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Endgame databases

Endgame databases

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Endgame databases

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Many chess programs can play all important major piece endings with four and five men on the board perfectly. This is to be taken literally.

They contain full information on every legal position that is possible in these endings. At any stage, the program knows whether the position is won, lost or drawn, and how many moves it takes to win or lose (assuming perfect play by both sides).

 

End Game Table Base support

 

Houdini integrates the Syzygy table probing code © Ronald de Man, the Gaviota EGTB probing code © Miguel A. Ballicora and the Nalimov EGTB probing code © Eugene Nalimov.

 

The Syzygy 6-men EGTB system is the recommended table base solution for Houdini.

It features by far the best compression (smallest file size) and best performance, especially when multiple threads perform simultaneous EGTB probing. Houdini has been extensively tuned for this state-of-the-art end game table base system so as to provide optimum precision and strength in the late endgame at any time control and with any number of cores. While installing the files on a SSD disk is recommended, the performance of the Syzygy on a normal hard disk is still very good.

 

The only drawback of Syzygy bases is that they do not contain the exact Distance to Mate information. If you require an exact mating distance in a position you'll need an alternative solution.

 

Syzygy EGTB

For the Syzygy EGTB support you'll need to install the Syzygy EGTB files. At the time of writing all the Syzygy files are available for torrent download at http://oics.olympuschess.com/tracker/index.php. The 3-4-5-men Syzygy are also available for direct download at http://olympuschess.com/egtb/sbases.

 

The total size of the 3-4-5-men files is 938 MB (290 files), the 6-men table bases require 149 GB (730 files).

 

The location of the Syzygy EGTB files is specified in the SyzygyPath option.

 

Nalimov EGTB

For the Nalimov EGTB support you'll need to install the Nalimov EGTB files. At the time of writing they are available for download at the address ftp://ftp.cis.uab.edu/pub/hyatt/TB or http://tablebase.sesse.net. Download the files and save them in a directory on your hard disk. The total disk space required for the 3-4-5-men table bases is about 7 GB (290 files). The space requirement for the 6-men Nalimov table bases exceeds 1 TB.

 

The location of the Nalimov EGTB files is specified in the NalimovPath option.

 

The endgame databases  in the Nalimov format and are know as "Tablebases".

 

nalimov1.jpg

 

Eugene Nalimov from Novosibirsk (currently in Redmond) wrote the powerful algorithms to generate the endgame tablebases.

 

Options – Tablebases

Accessing the endgame databases (Nalimov tablebases) from a hard disk is much faster than from the CD. It is advisable to install them onto your hard disk, if you have enough space.

 

Create a directory (e.g., e:\cbdata\tbs) on your hard disk and copy the content of the directory \TBS from the program CD into the new directory. Then set the path in the "Options" dialog box:

 

Start

 

 

Click More.

 

Select Format

 

Select the prefered Format and set the path.

 

Note that you can put the tablebase files into different directories, partitions or even different hard disks on your computer. Use the "Browse" button to locate the directories.

 

The cache memory is used to speed up access to the tablebases during a game. A value between one and eight MB is advisable.

 

Access to the tablebases improves the playing strength of the program in the endgame considerably. Whenever it hits on one of the five-piece endings in the search, it can stop and get a completely accurate assessment of the position from the tablebases. It does not have to generate thousands of follow-up positions. But, accessing the tablebases is quite slow (in comparison to the move generation and evaluation). You can speed things up by copying the tablebases onto your hard disk.

 

Use the endgame database to practice the endings or to study difficult positions. Not even the greatest experts in the world can give you more reliable analytical help.

 

Endgame Turbo

ChessBase has a product, the Endgame Turbo, which consists of five DVDs filled with Nalimov Tablebases.

 

Endgame Turbo

 

With the help of the Endgame Turbo, all five and a number of six-piece endgames will be played with absolute perfection. Since the positions are also indentified in the search the program played the entire endgame, including positions with more than six pieces on the board, much more accurately.

 

See also End Game Table Base support ....

 

Gaviota Endgame Databases

For the Gaviota EGTB support you'll need to download the Gaviota EGTB files. At the time of writing they are available for download at the address http://www.olympuschess.com/egtb/gaviota.Download all 145 files and save them in a directory on your hard disk. The total disk space required is about 7 GB.

 

The location of the Gaviota EGTB files is specified in the TbPath option.

 

Houdini will scan the folder for the "kqkr.gtb.cpX" file and accordingly decide which compression level to use.