Reviewed by Mads Brevik

          Computer         Graphics         Memory         Disk Space
Minimum   386SX/16 MHz     VGA 256 K        4 MB           11 MB 
Max/Rec.  386DX/40 MHz     SVGA 512 K       8 MB

Control:  Keyboard, Mouse
  Sound:  A soundcard that can play WAV and MIDI-files
  Notes:  Requires MS-DOS 5.0 & MS-Windows 3.1 (or higher versions).
          Windows accelerator recommended for 256-colour mode.
          No copy protection.

Reviewed version 1.0 on: 486/66 VESA Local-bus, 8 MB RAM, 256 K Cache,
                         Pro AudioSpectrum 16, Windows accelerator.
    Reviewer recommends: 486/33, 8 MB physical RAM, Windows accelerator.

The latest incarnation of CHESSMASTER is the fourth in a series of successful chess programs developed by Software Toolworks. The first program, CHESSMASTER 2000, appeared in the mid-eighties on the Amiga/Atari and was later transferred to the PC. Each version has offered more features than its predecessor and a modified chess engine. With its wide range of features and beautiful graphics, but weak gameplay, the Chessmaster-programs have mostly appealed to the novice and the average chessplayer. CHESSMASTER 4000 TURBO (CM4K), however, combines many sophisticated features and a stronger chess engine to form a more serious chess program. A new 32-bit chess engine, written by the well-known chess programmer Johan de Koning, has been implemented as well as other important enhancements. Before I go on, I will just mention that I am an average club player and a member of the Swedish Chess Computer Association-SSDF.


The package consists of three manuals: A quick start card, a well written owner's manual about the history of chess, and a 58-page user guide for the program itself. Though the user guide is comprehensive and more than adequately written, it is far from complete. For example, it does not say a single word about the accompanying opening-book editor and it also refers to a section that does not exist! Installation is fast and simple, and the program takes up 11 MB of disk-space. Unfortunately, there is no install-option enabling you to unselect unnecessary files.


CM4K has a new and improved graphical presentation. The windows and menus bears a distinctive metal-look, while the pieces and boards are neatly drawn with great attention to detail. By using a mouse or the keyboard you can access the program's features, which is logically organized in eight pull-down menus. As in earlier versions, certain commands are executed via handy hot-keys. For example, you can take back a move using the keys CTRL+T instead of the menus. Information windows and boards can be placed anywhere on the screen, and you can resize the windows to create custom arrangements. In contrast to CHESSMASTER 3000 (CM 3K), CM 4K remembers all the window-arrangements, so you do not have to resize windows every time you start the program. Software Toolworks has really come up with a flawless interface this time.


I will not go through the more basic features of CM4K in this review. So if you are not familiar with earlier versions of Chessmaster, I will refer to the review of CM 3K in GAME BYTES #2 for more information. A new useful feature is the support for MODEM/LAN-play. I have not tried it out myself, but a connection is made by selecting a remote player from the Game Details menu. The game parameters are set on the chosen Master-System, and finally you can connect via a null-modem cable, a Hayes compatible modem or a LAN-network. Another welcome feature is the use of transposition tables, which can make a drastic impact on the search depth (how far the program looks into the position) in the end-game. By using transpositions, CM4K finds the winning move in the Lasker-study (see screenshot) after 24 PLY and 8 seconds (looking 24 moves ahead). Without tables CM4K does not think farther than 14 PLY in one minute!

CM4K also handles transpositions in the opening-game, which means the program can recognize the board position in its opening-library and not only follows a sequence of moves. Besides traditional game-analysis and Natural Language Advice (NLA, from CM 3K), CM4K can 'annotate' a finished game in simple English. After you have entered the thinking time for each move, the computer will run through the whole game and add comments where it finds it necessary (mostly in tactical positions). The new auto- annotator is a combination of NLA with expanded vocabulary and opening-book comments. Despite its many restrictions, it has some practical value if you are a novice and its opening-book comments were often interesting. A drawback is that you cannot analyse a move for more than only 2 minutes, which makes it impossible to make deeper analyses. Even worse, the game- analysis function suffers from the same restriction, which makes deep game- analysis unnecessary cumbersome because you must manually analyse each move. Finally, there is an opening-book editor that comes as a separate program. It enables you to edit libraries, give preference to certain moves, add comments etc. This program requires that you have a videocard with minimum 512 K RAM, because it will only run with minimum 256-colours.


A dozen new chess sets have been added to CM4K. The 256-colour 3D-pieces are beautifully drawn (especially the dinosaurs!) and look very stunning. Not surprisingly, they are almost impossible to play with because they give a bad overview of the position. So I prefer to use the 2D wood-board and the Staunton pieces. Like in CM 3K you have the option to customize the program's playing style. By selecting the extensive Setup-menu, you have access to parameters for both position-evaluation and playing style. The parameters are expanded: You can, among other things, change values for King-safety, pawn-weaknesses, control of centre and mobility.

Furthermore, the number of predefined playing styles has increased to about 40, drawn from personalities like Kasparov and Seirawan. This high degree of customisation is undoubtedly one of CM4K's strongest sides. Other enhancements worth mentioning are the new chess tutorials, written by GM Yasser Seirawan, with emphasis on pawn structures. The useful Import/Export-functions have been improved, so you can copy games or board positions to the Windows-clipboard. I also appreciated the new fil- management system, which makes it much easier to copy, delete and find games or libraries.


CM4K has a varied opening-repertoire when using its standard-library of 40.000 moves. The choice of opening moves frequently leads to open play, which suits CM4K's aggressive playing style. So far, my only criticism concerns its size. I think it should be larger, at least 70.000 moves, to match the new engine. As mentioned earlier, CM4K incorporates a new chess engine based on the powerful King 2.0-program. This program originates from a dedicated ches -computer called ChessMachine 30 Mhz (CM 30). Given the difference in speed between a CM 30 and a 486/66, and the fact that CM4K is slower on the PC due to the C-code and the Windows-overhead, the estimated ELO-rating lies around 2.250 (add 220 for USCF). CM4K will thus perform around 2.190 and 2.000 ELO on a 486/33 and 386/16 respectively, a significant improvement of about 180 ELO over its predecessor CM 3K.

The following ratings will put these numbers into perspective:

Beginner < 1.000
Average club-player 1.500
Strong club-player or expert > 2.000
master > 2.300 ELO

Judging from the blitz-match and the tournament games, I have arranged against MChess 1.51 (a strong non-commercial program), CM4K handles the mid-game very well. It has good time-management, likes to control the terrain, often takes the initiative and has a good understanding of both tactical and positional play. Though CM4K has a firm grip on the mid-game, it has an unfortunate tendency to loosen its ties in the beginning of the end-game, giving the opponent a chance to counterattack. I also noticed that CM4K frequently failed to protect its king well enough, a typical weakness among strong programs. On the other hand, it did not make any apparent blunders in the end-game and it is among the best programs when it comes to analysing positions (probably inherited from The King!).


CM4K represents a major step forward, both in terms of playing strength and configurability, compared to its predecessor CM 3K. It is also the first mass-market program with a respectable strength. The retail price at $59. 95 is low when considering the strong chess engine. Normally you have to pay a lot more for a 'serious' program. CM4K puts some very high demands on the hardware to run smoothly however: A 486 equipped with a Windows- accelerator and 8 MB physical RAM or more is strongly recommended. I suspect the DOS-version will not be so power-hungry. Available in the second quarter this year, it will probably play even stronger than its Windows counterpart. A CD-ROM version will be released in the first quarter.

Though some users at the Internet have had some trouble with the program, like lockups and wrong colour-palettes, I have not encountered any major bugs myself (I've experienced some minor ones though). It looks like those bugs are very hardware-dependent. Which chessplayers are CM4K best suited for? I would say it is an excellent tool for both beginners and strong club-players. The beginner can take advantage of CM4K's many instructive teaching-tools, while the more experienced club-player will appreciate the analytical capabilities of the new engine. CM4K is currently the finest mass-market program for all chess-enthusiasts. Highly recommended!

This review is Copyright (C) 1994 by Mads Brevik for Game Bytes Magazine. All rights reserved.