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also called bitsets or bitmaps, or better '''Square Sets''', are among other things used to represent the [[Chessboard|board]] inside a chess program in a '''piece centric''' manner. Bitboards, are in essence, [https://en.wikipedia.org/wiki/Finite_set finite sets] of up to [https://en.wikipedia.org/wiki/64_%28number%29 64] [https://en.wikipedia.org/wiki/Element_%28mathematics%29 elements] - all the [[Squares|squares]] of a [[Chessboard|chessboard]], one [[Bit|bit]] per square. Other board [[Games|games]] with greater board sizes may be use set-wise representations as well <ref>[[Reijer Grimbergen]] ('''2007'''). ''Using Bitboards for Move Generation in Shogi''. [[ICGA Journal#30_1|ICGA Journal, Vol. 30, No. 1]], [http://www2.teu.ac.jp/gamelab/RESEARCH/ICGAJournal2007.pdf pdf]</ref>, but classical chess has the advantage that one [[Quad Word|64-bit word]] or register covers the whole board. Even more bitboard friendly is [[Checkers]] with 32-bit bitboards and less [[Pieces#PieceTypeCoding|piece-types]] than chess <ref>[http://www.3dkingdoms.com/checkers/bitboards.htm Checker Bitboards Tutorial] by [[Jonathan Kreuzer]]</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=64487 Checkers Bitboard representation] by Pranav Deshpande, [[CCC]], July 02, 2017</ref>.

* [[General Setwise Operations]]: operations, functions to manipulate bitboards such as set, clear bits in specific indexes, compare them...* [[Population Count]]: count all bit 1s, answer some questions such as how many pieces the Black side has* [[BitScan]]: find index of a bit 1 (usually the most left or most right), answer questions such as where a Rook is or where the targets of a given Knight. Those functions are called in high frequency when generating moves and evaluating

==Descriptions==* [httphttps://en.wikipedia.org/wiki/Bitboard Bitboards from Wikipedia]* [httphttps://en.wikipedia.org/wiki/Bit_array Bit-Array from Wikipedia]* [httphttps://en.wikipedia.org/wiki/Bitboard#History Bitboard-History from Wikipedia]* [httphttps://www.craftychess.com/hyatt/boardrep.html Chess board representations] by [[Robert Hyatt]]* [https://web.archive.org/web/20081007034904/http://webpages.charter.net/tlikens/bitmaps/bit_intro.html Bitboards (aka bitmaps)] by [[Tom Likens]]([https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine], 2008)

* [https://web.archive.org/web/20050205014648/http://www.onjava.com/pub/a/onjava/2005/02/02/bitsets.html Bitwise Optimization in Java: Bitfields, Bitboards, and Beyond] by [[Glen Pepicelli]], ([https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine], 2005), [http://en.wikipedia.org/wiki/O%27Reilly_Media O'Reilly's] [https://web.archive.org/web/20050203015229/http://onjava.com/ OnJava.com] » [[Java]], [[Bit-Twiddling]]* [httphttps://pages.cs.wisc.edu/~psilord/blog/data/chess-pages/index.html Chess and Bitboards] by [httphttps://pages.cs.wisc.edu/~psilord/ Peter Keller]* [httphttps://sanherlabraj.de/indexferi.htm?lang=eng&url=bitfuncs Bit functions for Delphi] by [[Andreas Herrmann]] » [[Delphi]]* [http://labraj.uni-mbum.si/en/Position_Representation Position Representation - Computer Architecture and Languages Laboratory], [[University of Maribor]]* [httphttps://stackoverflow.com/questions/tagged/bitboard Newest 'bitboard' Questions] - [http://en.wikipedia.org/wiki/Stack_Overflow Stack Overflow]==Libraries==* [https://github.com/sinandredemption/M42 GitHub - sinandredemption/M42: C++ Library for Bitboard Attack Mask Generation] by [[Syed Fahad]]* [https://github.com/kz04px/libchess GitHub - kz04px/libchess: C++ chess library]==Misc==