Questions tagged [tablebases]

Tablebases are databases that contain complete, exhaustively calculated moves and variations for a given collection of chess positions. E.g. the Nalimov tablebases contain full solutions for all endgames involving 6 pieces or less.

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Can a rook win against a knight in the endgame?

Suppose we have a rook and the opponent has a knight next to his king. Is it possible to win this game theoretically? E.g., in the following position (white to move), is it possible for white to ...
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28 votes
4 answers
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What is the status for seven man end game table bases?

There are complete (or nearly complete) six man end game table bases available for download, and even online. What is the status of seven man table bases? Is there still active development in this ...
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Is there a freely available online 7 piece Endgame tablebase?

The only 7 piece site I heard about is http://tb7.chessok.com/ , and upon registration I am able to setup various positions with 2-6 pieces . However as soon as I setup a position with 7 piece, I get ...
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21 votes
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Will quantum computers solve chess?

The theory is that there are more that 10^40 positions, and a computer that works with an atomic scale has to be impossibly large(As in galaxy-scale large), and well beyond our current level of ...
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What do DTM, DTZ, DTC, DTR, DTZ50, and DTZR mean?

I need help clarifying the abbreviations and acronyms used in endgame tablebases. Just what do DTM, DTZ, DTC, DTR, DTZ50, DTZR mean?
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What is Syzygy tablebases?

I just want to know in simple language exactly, What the Syzygy tablebases are, Why they are used, What are their advantages, disadvantages?
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Computer endgame strength without tablebases

I have seen that engines aren't particularly strong in the openings without access to a book. How strong are modern engines in the endgame when they are not allowed access to tablebases? E.g., can ...
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How is it possible that the Lomonosov-endgame-tablebase from 2012 still is the most powerful tablebase?

Due to Wikipedia: Endgame tablebase the Lomonosov endgame tablebase is still the biggest tablebase (with a size of 140TB). Now this tablebase was computed in the year 2012 with the Lomonosov 1 (Top500-...
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How many legal but unreachable positions exist?

Consider this legal chess position which can never be reached from the normal starting position. [FEN "6kb/6p1/6K1/8/8/8/8/8 w - - 0 1"] The Black bishop is placed on h8, but with the Black ...
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12 votes
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How does Syzygy store its information?

From reading everything I've found so far, I know that Syzygy uses both win/draw/loss files and distance-to-zero files, but I haven't found any information on the internal file format that these files ...
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Are there attempts at creating practical endgame tablebases?

As I understand it, 8-piece endgame tablebases have been in development for many years. The big issue is the sheer number of positions that are possible. Are there any attempts at making a "practical"...
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Do Stockfish and the tablebase work together or independently?

I use Arena GUI together with stockfish in engine games. I want to download a 6-piece tablebase but that is just a lot of work (and perhaps unnecessary). If I download the tablebase (syzygy), does ...
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How far from solving chess are we?

See here: Does there exist an algorithm that would play perfect chess if given infinite processing power? With infinite power, we could trivially recursively check every board state for winnability, ...
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Does the Lomonosov Tablebase (and others) include extra material positions such as KQQvKQQQ?

Lomonosov Endgame Tablebase says it includes all endgames with 7 pieces. But does that include things like KQQ v KQQQ? At every possible position? Such things seem highly unlikely, but theoretically ...
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Can the bishops and knights triumph over the queen?

I heard that two bishops and two knights have good winning chances against the queen according to the 7-man tablebases. Unfortunately, even the pawnless 7-man tablebases are not available online. So, ...
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Endgame Tablebases-What are they?

I've been reading and enjoying the site immensely. What is the "Endgame Tablebase"? I see it referenced frequently.
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6 votes
2 answers
407 views

What is the maximum DTM with K+J vs K?

What is the maximum DTM in the endgame king + janus vs king on a 10x8-board ? The janus can move like a bishop or like a knight. Since both sides have two additional pieces, the board has 10 columns ...
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Syzygy 6 man Tablebase Files Question

Is anyone familiar with the .wdl and .dtz formats for the 6 man tablebase that are available? I already confirmed that both aren't needed, however they both store different information. Goal is to ...
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Is there an online database for the endgame KRPPKRP?

It was stated at this forum that the 7-men-endgames are still not available online. What about the special endgame KRPPKRP (Rook and 2 pawns against Rook and 1 pawn) ? It would be nice if the ...
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KRPP vs KRP - maximum depth to conversion?

I am trying to learn single rook endgames with two pawns against one, with added stipulation that the two pawns of the attacking side are on neighboring files with the pawn of the defending side also ...
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Chess endgame database+50-move rule=potential error?

Are there any examples of positions where usage of the endgame tablebase gives an incorrect evaluation, due to the ignoring of the 50-move rule? At the moment I am not sure if endgame tablebases ...
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What are the winning chances of every pieces? (6men egtb)

Is there a site or document which shows what the winning chances are of every "Specific Pieces vs. Specific Pieces" endgame? e.g. What are the winning chances of Rook & Bishop vs 2 Knights?
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Where can I download gaviota endgame tables?

I am looking for a link to download all 5 pieces gaviota endgame tables (which can give me DTM values). A few links from google search (like this) lead me to the site which does not exist.
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What is the longest current tablebase mate with a unique optimal line?

Having been inspired by an article on ChessBase.com, what is the longest current tablebase mate with a unique optimal line? By unique, I mean for each of the winning side's plies, there is only one ...
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5 votes
2 answers
435 views

Is there a Web Service available for 6-piece endgame tablebases?

I use the LokaSoft web service for 5-piece endgames, but cannot find one for 6 pieces. BTW, by web service I mean a software function capable of being called over the internet (see http://en....
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4 votes
1 answer
671 views

What is the longest tablebase win that includes draw rules?

It has been asked the longest mate that includes draw rules is, and it is known what the longest tablebase mate is. However, what is the longest tablebase mate, i.e. 7 pieces or less, that accounts ...
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Where to download a 6 man Nalimov endgame tablebase?

Can anyone tell me whereabouts I can download a 6 man Nalimov endgame tablebase? I've seen some websites with 6 man Nalimov (case in point: http://contentdb.emule-project.net/view.php?pid=1630). ...
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4 votes
2 answers
261 views

What are the dates each of the endgame tablebases were completed?

I'm curious to get a rough sense for when chess could be solved if Moore's law, and algorithm improvements continue, and I thought a good way to get a rough idea would be to extrapolate based on when ...
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4 votes
1 answer
570 views

How long would it take China's Tianhe-2 Supercomputer to produce an 8-man tablebase?

Wondering how long it would take a TOP10 Supercomputer to fully construct an 8-man tablebase.
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4 votes
1 answer
189 views

Tablebases for variant where stalemate is a win?

Since time immemorial, some people have suggested that stalemate be declared a loss for the player who is unable to move. This proposal is sometimes called "abolishing the stalemate rule" although I ...
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4 votes
2 answers
812 views

6 man syzygy tablebase and ramdisk

I have downloaded a copy of the 6 man Syzygy tablebase and configured it on my Fritz 15 GUI. Due to obvious memory constraints, the full 6 man Syzygy tablebase cannot be loaded into memory (ie. ...
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Syzygy tablebases in xboard

I'm trying to set up the five-men syzygy tablebases for use in xboard 4.8. Stockfish 6 and Komodo 9 are both supposed to support Syzygy, but in Xboard, their SyzygyPath option is missing from the UCI ...
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4 votes
1 answer
284 views

Maximum DTC and maximum DTZ in the endgame KRPKRP

What is the maximum DTC and the maximum DTZ in the endgame KRPKRP (rook+pawn against rook+pawn) ?
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4 votes
1 answer
681 views

Mutual Zugzwangs & Longest Checkmates (DTM, DTC and DTZ) in the endgame KRPP vs. KRP

Are there any surveys on mutual zugzwang positions and the longest checkmates (split into categories of DTM, DTC, and DTZ) in the endgame KRPP vs. KRP (King+Rook+2 Pawns vs. King+Rook+Pawn)? In ...
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4 votes
1 answer
229 views

Longest DTC in the endgame KQPKQ depending on the place of the white pawn

I remember some statistics by Guy Haworth from the endgame KQPKQ (queen + pawn vs queen). One of the statistics was the maximum DTC depending on the place of the white pawn (due to symmetry, it can ...
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4 votes
1 answer
398 views

Obtaining the correct move from syzygy tablebases (Python)

I have created a chess engine in Python and now want to start using the endgame tables in syzygy. I have downloaded all the relevant files and is now ready to start. I have found how to access the ...
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4 votes
1 answer
663 views

Generate Simple Mate In 1 From Tablebases (for kids)

I was trying to find a kid's app for chess that has some incredibly simple problems. However, all the apps I found had rather tricky problems. So I thought I would download 3 piece table bases and use ...
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4 votes
1 answer
795 views

How to use ending evaluation in UCI interaction with Stockfish

Playing around with the Stockfish 8 UCI from the terminal, I've managed to make it compute moves, and set the position and load Syzygy tables. But how I can know if an endgame, one that corresponds ...
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4 votes
1 answer
147 views

Finding all critical endgames

A winning position is called critical, if all moves - except one - draw or lose (assuming the opponent plays perfectly). Similarly, a drawn chess position is called critical, if all moves - except one ...
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3 votes
3 answers
989 views

Tablebases say this position is drawn, but Stockfish disagrees-What does that mean?

Today I found myself in the below position as black (me to play). My gut told me it should be a draw, but as my opponent and I are both fairly weak there was a significant chance one of us would ...
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3 votes
2 answers
603 views

Longest way to mate with 1 queen against 4 queens

What is the longest way to checkmate with 1 queen against 4 queens, with no other pieces on the board? Since there are 13 moves long games with a queen vs two queens, I conjecture this should be ...
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3 votes
1 answer
980 views

How many positions are there in n-pieces endgame tablebases for different values of n? [duplicate]

Note that I don't want the exact values, I only need approximations. And I am only interested in small values of n (not more than 12).
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3 votes
1 answer
477 views

Is it possible to get DTM of a position from sygyzy tables?

This is a programming question related to chess endgame tables. As far as I know syzygy tables allow me to get WDL and DTZ information for a given position. Is it possible to somehow (without access ...
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3 votes
1 answer
216 views

Is there any method to determine if the weaker side in KQPKQ has a perpetual check?

Is there any possibility to check, without the use of the tablebases, if a position in the endgame queen+pawn vs queen (KQPKQ) allows a perpetual check for the weaker side?
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3 votes
1 answer
469 views

Longest DTM in the endgame KQPPKQ

What is the longest DTM in the endgame queen and two pawns versus a queen (KQPPKQ? This position is a mate in 167 moves. [FEN "8/k7/6K1/1Q6/8/P6q/7P/8 w - - 0 1"] Are the DTC and/or DTZ ...
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3 votes
1 answer
166 views

ChessBase Nalimov tablebases

I'm using Nalimov tablebases with Fritz14 and it basically works. Just one strange problems occurs: The engine doesn't mate because the final mating move isn't sorted correctly. It look like this: +- ...
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3 votes
1 answer
114 views

Free tablebase generator software?

I'd like to play a bit with fairy tablebases (Vaclav Kotesovec published quite a few) and am far too lazy to program them anew, especially as I wouldn't wonder if there is free code floating around, ...
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3 votes
1 answer
279 views

Looking for special chess freeware

I am looking for chess freeware that ideally has the following facilities, and I am wondering what compromises I'll need to accept. I am also requesting the results of your experiences. List Of Needs ...
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3 votes
1 answer
209 views

Have endgame tablebases ever been compiled for smaller variants of chess?

I am interested in compiling endgame tablebases for a few miniature chess variants, such as Chess Attack (5x6) and Los Alamos Chess (6x6). Have these ever been created before, and if so, are they ...
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3 votes
2 answers
163 views

Normal draw positions in the endgame KQPKQ with a bishop-pawn?

Suppose, in the endgame queen + pawn vs queen (KQPKQ) , the stronger side has a bishop-pawn (c-pawn or f-pawn). The weaker side cannot win the pawn, nor has a perpetual check, nor can play on ...
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