In chess, the endgame tablebase, or simply tablebase, is a computerised database containing precalculated evaluations of endgame positions. Tablebases are used to analyse finished games, as well as by chess engines to evaluate positions during play. Tablebases are typically exhaustive, covering every legal arrangement of a specific selection of pieces on the board, with both White and Black to move. For each position, the tablebase records the ultimate result of the game (i.e. a win for White, a win for Black, or a draw) and the number of moves required to achieve that result, both assuming perfect play. Because every legal move in a covered position results in another covered position, the tablebase acts as an oracle that always provides the optimal move.
Tablebases are generated by retrograde analysis, working backward from checkmated positions. By 2005, tablebases for all positions having up to six pieces, including the two kings, had been created.[1] By August 2012, tablebases had solved chess for almost every position with up to seven pieces, with certain subclasses omitted due to their assumed triviality;[2][3] these omitted positions were included by August 2018.[4] As of 2024[update], work is still underway to solve all eight-piece positions.
Tablebases have profoundly advanced the chess community's understanding of endgame theory. Some positions which humans had analysed as draws were proven to be winnable; in some cases, tablebase analysis found a mate in more than five hundred moves, far beyond the ability of humans, and beyond the capability of a computer during play. This caused the fifty-move rule to be called into question, since many positions were discovered that were winning for one side but drawn during play because of this rule. Initially, some exceptions to the fifty-move rule were introduced, but when more extreme cases were later discovered, these exceptions were removed. Tablebases also facilitate the composition of endgame studies.
While endgame tablebases exist for other board games, such as checkers,[5] nine men's morris,[6] and some chess variants,[7] the term endgame tablebase is usually assumed to refer to chess tablebases.
This article uses algebraic notation to describe chess moves.
^Cite error: The named reference lichess.org was invoked but never defined (see the help page).
^Gilbert, Ed. "Kingsrow". edgilbert.org. Retrieved 19 March 2023. Website of KingsRow about the creation of a tablebases for 8x8 and 10x10 checkers
^Ralpf Gasser (1996). "Solving nine men's morris" (PDF). Archived from the original (PDF) on 24 July 2015. Retrieved 13 April 2011.
^"Gothic Chess Javascript Endgames". gothicchess.com. 27 September 2011. Archived from the original on 27 September 2011. examples of long endings for Capablanca chess
chess, the endgametablebase, or simply tablebase, is a computerised database containing precalculated evaluations of endgame positions. Tablebases are used...
reach an endgame; some of them end earlier. All chess positions with up to seven pieces on the board have been solved by endgametablebases, so the outcome...
possibilities. Progress to date is extremely limited; there are tablebases of perfect endgame play with a small number of pieces (up to seven), and some chess...
years, other endgame database formats have been released including the Edward Tablebase, the De Koning Database and the Nalimov Tablebase which is used...
encoding, and his work on computer chess that included the creation of endgametablebases and the chess machine Belle. He won the Turing Award in 1983 with...
construction of endgametablebases. Grandmaster John Nunn wrote a book (Secrets of Pawnless Endings) summarizing the research of endgametablebases for several...
engines frequently use endgametablebases in their evaluation function, as it allows the engine to play perfectly in the endgame. Historically, evaluation...
benefit from solutions of the game from certain endgame positions (in the form of endgametablebases), which will allow it to play perfectly after some...
involves analyzing the endgame with two knights versus a pawn, see Troitsky line. John Nunn analyzed this endgame with an endgametablebase and stated that "the...
Nd7 and 3...Bxf6 hold the draw. (ii) the modern Lomonosov 7-piece endgametablebase shows White has a win after 4...Bxf6 with 5.Re2+, sacrificing White's...
engines use endgametablebases to increase their playing strength during the endgame. An endgametablebase includes all possible endgame positions with...
three books based on the most important endgames in the five-piece endgametablebases but omitted this endgame because "... it proved too hard to understand"...
system. endgame The third and last phase of the game, when there are few pieces left on the board. The endgame follows the middlegame. endgametablebase A computerized...
constructing endgametablebases. Some endgame books are general works about many different kinds of endgames whereas others are limited to specific endgames such...
Troitsky line] and above". John Nunn analyzed the endgame of two knights versus a pawn with an endgametablebase and stated that "the analysis of Troitsky and...
published a tablebase for select six-piece endgames, and by 2005, following the publication of Nalimov tablebases, all six-piece endgame positions were...
Pawnless chess endgame § Minor pieces only and Chess endgame § Effect of tablebases on endgame theory). Several important works on the endgame have been published...
became simple enough to use an endgametablebase. As of October 1999, however, there were no seven-piece endgametablebases, and seven pieces remained in...
where players attempt to establish connections Endgametablebase, a database saying how to play endgames Expectiminimax tree, an adaptation of a minimax...
contain data from prior games and provide engine analyses of games. Endgametablebases are also provided by the company. ChessBase's Indian YouTube channel...
Syzygy, in biology, the pairing of chromosomes during meiosis Syzygy endgametablebases, used by chess engines Syzygy, a concept in the philosophy of Vladimir...
passed pawns – both its own pawns and the opponent's. Endgametablebase – computer database of endgame positions giving optimal moves for both sides and the...
hardest endgames to draw." Being a five-piece endgame, the rook and bishop versus rook endgame has been fully analysed using computers. Endgametablebases show...
responsibility for handling endgametablebases, this is arguably better handled in the engine itself, as having tablebase information can be useful for...
trained via self-play, with no access to rules, opening books, or endgametablebases. The trained algorithm used the same convolutional and residual architecture...
Comparison of chess video games Computer chess Computer Olympiad Endgametablebase List of Internet chess servers Software for handling chess problems...
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