Endgame Tablebases Online
6-men endgame analysis free for everyone
 

News

September 27, 2013

Please be sure to verify the downloaded Syzygybases using the following checksums:

These checksums were provided by Joshua Shriver in a single file, I divided them into 4 files for convenience.

Note that md5sum from GnuWin32 Coreutils package computes wrong checksums. You need another build of md5sum, e.g., from Cygwin, or a different checksummer, such as fsum. Simply copy the md5 file into the corresponding Syzygybases directory and run "fsum -c Syzygybases-WDL-3-4-5.md5" (example).

September 14, 2013

Syzygybases is a new promising tablebase format developed by Ronald de Man. The main differences from Nalimov's format:

  • Syzygybases take 50 moves rule into account.
  • Probing code is distributed under permissive license (Nalimov's probing code can only be used under Nalimov's permission, which is hard to impossible to obtain).
  • Syzygybases include WDL (win/draw/loss) tables for fast access during search, as well as separate DTZ (distance to zeroing the 50 move counter) tables for finding the winning line.
  • Syzygybase are about 7 times smaller than Nalimov's tablebases (161 GB vs 1.2 TB).
  • Generating complete syzygybases for up to 6 pieces takes less than a month on a PC with 16 GB or RAM.

The generator source, probing code source and documentation are available on github: https://github.com/syzygy1/tb. As a proof of concept Ronald incorporated the probing code into Stockfish engine: https://github.com/syzygy1/Stockfish.

A few days ago Joshua Shriver started seeding the complete set of 3-4-5-6-piece Syzygybases on bittorrent (as well as hosting the tracker): http://oics.olympuschess.com/tracker/index.php. Already it looks like downloading might be faster than generating, and it will still get faster as more people join.

Still early days, but this could well become the standard tablebase format for the next decade of computer chess.

(Older news are archived here).

Introduction

Many chess enthusiasts would like to do 6-men endgame analysis, but no one wants to host 1 TB of files for download. So we have to help ourselves. This page is an attempt to organize a persistent online availability of the whole set of Nalimov 6-men tablebases. This project depends solely on chess lovers community, it's up to us to choose if we will download any tablebases for free, or if we will have to buy them on DVD from Chessbase etc..

If you are not sure what endgame tablebases are or how to use them, you can learn the basics from Wikipedia or from Aaron Tay's EGTB Guide.

eMule

We use eDonkey and KAD networks, and eMule software for sharing the tablebase files, so if you want to download them you will have to install eMule (or aMule if you use Mac or Linux). If you are new to eMule please take a look at the tutorial, and official help pages. Here you can learn how to set up eMule behind a firewall or router.

Some hints about configuring eMule the best way by our eMule expert Thomas: Thread 1, Thread 2. If you will have any questions or problems, please ask at EGTB forum. Good luck!

Please keep sharing the files after you downloaded them.

3-4-5 men bases

Just in case you don't have them, you should download and install all 3-4-5 men tables before even thinking of using 6-men tables. You can get them from Bob Hyatt, Chesslib Norm Pruitt (also FTP) or Joshua Shriver, but you might as well try using eMule and download them by these links:

6-men endgame tablebases

All files in this section are "emulecollections" - simple text files containing one or several ed2k links. Paste those links into your eMule and it will start trying to download the files.

Smileys show 'spread status' of each tablebase:
 – Super-shared tablebase – All files have 10 full sources (peers with complete files).
 – Well-shared tablebase – At least 3 full sources exist.
 – At least one full source exist - a recently shared base, not spread yet.
 – Tablebase disappeared from the network. It was available for some while, but now the original releaser disconnected before anyone else could get the files. If you have any sets marked with this smiley, please share them online!
 – Tablebase was never released yet.
If you notice that some tablebase is spread more, or less, than stated here, please drop me email and I'll update this page.

The download order is completely up to you. A few things that you may consider:
1. It's good to get small bases before trying the big ones. The best start would be KNNKNN and KBBKBB.
2. It's better to get pawnless bases before getting those with pawns, to avoid the possible "incomplete tablebase problem".
3. You will have better experience if you start with bases which are already shared by many people ( and ).
4. You may like to download tablebases by "importance" order, which is based on statistics of occurrance of each ending in real games. Several such lists exist: by Dieter Bürßner, Nelson Hernandez, and Peter Kasinski.
5. You may like to first download tablebases for endgames where longer checkmates are possible.

[ Sorted by piece value: P⇒N⇒B⇒R⇒Q  |  Sorted by alphabet: B⇒N⇒P⇒Q⇒R ]





Additional information

Checking tablebase integrity

Tablebase files are big and anything can happen while you download, copy or keep them. You should always check their integrity after you downloaded new files, and also before sharing new tablebases. You can either check them using md5sum program and *.md5 files from this page, or with Wilhelm program. If you prefer Wilhelm be sure to use the latest version - 1.50, as earlier versions may incorrectly report corrupted files. Aaron's FAQ also has detailed explanation.

Caution! A number of people seem to have corrupted files now, for various bases. I can tell because when I search in eMule for the bases that I have, I see not only the links to the same files, but also links to the files with same names and same size, but with different hash. I urge everyone to re-check the tablebases before sharing any new files, and after you downloaded a new files too.

Other ways to download 6-men tablebases

Several members of this community volanteered to host some of the 6-men tablebases for those who can't use eMule for some reason. Servers known to me are listed here. (Please let me know if you know other servers, or if one of the listed servers is dead).

Please try to share with eMule all files downloaded from those sites.

Engines which support 6-men Nalimov endgame tablebases

Commercial engines accessing 6-men Nalimov tables in search: Chess Tiger 15.0, Fruit 2.2.1, Gandalf 6.0, Rybka 1.1 - 2.3.2a, Shredder 9.

Free engines accessing 6-men Nalimov tables in search: Crafty 21.5, Yace 0.99.87, Spike 1.2 Turin, Colossus 2007c.

Online interfaces to endgame tablebases

These web-sites allow you to probe endgame positions online using your browser.

Pros of probing online:

Cons:

Links:

Other types of tablebases

Scorpio bitbases by Daniel Shawul are used by Scorpio, latest Toga and by other engines, thanks to open source probing code. You can download them from eD2K/KAD network with these liks (You need eMule for these links to work):

After you downloaded them, check their integrity with the included MD5 files, move all 3-4-5 files and "egbbdll.dll" into single directory, and point your engines to that directory. Run some endgame tests to see if the engine is really using those bitbases.

Source code of Scorpio bitbases compressor and probing code is available at Scorpio homepage.

Thanks

The biggest thanks go to Eugene Nalimov and Andrew Kadatch, who generated the "Nalimov tablebases" and who are providing the probing code for free to many engine authors.

Thanks to Daniel Shawul for creating Scorpio bitbases and sharing them along with the access code.

Following people contributed to this project by sharing their tablebases, sending links, making suggestions, and active discussion (in no particular order): Dan Wulff, A. Steen, Chuck Wilson, Joachim Rang, Sarah Bird, Alberto Gueci, Vincent Diepeveen, Thomas Mayer, Richard Pijl, Renze Steenhuisen, Gordon Evans, Nelson Hernandez, Keith Ian Price, Wilfried Eberl, Guy Haworth, Rafael Andrist, Eiko Bleicher, Ryan Hirst, Marc Bourzutschky, Joshua Shriver, Thomas Scherk, John Kominek, Norm Pruitt/PAKman.

(Please tell me if I forgot to mention someone, or if you have any correction)

Of course, many more people are joining by downloading and sharing the tablebase files, and by keeping them shared. Sharing the tablebase files is the meaning of this project, this page is simply an index page to make it easier to find them.

Feedback

If you have any questions, comments, ideas, suggestions, or any contribution, the best you can do is posting it in Endgame Tablebases Forum where other people involved with EGTB will see it.

Alternatively you can post in general chess discussion boards like Computer Chess Club and Winboard Forum, or contact me privately.


© 2005-2013 Kirill Kryukov
This page is available under the CC BY 3.0 License