REBEL (chess) explained

REBEL
Author:	Ed Schröder
Released:	1980
Discontinued:	no
Latest Release Version:	16.3
Latest Release Date:	^[1] ^[2] ^[3]
Genre:	Chess engine
License:	GNU General Public License v3.0 (14 and after) proprietary commercial software (13 and before)

REBEL is a world champion chess program developed by Ed Schröder. Development of REBEL started in 1980 on a TRS-80, and it was ported many times to dedicated hardware and the fastest microprocessors of the day:

• 1980s – Running on a TRS-80, Apple II, and inside of Mephisto brand dedicated chess computers, it won the Dutch open computer chess championship four times.
• 1991 – Ported to the ARM ChessMachine and named Gideon, it won the World Microcomputer Chess Championship.
• 1992 – Gideon won the World Computer Chess Championship, the first time a microprocessor came ahead of a field of mainframes, supercomputers, and custom chess hardware.
• 1990s – REBEL was ported to MS-DOS and then Microsoft Windows and sold commercially
  • 1997 – REBEL won a match with GM Arthur Yusupov 10.5–6.5, the first successful challenge of a chess grandmaster by a commercial program.
  • 1998 – REBEL won a match with GM Viswanathan Anand 5–3 (but lost 0.5–1.5 in the standard time control section of the match). He was rated number two in the world at the time.
• 2004 – Ed Schröder retired, releasing the last version of REBEL as the freeware chess engine Pro Deo.
• 2022 - On January 12, 2022, Ed Schröder came out of retirement to release REBEL 14 as a free chess engine. It incorporates an efficiently updatable neural network in REBEL's evaluation function, along with a heavily modified version of Fruit's search.^{[4] [5]}

See also

• Fruit (software)

External links

• Web site: Ed's recollection of REBEL's history . https://web.archive.org/web/20201106232424/http://members.home.nl/matador/chess.htm . 6 November 2020.
• Web site: Wealth of information on the inner workings of a professional program . https://web.archive.org/web/20110426201227/http://www.top-5000.nl/authors/rebel/chess840.htm . 26 April 2011.
• Web site: How REBEL Plays Chess . Ed . Schröder . https://web.archive.org/web/20201106232751/http://members.home.nl/matador/Inside%20Rebel.pdf . 6 November 2020.
• Rebel (Chess Programming Wiki)

Notes and References

1. Web site: rebel-16. February 17, 2023. HOME OF THE DUTCH REBEL. June 19, 2023. Ed Schröder. https://web.archive.org/web/20230622210046/https://rebel13.nl/windows/rebel-16.html. June 22, 2023.
2. Web site: Rebel 16.2 release. February 18, 2023. Prodeo Computer Chess Forum. June 19, 2023. Ed Schröder.
3. Web site: Rebel 16.2: Impressive!. February 21, 2023. Computer Chess Club Forum. June 19, 2023. Steve Maughan.
4. Web site: REBEL 14. HOME OF THE DUTCH REBEL. June 19, 2023. Ed Schröder. https://web.archive.org/web/20230622210042/https://rebel13.nl/windows/rebel-14.html. June 22, 2023.
5. Web site: Rebel 14. Computer Chess Club Forums. Ed Schröder. January 12, 2022. June 19, 2022.