CCRL Discussion Board

When I do DTC50, I actually do not mark positions that take longet than 50 reversible moves to win in this or any later phase as draws, but as won positions with DTC > 50. (So that anyone probing them can see that they are draws, but nevertheless can play them optimally and exploit any fallibility ...

Hi John, I will keep an eye for your posts. This is an eyeball alertness quiz. Attached are two archive files. One with Nalimov-style stats files for the 35 pawnless 5-1 endgames. The second has four pawnfull stats files, for positions of the form kxxxpk, x={b,n,r,q}. All of these files have been c...

guyhaw wrote:I seem not to be able to attach .pdf or .doc files here, so will ponder what to do next.

Zip your document file before uploading. The extensions .zip and .gz make it through.

john

Excellent. Nice to see the update.

BTW, when I said 70 files that was a mistake. There are 65 for 33p.

john

I only have those 37 files. If other files are posted, could you please tell me where? Thanks! The post above in this thread by Jaroslav on Wed Jan 24, 2007 4:00 am has an attachment with all 70 33p tbs files. From the discussion I'm led to believe that they are correct (no 32 bit rollovers, etc.)....

jshriver wrote: What are the different metrics used in egtb's, and second among the known egtb tablebases (nalimov, chessmaster, etc) what do they use as a metric? Metrics that have been used: DTM - distance to mate DTC - distance to conversion DTZ - distance to zeroing move DTZ50 - above, consider...

Hi Kirill, Added to the web-page now, so now we have all 65 33p tbs files online. Thanks Jaroslav, John and Guy! :-) While reading through this old thread I realized something that slipped through. While you did post all of the 33p stats to the EGTB Online page separately, the zipfile all-33p-tbs.zi...

With the author being a Guido Antonelli, we can all strike a guess at one half of the acronym GAFS. I wonder if FS is "final system"? This forum has not seen Guido in half a year. At one time he posted with regularity and in abundant detail.

john

I remember that one. The thread in which a certain guy assured us that yes, "Actually, I am listening ...". As the Chief Gatherer of endgame knowledge it is reassuring that you were on top of this error. Less so that it slipped my attention. Robert Hyatt is no longer distributing the incor...

Try expanding your sense of the term "generic" ... The trick to reconciling pawnless stats is to run through all positions, separating out those with both kings on the same diagonal. Since, unlike Marc B., I have no idea how to read FEG tablebase files, I scan my own. There is no other way...

I'm sad to hear this Kirill. You have been a steady hand on the till. I hope that a smooth handover can be effected and that when personal circumstances allow, you visit us again. With the recent burst in activity involving your test suite, an early departure comes as a surprise. All the same, thank...

Hi All, This is a brief note to announce that I've solved the problem of reconciling DeKoning (FEG) and Nalimov stats files. Rather important, for now we have two independent "signatures" available for each tablebase, which can be validated against each other. Some limitations apply. I'll ...

The metrics DTM, DTC, DTZ50 do not "only summarize the total path length". In fact, only DTM does that. The DTR metric is a 'summary statistic' about the whole optimal path but does not specify the total path length. The DTC, DTZ50 and DTZR metrics are about 'the current phase to next rel...

Thanks for the quick response Kirill. In response I've updated the subject line accordingly.

john

This is mostly directed at Kirill, but other people will likely want to be aware of this as well. The stats file kbpkn.tbs that is distributed on Kirll's EGTB Online web page is incorrect. It's packaged in the file all-5-men-32p-tbs.zip. I discovered this in the process of working on my revamped ver...

Guy's reply recalls the old joke about the baloonist and the mathematician. (*) Okay, that's a bit unfair because he reminds us that a) there is more than one sense of "shortest" path b) every shortest path assumes a pair of minimaxing competitors (helpmate puzzles excepted) c) shortness a...

I would. Thanks! :) Though while you are at it you might think about doing a DTC or DTZ tablebases. Guy Haw. has made a similar suggestion. I'm particularly intrigued by the prospect of DTZ50 data, so that "this is the truth" may be accompanied by "this is what's legal". Yakov K...

Yes, the matter of simple hosting is more important to us. But it is not necessarily more important to them.

john

An attractive idea indeed! As it is, I have a contact within google that already was making plans to have the full complement of tablebases hosted by Google. He has most of everything already, and I've offered to fill out the few he misses, plus the forthcoming 5-1 set. This is nothing official by a...

Hi Dann, Thanks for pointing out QuickLZ (a library I hadn't heard of before) and running some tests. My standard disclaimer applies: unless it is block-indexable, the compression library is not suitable for the large DTM and DTC tablebases. It may be suitable for bitbases and the smaller tables tha...

That's a nice offer Josh. I have 70 GB of free space. With some shuffling I should be able to manage. Though, I like the idea of adopting you as a beta tester if you are up for that -- once the potholes in the code have been filled, that is. Progress has slowed in January as I've needed to attend to...

Good point. Those were generated by a program called FEG - "Final Endgame Generator" - a tool from the old ChessMaster suite. (ChessMaster was commercial but the FEG tool was free, though closed source.) Much of the discussion in these boards revolved around converting the statistics files...

Hi, thanks for your interest. Efforts have been diverted recently, as anticipated. As of my last checkpoint I can report progress on pawnfull 51p, though it is not finished work. The sets kqqqpk, krrrpk, kbbbpk, and knnnpk have been generated, but not verified, so I'm going to sit on the tbs files u...

Denis - While aware of the program Chesterfield, I can only guess at decoding "CL" and fess ignorance to ask: what is the ChesterfieldCL project?

From your perspective, are there any shortcomings to converting the Nalimov tables to bitbases?

john

If it could be tracked down that would be great, but I have my doubts about an institution holding on to such a thing, or if they have, knowing where it is. A Masters thesis yes, but a piece of software no. ... In a similar quest, it would be great to unearth R. Gasser's RETROENGINE which served as ...