Reference
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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.
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