Chess-Playing Software

The strength of chess-playing software is highly dependent on the hardware it runs on (all software discussed is for MS-DOS; programs available for MacOS are noted). Here is a method to approximate the strength differences for the same software running on different hardware (source: _Computer Chess Reports_).

Processor "Chess MIP's"

8088                      Speed in MHz divided by 19
80286, 1 wait state       Speed in MHz divided by 8
80286, 0 wait states      Speed in MHz divided by 6
80386, no cache memory    Speed in MHz divided by 6
80386 with cache          Speed in MHz divided by 4.7
80486                     Speed in MHz divided by 2.3

Now, if a program has a given rating on a 1 (Chess) MIP machine, this is how to adjust the rating for other MIP's (interpolate between points):

MIP:  0.25 0.5 1 1.5  2  3   4   6   8   12  16  24  32  48  64
Adj.: -180 -87 0  47 80 124 154 195 223 261 287 323 347 379 402

CCR Ratings List PC Program Ratings

ChessMachine Madrid King 2.0        2558
ChessMachine Madrid Schroder 3.0    2498
Chess Genius                        2494
MChess Professional                 2460
ChessMachine Schroder ARM2          2420
ChessMachine King ARM2              2399
Socrates                            2392
Fritz 2.0                           2360
Zarkov 3.0                          2350
Psion 2                             2318
Zarkov 2.5 & 2.6                    2312
Grandmaster                         2297
Rexchess 2.3                        2283
Sargon 5                            2278
Alpha                               2274
Fritz 1/Knightstalker               2237
Chessmaster 3000                    2201
Chess Champion                      2175
Psion 1                             2121
Colossus x                          2070
Chessmaster 2100                    2057
Final Chesscard                     1894

Ratings are the average of autotest at 30" to 1' per move, Computer Chess News Sheet from England and the "Ply" list from Sweden. PC programs are rated on an i486 PC running at 33MHz. See the Volume 3, Number 2 issue of _Computer Chess Reports_ for more details.

• MChess Pro ~2480 by Marty Hirsch, San Rafael, California Runs on a 286 with 640K, but a 386 with 12 Meg is recommended (10 are used for hash tables). Opening book is 7x as large as amateur version and is programable. Improved graphics. DM 250
• Rebel 7 ~ by Ed Schroeder Optimized for 386, 486 and Pentium. DM 199 $150 550,00 Opening Moves. PGN import. Builtin 1000 game database. for more information: http://www.xs4all.nl/~rebchess/
• Rebel Decade ~2200 by Ed Shroeder Available for free on the net at: http://www.xs4all.nl/~rebchess/
• MChess 1.1 - 1.72 2400 by Marty Hirsch DM 180
• Zarkov 2.6 2350 by John Stanback / Interfacing to the chess database software Bookup. Supersedes Zarkov 2.5 (USCF 2280) by John Stanback. Best analyzation features. DM 135
• ChessChampion 2175 2340 by Chris Whittington Program uses Shannon B strategy, not brute force like all the others. Supersedes ChessPlayer by Chris Whittington. DM 115
• KnightStalker II ~2300 by Frans Morsch / ChessBase Interfacing to the chess database software ChessBase. Program can be used as background-evaluator while working with ChessBase 4.0. It can read ChessBase libraries. DM 178 Supersedes KnightStalker I (USCF 2260, DM 99) by ChessBase.
• Grandmaster Chess 2300 by John Stanback / Capstone Mass market version of Zarkov 2.55 with pull-down menus and fancier graphics (2d and 3d board), but is missing some of Zarkov2.6's features such as generating multiple candidate moves when analyzing games, annotations, generating PCX or WPG chess diagrams, interfacing to Bookup7 etc. DM 110
• Rexchess 2.30 2290 by Larry Kaufman DM 99. Will be superseded by TitanChess by Larry Kaufman, which is expected to come out Dec 92.
• Heuristic Alpha by Larry Kaufman Written for 8086er and 80286er in C. Selled to Electronic Arts. Expected to come out spring 93.
• Sokrates by Larry Kaufman Written for 80386er and 80486er in Assembler. Hasn't found any publisher up to now.
• Psion 2 2290 by Richard Lang / Psion Ltd. Supersedes Psion 1 (USCF 2140) by Psion Ltd. Program of Mephisto Amsterdam, recompiled for IBM PC.
• CheckCheck by Wolfgang Delmare / Digital Concepts German but completely self-explaining (mouse/buttons/icons). Full version contains complete database of four-piece-finishings. That needs 16 Mb on the hard disk. DM 99 without database or DM 168 for full version. VGA only
• Chessmaster 4000 (2304 ELO) by Software Toolworks (mscape@aol.com). No copy protection. No limited number of installs. Auto annotation. CD ROM version for windows available. CD Rom Version has larger library of annotated games and Karpov (voice) discussing several of his games - you can here him moving pieces in the background. Approximately $40. Incredibly good cost to game quality ratio! Chessmaster 5000 is expected sometime in the spring, 1996. Features expected include a link to Bookup for analysis and ChessAssistant via epd files. The game quality is expected to improve - but a rating of 2304 will beat most of us anyway. If you think you are beating chessmaster 4000 easily and have only recently started to play - check the level and time you are allowing for thought and make sure deep thinking is on. You may reach the ChessMaster 5000 team at: cjustiniano@mindscape.com. Information may also be found on Eric Schiller's page, listed elsewhere in the FAQ.
• Chessmaster 3000 2170 by Software Toolworks Excellent graphics. DM 99 A windows version of Chessmaster 3000 is marketed as well for DM 119. A CD ROM version can be bought for DM 145. Supersedes Chessmaster 2100 (USCF 2070) by Software Toolworks.
• Sargon V ~2100? by Dan and Kathy Spracklen / Activision DM 115. Supersedes Sargon IV by Spinnaker.
• Colossus Chess X 2090 DM 50
• BattleChess by Interplay Very weak program with the most entertaining graphics. DM 50 A windows version of BattleChess is marketed as well for DM 110. Little trap: BattleChess II isn't a chess but a chinese chess program.

Available for MacOS: Chessmaster 3000 & 2100, Sargon IV (V due soon), BattleChess and CheckMate. Available for the Amiga: Chessmaster 2000 and 2100, Sargon III and IV, Chessplayer 2150 and Chess Champion 2175, BattleChess and CheckMate, ChessMate, The Art of Chess, Colossus Chess and the ChessMachine.

Gnuchess is a freely available chess-playing software program (see [18]). Its strength varies widely based on the machine for which it's compiled.