Search found 691 matches
- Mon May 30, 2011 11:34 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Zugzwang marking should be fixed now. So now there are no zugzwangs in the 5-man MaxDTM line, but there is one in the 6-man maxDTM line, on move 25.
- Mon May 30, 2011 7:36 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
"☉" - Move leads to a mutual zugzwang. Then there is a serious bug... Look at the 5 pieces maxDTM. 1.Rb3 doesn't lead to mutual zugzwang, black just captures the rook. Probably you have marked with circles the positions with different outcome if WTM and BTM. Only a small percentage of the...
- Mon May 30, 2011 5:33 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Forbidden You don't have permission to access /chess/4x4-chess/ on this server. Thanks for testing!! OK, this one is fine for now, as the "home" page does not exist yet. 2rp/k1N1/2R1/K3 w - - 0 1 1.Na4?? Rxc2☉!! 2.Nc3 Rc1+ 3.Nb1+□ 3.Nb1+□ ?? Looks OK to me? "□" means the only po...
- Mon May 30, 2011 5:26 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Sorry, I know it's confusing, I should add the notation legend soon. In the meantime:Arpad Rusz wrote:Nice! What are those circles and squares?
"□" - The only possible move
"♢" - Winning move, which has equally good alternatives.
"☉" - Move leads to a mutual zugzwang.
- Sun May 29, 2011 3:28 pm
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
I'm testing the 4x4 chess database interface, any help with testing will be appreciated. It's still buggy and lacks features. Some maxDTM positions as examples: 5 pieces, mate in 33 6 pieces, mate in 52 (although any position can be queried by putting a proper FEN into the address line). Notation ex...
- Tue May 17, 2011 4:03 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Compactness of different metrics: http://kirill-kryukov.com/chess/various/4x4-ULP-per-Byte-7-pieces.png All compressed. 2 metrics in 3x4 (3 to 12 pieces), 4 metrics in 4x4 (3 to 7 pieces). Some observations: - DTM is around 3 pos/byte in both 3x4 and 4x4, slightly more compact in 4x4. - The gap betw...
- Tue May 17, 2011 3:39 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Database sizes for 3x4 and 4x4 chess. http://kirill-kryukov.com/chess/various/4x4-DB-Size-7-pieces.png "raw" means uncompressed, the rest are all compressed (2 metrics on 3x4 and 4 metrics on 4x4 board). Board occupancy means how large area of the board is occupied. e.g., 3 pieces on 4x4 b...
- Tue May 10, 2011 11:30 am
- Forum: Endgame Tablebases
- Topic: Polgar Superstar Chess (Starchess)
- Replies: 14
- Views: 15665
Re: Polgar Superstar Chess (Starchess)
By the way, do you know how many unique legal positions are possible with 5 pieces in this variant? (Also with 2, 3, 4 pieces).
- Tue May 10, 2011 2:49 am
- Forum: Endgame Tablebases
- Topic: Polgar Superstar Chess (Starchess)
- Replies: 14
- Views: 15665
Re: Polgar Superstar Chess (Starchess)
Interesting comparison, thanks for posting! How do you compute the AverageDTM? Is it for all positions, where draw counts as 0, or only for won/lost positions? I'm curious to compute the AvgDepth in my variants. MaxDepth tables look beautiful, I wonder how to do the same with 6 pieces, 7, 8... Or in...
- Mon May 09, 2011 3:03 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Since there are no more guesses, here is the summary of currently known 4x4 chess MaxDepth values, compared with all known values from 3x4 and 3x3 chess: http://kirill-kryukov.com/chess/various/4x4-MaxDepth-up-to-7-pieces-1.png Yes, 52 moves DTM with 6 pieces, 54 with 7 pieces. (I still did not walk...
- Mon May 09, 2011 2:30 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Yes, the wK can be shifted to c1,d2, or d3 and after 1.Kc2 the result is the same as in (Kd1,Pb1/Kb4). So probably these are the other 3 maximum length positions: (Kc1, Pb1/Kb4), (Kd2, Pb1/Kb4) and (Kd3, Pb1/Kb4). (Kc1, Pb1/Kb4) is only mate in 9, throuhg 1.Kb2. The other two are wins in 12. So one...
- Sun May 08, 2011 1:10 am
- Forum: Endgame Tablebases
- Topic: I am John Daniel Bryant FIDE 2367
- Replies: 7
- Views: 10507
Re: I am John Daniel Bryant FIDE 2367
Does anyone know how I could obtain a program that can calculate tablebases where other pieces are treated as kings, like a 2-man tablebase where the goal is simply to stalemate/checkmate the other piece. Solving variants with fairy piece and exotic rules is exciting topic. Currently my resources a...
- Fri May 06, 2011 3:08 pm
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Great, yes, this is 12#! According to the database, there are 3 more wins in 12 in kpk. (Unique positions, not just reflections).Arpad Rusz wrote:This was my position: (Kd1,Pb1/Kb4 12#). Sorry for the wrong coordinates.
- Fri May 06, 2011 12:39 pm
- Forum: CCRL Public
- Topic: Famous chess books - free download!
- Replies: 2
- Views: 1835
Re: Famous chess books - free download!
Do you have the rights to distribute those books? It's not clear so I'm removing the link for now. Welcome to the forum!
- Fri May 06, 2011 12:35 pm
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Status update. 7-piece DTM verified OK, 8-piece DTM computation is underway. 3-to-5-piece DTC and DTZ tables are built and verified with no errors.
- Fri May 06, 2011 12:31 pm
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Hi Arpad! 3 men pawnless tablebases: the KR/K endgame has the longest line. Maximum DTM probably 8. (Ka1,Rd4/Kc3) Yeah, of course KRK for pawnless, however maxDTM is only 7 moves. "Ka1,Rd4/Kc3" is one of those mates in 7: "3R/2k1/4/K3 w - - 0 1" 1.Ra4 Kb3 2.Ra2 Kc3 3.Ra3+ Kc2 4.K...
- Thu May 05, 2011 5:25 am
- Forum: Endgame Tablebases
- Topic: 4x4 chess
- Replies: 60
- Views: 77771
Re: 4x4 chess
Finally I have a seemingly functional 4x4 chess solver - that is, it can build DTM tables which pass verification. It's very rough bare solver, no compression, no other metrics, no mining, no stats, no web-interface, etc.. It's full of debugging code, and I did not even begin optimizing for speed. S...
- Wed Apr 27, 2011 10:34 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - Metric Discussion
- Replies: 20
- Views: 27231
Re: 7-man EGTB Bounty Reborn - Metric Discussion
Of course there is no point in trying to push people in directions they don’t want. But releasing a code and letting uncoordinated people do what they want for themselves isn’t probably best either. Agreed. I've been advocating for coordinating the efforts for a few years now, in both sharing and c...
- Wed Apr 27, 2011 5:23 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - Metric Discussion
- Replies: 20
- Views: 27231
Re: 7-man EGTB Bounty Reborn - Metric Discussion
I added DTZ and DTC into the requirement specs draft. DTZ - for symmetry with DTZ50. It allows to skip uninteresting endgames by solving them in WDL, and only solve interesting ones in DTZ. DTZ50/WDL50 allows to do this with 50-move rule, so DTZ/WDL combination will make the same strategy possible f...
- Tue Apr 26, 2011 2:18 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - Metric Discussion
- Replies: 20
- Views: 27231
Re: 7-man EGTB Bounty Reborn - Metric Discussion
Basically, EGTBs is a two-dimensional space, with positions and metrics. To raise new knowledge, one can concentrate the effort in one direction, exploring more complex endings on simplest metrics (7-men WDL(50)) or more complex metrics on simplest endings (3-5 men DTM50/DTR). One can also make a “...
- Tue Apr 26, 2011 2:04 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - Metric Discussion
- Replies: 20
- Views: 27231
Re: 7-man EGTB Bounty Reborn - Metric Discussion
Regarding the idea of everyone focusing on just WDL and not WDL50 (or vice versa), I'm not sure. I think there is no necessity to impose any order on the community, and just let everyone enjoy building the tables in his favorite metric. Eventually the whole 7-piece solution should be complete in bo...
- Tue Apr 26, 2011 12:52 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - General Discussion
- Replies: 11
- Views: 22854
Re: 7-man EGTB Bounty Reborn - General Discussion
I like the idea and already sponsored the project with a symbolical amount. I see two challenges: 1) You have to attract a programmer who likes the challenge. 2) You have to have the hardware necessary to produce the tables. 3) Distribution (which I don't discuss here because once the tables are th...
- Tue Apr 26, 2011 12:42 am
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - General Discussion
- Replies: 11
- Views: 22854
Re: 7-man EGTB Bounty Reborn - General Discussion
I think it would be nice if the demand for speed is lax as it is much easier to implement something when you are allowed to be half as fast as optimum, and more laxity gives more ease. I think the question is: With the project that will run for years (generating the tables), do we want a generator ...
- Sat Apr 23, 2011 5:04 am
- Forum: Endgame Tablebases
- Topic: Bittorrent downloads of EGTB
- Replies: 10
- Views: 13916
Re: Bittorrent downloads of EGTB
I did not hear about md5summer problems before, but I've seen here reports of problems with some windows builds of md5sum. I wonder what is the cause for these issues, considering how trivial md5 calculation is. Among those that work fine I can also recomment fsum.
- Thu Apr 21, 2011 12:42 pm
- Forum: Endgame Tablebases
- Topic: 7-man EGTB Bounty Reborn - Metric Discussion
- Replies: 20
- Views: 27231
Re: 7-man EGTB Bounty Reborn - Metric Discussion
No misunderstanding. When I mentioned simultaneous WDL + WDL50 generation, I am assuming two totally independent processes. However, now that I think about it, perhaps generation can be speeded up if the same table is already available in a counterpart metric. But this is not too important optimizat...