CCRL Discussion Board

Here's where you'll find the FEG-generated 5-1 tablebases archived. I think this is what you mean by "5-1 List"?

ftp address: kd.lab.nig.ac.jp
username: egtb51
password: egtb51

john

The weekend is over now, which means EGTB work must fall into hiatus until next Saturday. Before I duck away, though, let me post the stats files for all 35 5-1 pawnless tablebases. Again, these are tentative results, so please treat them as such. (Not that there is strong reason to believe they are...

Now that's an interesting task of computer archaeology. Quickly scanning his major publication on the subject ... Wirth, C. and Nievergelt, J. (1999). Exhaustive and Heuristic Retrograde Analysis of the KPPKP Endgame. ICCA Journal, Vol. 22, No. 2, pp. 67-80 ... there is no indication of how to get h...

Please bear in mind that it is space after compression, not before, that is to be minimized. The percentage of broken positions is related to this, though loosely. The degree of impact can only truly be measured empirically, and I bet it won't be all that much. There are easier gains to be had (on ...

<SSS> Great going John I am so excitied that you are generating these for the most part useless egtb's as others have said but to me it will allow me to complete my study of egtb's 3 to 6. You know I will be watching patiently for the arrival of others. BTW John how long does it take to complete on...

Some 7 men endgames do exist (http://www.gothicchess.com/javascript_8x8_chess_endings.html) but as far as I know, none including pawns have been generated yet. Codeman A caveat here -- those super-long 7-man checkmates are due to the work of Konoval and Bourzutschky and are with respect to the DTC ...

guyhaw, thank you for your critical comments. But concerning my statement about the improvement of index-scheme, I am still convinced of the potencial. Please bear in mind that it is space after compression, not before, that is to be minimized. The percentage of broken positions is related to this,...

I have done some preliminary tests in EGTB generation, which led me to the following conclusions. Always use a trivial scheme, where the index is simply the 6-bit square numbers concatenated, or at least where it is a linear combination of the square numbers of the pieces (for non-8x8 boards). 2) N...

Probably the gentlemen you have in mind are Yakov Konoval and Marc Bourzutschky. They are - or at least were - leading the chase in the field of 7-man tablebase generation. Though, their game of prey is DTC. In that regard I'm after a different animal. DTM is my interest.

john

Hmm. My session timed-out while composing, and it seems the attachment got lost in the shuffle. Let me post again.

john

Dear Les, Your plea is heard and not forgotten -- and can be answered in the affirmative for both your indirect ("if anyone knows?") and direct forms ("if anyone is?"). In the attached tar file you will find - hot off the grill - tbs files for 15 of the 70 5-1 tablebases. These a...

Hi Norm,

What do we still have as incomplete 42p's?

Glad to see you could put up a server while still pinching pennies - as well as finding the work rewarding.

jk

Hi everyone, What has it been? Nearly two months since last making a squawk on these boards. Oh my. New server, new look! So much has happened since. And where have I been exactly, after making a pledge to be a more active member? Turns out the project I expected to end in June pushed well into July...

In the name of round numbers, I thought I'd bring this thread to the top of the subject stack. According to emule I have now uploaded exactly 2.0 TB of tablebase data. A nice milestone. Besides clocks and kirill, who can beat that? By the way, what has happened to clocks? Before moving to California...

Guy - Yes, I now recall your interest in extrema positions (maxDTMx and zugs) as being best for spot checks. Will co-ordinate with you on that when the time comes. Ernest - Thank you. Some thought needs to go into the problem of distributed EGTB computation since, unlike SETI or protein folding or p...

Hi Ernest, Way back in early January, still feeling the liberation of Christmas holidays, I made headway in the task of extending tbgen for this purpose. In a spate of New Years resolutions of Great Progress This Year I had, well, uh, visages of great progress -- of the generation code churning away...

Hi, It has been a while since poking my head in this forum, and I find myself amused by the off-topic exchange between (eager and frustrated) vb4 and (the tad haughty) guyhaw. Actually, vb4, I'm on sufficiently familiar terms with tbgen to perform the extension. I'm interested in doing this, at some...

Uh oh Norm. Have I filled up all your disk space? I'm looking at kqnbkp for instance (a recent set being worked on) and am seeing that it is all partial files. Maybe I need to hold off for a while to give a chance to sort it all out.

john

Hi,

Well, I think I've got all board combinations with impossible force pruned out, but I wouldn't mind you double-checking. The new results are attached.

The total number of positions has gone down from 190.5 T to 151.5 T: 20.4% less.

john

Lutz -- Yes, I agree you're right! Let me figure out how they got in there and report back with corrected figures. (Already have a good idea of where the mistake lies.) Thanks for drawing my attention to this. It implies a smaller number of positions, for one thing. Which is good news. Will find out...

Hi Lutz, You missed a diagonal symmetry that e.g. Nalimov incorporates in his indexing scheme. When the white king is on the a1-d4 diagonaly, the location is the black king is symmetric about this diagonal (one board position can be transformed into the other without changing the dtm value). In thes...

Hi Lutz, Thanks for you interest. I have revised numbers to present, but first a point of clarification. I'm referring to "index space size" of the entire game, not just one combination. This is different - usually smaller - than the number of physical positions possible on the board. The ...

Ernest -- Not much. Wikipedia and the Chess Variants website have short articles. I plan to look up the Martin Gardner article in which he introduces the game. http://en.wikipedia.org/wiki/Minichess http://www.chessvariants.org/small.dir/hpmini.html In the Wikipedia article I'm intruiged by the popu...

I appreciate the effort it takes to maintain this spreadsheet and be the "minder of chess endgame knowledge." Glad you make it available. May I ask about the sheet "occurances by endgame force"? What database does it distill, and are you multi-counting? That is, is a combination ...

I would be OK to change stats file format, but only if we can re-compute the stats in new format for all files, starting from 3-men. Yes, you're exactly right about that. They should be consistent, i.e. both in format and generated by the same program. It's worth remembering that technically, the e...