Quick advice on using the ratings: if you want the best, go with a Class A program. You might go to Class B to select entries smaller in size or with special visual appeal. You might consider Class C for certain needs, such as Linux programs. Avoid Classes D and F unless you're looking for a children's program or have a specific reason, and even then, be very selective.
There are many, many checker programs out there; every time I search the net I find new ones or ones not previously discovered. While a few are really worthy, most of them are pure junk. I review as many as I can, but I can't possibly buy and review them all, and in recent months (fall 2005 onward) I've not been trying to keep up with the all-too-numerous new releases of unworthy dreck.
And anyways, who am I, a poor player on a good day, to be reviewing checker programs? Well, I've worked with software for decades, played board games even longer, and I have ideas which I am not reluctant to express. You are completely at liberty to ignore my opinions! However, if you feel an injustice has been done, please contact me. Those who have done so have found me to be very willing, and in fact anxious, to correct errors.
2. Rating Parameters. I rate programs according to several criteria. Again, I use the American school grading system, where A is the best grade and F is the worst (failing, in fact). The criteria are these:
I do include screen shots for nearly all programs for which the review is complete. These screen shots are on separate pages so that this page won't have an enormously long loading time. I did prefer larger graphics to preserve detail and give a more accurate impression of the game's apprearance.
CheckerBoard is an interface, not a complete game-playing program. With it you use any of several engines. Cake Manchester, a world class competitor, comes with CheckerBoard; but you can also use KingsRow, another world class engine, or any of several others of lesser strength. I have just upgraded to version 1.611 and CheckerBoard's feature set continues to grow (and there is an even more recent release just out that improves the database search capabilities).
Sage 9.0 is a very nice shareware program with good playing strength, an attractive presentation, and numerous features. The 'full' version is only $19. The policy on upgrades is not clear but the author has been more than willing to send them to me without additional cost.
As one of the strongest programs in Class B, Sage plays a very strong game indeed. A feature that you might or might not consider an advantage is that the Sage opening book appears to be based on published play. (I say 'appears' because the documentation is not clear about this. But it looks to be this way.) I personally find this useful; I can compare my moves with published play later on and see howthey may differ. Sage will use the Chinook 6-piece end game data base as well (although it seems up to you to be sure it's installed).
The feature set is very good. There is the usual import and export of games in PDN format, and there are some very nice database features. The program comes with a large database of games, and you can add more from various sources on the internet. The database search feature is especially well done; you can search by player, by date, and notably, you can search for positions similar to one you're interested in. The database features seem to be among the most complete and extensive of any program I've reviewed here. You can also look at positions and groups of positions, although this is a feature I don't fully understand (and it's not in the shareware version).
Sage, in my subjective judgement, seems to have a less 'intense' overall feel than KingsRow or Cake. (Sage allows substitution of engines, though, at the loss of some features. Cake will run with Sage, for instance.) This does not mean that Sage is not a good playing partner; it is an excellent one (I've managed two draws with Sage in quite a number of games). In my own practice play, I often alternate between Sage and KingsRow. Sometimes I just want that 'softer' feel and a look at Sage's opening book. If you want a shareware program, this is the best $19 you will ever spend.
A strong program with excellent features, including identification by name of the opening being played. This is the predecessor of Nemesis; you could think of it now as the little brother, but it is a real competitor. It is available as shareware on a trial basis and in a full version, on CD, for $25, which includes large ending databases. If you don't want to go all the way and buy Nemesis, certainly this is an inexpensive and most viable option.
The program is loaded with play features, from good opening databases (which appear to be published play rather than calculated, but I don't know this for sure) to game analysis, and fine-grained control over all important game settings.
WCC Gold Plus is a very strong program with reasonable features and a unique end-game database. They call it the 'perfect play' database and I do not pretend to understand the details, except that the authors have written papers to show why it is better than the Chinook databases, and they may be right. (Ed Trice was kind enough to send me this very clear explanation.)
The display is very nice and unique among high-end programs; it is a 3D perspective of a marble board (much like the faux marble one on my coffee table), and pieces that remind you of the stacking plastic ones that you buy in toy stores (but these at least are not red and black). There are a few different display options, but no way to get a top-down view.
Blitz is an older DOS game that was a predecessor to Sage. In its time it was a 'very serious' program and is downgraded only due to extreme age. I list it here because I actually use it, on a couple of my ancient machines, like my Honolulu computer. It has the advantage of being small (about 30k!) and very portable; I sometimes run it from a bootable floppy disk (see my web page on bootables for an explanation of this concept).
Blitz plays a rather strong game. It is certainly stronger than Simple Checkers. It has a small built-in opening book which is certainly adequate for a few moves or so, and there is an undocumented option for adding an external opening book, which I have yet to figure out. Like many older, smaller programs, it plays a good tactical game. It won't miss, or allow, shots and combinations. It has a bit less of an understanding of positional play, of course, but it does well even in that regard.
It is not my playing partner of choice when I'm able to play Sage or KingsRow, and I even won a game against it once, but it is still an interesting piece of history that plays well and credibly. It is very probably best-in-class for DOS programs (and I plan a 'playoff' to find this out definitively).
The only real reason to review Cake++ (having been long superceded by the rest of the Cake series) is because it is an engine option for Xcheckers and Capers. This is likely to be a strong Class B entrant. Author Martin Fierz, by the way, has an update in progress (February 2005) supplying Cake++ with a very large opening book, which will make this a formidible Linux engine.
Some years ago, Jon Kreuzer started work on a checker playing program as an experiment in developing game-tree searching code. The experiment was refined over time, and when a graphical-user interface (GUI) was added, Jon gave his program a logical name: GUI Checkers.
The nascent GUI Checkers got the attention of world-class checker programmer Martin Fierz (creator of CheckerBoard and the Cake series of engines), and Jon was inspired to invest additional effort to improve GUI's playing strength and features.
But we had a hunch, and so we played GUI against Nexus, the strong forerunner of the world-class Nemesis program. Amazingly, GUI won the encounter! Of course, one game doesn't tell the whole story, but the win was most impressive, and you can click here to see an animation.
GUI Checkers 1.00 is thus established as an excellent Class B entry. It doesn't beat the Class A programs, but it certainly plays a very worthy game. GUI features a small opening book and a small endgame database, a really nice look and feel, serious-minded features such as FEN and PDN import and export, and basic features such as move review and the like. GUI has a small opening book and a small 2x2 endgame database.
The author calls his program 'very strong' and that is somewhat understated. While it isn't world class, it certainly plays very well indeed. In my standard test run, it handily defeats Simple Checkers, showing that the authors claim of strength is in fact substantiated. (It draws against the strong Class B program GUI Checkers.) This is a very compact program packed with playing ability and everyone should get a copy. Of course, the weaknesses are evident: there are no opening or endgame databases, and the features are basic (save, restore, set-up, undo moves). There is no move list, analysis, etc., but then again, this is a small and unpretentious item that just happens to play a fine game of checkers. It is no longer in development and one wonders what it could have become had it been pursued further.
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