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Generation of 7-man tablebases would require about 1 TB of RAM. Generation time will be about 64 x per table, which means around 175 x time total <ref>[http://kirill-kryukov.com/chess/discussion-board/viewtopic.php?f=6&t=7396#p83338 Re: Syzygy tb generator for windows] by [[Ronald de Man|syzygy]], [[Computer Chess Forums|CCRL Discussion Board]], June 01, 2014</ref> . Ronald de Man wasn't initially interested in creation of 7-men Syzygy Based <ref>[http://kirill-kryukov.com/chess/discussion-board/viewtopic.php?f=6&t=7618#p83771 Re: 7-piece syzygy] by [[Ronald de Man|syzygy]], [[Computer Chess Forums|CCRL Discussion Board]], July 03, 2014</ref>. But in 2018, he supported [[Bojun Guo]] in his 5 month attempt to generated them <ref>[http://www.talkchess.com/forum/viewtopic.php?t=66797 7-men Syzygy attempt] by [[Bojun Guo]], [[CCC]], March 10, 2018</ref>. In August of 2018 their creation was completed<ref>[https://syzygy-tables.info/ Powered by Ronald de Man's Syzygy endgame tablebases, 7-piece tables generated by Bojun Guo and a public API hosted by lichess.org], August 19, 2018</ref><ref>[http://tablebase.lichess.ovh/tables/standard/7/ Index of /tables/standard/7/ on lichess], August 19, 2018</ref>.
=Search= ==During the Search==
During the [[Search|search]], with the WDL tables stored on [https://en.wikipedia.org/wiki/Solid-state_drive SSD] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=47931&start=2 Re: SSD and the use of Tablebases] by [[Ronald de Man]], [[CCC]], May 08, 2013</ref> , it is possible to probe the tables at all [[Depth|depths]] without much slowdown. They have been tested in Ronald de Man's engine [[Sjaak]] (playing on [[FICS]] as TrojanKnight(C)) a couple of months quite successfully, don't probing in [[Quiescence Search|quiescence search]].
==At the Root== At the [[Root|root]], since pure DTZ50-optimal play (i.e. minimaxing the number of moves to the next [[Captures|capture]] or [[Pawn Push|pawn move]] by either side) can be very unnatural, it might be desirable to let the engine search on the winning moves until it becomes clear that insufficient progress is being made and only then switch to DTZ-optimal play (e.g. by detecting [[Repetitions|repetitions]] and monitoring the [[Halfmove Clock|halfmove clock]]) <ref>[http://www.talkchess.com/forum/viewtopic.php?t=47681&start=8 Re: New 6-piece tablebases] by [[Ronald de Man]], [[CCC]], April 05, 2013</ref> .
=Quotes=
by [[Ronald de Man]] in a reply to [[Guy Haworth]], April 06, 2013 <ref>[http://kirill-kryukov.com/chess/discussion-board/viewtopic.php?f=6&t=6971&start=6 Re: New 6-piece tablebase generator] by [[Ronald de Man|syzygy]], [[Computer Chess Forums|CCRL Discussion Board]], April 06, 2013</ref> :
I create both WDL and DTZ in one go, so I don't use WDL in the creation of DTZ. The algorithm used is the [[Retrograde Analysis#Algorithm|grandfather algorithm]] with 2 plies per iteration (I think [[Harm Geert Muller|HGM]] calls this leapfrogging, but I might be wrong). I tried the outcounting method, but it didn't seem to be competitive (and it makes things more complicated). <ref>[http://www.open-chess.org/viewtopic.php?f=5&t=779 Retrograde tablebase methods] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], November 26, 2010</ref> <ref>[http://home.hccnet.nl/h.g.muller/EGT7/retro.html Leapfrog: Retrograde Analysis] from [http://home.hccnet.nl/h.g.muller/EGT7/7-men.html Leapfrog tablebase generator] by [[Harm Geert Muller]]</ref>
=Pros=
* Small sizes. It is about 8 times (it omitted data of one side, thus if it has full data, the factor is actually 3 times) as small as the second-best EGTBs. Having small sizes is the main success key of Syzygy Bases since it helps to create, store and provide it much easier than other EGTBs
* Free and more popular (than other EGTBs) to find on the Internet
* Support [[Endgame Tablebases#DTZ50|DTZ50]] metric. That metric can help engines to have better results than [[Endgame Tablebases#DTM|DTM]] which is supported widely by other EGTBs
===7 men===
All 7 men files' size is over 16.7 TiB, over storages of typical modern computers. They also require a long time to download too. Thus some users choose to download one or a few endgames only, based on their statistics of use in endgames. Bellow is the top 20 of those endgames by their order. The first one, KRPPvKRP, has a significantly higher frequency of use than the others and should be always downloaded.:
1) KRPPvKRP, 2) KBPPvKBP, 3) KPPPvKPP, 4) KRPPPvKR, 5) KQPPvKQP, 6) KNPPvKNP, 7) KNPPvKBP, 8) KRBPvKRP, 9) KQPPvKPP, 10) KQPPPvKP,11) KBPPvKNP, 12) KRPPvKRB, 13) KRPPvKPP, 14) KBPPvKRP, 15) KRNPvKRP, 16) KRBPPvKR, 17) KBPPvKPP, 18) KRPPPvKP, 19) KRBPvKRB, 20) KRPPvKRN
=Checksums=
* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=71896 Syzygy DTZ data explaination?] by [[Pham Hong Nguyen|Nguyen Pham]], [[CCC]], September 23, 2019
==2020 ...==* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=73598 Almost perfect DTM tablebase] by [[Dann Corbit]], [[CCC]], April 08, 2020 =External Links=
==Tablebase==
* [https://github.com/syzygy1/tb syzygy1/tb · GitHub] by [[Ronald de Man]]
