OBender

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|| [[image:Monument_to_Ostap_Bender_in_Kremenchuk.JPG link="https://commons.wikimedia.org/wiki/File:Monument_to_Ostap_Bender_in_Kremenchuk.JPG"]] ||~ || **OBender**, (previously called Qchess and Chess)
a [[Chess Engine Communication Protocol]] compliant [[Open Source Engines|open source chess program]] by [[Evgeniy Korniloff]], written in [[C]], with recent modifications by [[Serg Nifont]]. Sources of various versions are hosted by [[Jim Ablett]] <ref>[[http://evgeniy-korniloff.narod.ru/|Домашняя страничка Евгения Корнилова | Evgeniy Korniloff Home Page]]</ref> <ref>[[http://kirr.homeunix.org/chess/engines/Jim%20Ablett/OBENDER/|Index of /chess/engines/Jim Ablett/OBENDER]] by [[Jim Ablett]], hosted by [[Kirill Kryukov]]</ref>. Despite released more recently, OBender aka Qchess seems to be the oldest Russian [[WinBoard Engines|WinBoard engine]]. QChess was a demonstration program of [[Selectivity|selective]] [[Search|search]] as an example in Evgeniy Korniloff's book //Программирование шахмат и других логических игр// (Programming Chess and other logical games) <ref>[[Evgeniy Korniloff]] (**2005**). //Программирование шахмат и других логических игр//. (Programming Chess and other logical games), ISBN 5-94157-497-5, [[http://static.ozone.ru/multimedia/book_file/1007127469.pdf|Глава 1. Общие сведения (Chapter I) as pdf]]</ref>. The program has an own [[GUI|graphical user interface]], but can also play via WinBoard. A newer version of the engine was called Chess, applying a deeper but narrower selective search with an extended positional [[Evaluation|evaluation]], until it evolved to OBender with an additional side branch called [[Woodpecker]] <ref>[[http://www.sdchess.ru/OBender.htm|OBender (ранее - Qchess-chess) by Evgeniy Korniloff, Russia]] from [[http://www.sdchess.ru/|sdchess.ru]]</ref>. ||
|| Monument of Ostap Bender <ref>Monument of Ostap Bender in [[https://en.wikipedia.org/wiki/Kremenchuk|Kremenchuk]], [[https://en.wikipedia.org/wiki/Ukraine|Ukraine]], Photo by [[https://commons.wikimedia.org/wiki/User:TheVovaNik|TheVovaNik]], June 29, 2014, [[https://creativecommons.org/licenses/by-sa/3.0/deed.en|CC BY-SA 3.0]], [[https://en.wikipedia.org/wiki/Wikimedia_Commons|Wikimedia Commons]], [[https://en.wikipedia.org/wiki/Ostap_Bender|Ostap Bender from Wikipedia]]</ref> ||~ ||^ ||
[[toc]]
=Description=
OBender [[Board Representation|represents the board]] with [[8x8 Board|8x8 arrays]] and [[Piece-Lists|piece-lists]], and applies [[Negamax|negamax]] [[Principal Variation Search|PVS]] with [[Null Move Pruning|null move pruning]], [[Mate Threat Extensions|mate threat extensions]], [[Check Extensions|check extensions]], [[Late Move Reductions|LMR]] and [[Quiescence Search|quiescence search]] inside the [[Iterative Deepening|iterative deepening]] framework. Beside the [[Transposition Table|transposition table]] and a tree structure of [[Principal Variation|principal variations]], OBender features a [[Persistent Hash Table|persistent learn file]] and various personalities. [[Move Ordering|Move ordering]] is further enhanced by the [[Killer Heuristic|killer heuristic]] and [[History Heuristic|history heuristic]], and the [[Evaluation|evaluation]] takes [[Material|material]], [[Piece-Square Tables|piece squares]], [[Pawn Structure|pawn structure]], [[King Safety|king safety]], and [[Mobility|mobility]] into account, also considering [[Attacks|attacks]] and [[X-ray|x-ray]] attacks and [[Pin|pinned pieces]] <ref>Description based on OBender-3.2.x.s.7.5</ref>.

=Etymology=
OBender is named after the main character of the classic [[https://en.wikipedia.org/wiki/Satire|satirical novel]] //[[https://en.wikipedia.org/wiki/The_Twelve_Chairs|The Twelve Chairs]]// by the [[https://en.wikipedia.org/wiki/Odessa|Odessan]] [[https://en.wikipedia.org/wiki/Soviet_Union|Soviet]] authors [[https://en.wikipedia.org/wiki/Ilf_and_Petrov|Ilf and Petrov]], released in 1928, and its 1931 sequel //[[https://en.wikipedia.org/wiki/The_Little_Golden_Calf|The Little Golden Calf]]//. “[[https://en.wiktionary.org/wiki/smooth_operator|Smooth operator]]” and [[https://en.wiktionary.org/wiki/conman|conman]] [[https://en.wikipedia.org/wiki/Ostap_Bender|Ostap Bender]] is a tricky individual who makes people believe he's a chess grandmaster and makes a now very well-known speech about making a small town called Vasiuki very famous by engaging it into a series of chess matches against the whole world, and even against other planets <ref>[[http://www.uschess.org/content/view/8881/475/|The United States Chess Federation - Ostap Bender and the Space Chess Game]] by [[https://en.wikipedia.org/wiki/Chess_Life|Glenn Petersen]], November 8, 2008 </ref> <ref>[[http://www.chessgames.com/perl/chessplayer?pid=137965|The chess games of Ostap Bender]] from [[http://www.chessgames.com/index.html|chessgames.com]]</ref> <ref>[[http://www.chess.com/blog/colibas/the-interplanetary-chess-congress|The Interplanetary Chess Congress]] by [[http://www.chess.com/members/view/colibas|colibas]], [[https://en.wikipedia.org/wiki/Chess.com|Chess.com]], August 17, 2012</ref>.

=See also=
* [[Various Classifications#Fiction|Fiction]]
* [[Ippolit]]
* [[QCHESS]]
* [[Woodpecker]]

=Forum Posts=
* [[http://www.open-aurec.com/wbforum/viewtopic.php?f=2&t=6526&p=3065|Problems with OBender]] by [[Harm Geert Muller]], [[Computer Chess Forums|Winboard Forum]], May 30, 2007
* [[http://www.talkchess.com/forum/viewtopic.php?t=17474|Highest number of programs?]] by Tony Thomas, [[CCC]], October 30, 2007
* [[http://www.talkchess.com/forum/viewtopic.php?t=23718|OBender 3.29a by Evgeniy Korniloff]] by [[Norbert Raimund Leisner]], [[CCC]], September 14, 2008
* [[http://www.talkchess.com/forum/viewtopic.php?t=28082|OBender by Evgeniy Korniloff (formely: QChess) as x64?]] by [[Norbert Raimund Leisner]], [[CCC]], May 23, 2009
* [[http://www.talkchess.com/forum/viewtopic.php?t=34787|Silent updates to Woodpecker and OBender]] by [[Tony Mokonen]], [[CCC]], June 07, 2010
* [[http://www.talkchess.com/forum/viewtopic.php?t=59876|Obender 03.2016 64-bit (working compile by Andrew Fan)]] by [[Graham Banks]], [[CCC]], April 16, 2016

=External Links=
==Chess Engine==
* [[http://evgeniy-korniloff.narod.ru/|Домашняя страничка Евгения Корнилова | Evgeniy Korniloff Home Page]]
> [[http://serg-nifont.narod.ru/obender.html|Chess OBender Download Free]] by [[Serg Nifont]]
* [[http://kirr.homeunix.org/chess/engines/Jim%20Ablett/OBENDER/|Index of /chess/engines/Jim Ablett/OBENDER]] by [[Jim Ablett]], hosted by [[Kirill Kryukov]]
* [[http://www.sdchess.ru/OBender.htm|OBender (ранее - Qchess-chess) by Evgeniy Korniloff, Russia]] from [[http://www.sdchess.ru/|sdchess.ru]]
* [[http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?print=Details&eng=OBender%203.2.4.2#OBender_3_2_4_2|OBender 3.2.4.2]] in [[CCRL|CCRL 40/40]]
==Misc==
* [[https://en.wikipedia.org/wiki/Ostap_Bender|Ostap Bender from Wikipedia]]
* [[https://en.wikipedia.org/wiki/The_Twelve_Chairs|The Twelve Chairs from Wikipedia]]
* [[http://www.chessgames.com/perl/chessplayer?pid=137965|The chess games of Ostap Bender]] from [[http://www.chessgames.com/index.html|chessgames.com]]
* Шахматы в фильме from the 1976 USSR series "12 стульев" ([[https://en.wikipedia.org/wiki/The_Twelve_Chairs_%281976_film%29|The Twelve Chairs]]) with [[https://en.wikipedia.org/wiki/Andrei_Mironov_%28actor%29|Andrei Mironov]] as [[https://en.wikipedia.org/wiki/Ostap_Bender|Ostap Bender]], [[https://en.wikipedia.org/wiki/YouTube|YouTube]] Video
> [[media type="youtube" key="USOvxS9RKa8" width="560"]]

=References= 
<references />
=What links here?= 
[[include component="backlinks" page="OBender" limit="50"]]
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