Arasan
On this page
Arasan, | |
an open source engine written by Jon Dart in C++. Arasan’s development started in the early 90s, the first version, released in 1994 was a 16-bit program running under Windows 3.1 using an 8x8 Board, incremental updated attack tables and its own GUI, evolving to a portable 32-bit and later 64-bit program, utilizing bitboards to determine its sliding piece attacks with rotated bitboard lookups. In 2008, rotated were replaced by Magic bitboards, which gave Arasan about a 20-25% speedup [1]. | |
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 [2]. 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 [3] . Jon’s change logs, bug fix reports and tournament reports over the time are available from forum archives, as well the recent ones from the Arasan blog [4] | |
அரசன் | |
அரசன் [5] (Arasan) , King in Tamil language [6] |
Selected Features
Board Representation
Bitboard Trials
Magic Bitboards
PEXT/PDEP Bitboards
Arasan 20.3, released in November 2017, performs PEXT/PDEP Bitboards if compiled for the BMI2 instruction set [10] to replace Fancy Magic Bitboards in looking up sliding piece attacks [11]
Search
- Lazy SMP 21.0
- Iterative Deepening Depth Resolution 4
- Aspiration Windows
- Principal Variation Search
- Transposition Table
- Move Ordering
- Selectivity
Evaluation
NNUE
Arasan 23.0, released in September 2021, uses a Stockfish 13 compatible NNUE - trained by selfplay positions - to evaluate its positions [12]. The neural network file is external to the program and is loaded at runtime.
Traditional
Automated Tuning
Arasan 19.2, released in November 2016, applies Texel’s Tuning Method by default and supports the Adam gradient descent algorithm [13] [14].
Syzygy Bases
Arasan uses a Fathom fork with some bug fixes and enhancements [15], also supporting 7-man [16].
Tournament Play
Arasan went online in December, 1996 [17] , 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 International Gsei Web Tournaments. Arasan 15.1 [18] won the ACCA 2012 [19] , Arasan 16.0 the WCRCC 2013 [20] . Over the board, Arasan was active at the 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 [21].
Photos & Games
PT 48, Two Kings fighting, Johan de Koning and Tessa Pijl in Arasan vs. The King [22]
See also
Forum Posts
1995 …
- Arasan 2.0 (Windows chess program) available via ftp by Jon Dart, rec.games.chess, July 4, 1995
- Arasan 2.1 (Windows chess program) available via ftp by Jon Dart, rec.games.chess.misc, October 23, 1995
- Arasan 2.2 (Windows chess program) available via ftp by Jon Dart, rec.games.chess.misc, December 10, 1995
- Arasan progress report by Jon Dart, rgcc, May 23, 1996
- Arasan 3.0 (Windows chess program) available by Jon Dart, rgcc, July 8, 1996
- Arasan goes online by Jon Dart, rgcc, January 6, 1997
- Arasan 4.0 is available by Jon Dart, rgcc, July 15, 1997
- Arasan 5.0 released by Jon Dart, CCC, January 13, 1999
2000 …
- Arasan 5.4 released by Jon Dart, CCC, May 25, 2000
- Arasan vs. IM Paunovic by Jon Dart, CCC, June 16, 2000
- Arasan now under Linux by Jon Dart, CCC, September 02, 2000
- A few notes from Arasan’s games in CCT2 by Jon Dart, CCC, November 05, 2000 » CCT2
- CCT4 notes - Arasan by Jon Dart, CCC, January 20, 2002 » CCT4
- Arasan 6.0 by Jon Dart, CCC, September 24, 2002
- Arasan 6.3 by Jon Dart, CCC, January 26, 2003
- Arasan 7.0 by Jon Dart, CCC, August 09, 2003
- Arasan 7.4 by Jon Dart, CCC, February 28, 2004
- Arasan 7.4 64-bit Speedup by Slater Wold, CCC, March 30, 2004
- Arasan 8.0 by Jon Dart, CCC, August 22, 2004
- Arasan 8.2 by Jon Dart, CCC, November 26, 2004
2005 …
- Arasan 8.4 by Jon Dart, CCC, February 26, 2005
- Arasan in CCT8 by Jon Dart, CCC, February 26, 2006 » CCT8
- Arasan @ WCRCC tournament by Jon Dart, CCC, July 23, 2007 » WCRCC 2007
- Arasan 10.0 by Jon Dart, CCC, September 02, 2007
- Arasan 10.2 by Jon Dart, CCC, February 16, 2008
- Arasan 10.4 by Jon Dart, CCC, June 27, 2008
- Arasan 11.0 by Jon Dart, CCC, November 28, 2008
- Arasan 11.3 by Jon Dart, CCC, March 24, 2009
- Arasan 11.4 by Jon Dart, CCC, June 20, 2009
- Arasan 11.5 by Jon Dart, CCC, September 05, 2009
- Arasan 11.6 by Jon Dart, CCC, November 18, 2009
2010 …
- Arasan 11.7 by Jon Dart, CCC, February 07, 2010
- Arasan 12.0 released by Jon Dart, CCC, August 07, 2010
- Arasan 12.2 released by Jon Dart, CCC, November 11, 2010
2011
- Arasan 12.3 released by Jon Dart, CCC, February 02, 2011
- Arasan 13.0 by Jon Dart, CCC, August 18, 2011
- Arasan 13.1 by Jon Dart, CCC, August 23, 2011
- MORE about Arasan 13.1 by Fernando Villegas, CCC, August 26, 2011
- Arasan 13.2 by Jon Dart, CCC, October 02, 2011
- Arasan 13.3 by Jon Dart, CCC, November 14, 2011 » ACCA 2011
- Arasan 13.4 by Jon Dart, CCC, December 07, 2011
2012
- Arasan 14.0 by Jon Dart, CCC, March 04, 2012
- Arasan 14.2 by Jon Dart, CCC, June 12, 2012
- Arasan 14.3 by Jon Dart, CCC, July 18, 2012
- Arasan 15.0 by Jon Dart, CCC, September 20, 2012
- Arasan 15.1 by Jon Dart, CCC, November 19, 2012
2013
- Arasan 15.2 by Jon Dart, CCC, February 26, 2013
- Arasan 15.4 by Jon Dart, CCC, April 24, 2013
- Arasan 15.6 by Jon Dart, CCC, May 21, 2013
- Arasan on github by Jon Dart, CCC, May 22, 2013 [23]
- Arasan games from WCRCC by Jon Dart, CCC, July 21, 2013 » WCRCC 2013
- Arasan 16.0 by Jon Dart, CCC, July 24, 2013
- Arasan 16.1 by Jon Dart, CCC, September 01, 2013
- Arasan 16.2 by Jon Dart, CCC, October 25, 2013
- Arasan 16.3 by Jon Dart, CCC, December 06, 2013
2014
- test position: Rookie-Arasan by Jon Dart, CCC, January 27, 2014 » Rookie, Zugzwang
- Arasan 17.0 by Jon Dart, CCC, March 27, 2014
- Arasan GUI fixes by Jon Dart, CCC, April 02, 2014
- Arasan 17.1 by Jon Dart, CCC, May 07, 2014
- Arasan 17.2 by Jon Dart, CCC, May 30, 2014
- Arasan 17.3 by Jon Dart, CCC, September 01, 2014
- Arasan 17.4 by Jon Dart, CCC, October 08, 2014
2015 …
- Arasan 17.5 by Jon Dart, CCC, January 24, 2015
- Experiments with eval tuning by Jon Dart, CCC, March 10, 2015 » Automated Tuning, Texel’s Tuning Method
- Arasan 18.0 by Jon Dart, CCC, July 30, 2015
- Arasan 18.1 by Jon Dart, CCC, November 02, 2015
- Arasan 18.2 by Jon Dart, CCC, December 03, 2015
2016
- Arasan 18.3 by Jon Dart, CCC, February 02, 2016
- Arasan Syzygy support (working with Windows, too) by Jon Dart, CCC, March 10, 2016 » Syzygy Bases
- Arasan 19.0 + updated test suite by Jon Dart, CCC, April 29, 2016
- Arasan 19.1 by Jon Dart, CCC, August 09, 2016
- Arasan 19.2 by Jon Dart, CCC, November 03, 2016
2017
- Arasan 20.0 by Jon Dart, CCC, January 31, 2017
- building for Android by Jon Dart, CCC, April 19, 2017 » Android
- Arasan 20.1 by Jon Dart, CCC, April 28, 2017
- Arasan Programmer’s Guide by Jon Dart, CCC, June 21, 2017
- Arasan 20.2 by Jon Dart, CCC, July 15, 2017
- Arasan 20.3 by Jon Dart, CCC, November 05, 2017
2018
- Arasan 20.4 by Jon Dart, CCC, January 03, 2018
- Arasan 20.4.1 by Jon Dart, CCC, January 05, 2018
- Arasan 20.5 by Jon Dart, CCC, April 08, 2018
- Arasan 21.0 beta by Jon Dart, CCC, June 23, 2018
- Arasan 21.0 by Jon Dart, CCC, June 30, 2018
- Arasan 21.1 by Jon Dart, CCC, October 02, 2018
- Arasan 21.2 by Jon Dart, CCC, December 31, 2018
2019
- Arasan 21.3 by Jon Dart, CCC, March 29, 2019
- Arasan 21.4 by Jon Dart, CCC, July 02, 2019
- Arasan 22.0 by Jon Dart, CCC, December 10, 2019
2020 …
- Arasan 22.1 by Jon Dart, CCC, July 01, 2020
- Arasan 22.2 by Jon Dart, CCC, December 22, 2020
2021
- Arasan 22.3 by Jon Dart, CCC, May 31, 2021
- Arasan 23.0 by Jon Dart, CCC, September 06, 2021
Re: Arasan 23.0 by Jon Dart, CCC, September 08, 2021 2022
- Arasan 23.3 by Jon Dart, CCC, March 12, 2022
External Links
Chess Engine
- jdart1/arasan-chess · GitHub [24]
- Arasan Chess by Jon Dart
- Arasan Programmer’s Guide by Jon Dart [25]
- Arasan Test Suite
- Arasan 8.4 released, short interview with Jon Dart by Frank Quisinsky, March 01, 2005, Arena Chess GUI, Archive 5, 72 ( Wayback Machine)
- Arasan in CCRL 40/15
Misc
References
- ↑ Arasan Blog - Aug 26, 2008
- ↑ Arasan chess
- ↑ Arasan Downloads
- ↑ Arasan Tech Blog
- ↑ Tamil script from Wikipedia
- ↑ அரசன் (சதுரங்கம்) - தமிழ் விக்கிப்பீடியா
- ↑ Arasan Programmer’s Guide
- ↑ Arasan progress report by Jon Dart, rgcc, May 23, 1996
- ↑ Arasan Blog - Aug 26, 2008
- ↑ Arasan 20.3 by Jon Dart, CCC, November 05, 2017
- ↑ arasan_source20.3.zip/src/attacks.h
- ↑ Re: Arasan 23.0 by Jon Dart, CCC, September 08, 2021
- ↑ Arasan 19.2 by Jon Dart, CCC, November 03, 2016
- ↑ Diederik P. Kingma, Jimmy Lei Ba (2015). Adam: A Method for Stochastic Optimization. arXiv:1412.6980v8, ICLR 2015
- ↑ jdart1/Fathom · GitHub by Jon Dart
- ↑ 7-man Syzygy support in Fathom by Jon Dart, CCC, April 23, 2019
- ↑ Arasan goes online by Jon Dart, rgcc, January 6, 1997
- ↑ Arasan 15.1 by Jon Dart, CCC, November 19, 2012
- ↑ Seventh Annual ACCA Americas’ Computer Chess Championships by Jon Dart, CCC, November 18, 2012
- ↑ Arasan games from WCRCC by Jon Dart, CCC, July 21, 2013
- ↑ Baron 1st, Arasan 2nd by Jon Dart, CCC, June 14, 2015
- ↑ PT48 Round 7
- ↑ jdart1/arasan-chess · GitHub
- ↑ Arasan on github by Jon Dart, CCC, May 22, 2013
- ↑ Arasan Programmer’s Guide by Jon Dart, CCC, June 21, 2017