Ghost

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|| [[image:ghostseawolf.png link="http://etc.usf.edu/lit2go/153/the-sea-wolf/"]] ||~   || **Ghost**,
a [[Chess Engine Communication Protocol]] compatible, free chess engine written in [[Cpp|C++]] by [[Philipp Claßen]], supported by his brother Michael Claßen <ref>[[http://de.linkedin.com/pub/michael-cla%C3%9Fen/13/76/908?trk=pub-pbmap|Michael Claßen - Germany | LinkedIn]]</ref> . The name was taken from the name of [[https://en.wikipedia.org/wiki/The_Sea-Wolf#Wolf_Larsen|Wolf Larsen's]] seal-hunting schooner in the novel [[https://en.wikipedia.org/wiki/The_Sea-Wolf|The Sea-Wolf]] by [[https://en.wikipedia.org/wiki/Jack_London|Jack London]].

Ghost started its life in about 2000 as subject of a school project, the first version appeared in early 2001, playing online at [[Internet Chess Club]] <ref>[[http://www.stmintz.com/ccc/index.php?id=194607|crafty vs ghost on ICC ...could Kasparov himself execute such an attack?]] by Jeffrey Wadsworth, [[CCC]], October 28, 2001</ref> , and later in rating list tournaments such as [[CCRL]] <ref>[[http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?print=Details&each_game=1&eng=Ghost%202.0.1#Ghost_2_0_1|Ghost 2.0.1 in CCRL 40/40]]</ref> . Subsequent versions were Ghost 1, Ghost 2, and Ghost 3. Executables are available for [[Windows]] and [[Linux]] platforms. Likely, the current Ghost is [[Bitboards|bitboard]] based, due to the much faster 64-bit executable. ||
||  The Ghost <ref>[[http://etc.usf.edu/lit2go/153/the-sea-wolf/|The Sea-Wolf | Jack London | Lit2Go ETC]], Copyright © 2006—2018 by the [[https://fcit.usf.edu/|Florida Center for Instructional Technology]], [[http://www.usf.edu/education/|College of Education]], [[https://en.wikipedia.org/wiki/University_of_South_Florida|University of South Florida]]</ref> ||~   ||^   ||
[[toc]]
=Ghost 1= 
Ghost 1 performed [[NegaScout]], [[Internal Iterative Deepening|IID]], [[Killer Heuristic|killer-]] and [[History Heuristic|history heuristics]], [[Recursion|recursive]] [[Null Move Pruning|null move pruning]] with [[Depth Reduction R|depth reduction]] of 3, [[Razoring|razoring]] and [[Futility Pruning|futility pruning]], and a unique technique to detect [[Check#Perpetual|perpetual checks]]. It further used the [[Oracle|oracle]] approach of pre-scanned [[Piece-Square Tables|piece-square tables]] at the [[Root|root]] <ref>[[http://www.ghostchess.de/|Ghost | Search algorithms: Ghost 1]] by [[Philipp Claßen]]</ref> .

=Ghost 2= 
The second version, first released in 2003, is a [[MTD(f)]] searcher, further utilizing [[Late Move Reductions|late move reductions]], [[Null Move Pruning#AdaptiveNullMovePruning|adaptive null move pruning]] with [[Depth Reduction R|R]] of 2 or 3 [[Ply|plies]], [[Enhanced Transposition Cutoff|ETC]], and a unique [[Pin|pin]] detection [[Extensions|extension]]. Ghost 2 has a safer perpetual check detection than Ghost 1, and usus local history counters <ref>[[http://www.ghostchess.de/|Ghost | Search algorithms: Ghost 2]] by [[Philipp Claßen]]</ref> .

=Ghost 3= 
Still using [[MTD(f)]], the [[Search|search]] has been rewritten from scratch to support [[Parallel Search|parallelism]] using [[https://en.wikipedia.org/wiki/Work_stealing|work stealing]] provided by the [[https://en.wikipedia.org/wiki/Threading_Building_Blocks|Threading Building Blocks]] library. The stable version 3.1 was released on May 30, 2017 <ref>[[http://www.talkchess.com/forum/viewtopic.php?t=64143|Ghost 3.1 released!]] by [[Günther Simon]], [[CCC]], June 01, 2017</ref>.

=See also= 
* [[Various Classifications#Demonology|Demonology]]
* [[Various Classifications#Fiction|Fiction]]
* [[Various Classifications#Ship|Ship]]

=Forum Posts= 
* [[http://www.stmintz.com/ccc/index.php?id=194607|crafty vs ghost on ICC ...could Kasparov himself execute such an attack?]] by Jeffrey Wadsworth, [[CCC]], October 28, 2001 » [[Crafty]]
* [[http://www.open-aurec.com/wbforum/viewtopic.php?f=18&t=49019|new ghost homepage]] by Michael Claßen, [[Computer Chess Forums|Winboard Forum]], September 22, 2004
* [[http://www.talkchess.com/forum/viewtopic.php?t=64143|Ghost 3.1 released!]] by [[Günther Simon]], [[CCC]], June 01, 2017 

=External Links= 
==Chess Engine==
* [[http://www.ghostchess.de/|Ghost]] by [[Philipp Claßen]]
* [[http://wbec-ridderkerk.nl/html/details1/Ghost.html|Ghost]] from [[WBEC|WBEC Ridderkerk]]
==Misc==
* [[https://en.wikipedia.org/wiki/Ghost_%28disambiguation%29|Ghost (disambiguation) from Wikipedia]]
* [[https://en.wikipedia.org/wiki/Ghost|Ghost from Wikipedia]]
* [[https://en.wikipedia.org/wiki/List_of_ghost_ships|List of ghost ships from Wikipedia]]
* [[Adam Marczyk]] (**2003**). //[[http://www.ebonmusings.org/atheism/ghost.html|A Ghost in the Machine]]//. [[http://www.ebonmusings.org/atheism/index.html|EBON MUSINGS: The Atheism Pages]]
* [[https://de.wikipedia.org/wiki/John_Ruocco|John Ruocco]] - A Ghost of a Chance, [[http://english.culture.gov.taipei/News_Content.aspx?n=8328A0B4118F4B0D&sms=72542738B8C4C5D9&s=4C4EEACB6CFB48ED|Taipei Jazz Festival]], 2013, [[https://en.wikipedia.org/wiki/YouTube|YouTube]] Video
> feat.: [[http://www.joachimschoenecker.com/no_flash.php|Joachim Schoenecker]], [[http://www.jazzinbelgium.com/person/id=90?lang=en|Bart De Nolf]], [[http://www.mimiverderame.com/|Mimi Verderame]]
> [[media type="youtube" key="GtbTC-EUvn4"]]

=References= 
<references />
=What links here?= 
[[include page="Ghost" component="backlinks" limit="30"]]
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