25,161
edits
Changes
Created page with "'''Home * Engines * Arasan''' {| |- | rowspan="2" | '''Arasan''',<br/> an open source engine written by Jon Dart in [[Cpp|C++]..."
'''[[Main Page|Home]] * [[Engines]] * Arasan'''
{|
|-
| rowspan="2" | '''Arasan''',<br/>
an [[:Category:Open Source|open source engine]] written by [[Jon Dart]] in [[Cpp|C++]]. Arasan's development started in the early 90s, the first version, released in 1994 was a 16-bit program running under [[Windows|Windows 3.1]] using an [[8x8 Board]], [[Incremental Updates|incremental updated]] [[Attack and Defend Maps|attack tables]] and its own [[GUI]], evolving to a portable 32-bit and later 64-bit program, utilizing [[Bitboards|bitboards]] to determine its [[Sliding Piece Attacks|sliding piece attacks]] with [[Rotated Bitboards|rotated bitboard lookups]]. In 2008, rotated were replaced by [[Magic Bitboards|Magic bitboards]], which gave Arasan about a 20-25% speedup <ref>[http://www.arasanchess.org/blogs/aug08.html Arasan Blog - Aug 26, 2008]</ref>.
Despite its own GUI, Arasan early supported the [[Chess Engine Communication Protocol]] and later [[UCI]] as well, to run under [[Windows]], [[Linux]] and [[Mac OS]] <ref>[http://www.arasanchess.org/ Arasan chess]</ref>. The latest version of Arasan and all major versions, including Version 1.0 from March 1994, are available as source code from the Arasan.org site <ref>[http://www.arasanchess.org/downld.shtml Arasan Downloads]</ref> . Jon's change logs, bug fix reports and tournament reports over the time are available from [[Computer Chess Forums|forum archives]], as well the recent ones from the Arasan blog <ref>[http://arasanchess.org/blog.shtml Arasan Tech Blog]</ref>
| <span style="font-size: 600%;">அரசன்</span>
|-
| அரசன் <ref>[https://en.wikipedia.org/wiki/Tamil_script Tamil script from Wikipedia]</ref> (Arasan) , King in [https://en.wikipedia.org/wiki/Tamil_language Tamil language] <ref>[https://ta.wikipedia.org/wiki/%E0%AE%85%E0%AE%B0%E0%AE%9A%E0%AE%A9%E0%AF%8D_(%E0%AE%9A%E0%AE%A4%E0%AF%81%E0%AE%B0%E0%AE%99%E0%AF%8D%E0%AE%95%E0%AE%AE%E0%AF%8D) அரசன் (சதுரங்கம்) - தமிழ் விக்கிப்பீடியா]</ref>
|}
=Bitboard Trials=
[[Jon Dart]], May 1996 <ref>[http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/d75cd258ea73a4a7 Arasan progress report] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], May 23, 1996</ref>
Lately I've been working on a new major release of Arasan. I have spent the last few months working on the search engine, trying to improve speed and performance. I tried some experiments with a [[Bitboards|bitboard]] move representation, but I have backed off on that for now.
With bitboards, I got a nice reduction in tree size (bitboards allow a more accurate [[Static Exchange Evaluation|swap-down analysis]] than I had before, and this improves [[Move Ordering|move ordering]] and allows better "culling" of losing captures in the [[Quiescence Search|quiescence search]]).
However, currently the program relies pretty heavily on [[Incremental Updates|incrementally generated]] [[Attack and Defend Maps|attack information]], and I didn't have that implemented to work with bitboards, so I had to compute attacks as needed. Unfortunately, the current program "needs" to do this much more often than [[Crafty]] does, so the loss from computing attacks more than balanced out the gains from bitboards. This is fixable, I'm sure, but I've put off further work on it for now.
=Magic Bitboards=
[[Jon Dart]], August 2008 <ref>[http://www.arasanchess.org/blogs/aug08.html Arasan Blog - Aug 26, 2008]</ref> :
The main change has been to re-work the code to use [[Magic Bitboards|"magic" bitboard logic]] instead of [[Rotated Bitboards|rotated bitboards]]. This has given about a 20-25% speedup. I have also had to re-write the [[Evaluation|evaluation function]] to take advantage of bitboard attack functions for [[King Safety|king safety]] and [[Mobility|mobility]].
=PEXT/PDEP Bitboards=
Arasan '''20.3''', released in November 2017, performs [[BMI2#PDEPBitboards|PEXT/PDEP Bitboards]] if compiled for the [[BMI2]] instruction set <ref>[http://www.talkchess.com/forum/viewtopic.php?t=65636 Arasan 20.3] by [[Jon Dart]], [[CCC]], November 05, 2017</ref> to replace [[Magic Bitboards#Fancy|Fancy Magic Bitboards]] in looking up [[Sliding Piece Attacks|sliding piece attacks]] <ref>arasan_source20.3.zip/src/attacks.h</ref>
<span id="Tuning"></span>
=Automated Tuning=
Arasan '''19.2''', released in November 2016, now applies [[Texel's Tuning Method]] by default and supports the ''Adam'' [https://en.wikipedia.org/wiki/Gradient_descent gradient descent] algorithm <ref>[http://www.talkchess.com/forum/viewtopic.php?t=61948 Arasan 19.2] by [[Jon Dart]], [[CCC]], November 03, 2016</ref> <ref>[https://scholar.google.nl/citations?user=yyIoQu4AAAAJ Diederik P. Kingma], [https://scholar.google.ca/citations?user=ymzxRhAAAAAJ&hl=en Jimmy Lei Ba] ('''2015'''). ''Adam: A Method for Stochastic Optimization''. [https://arxiv.org/abs/1412.6980v8 arXiv:1412.6980v8], [http://www.iclr.cc/doku.php?id=iclr2015:main ICLR 2015]</ref>.
=Lazy SMP=
As of version 21.0 in June 2018 Arasan comes with a [[Lazy SMP]] implementation.
=Tournament Play=
Arasan went online in December, 1996 <ref>[http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/4a4705301c3c3229 Arasan goes online] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], January 6, 1997</ref> , and played almost all major online computer chess tournaments, such as [[CCT Tournaments]], [[ACCA Americas' Computer Chess Championship]], [[ACCA World Computer Rapid Chess Championship]], [[TCEC]], and [[Italian Computer Chess Championship#IGWT|International Gsei Web Tournaments]]. Arasan 15.1 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46077 Arasan 15.1] by [[Jon Dart]], [[CCC]], November 19, 2012</ref> won the [[ACCA 2012]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46047 Seventh Annual ACCA Americas' Computer Chess Championships] by [[Jon Dart]], [[CCC]], November 18, 2012</ref> , Arasan 16.0 the [[WCRCC 2013]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=48703 Arasan games from WCRCC] by [[Jon Dart]], [[CCC]], July 21, 2013</ref> . Over the board, Arasan is active at the [[CSVN Programmers Tournament|CSVN Programmers Tournaments]] operated by [[Tessa Pijl]]. Arasan was runner-up behind [[The Baron]] in May 2014 at the [[PT 46]] one point behind, as well in June 2015 at the [[PT 48]] with the same score according to the tiebreak rules <ref>[http://www.talkchess.com/forum/viewtopic.php?t=56645&start=3 Baron 1st, Arasan 2nd] by [[Jon Dart]], [[CCC]], June 14, 2015</ref>.
=Photos & Games=
[[FILE:ArasanTheKingPT48.jpg|none|border|text-bottom|link=http://www.computerschaak.nl/index.php/nieuws/51-toernooien/704-pt48-round-7]]
[[PT 48]], Two Kings fighting, [[Johan de Koning]] and [[Tessa Pijl]] in [[Arasan]] vs. [[The King]] <ref>[http://www.computerschaak.nl/index.php/nieuws/51-toernooien/704-pt48-round-7 PT48 Round 7]</ref>
<pre>
[Event "PT 48"]
[Site "Leiden, NL"]
[Date "2015.06.14"]
[Round "7"]
[White "Arasan"]
[Black "The King"]
[Result "1-0"]
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6
9.a4 b4 10.Ne4 c5 11.Nxf6+ Nxf6 12.dxc5 Bxc5 13.e4 Bb7 14.Qe2 O-O 15.O-O e5
16.Bg5 h6 17.Bh4 Qd6 18.Bg3 Rfe8 19.Rfd1 Re7 20.Bh4 Qc6 21.Rac1 Rc8 22.Rc4 Re6
23.Bxf6 Rxf6 24.Rdc1 Qb6 25.Kh1 a5 26.Qc2 b3 27.Qe2 Qd6 28.R4c3 Rf4 29.g3 Rf6
30.Bc4 Rb8 31.Rxb3 Bb4 32.Rd3 Qc7 33.Kg2 Rf8 34.Rdd1 Rc6 35.b3 Re8 36.Kg1 Rc8
37.Rd5 Re6 38.Rd3 Rf6 39.Rcd1 Re8 40.Nh4 Qb6 41.Nf5 Rf8 42.Rf3 Kh8 43.Nh4 Kg8
44.Rd7 Bc8 45.Rd5 Rd6 46.Rxd6 Qxd6 47.Rd3 Qc7 48.Qh5 Kh7 49.Nf3 f6 50.Nh4 Bd7
51.Bf7 Bc8 52.Bg6+ Kg8 53.Bf5 Qc2 54.Qf3 Re8 55.Kg2 Rf8 56.Rd5 Bc5 57.Bxc8 Rxc8
58.Rd7 Bf8 59.Qg4 h5 60.Qg6 Qe2 61.Nf3 Qc2 62.Qf7+ Kh8 63.Qxh5+ Kg8 64.Nd2 Rb8
65.g4 Rc8 66.Qf7+ Kh8 67.Qh5+ Kg8 68.Qg6 Kh8 69.Qf5 Kg8 70.g5 fxg5 71.Nf3 Qc6
72.Nxg5 Qh6 73.Rd3 Rc7 74.Rf3 Bb4 75.Rh3 Bf8 76.Rxh6 1-0
</pre>
=See also=
* [[:Category:Chess Pieces|Chess Pieces]]
* [[King]]
* [[:Category:Nobility|Nobility]]
=Forum Posts=
==1995 ...==
* [http://groups.google.com/group/rec.games.chess/browse_frm/thread/489bd1c77cf3f5a3 Arasan 2.0 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess]], July 4, 1995
* [http://groups.google.com/group/rec.games.chess.misc/browse_frm/thread/feab13109d3fea8d Arasan 2.1 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess.misc]], October 23, 1995
* [http://groups.google.com/group/rec.games.chess.misc/browse_frm/thread/353af31249b8e71a Arasan 2.2 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess.misc]], December 10, 1995
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/d75cd258ea73a4a7 Arasan progress report] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], May 23, 1996
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/da81bfa994db07e Arasan 3.0 (Windows chess program) available] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], July 8, 1996
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/4a4705301c3c3229 Arasan goes online] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], January 6, 1997
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/400f58ce4133b3dc Arasan 4.0 is available] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], July 15, 1997
* [https://www.stmintz.com/ccc/index.php?id=39273 Arasan 5.0 released] by [[Jon Dart]], [[CCC]], January 13, 1999
==2000 ...==
* [https://www.stmintz.com/ccc/index.php?id=112475 Arasan 5.4 released] by [[Jon Dart]], [[CCC]], May 25, 2000
* [https://www.stmintz.com/ccc/index.php?id=114810 Arasan vs. IM Paunovic] by [[Jon Dart]], [[CCC]], June 16, 2000
* [https://www.stmintz.com/ccc/index.php?id=127953 Arasan now under Linux] by [[Jon Dart]], [[CCC]], September 02, 2000
* [https://www.stmintz.com/ccc/index.php?id=136752 A few notes from Arasan's games in CCT2] by [[Jon Dart]], [[CCC]], November 05, 2000 » [[CCT2]]
* [https://www.stmintz.com/ccc/index.php?id=208715 CCT4 notes - Arasan] by [[Jon Dart]], [[CCC]], January 20, 2002 » [[CCT4]]
* [https://www.stmintz.com/ccc/index.php?id=253897 Arasan 6.0] by [[Jon Dart]], [[CCC]], September 24, 2002
* [https://www.stmintz.com/ccc/index.php?id=279622 Arasan 6.3] by [[Jon Dart]], [[CCC]], January 26, 2003
* [https://www.stmintz.com/ccc/index.php?id=310679 Arasan 7.0] by [[Jon Dart]], [[CCC]], August 09, 2003
* [https://www.stmintz.com/ccc/index.php?id=351899 Arasan 7.4] by [[Jon Dart]], [[CCC]], February 28, 2004
* [https://www.stmintz.com/ccc/index.php?id=357325 Arasan 7.4 64-bit Speedup] by [[Slater Wold]], [[CCC]], March 30, 2004
* [https://www.stmintz.com/ccc/index.php?id=383566 Arasan 8.0] by [[Jon Dart]], [[CCC]], August 22, 2004
* [https://www.stmintz.com/ccc/index.php?id=397817 Arasan 8.2] by [[Jon Dart]], [[CCC]], November 26, 2004
==2005 ...==
* [https://www.stmintz.com/ccc/index.php?id=414274 Arasan 8.4] by [[Jon Dart]], [[CCC]], February 26, 2005
* [https://www.stmintz.com/ccc/index.php?id=489903 Arasan in CCT8] by [[Jon Dart]], [[CCC]], February 26, 2006 » [[CCT8]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15306 Arasan @ WCRCC tournament] by [[Jon Dart]], [[CCC]], July 23, 2007 » [[WCRCC 2007]]
* [http://www.talkchess.com/forum/viewtopic.php?t=16221 Arasan 10.0] by [[Jon Dart]], [[CCC]], September 02, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=19673 Arasan 10.2] by [[Jon Dart]], [[CCC]], February 16, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=22020 Arasan 10.4] by [[Jon Dart]], [[CCC]], June 27, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=25134 Arasan 11.0] by [[Jon Dart]], [[CCC]], November 28, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=27151 Arasan 11.3] by [[Jon Dart]], [[CCC]], March 24, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=28528 Arasan 11.4] by [[Jon Dart]], [[CCC]], June 20, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=29668 Arasan 11.5] by [[Jon Dart]], [[CCC]], September 05, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=30678 Arasan 11.6] by [[Jon Dart]], [[CCC]], November 18, 2009
==2010 ...==
* [http://www.talkchess.com/forum/viewtopic.php?t=32449 Arasan 11.7] by [[Jon Dart]], [[CCC]], February 07, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=35724 Arasan 12.0 released] by [[Jon Dart]], [[CCC]], August 07, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=36661 Arasan 12.2 released] by [[Jon Dart]], [[CCC]], November 11, 2010
'''2011'''
* [http://www.talkchess.com/forum/viewtopic.php?t=37921 Arasan 12.3 released] by [[Jon Dart]], [[CCC]], February 02, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40091 Arasan 13.0] by [[Jon Dart]], [[CCC]], August 18, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40157 Arasan 13.1] by [[Jon Dart]], [[CCC]], August 23, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40186 MORE about Arasan 13.1] by [[Fernando Villegas]], [[CCC]], August 26, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40617 Arasan 13.2] by [[Jon Dart]], [[CCC]], October 02, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=41086 Arasan 13.3] by [[Jon Dart]], [[CCC]], November 14, 2011 » [[ACCA 2011]]
* [http://www.talkchess.com/forum/viewtopic.php?t=41369 Arasan 13.4] by [[Jon Dart]], [[CCC]], December 07, 2011
'''2012'''
* [http://www.talkchess.com/forum/viewtopic.php?t=42736 Arasan 14.0] by [[Jon Dart]], [[CCC]], March 04, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=44044 Arasan 14.2] by [[Jon Dart]], [[CCC]], June 12, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=44492 Arasan 14.3] by [[Jon Dart]], [[CCC]], July 18, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=45229 Arasan 15.0] by [[Jon Dart]], [[CCC]], September 20, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=46077 Arasan 15.1] by [[Jon Dart]], [[CCC]], November 19, 2012
'''2013'''
* [http://www.talkchess.com/forum/viewtopic.php?t=47333 Arasan 15.2] by [[Jon Dart]], [[CCC]], February 26, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=47845 Arasan 15.4] by [[Jon Dart]], [[CCC]], April 24, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=48070 Arasan 15.6] by [[Jon Dart]], [[CCC]], May 21, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=48082 Arasan on github] by [[Jon Dart]], [[CCC]], May 22, 2013 <ref>[https://github.com/jdart1/arasan-chess jdart1/arasan-chess · GitHub]</ref>
* [http://www.talkchess.com/forum/viewtopic.php?t=48703 Arasan games from WCRCC] by [[Jon Dart]], [[CCC]], July 21, 2013 » [[WCRCC 2013]]
* [http://www.talkchess.com/forum/viewtopic.php?t=48748 Arasan 16.0] by [[Jon Dart]], [[CCC]], July 24, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=49205 Arasan 16.1] by [[Jon Dart]], [[CCC]], September 01, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=49824 Arasan 16.2] by [[Jon Dart]], [[CCC]], October 25, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=50348 Arasan 16.3] by [[Jon Dart]], [[CCC]], December 06, 2013
'''2014'''
* [http://www.talkchess.com/forum/viewtopic.php?t=51071 test position: Rookie-Arasan] by [[Jon Dart]], [[CCC]], January 27, 2014 » [[Rookie]], [[Zugzwang]]
* [http://www.talkchess.com/forum/viewtopic.php?t=51760 Arasan 17.0] by [[Jon Dart]], [[CCC]], March 27, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=51839 Arasan GUI fixes] by [[Jon Dart]], [[CCC]], April 02, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=52242 Arasan 17.1] by [[Jon Dart]], [[CCC]], May 07, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=52474 Arasan 17.2] by [[Jon Dart]], [[CCC]], May 30, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=53532 Arasan 17.3] by [[Jon Dart]], [[CCC]], September 01, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=53987 Arasan 17.4] by [[Jon Dart]], [[CCC]], October 08, 2014
==2015 ...==
* [http://www.talkchess.com/forum/viewtopic.php?t=55072 Arasan 17.5] by [[Jon Dart]], [[CCC]], January 24, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=55621 Experiments with eval tuning] by [[Jon Dart]], [[CCC]], March 10, 2015 » [[Automated Tuning]], [[Texel's Tuning Method]]
* [http://www.talkchess.com/forum/viewtopic.php?t=57122 Arasan 18.0] by [[Jon Dart]], [[CCC]], July 30, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=58130 Arasan 18.1] by [[Jon Dart]], [[CCC]], November 02, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=58460 Arasan 18.2] by [[Jon Dart]], [[CCC]], December 03, 2015
'''2016'''
* [http://www.talkchess.com/forum/viewtopic.php?t=59138 Arasan 18.3] by [[Jon Dart]], [[CCC]], February 02, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=59463 Arasan Syzygy support (working with Windows, too)] by [[Jon Dart]], [[CCC]], March 10, 2016 » [[Syzygy Bases]]
* [http://www.talkchess.com/forum/viewtopic.php?t=59997 Arasan 19.0 + updated test suite] by [[Jon Dart]], [[CCC]], April 29, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=61077 Arasan 19.1] by [[Jon Dart]], [[CCC]], August 09, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=61948 Arasan 19.2] by [[Jon Dart]], [[CCC]], November 03, 2016
'''2017'''
* [http://www.talkchess.com/forum/viewtopic.php?t=62987 Arasan 20.0] by [[Jon Dart]], [[CCC]], January 31, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=63773 building for Android] by [[Jon Dart]], [[CCC]], April 19, 2017 » [[Android]]
* [http://www.talkchess.com/forum/viewtopic.php?t=63855 Arasan 20.1] by [[Jon Dart]], [[CCC]], April 28, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=64364 Arasan Programmer's Guide] by [[Jon Dart]], [[CCC]], June 21, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=64610 Arasan 20.2] by [[Jon Dart]], [[CCC]], July 15, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=65636 Arasan 20.3] by [[Jon Dart]], [[CCC]], November 05, 2017
'''2018'''
* [http://www.talkchess.com/forum/viewtopic.php?t=66232 Arasan 20.4] by [[Jon Dart]], [[CCC]], January 03, 2018
* [http://www.talkchess.com/forum/viewtopic.php?t=66254 Arasan 20.4.1] by [[Jon Dart]], [[CCC]], January 05, 2018
* [http://www.talkchess.com/forum/viewtopic.php?t=67040 Arasan 20.5] by [[Jon Dart]], [[CCC]], April 08, 2018
* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=67805&p=766218 Arasan 21.0 beta] by [[Jon Dart]], [[CCC]], June 23, 2018
* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=67855&p=766972 Arasan 21.0] by [[Jon Dart]], [[CCC]], June 30, 2018
=External Links=
==Chess Engine==
* [http://arasanchess.org/index.shtml Arasan Chess] by [[Jon Dart]]
* [https://arasanchess.org/programr.shtml Arasan Programmer's Guide] by [[Jon Dart]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=64364 Arasan Programmer's Guide] by [[Jon Dart]], [[CCC]], June 21, 2017</ref>
* [http://www.arasanchess.org/testsuite.shtml Arasan Test Suite]
* [http://www.playwitharena.com/?Newsticker:Archive_5 Arasan 8.4 released, short interview with Jon Dart] by [[Frank Quisinsky]], March 01, 2005, [[Arena|Arena Chess GUI]], Archive 5, 72
* [https://github.com/jdart1/arasan-chess jdart1/arasan-chess · GitHub] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=48082 Arasan on github] by [[Jon Dart]], [[CCC]], May 22, 2013</ref>
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Arasan%2017.0%2064-bit#Arasan_17_0_64-bit Arasan 17.0 64-bit] in [[CCRL|CCRL 40/40]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Arasan%2018.0%2064-bit%204CPU#Arasan_18_0_64-bit_4CPU Arasan 18.0 64-bit] in [[CCRL|CCRL 40/40]]
==Misc==
* [https://en.wikipedia.org/wiki/Arasan Arasan from Wikipedia]
* [https://en.wikipedia.org/wiki/Imsai_Arasan_23rd_Pulikecei Imsai Arasan 23rd Pulikecei from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Chess Pieces]]
[[Category:Nobility]]
[[Category:UCI]]
[[Category:WinBoard]]
[[Category:XBoard]]
[[Category:Open Source]]
{|
|-
| rowspan="2" | '''Arasan''',<br/>
an [[:Category:Open Source|open source engine]] written by [[Jon Dart]] in [[Cpp|C++]]. Arasan's development started in the early 90s, the first version, released in 1994 was a 16-bit program running under [[Windows|Windows 3.1]] using an [[8x8 Board]], [[Incremental Updates|incremental updated]] [[Attack and Defend Maps|attack tables]] and its own [[GUI]], evolving to a portable 32-bit and later 64-bit program, utilizing [[Bitboards|bitboards]] to determine its [[Sliding Piece Attacks|sliding piece attacks]] with [[Rotated Bitboards|rotated bitboard lookups]]. In 2008, rotated were replaced by [[Magic Bitboards|Magic bitboards]], which gave Arasan about a 20-25% speedup <ref>[http://www.arasanchess.org/blogs/aug08.html Arasan Blog - Aug 26, 2008]</ref>.
Despite its own GUI, Arasan early supported the [[Chess Engine Communication Protocol]] and later [[UCI]] as well, to run under [[Windows]], [[Linux]] and [[Mac OS]] <ref>[http://www.arasanchess.org/ Arasan chess]</ref>. The latest version of Arasan and all major versions, including Version 1.0 from March 1994, are available as source code from the Arasan.org site <ref>[http://www.arasanchess.org/downld.shtml Arasan Downloads]</ref> . Jon's change logs, bug fix reports and tournament reports over the time are available from [[Computer Chess Forums|forum archives]], as well the recent ones from the Arasan blog <ref>[http://arasanchess.org/blog.shtml Arasan Tech Blog]</ref>
| <span style="font-size: 600%;">அரசன்</span>
|-
| அரசன் <ref>[https://en.wikipedia.org/wiki/Tamil_script Tamil script from Wikipedia]</ref> (Arasan) , King in [https://en.wikipedia.org/wiki/Tamil_language Tamil language] <ref>[https://ta.wikipedia.org/wiki/%E0%AE%85%E0%AE%B0%E0%AE%9A%E0%AE%A9%E0%AF%8D_(%E0%AE%9A%E0%AE%A4%E0%AF%81%E0%AE%B0%E0%AE%99%E0%AF%8D%E0%AE%95%E0%AE%AE%E0%AF%8D) அரசன் (சதுரங்கம்) - தமிழ் விக்கிப்பீடியா]</ref>
|}
=Bitboard Trials=
[[Jon Dart]], May 1996 <ref>[http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/d75cd258ea73a4a7 Arasan progress report] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], May 23, 1996</ref>
Lately I've been working on a new major release of Arasan. I have spent the last few months working on the search engine, trying to improve speed and performance. I tried some experiments with a [[Bitboards|bitboard]] move representation, but I have backed off on that for now.
With bitboards, I got a nice reduction in tree size (bitboards allow a more accurate [[Static Exchange Evaluation|swap-down analysis]] than I had before, and this improves [[Move Ordering|move ordering]] and allows better "culling" of losing captures in the [[Quiescence Search|quiescence search]]).
However, currently the program relies pretty heavily on [[Incremental Updates|incrementally generated]] [[Attack and Defend Maps|attack information]], and I didn't have that implemented to work with bitboards, so I had to compute attacks as needed. Unfortunately, the current program "needs" to do this much more often than [[Crafty]] does, so the loss from computing attacks more than balanced out the gains from bitboards. This is fixable, I'm sure, but I've put off further work on it for now.
=Magic Bitboards=
[[Jon Dart]], August 2008 <ref>[http://www.arasanchess.org/blogs/aug08.html Arasan Blog - Aug 26, 2008]</ref> :
The main change has been to re-work the code to use [[Magic Bitboards|"magic" bitboard logic]] instead of [[Rotated Bitboards|rotated bitboards]]. This has given about a 20-25% speedup. I have also had to re-write the [[Evaluation|evaluation function]] to take advantage of bitboard attack functions for [[King Safety|king safety]] and [[Mobility|mobility]].
=PEXT/PDEP Bitboards=
Arasan '''20.3''', released in November 2017, performs [[BMI2#PDEPBitboards|PEXT/PDEP Bitboards]] if compiled for the [[BMI2]] instruction set <ref>[http://www.talkchess.com/forum/viewtopic.php?t=65636 Arasan 20.3] by [[Jon Dart]], [[CCC]], November 05, 2017</ref> to replace [[Magic Bitboards#Fancy|Fancy Magic Bitboards]] in looking up [[Sliding Piece Attacks|sliding piece attacks]] <ref>arasan_source20.3.zip/src/attacks.h</ref>
<span id="Tuning"></span>
=Automated Tuning=
Arasan '''19.2''', released in November 2016, now applies [[Texel's Tuning Method]] by default and supports the ''Adam'' [https://en.wikipedia.org/wiki/Gradient_descent gradient descent] algorithm <ref>[http://www.talkchess.com/forum/viewtopic.php?t=61948 Arasan 19.2] by [[Jon Dart]], [[CCC]], November 03, 2016</ref> <ref>[https://scholar.google.nl/citations?user=yyIoQu4AAAAJ Diederik P. Kingma], [https://scholar.google.ca/citations?user=ymzxRhAAAAAJ&hl=en Jimmy Lei Ba] ('''2015'''). ''Adam: A Method for Stochastic Optimization''. [https://arxiv.org/abs/1412.6980v8 arXiv:1412.6980v8], [http://www.iclr.cc/doku.php?id=iclr2015:main ICLR 2015]</ref>.
=Lazy SMP=
As of version 21.0 in June 2018 Arasan comes with a [[Lazy SMP]] implementation.
=Tournament Play=
Arasan went online in December, 1996 <ref>[http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/4a4705301c3c3229 Arasan goes online] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], January 6, 1997</ref> , and played almost all major online computer chess tournaments, such as [[CCT Tournaments]], [[ACCA Americas' Computer Chess Championship]], [[ACCA World Computer Rapid Chess Championship]], [[TCEC]], and [[Italian Computer Chess Championship#IGWT|International Gsei Web Tournaments]]. Arasan 15.1 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46077 Arasan 15.1] by [[Jon Dart]], [[CCC]], November 19, 2012</ref> won the [[ACCA 2012]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46047 Seventh Annual ACCA Americas' Computer Chess Championships] by [[Jon Dart]], [[CCC]], November 18, 2012</ref> , Arasan 16.0 the [[WCRCC 2013]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=48703 Arasan games from WCRCC] by [[Jon Dart]], [[CCC]], July 21, 2013</ref> . Over the board, Arasan is active at the [[CSVN Programmers Tournament|CSVN Programmers Tournaments]] operated by [[Tessa Pijl]]. Arasan was runner-up behind [[The Baron]] in May 2014 at the [[PT 46]] one point behind, as well in June 2015 at the [[PT 48]] with the same score according to the tiebreak rules <ref>[http://www.talkchess.com/forum/viewtopic.php?t=56645&start=3 Baron 1st, Arasan 2nd] by [[Jon Dart]], [[CCC]], June 14, 2015</ref>.
=Photos & Games=
[[FILE:ArasanTheKingPT48.jpg|none|border|text-bottom|link=http://www.computerschaak.nl/index.php/nieuws/51-toernooien/704-pt48-round-7]]
[[PT 48]], Two Kings fighting, [[Johan de Koning]] and [[Tessa Pijl]] in [[Arasan]] vs. [[The King]] <ref>[http://www.computerschaak.nl/index.php/nieuws/51-toernooien/704-pt48-round-7 PT48 Round 7]</ref>
<pre>
[Event "PT 48"]
[Site "Leiden, NL"]
[Date "2015.06.14"]
[Round "7"]
[White "Arasan"]
[Black "The King"]
[Result "1-0"]
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6
9.a4 b4 10.Ne4 c5 11.Nxf6+ Nxf6 12.dxc5 Bxc5 13.e4 Bb7 14.Qe2 O-O 15.O-O e5
16.Bg5 h6 17.Bh4 Qd6 18.Bg3 Rfe8 19.Rfd1 Re7 20.Bh4 Qc6 21.Rac1 Rc8 22.Rc4 Re6
23.Bxf6 Rxf6 24.Rdc1 Qb6 25.Kh1 a5 26.Qc2 b3 27.Qe2 Qd6 28.R4c3 Rf4 29.g3 Rf6
30.Bc4 Rb8 31.Rxb3 Bb4 32.Rd3 Qc7 33.Kg2 Rf8 34.Rdd1 Rc6 35.b3 Re8 36.Kg1 Rc8
37.Rd5 Re6 38.Rd3 Rf6 39.Rcd1 Re8 40.Nh4 Qb6 41.Nf5 Rf8 42.Rf3 Kh8 43.Nh4 Kg8
44.Rd7 Bc8 45.Rd5 Rd6 46.Rxd6 Qxd6 47.Rd3 Qc7 48.Qh5 Kh7 49.Nf3 f6 50.Nh4 Bd7
51.Bf7 Bc8 52.Bg6+ Kg8 53.Bf5 Qc2 54.Qf3 Re8 55.Kg2 Rf8 56.Rd5 Bc5 57.Bxc8 Rxc8
58.Rd7 Bf8 59.Qg4 h5 60.Qg6 Qe2 61.Nf3 Qc2 62.Qf7+ Kh8 63.Qxh5+ Kg8 64.Nd2 Rb8
65.g4 Rc8 66.Qf7+ Kh8 67.Qh5+ Kg8 68.Qg6 Kh8 69.Qf5 Kg8 70.g5 fxg5 71.Nf3 Qc6
72.Nxg5 Qh6 73.Rd3 Rc7 74.Rf3 Bb4 75.Rh3 Bf8 76.Rxh6 1-0
</pre>
=See also=
* [[:Category:Chess Pieces|Chess Pieces]]
* [[King]]
* [[:Category:Nobility|Nobility]]
=Forum Posts=
==1995 ...==
* [http://groups.google.com/group/rec.games.chess/browse_frm/thread/489bd1c77cf3f5a3 Arasan 2.0 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess]], July 4, 1995
* [http://groups.google.com/group/rec.games.chess.misc/browse_frm/thread/feab13109d3fea8d Arasan 2.1 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess.misc]], October 23, 1995
* [http://groups.google.com/group/rec.games.chess.misc/browse_frm/thread/353af31249b8e71a Arasan 2.2 (Windows chess program) available via ftp] by [[Jon Dart]], [[Computer Chess Forums|rec.games.chess.misc]], December 10, 1995
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/d75cd258ea73a4a7 Arasan progress report] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], May 23, 1996
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/da81bfa994db07e Arasan 3.0 (Windows chess program) available] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], July 8, 1996
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/4a4705301c3c3229 Arasan goes online] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], January 6, 1997
* [http://groups.google.com/group/rec.games.chess.computer/browse_frm/thread/400f58ce4133b3dc Arasan 4.0 is available] by [[Jon Dart]], [[Computer Chess Forums|rgcc]], July 15, 1997
* [https://www.stmintz.com/ccc/index.php?id=39273 Arasan 5.0 released] by [[Jon Dart]], [[CCC]], January 13, 1999
==2000 ...==
* [https://www.stmintz.com/ccc/index.php?id=112475 Arasan 5.4 released] by [[Jon Dart]], [[CCC]], May 25, 2000
* [https://www.stmintz.com/ccc/index.php?id=114810 Arasan vs. IM Paunovic] by [[Jon Dart]], [[CCC]], June 16, 2000
* [https://www.stmintz.com/ccc/index.php?id=127953 Arasan now under Linux] by [[Jon Dart]], [[CCC]], September 02, 2000
* [https://www.stmintz.com/ccc/index.php?id=136752 A few notes from Arasan's games in CCT2] by [[Jon Dart]], [[CCC]], November 05, 2000 » [[CCT2]]
* [https://www.stmintz.com/ccc/index.php?id=208715 CCT4 notes - Arasan] by [[Jon Dart]], [[CCC]], January 20, 2002 » [[CCT4]]
* [https://www.stmintz.com/ccc/index.php?id=253897 Arasan 6.0] by [[Jon Dart]], [[CCC]], September 24, 2002
* [https://www.stmintz.com/ccc/index.php?id=279622 Arasan 6.3] by [[Jon Dart]], [[CCC]], January 26, 2003
* [https://www.stmintz.com/ccc/index.php?id=310679 Arasan 7.0] by [[Jon Dart]], [[CCC]], August 09, 2003
* [https://www.stmintz.com/ccc/index.php?id=351899 Arasan 7.4] by [[Jon Dart]], [[CCC]], February 28, 2004
* [https://www.stmintz.com/ccc/index.php?id=357325 Arasan 7.4 64-bit Speedup] by [[Slater Wold]], [[CCC]], March 30, 2004
* [https://www.stmintz.com/ccc/index.php?id=383566 Arasan 8.0] by [[Jon Dart]], [[CCC]], August 22, 2004
* [https://www.stmintz.com/ccc/index.php?id=397817 Arasan 8.2] by [[Jon Dart]], [[CCC]], November 26, 2004
==2005 ...==
* [https://www.stmintz.com/ccc/index.php?id=414274 Arasan 8.4] by [[Jon Dart]], [[CCC]], February 26, 2005
* [https://www.stmintz.com/ccc/index.php?id=489903 Arasan in CCT8] by [[Jon Dart]], [[CCC]], February 26, 2006 » [[CCT8]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15306 Arasan @ WCRCC tournament] by [[Jon Dart]], [[CCC]], July 23, 2007 » [[WCRCC 2007]]
* [http://www.talkchess.com/forum/viewtopic.php?t=16221 Arasan 10.0] by [[Jon Dart]], [[CCC]], September 02, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=19673 Arasan 10.2] by [[Jon Dart]], [[CCC]], February 16, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=22020 Arasan 10.4] by [[Jon Dart]], [[CCC]], June 27, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=25134 Arasan 11.0] by [[Jon Dart]], [[CCC]], November 28, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=27151 Arasan 11.3] by [[Jon Dart]], [[CCC]], March 24, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=28528 Arasan 11.4] by [[Jon Dart]], [[CCC]], June 20, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=29668 Arasan 11.5] by [[Jon Dart]], [[CCC]], September 05, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=30678 Arasan 11.6] by [[Jon Dart]], [[CCC]], November 18, 2009
==2010 ...==
* [http://www.talkchess.com/forum/viewtopic.php?t=32449 Arasan 11.7] by [[Jon Dart]], [[CCC]], February 07, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=35724 Arasan 12.0 released] by [[Jon Dart]], [[CCC]], August 07, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=36661 Arasan 12.2 released] by [[Jon Dart]], [[CCC]], November 11, 2010
'''2011'''
* [http://www.talkchess.com/forum/viewtopic.php?t=37921 Arasan 12.3 released] by [[Jon Dart]], [[CCC]], February 02, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40091 Arasan 13.0] by [[Jon Dart]], [[CCC]], August 18, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40157 Arasan 13.1] by [[Jon Dart]], [[CCC]], August 23, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40186 MORE about Arasan 13.1] by [[Fernando Villegas]], [[CCC]], August 26, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=40617 Arasan 13.2] by [[Jon Dart]], [[CCC]], October 02, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=41086 Arasan 13.3] by [[Jon Dart]], [[CCC]], November 14, 2011 » [[ACCA 2011]]
* [http://www.talkchess.com/forum/viewtopic.php?t=41369 Arasan 13.4] by [[Jon Dart]], [[CCC]], December 07, 2011
'''2012'''
* [http://www.talkchess.com/forum/viewtopic.php?t=42736 Arasan 14.0] by [[Jon Dart]], [[CCC]], March 04, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=44044 Arasan 14.2] by [[Jon Dart]], [[CCC]], June 12, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=44492 Arasan 14.3] by [[Jon Dart]], [[CCC]], July 18, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=45229 Arasan 15.0] by [[Jon Dart]], [[CCC]], September 20, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=46077 Arasan 15.1] by [[Jon Dart]], [[CCC]], November 19, 2012
'''2013'''
* [http://www.talkchess.com/forum/viewtopic.php?t=47333 Arasan 15.2] by [[Jon Dart]], [[CCC]], February 26, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=47845 Arasan 15.4] by [[Jon Dart]], [[CCC]], April 24, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=48070 Arasan 15.6] by [[Jon Dart]], [[CCC]], May 21, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=48082 Arasan on github] by [[Jon Dart]], [[CCC]], May 22, 2013 <ref>[https://github.com/jdart1/arasan-chess jdart1/arasan-chess · GitHub]</ref>
* [http://www.talkchess.com/forum/viewtopic.php?t=48703 Arasan games from WCRCC] by [[Jon Dart]], [[CCC]], July 21, 2013 » [[WCRCC 2013]]
* [http://www.talkchess.com/forum/viewtopic.php?t=48748 Arasan 16.0] by [[Jon Dart]], [[CCC]], July 24, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=49205 Arasan 16.1] by [[Jon Dart]], [[CCC]], September 01, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=49824 Arasan 16.2] by [[Jon Dart]], [[CCC]], October 25, 2013
* [http://www.talkchess.com/forum/viewtopic.php?t=50348 Arasan 16.3] by [[Jon Dart]], [[CCC]], December 06, 2013
'''2014'''
* [http://www.talkchess.com/forum/viewtopic.php?t=51071 test position: Rookie-Arasan] by [[Jon Dart]], [[CCC]], January 27, 2014 » [[Rookie]], [[Zugzwang]]
* [http://www.talkchess.com/forum/viewtopic.php?t=51760 Arasan 17.0] by [[Jon Dart]], [[CCC]], March 27, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=51839 Arasan GUI fixes] by [[Jon Dart]], [[CCC]], April 02, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=52242 Arasan 17.1] by [[Jon Dart]], [[CCC]], May 07, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=52474 Arasan 17.2] by [[Jon Dart]], [[CCC]], May 30, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=53532 Arasan 17.3] by [[Jon Dart]], [[CCC]], September 01, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=53987 Arasan 17.4] by [[Jon Dart]], [[CCC]], October 08, 2014
==2015 ...==
* [http://www.talkchess.com/forum/viewtopic.php?t=55072 Arasan 17.5] by [[Jon Dart]], [[CCC]], January 24, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=55621 Experiments with eval tuning] by [[Jon Dart]], [[CCC]], March 10, 2015 » [[Automated Tuning]], [[Texel's Tuning Method]]
* [http://www.talkchess.com/forum/viewtopic.php?t=57122 Arasan 18.0] by [[Jon Dart]], [[CCC]], July 30, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=58130 Arasan 18.1] by [[Jon Dart]], [[CCC]], November 02, 2015
* [http://www.talkchess.com/forum/viewtopic.php?t=58460 Arasan 18.2] by [[Jon Dart]], [[CCC]], December 03, 2015
'''2016'''
* [http://www.talkchess.com/forum/viewtopic.php?t=59138 Arasan 18.3] by [[Jon Dart]], [[CCC]], February 02, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=59463 Arasan Syzygy support (working with Windows, too)] by [[Jon Dart]], [[CCC]], March 10, 2016 » [[Syzygy Bases]]
* [http://www.talkchess.com/forum/viewtopic.php?t=59997 Arasan 19.0 + updated test suite] by [[Jon Dart]], [[CCC]], April 29, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=61077 Arasan 19.1] by [[Jon Dart]], [[CCC]], August 09, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=61948 Arasan 19.2] by [[Jon Dart]], [[CCC]], November 03, 2016
'''2017'''
* [http://www.talkchess.com/forum/viewtopic.php?t=62987 Arasan 20.0] by [[Jon Dart]], [[CCC]], January 31, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=63773 building for Android] by [[Jon Dart]], [[CCC]], April 19, 2017 » [[Android]]
* [http://www.talkchess.com/forum/viewtopic.php?t=63855 Arasan 20.1] by [[Jon Dart]], [[CCC]], April 28, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=64364 Arasan Programmer's Guide] by [[Jon Dart]], [[CCC]], June 21, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=64610 Arasan 20.2] by [[Jon Dart]], [[CCC]], July 15, 2017
* [http://www.talkchess.com/forum/viewtopic.php?t=65636 Arasan 20.3] by [[Jon Dart]], [[CCC]], November 05, 2017
'''2018'''
* [http://www.talkchess.com/forum/viewtopic.php?t=66232 Arasan 20.4] by [[Jon Dart]], [[CCC]], January 03, 2018
* [http://www.talkchess.com/forum/viewtopic.php?t=66254 Arasan 20.4.1] by [[Jon Dart]], [[CCC]], January 05, 2018
* [http://www.talkchess.com/forum/viewtopic.php?t=67040 Arasan 20.5] by [[Jon Dart]], [[CCC]], April 08, 2018
* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=67805&p=766218 Arasan 21.0 beta] by [[Jon Dart]], [[CCC]], June 23, 2018
* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=67855&p=766972 Arasan 21.0] by [[Jon Dart]], [[CCC]], June 30, 2018
=External Links=
==Chess Engine==
* [http://arasanchess.org/index.shtml Arasan Chess] by [[Jon Dart]]
* [https://arasanchess.org/programr.shtml Arasan Programmer's Guide] by [[Jon Dart]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=64364 Arasan Programmer's Guide] by [[Jon Dart]], [[CCC]], June 21, 2017</ref>
* [http://www.arasanchess.org/testsuite.shtml Arasan Test Suite]
* [http://www.playwitharena.com/?Newsticker:Archive_5 Arasan 8.4 released, short interview with Jon Dart] by [[Frank Quisinsky]], March 01, 2005, [[Arena|Arena Chess GUI]], Archive 5, 72
* [https://github.com/jdart1/arasan-chess jdart1/arasan-chess · GitHub] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=48082 Arasan on github] by [[Jon Dart]], [[CCC]], May 22, 2013</ref>
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Arasan%2017.0%2064-bit#Arasan_17_0_64-bit Arasan 17.0 64-bit] in [[CCRL|CCRL 40/40]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Arasan%2018.0%2064-bit%204CPU#Arasan_18_0_64-bit_4CPU Arasan 18.0 64-bit] in [[CCRL|CCRL 40/40]]
==Misc==
* [https://en.wikipedia.org/wiki/Arasan Arasan from Wikipedia]
* [https://en.wikipedia.org/wiki/Imsai_Arasan_23rd_Pulikecei Imsai Arasan 23rd Pulikecei from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Chess Pieces]]
[[Category:Nobility]]
[[Category:UCI]]
[[Category:WinBoard]]
[[Category:XBoard]]
[[Category:Open Source]]
