Sargon (chess)

Sargon

Company type	Software
Industry	Computer software, Chess software
Founded	1978
Founder	Dan Spracklen, Kathleen "Kathe" Spracklen
Headquarters	United States
Area served	Worldwide
Key people	Dan Spracklen, Kathleen "Kathe" Spracklen, Paul Lohnes, Gary Shannon
Products	Sargon chess software series (Sargon I, II, 2.5, III, 4, V)
Parent	Hayden Software (original publisher)

SARGON (presented in all caps) represents a collection of chess software designed for personal computers. The initial release in 1978 was developed in assembly language by Dan and Kathleen "Kathe" Spracklen, specifically for the Z80-powered Wavemate Jupiter II.

History

The debut of Sargon occurred at the 1978 West Coast Computer Faire, where it secured victory in the first-ever computer chess competition dedicated solely to microcomputers, achieving an undefeated 5–0 record. This accomplishment inspired its creators to commercialize the program by offering photocopied listings for $15 through an advertisement in Byte magazine, targeting users of Z80-based microcomputers. Because the source code was accessible, enthusiasts were able to adapt Sargon to different platforms; for instance, a 1979 edition of Recreational Computing explained how to modify Sargon for the 8080 processor using macros. Following this, Hayden Books published a volume authored by the Spracklens that detailed the program.

Commercialization

As magnetic media distribution grew in popularity, US Navy petty officer Paul Lohnes adapted Sargon for the TRS-80, improving graphics and input methods while preserving the original chess algorithm developed by the Spracklens. Working alongside them in San Diego, Lohnes contributed to making the TRS-80 version successful under Hayden Book's software branch, Hayden Software. However, Lohnes was unable to continue further updates due to his reassignment to sea duty.

During the early 1980s, Sargon Chess was also ported to various platforms such as the Nascom (by Bits & PCs in 1981), the Exidy Sorcerer, and the Sharp MZ 80K. A full rewrite was subsequently created for the Apple II, programmed by Gary Shannon—Kathleen Spracklen’s brother—with publication handled by Hayden Software.

Improved versions

The Spracklens developed enhancements to their original software, releasing Sargon II. In an October 1980 issue of The Space Gamer, J. Mishcon reviewed this edition, reporting that it consistently defeated him at level 5 (allowing 40 minutes per move) but could be overcome at level 3 (2 minutes per move). He characterized level 0 as a "quick but weak" opponent.

The version named Sargon 2.5, distributed as a ROM module compatible with the Chafitz Modular Game System, mirrored Sargon II but incorporated pondering. It earned ratings of 1641 at the Paul Masson tournament (June–July 1979) and 1736 during the San Jose City College Open (January 1980).

At the October 1979 North American Computer Chess Championship, Sargon 3.0 secured seventh place, drawing against Cray Blitz and defeating its primary microcomputer competitor, Mychess. Later that year in December, it claimed victory at the second microcomputer championship held in London.

Sargon III, a comprehensive rewrite, introduced a capture search algorithm replacing the previous exchange evaluator and included an opening repertoire for chess. Initially written in 6502 assembly language, it was later converted to Z80 assembly by Paul H. Lohnes while still serving in the US Navy. Published commercially across multiple platforms by Hayden Software in 1983, after Apple commissioned a port using 68000 assembly language, Sargon III became notable as the first third-party executable software available for the Macintosh.

Legacy

After the shutdown of Hayden Software, the Sargon brand persisted through subsequent chess software releases, such as Sargon 4 by Spinnaker Software, Sargon V from Activision, and a CD-i edition simply named Sargon Chess. The CD-i iteration received a 75% score from the French publication Génération 4. In 1992, the 4-in-1 Fun Pak compilation was launched for the Game Boy, which included Sargon Chess among its featured titles.

At the same time, the Spracklen brothers engineered chess engines for Fidelity Electronics' dedicated chess devices, which achieved first-place finishes in the initial four World Microcomputer Chess Championships.

The Botvinnik Game

In 1983, during an event in Hamburg, three-time world chess champion Mikhail Botvinnik engaged in a test match against Sargon. This encounter was intended to assess the software’s abilities rather than to serve as a competitive game at full intensity. Botvinnik himself contributed to the advancement of chess programming.

White: Mikhail Botvinnik Black: SARGON Hamburg, 1983

1.c4 e5 2.Nc3 d6 3.g3 Be6 4.Bg2 Nc6 5.d3 Nf6 6.f4 Be7 7.Nf3 O-O 8.O-O Qd7 9.e4 Bg4 10.h3 Bxh3 11.f5 Bxg2 12.Kxg2 Nb4 13.a3 Na6 14.b4 c5 15.b5 Nc7 16.Rh1 a6 17.b6 Nce8 18.Ng5 Qc6 19.Rb1 Bd8 20.Nd5 h6 21.Nf3 Nxd5 22.exd5 Qd7 23.g4 a5 24.Nd2 Ra6 25.Ne4 Rxb6 26.Rxb6 Bxb6 27.f6 Nxf6 28.Nxf6+ gxf6 29.Bxh6 Re8 30.Qf3 Bd8 31.Qh3 Qa4 32.Bd2 Kf8 33.Rf1 Kg8 34.Qh6 Qd7 35.Kg3 f5 36.Rh1 f4+ 37.Kf3 1-0