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When a chess program (e.g., a chess engine or a chess GUI) works with an EGTB, it needs to retrieve data (integer numbers) for some given chess positions. The process named probe and has below steps:
* convert a given chess position into an index via indexing algorithms
* access data (typically organized organised as an integer arrayarrays of integers) using the index to retrieve the integer of that chess position
If data of that endgame is not ready in memory, usually the probe process has to do some extra work:
* From data index calculate to the block index
* Read data of that block from storage into memory
* Uncompress the block data (if it is compressed)* Convert the endgame index into block index and retrieve the right needed data
==Search==
==Speed==
Typically the probe process requires some computing and it may access storage and decompress which is usually so slow, compared with one stored in memory. All may make it be a slow one. An engine that probes EGTB when searching may make the whole search be slower. Sometimes the benefit from probing EGTBs maybe not enough to cover the loss of slower search. That’s why the probing should be planned and implemented carefully. EGTB files may have to store in fast storage and/or using some huge systems’ caches. The good point is that the engine can stop searching on the branch probed the EGTB.
=Brief Info=
* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=73481 Using Freeware AI and Dynamically Generated Endgame Tablebases] by Steve Schooler, [[CCC]], March 27, 2020
* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=73598 Almost perfect DTM tablebase] by [[Dann Corbit]], [[CCC]], April 08, 2020
* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=76089 Asynchronous tablebase lookups] by [[Steinar H. Gunderson|Sesse]], [[CCC]], December 17, 2020 <ref>[https://kernel.dk/io_uring.pdf?source=techstories.org io_uring.pdf]</ref>'''2021'''* [http://www.talkchess.com/forum3/viewtopic.php?f=7&t=76089 Asynchronous tablebase lookups76659 Stalemate Tablebases] by [[Steinar H. Gunderson|Sesse]]Dries De Clercq, [[CCC]], December 17February 21, 2020 <ref>2021 » [[https://kernel.dk/io_uring.pdf?source=techstories.org io_uring.pdfStalemate]]</ref>
=External Links=
