A year ago, there was one good Macintosh chess program on Info-Mac and AOL (GNUChess 4.0). Now there are five - all free! Here I review MacChess 2.5 (the best overall), RChess 2.2.2 (a beatable program), and Crafty 9.30 Mac (the strongest, but cryptic).
MacChess 2.5 and Crafty seem clearly stronger than the most popular commercial chess programs (Chessmaster 3000 and Battlechess) and have more features than many commercial chess programs. The stronger commercial programs are not well known - I hope to review them later.
Chess software strength is tricky to gauge, so the ranking table below may have some errors. I tested each program on at least 60 test positions designed to measure computer software chess strength. The strongest chess programs seem to be:
Power Mac with PowerMac w/o 680X0
Speed Doubler Speed Doubler Macintoshes
#1 HIARCS Mac 1.0 HIARCS Mac 1.0 HIARCS Mac 1.0
#2 Sigma Chess 2.0 Crafty 9.30 Mac Sigma Chess 2.0
All chess programs except the “native” programs (Crafty, Grandmaster Chess and GNUChess 4.0b5) are much stronger on Power Macintoshes when the Connectix utility “Speed Doubler” is used - they run two to five times faster.
Two tips: background applications can slow down chess software, and some will not run with a screensaver on.
The first six Macintosh chess programs I reviewed had every “standard” feature below. A “-” indicates a missing feature.
Chess-Playing Software Features
MacChess RChess Crafty Feature
Standard Features
• • - Provides graphical position display
• • • Reads games from files
• • • Writes games from files
• - • Displays White at top or bottom of screen
• • • Displays time used by each side
• • • Lists the continuation the computer expects
• • • Allows setup of an arbitrary position
• - • Infinite time mode
• • • Plays with and without memorized openings
• • • Gives hints
• - - Either human or computer can play either side
• • • “Move now” (force computer to move immediately)
• - • Allows moves to be taken back
Advanced Features
• - - Prints diagrams as graphics
• - • Reads/writes games in Portable Game Notation (PGN)
• - • Runs batch problem tests
- - • Lets user edit its opening books
- - • Annotates games
- - • Uses ending tablebases
Two good freeware programs are not reviewed here. GNUChess 4.0b5, a “fat” program with available source code, was omitted because MacChess is stronger and has more features. The HIARCS Mac demo will be covered in a later HIARCS review. Information on these and other Mac chess software can be found on the Web in the Mac Chess FAQ:
MacChess began as the Atari program, “TOBBER”, that Wim entered in the 1989 Dutch Computer Chess Championship. In 1995, MacChess 2.0 scored 5 1/2 - 5 1/2. Pretty good for a program running on a Centris 610 (20 Mhz 68040) against 100+ Mhz Pentiums! MacChess owes some of its strength to the fact that its chess engine is hand-coded in 680X0 assembler.
MacChess has the best graphics and controls of any noncommercial chess program - better than most commercial programs. Choose from five two-dimensional piece sets and eight boards in the Preferences menu, and set color, sound and notation settings. The cursor changes color when it’s your move. The move list has seven “VCR-style” control buttons to step through games forward or backwards, go the start or end, or playback the game forwards or backwards. The “pause” button stops playback if you hold the mouse button down on it for a while. Double-clicking on any move in the move list takes you to the position immediately preceding that move.
 
MacChess prints diagrams like those in chess books and magazines. For best results, go to the Preferences menu and select the “American” pieces, the “Green and Buff” squares, and turn off the “Color” checkbox. Then under the “File” menu, under “Print”, select “Print Board Graphic”.
Any chess program will be too weak for some, and too strong for others. If MacChess is too strong, lower the level using the “Fixed Depth” Level setting (“Depth 1” is the weakest). If that doesn’t work, try switching sides when the computer is winning, or play against RChess instead.
If MacChess is too weak, Crafty is the cheapest solution. Other alternatives are Speed Doubler (for Power Macintoshes), HIARCS, a faster Macintosh (you wanted one anyway), or all three. For Power Macintoshes, MacChess 3.0 (native only) should be out by January — the beta I tested seems stronger than Crafty.
Everyone with access to a Macintosh and an interest in chess should have a copy of MacChess. It is the nicest noncommercial program, and has features that no commercial chess-playing program has.
Pros
• Strongest noncommercial program on 680X0 systems
• Many features
• Nice piece sets
Cons
• Hard to beat at weakest setting
• Not PPC Native
• Won’t annotate games
Publisher Info
Wim van Beusekom
Hogenbanweg 72d
3028 GP Rotterdam
The Netherlands
beusekom@knoware.nl
 
 
 
RChess is reviewed because MacChess is too strong for many people. The RChess ReadMe file states: “Fills a market gap, by being easily beaten at its lower levels. Unkind people have suggested that this feature applies at the higher levels too.” Humor aside, Robert has put a lot of thought into RChess’s lower strength settings, so that even amateur chess players can beat it. At higher levels, RChess plays fairly strong chess (e.g., it wins the tough King, Bishop and Knight against King ending).
RChess has reasonable graphics. It provides two board sizes, a nice touch that few commercial programs provide. It allows pieces to be moved either by clicking and dragging, or by clicking a piece, then the destination square. RChess is unique in handling either method transparently. It also has a “side on move” cursor indication. When RChess is to move, the cursor is a face whose expression indicates RChess’s evaluation of the position. When the human is on the move, the cursor is a plain arrow. The piece set is clear and serviceable, but not elegant.
 
RChess is missing a few “standard” features. The human’s side is always at the bottom of the screen, the maximum thinking time is 9999 seconds, and RChess does not directly support human-human games. The menu that lets the human cheat (Hint, Force move) is a very inconspicuous menu to the right of the “Play” menu). Also, the position setup option (“Modify Position”) neither lets you add, nor directly remove, pieces. You can remove pieces in this mode by “taking” them with pieces of the opposite color, but this is much less convenient than in MacChess or commercial programs.
I recommend RChess to people who find MacChess too strong a sparring partner. That may be most people.
Pros
• Easy to beat at low levels
Cons
• Few features
Publisher Info
Robert Purves
Pharmacology Department
Medical School
University of Otago
PO Box 913
Dunedin
New Zealand
robert.purves@stonebow.otago.ac.nz
 
 
 
Crafty is the strongest noncommercial chess program . It has powerful features no other Macintosh chess program (free or commercial) has, such as perfect endgame play. I gave it two joysticks because Crafty is text-only, with scanty documentation. Many people will want to wait for the planned graphical user interface (GUI). Despite our Macintosh user prejudices, this program nevertheless deserves a hearing.
Robert Hyatt has written chess programs for over 20 years. His “Cray Blitz” was World Computer Chess Champion in 1983 and 1986. “Crafty” is his latest project. For those interested in computer chess programming, Robert makes Crafty’s source code available for downloading and provides many informative posts on computer chess programming in the Internet newsgroup, rec.chess.computer. Crafty’s development is guided by its games on the Internet Chess Club
<http://www.hydra.com/icc/> (roughly 30,000/year). Robert makes changes, then sees if Crafty’s results improve or not. Because of this Darwinian development, Crafty should be at its best when playing fast games (10 seconds/move or less) against humans. Many people wanted Crafty available on Macintoshes, so Lloyd Lim ported it.
 
Crafty has the widest number of chess engine options of any Macintosh chess program. It has three standard opening books (the smallest is on this CD-ROM, with instructions on how to download the larger ones), together with many commands for creating custom opening books. It also supports ending “tablebases”. Tablebases are files covering positions with few pieces (five or less), telling the computer the best move for all such positions. It’s daunting when Crafty announces “mate in 45”! The tablebases aren’t included with this review - the set for four pieces or less is 34Mb compressed, 245 Mb decompressed.
Crafty’s main flaws are the missing GUI, and the scanty, cryptic documentation. Robert seems to have made Crafty available to help computer chess programmers who are familiar with computer chess terms and read the source code comments. The online help doesn’t discuss “hint” or “move now”, though the source code mentions them. Still, most people should be able to get it going with a little experimentation.
Crafty should be considered by serious players. The game annotation is great for postmortem game review, and the tablebases are good for ending study (if you have the disk space). Casual players may find Crafty too much trouble.
