draw information.  krpkr and krkrp in FEG format togther occupy a
>>>>>>little under 127Mb, while the krpkr.nb?.emd files take 150Mb.  The complete
>>>>>>5-man set in FEG is about 5.6Gb.
>>>>>
>>>>>Ok, let's assume that position in krpkr is loss for white to move. Where in FEG
>>>>>that information is stored? Not in krpkr, because it is not win for side to
>>>>>move. Not in krkrp because other side is to move.
>>>>>
>>>>>What I don't understand?
>>>>>
>>>>
>>>>Yes, the information is stored in krkrp "flipped" with black to move.  In the
>>>>Nalimov format you don't need krkrp because krpkr stores both wins and losses,
>>>>while the FEG format does not need to store losses because they are in krkrp.
>>>>In fact, I used the 1-1 correspondence between Nalimov and FEG to trace an e.p.
>>>>bug in an earlier version of FEG :-)
>>>
>>>I see. So in FEG your have krpkr wtm, krpkr btm, krkrp wtm, and krkrp btm. Than
>>>yes, you can figure value without the search, at a cost of (probable) extra TB
>>>probe. Extra probe is unavoidable when the score is a draw.
>>>
>>>So your are paying that price, and slower access due to 4x larger block size, to
>>
>>I would agree with the term 'more efficient access'.
>>
>>Just admit that Johan has done a better job there and that i'm doing an even
>>better job there.
>>
>>>achieve ~30% smaller TBs. Reasonable tradeoff, but I would not call it "better"
>>>:-)
>>
>>For a factor 10 slowdown of your indexing code you save in your indexing scheme
>>about 10% positions. The biggest difference i saw so far was
>>
>>16.1G hardcoded entries for a 6 men yours, versus 18.1G entries for DIEP.
>>
>>By the way that 16.1G positions is compressed around 17GB in total (black &
>>white) and in diep format *uncompressed* 7.2 GB.
>>
>>You probably want to know what the sizes are compressed but i'm still busy
>>optimizing that.
>>
>>>BTW you can achieve better compression in .emd files by replacing all "broken"
>>>scores by the most common non-broken score in the TB. I always was curious how
>>>much it will save, but never made the experiment...
>>
>>I will save you from from crying and not show you the size of my EGTBs so far
>>converted. Let's put it this way, Kadatch is doing a brilliant work there.
>>
>>Note it's w/d/l so i should be 'only' factor 5 better anyway according to your
>>theories, isn't it?
>>
>>In general i'm amazed that someone whose job it is to make compilers which
>>produce efficient code, that he's doing such a bad job in coding himself.
>>
>>But well, just like me and Johan you do not get paid to create your egtb's. It's
>>all volunteer work with no one volunteering to generate them, even though
>>certain generators are pretty fast. I just lack the RAM to generate mine.
>>
>>>Thanks,
>>>Eugeen
>>
>>>>>Thanks,
>>>>>Eugene
>>>>>
>>>>>>>And as was pointed by Gian-Carlo Pascutto FEN format does not allow you to
>>>>>>>search in the tree -- i.e. it allows slower decompression. For example, you can
>>>>>>>achieve ~10% better compression with Kadatch algorithm just increasing block
>>>>>>>size from 8k to 16k. For larger block sizes you can achieve even better
>>>>>>>compression using slightly modified algorithm (modifications are useless with
>>>>>>>small block sizes).
>>>>>>>
>>>>>>
>>>>>>Yes, the block sizes may be an important factor.  FEG uses 32k.  How much of the
>>>>>>compression advantage would disappear with smaller block sizes only Johan de
>>>>>>Koning knows...
>>>>>>
>>>>>>-Marc
>>>>>>
>>>>>>>But I believe main reason for better compression is just less information in the
>>>>>>>files.
>>>>>>>
>>>>>>>Thanks,
>>>>>>>Eugene
>>>>>>>
>>>>>>>>-Marc
>>>>>>>>
>>>>>>>>>Thanks,
>>>>>>>>>Eugene
>>>>>>>>>
>>>>>>>>>>but no interface other than through
>>>>>>>>>>Chessmaster is available.  Besides, the Nalimov format has become a quasi
>>>>>>>>>>industry standard.  Since the contents of the two tablebases is the same, the
>>>>>>>>>>main advantage of the Chessmaster is faster generation with less RAM, and
>>>>>>>>>>somewhat smaller compressed file sizes.  If there were a tool to translate
>>>>>>>>>>Chessmaster format to Nalimov format we would already have all the 6-man
>>>>>>>>>>tablebases by now.
>>>>>>>>>>
>>>>>>>>>>On April 01, 2004 at 14:18:16, Jason Kent wrote:
>>>>>>>>>>
>>>>>>>>>>>On April 01, 2004 at 14:07:22, Kurt Utzinger wrote:
>>>>>>>>>>>
>>>>>>>>>>>>On April 01, 2004 at 13:56:25, Jason Kent wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>>I just read this in the FEG.txt that i got off the chessmaster website.
>>>>>>>>>>>>>
>>>>>>>>>>>>>XVI. WHY THE FEG FORMAT? ================================================
>>>>>>>>>>>>>
>>>>>>>>>>>>>Perhaps, after reading all of this, you are wondering why Chessmaster
>>>>>>>>>>>>>9000 does not use either of the more commonly used EGDB formats, namely
>>>>>>>>>>>>>those created by Eugene Nalimov or Ken Thompson (both of which bear the
>>>>>>>>>>>>>names of their creators). There are many reasons for this:
>>>>>>>>>>>>>
>>>>>>>>>>>>>1. FEG data is about 20% smaller. Additionally, half-sets can be used if
>>>>>>>>>>>>>   hard drive space is an issue, making a "full useable" file set that is
>>>>>>>>>>>>>   almost 1/3 the size of the complete Nalimov file set.
>>>>>>>>>>>>>2. FEG generation is much faster and doesn't need a huge amount of free
>>>>>>>>>>>>>   RAM to create a set of files.
>>>>>>>>>>>>>3. FEG can do any 6-man files on a 32-bit platform.
>>>>>>>>>>>>>4. The Thompson format is not a complete set (especially pawns on both
>>>>>>>>>>>>>   sides are lacking).
>>>>>>>>>>>>>5. The Thompson format stores DTC (Distance to Conversion) values,
>>>>>>>>>>>>>   meaning that it stores the number of moves to either mate OR to a
>>>>>>>>>>>>>   capture/promotion, and will play whichever move has the smallest
>>>>>>>>>>>>>   winning value. This can result in silly moves (a capture that leads to
>>>>>>>>>>>>>   a mate in eight moves instead of a non-capture that leads to mate in
>>>>>>>>>>>>>   three moves).
>>>>>>>>>>>>>6. Since Chessmaster 9000 is a mass market product, the majority of its
>>>>>>>>>>>>>   users are not aware of these other formats and how to get them. Also
>>>>>>>>>>>>>   for the ease of development it is easier not to be dependent on
>>>>>>>>>>>>>   technical support for data that was created using tools that were not
>>>>>>>>>>>>>   developed by Ubi Soft.
>>>>>>>>>>>>
>>>>>>>>>>>>     Hi Jason
>>>>>>>>>>>>     Maybe you have asked the wrong question: "Why does Chessmaster 9000
>>>>>>>>>>>>     not support the egtb format that all other engines do?".
>>>>>>>>>>>>     Kurt
>>>>>>>>>>>
>>>>>>>>>>>The reason I ask is because the egtb format sounds like its a little better.  I
>>>>>>>>>>>kinda wish cm9k used nalimov so it would be more compatible.



This page took 0.01 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.