The program supports a relatively new endgame database format, the Syzygy Endgame Tablebases.  The new format was designed by Ronald de Man from Holland. Most new chess engines already support this format.

 

You can activate the Syzygy Endgame Tablebases in the program settings, in the menu File – Options – TableBases – More.

 

 

 

Enter the path of the folder where the Syzygy tablebases are stored in the "GUI" and "Engine" tabs. Clicking on the button with the three dots activates the standard Windows dialog to select the folder. Click OK to confirm the settings, and the program will now use the information in the tablebases.

 

You can check whether the access is working by looking at the output of a chess engine.

 

 

In this example you can see entries "tb= xxx", which show how often the Houdini chess engine is accessing the endgame tablebases. A big advantage of the Syzygy Endgame Tablebases is that they are much smaller. The 6-man Syzygy tablebases need 150 GB disc space, whereas the Nalimov tablebases need more than 1 TB.

 

The Syzygy Endgame Tablebases pay attention to the 50 move stalemate rule. If there are 50 moves without a piece being taken or a pawn being moved, the game is drawn. Since the data can be accessed in RAM very fast and effectively the Syzygy Endgame Tablebases are now used exclusively by many modern chess engines.

 

For instance, the chess engine only uses the Syzygy tablebases during the search, but it also uses the Nalimov tablebases when a position is on the board. It is to be expected that the Syzygy tablebases will become increasingly popular with engine developers.

 

The best way to get the complete Syzygy Endgame Tablebases is to buy the Endgame Turbo 4 from our online shop.

 

Because of the size of the tablebases it is best to install them outside of the Documents folder, for instance in C:/Tablebases/.

 

There are two different types of Syzygy tablebases.

 

WDL (Win-Draw-Loss). 

In these files only information about the result of the position is stored. This is the only information used in the search. Based on this information the chess engine cannot tell how many moves it will take to win the game. The engine is merely informed whether the position is a Win, a Loss or a Draw.

 

DTZ (Distance to zero).

These tablebases are used by the GUI to generate a value which states how many moves it will take to win the game. Some engines use this information during the search.

 

The Syzygy tablebases support bitbases in both WDL and DTZ format. The latter format is only used when an exact position is already on the board. However, only the number of moves to reach another endgame (or sometimes checkmate). Another endgame begins after any move that resets the 50 move rule. By this definition, every time a piece is taken or a pawn moves a new endgame has begun and the count is set to 1. If a pawn keeps advancing, after every move the count is 1 again. That means that the count is reset after every move which changes the position irreversibly.

 

This means that the Syzygy Endgame Tablebases are different to the tablebases that have been used until now. This means that the moves to mate are not necessarily displayed, but the moves to the transition into another endgame. When sorting the moves pawn, capture and promotion moves are put first, because these are the moves that bring the game forwards.

 

For example, if you are using the engine to analyse a 5 or 6 piece endgame that can definitely be won, the Syzygy tableBases might give an evaluation of +250. There is no longer a display of "Mate in x moves".

 

As in the case of the Nalimov tablebases there are 290 files for the 3/4/5-piece endgames, but they are differently distributed. The Nalimov tablebases have two files per endgame, one for "White To Move", one for "Black To Move". The Syzygy tablebases only need one file, regardless of who is moving, but there are two versions of each tablebase: one contains the WDL (Win-Draw-Loss) result and the other contains the DTZ (Distance-To-Zero) result.