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REBEL 11.0 review

by Jeff Lischer


I have been a loyal Rebel user since Rebel 8, but am new to the Rebel Beta team this year. I apologize for my tardiness in submitting this review, but it did give me the opportunity to read the other reviews before starting mine. The reviews have been excellent and have given a very good idea of the many features of these programs so I won't repeat them all. Instead I will try to highlight just the features that are most important to me.

There are two things to keep in mind regarding my comments below. The first is that I am an intermediate level chess player, so I'm not able to judge the strength of these strong programs based on their play against me. I prefer to have the programs analyze GM games and interesting positions in an attempt to understand their strengths and weaknesses.

The second is that I have only limited experience with other chess software. I have experimented with a few of the free Winboard engines such as Crafty and Little Goliath, but I have not purchased any other commercial software. I use Rebel mostly for analysis and occasionally for playing against it. I've always felt Rebel was the most complete package for me and haven't felt the need for another package. Well, actually I have been tempted occasionally in the past, but with the release of Rebel 11, I think those temptations will be gone for quite a while….

Rebel Century 3

Testing this beta release was almost like playing with a final release - there were so few glitches found in the program. Although the improvements made in Century 3 were confined mostly to speed-up of the search algorithms, I was amazed by the results. Suddenly, Rebel was showing well against the top programs again, while maintaining its positional, human-like style.

The results in computer-computer games show a considerable improvement over the earlier Century 1.0 and 1.2, but the real test will be seeing how much the improved search helps in games versus humans. I am eagerly awaiting the continuation of Rebel Grandmaster Challenge series starting with the 6 game match versus the anti-computer expert van der Wiel.

Besides Century's positional style, one of my favorite aspects of Century is its easy-to-use and extremely flexible analysis features. There is no n-best option, but I actually prefer the approach of Century. I program buttons for Analysis, Analysis Include, and Analysis Exclude to be able to quickly switch between these different modes. 'Analysis' allows Century to analyze as it normally would, while the 'Include' option forces analysis of only my selected moves, and the 'Exclude' options does the reverse and forces analysis of all moves except those I select. With just a few clicks of the mouse and I can see what move Century prefers, then easily see its next best moves, and then finally see what it thinks about my suggested moves.

The Analyze Game feature is also very well set up. You can easily have Century analyze just white's moves, just black's, or both. Or you can set it up to just analyze certain selected moves. The program first analyzes its preferred move, then if that doesn't match the move actually played it goes on to analyze the actual move as well and outputs both analysis lines for comparison.

Century is also very enjoyable to play against - in some weakened setting such as a specific Elo rating or a weakened personality, of course!. The games always seem very real - there's a natural give and take to them as small to medium mistakes are made by both sides. Unlike some other weakened programs Century does not make obvious blunders, which just take all the tension out of a good game. I also dislike programs that you can only weaken by changing their average time or ply depth. They are usually still too strong and I find it highly irritating for my opponent to be constantly making instantaneous moves. By using the weakened Century settings I can play a nice 40/40 game in which there are healthy pauses as we both consider our moves.

Some people complain about the fact that Century is still a DOS program. In all honesty I often forget that it's DOS-based because it is so stable running under Windows. There is an occasional position that will make it crash when using Analysis Exclude (a pesky bug from earlier versions that hasn't been solved yet), but that really is the exception. You can Alt-Tab back into Windows, but Century's pondering will slow to a crawl when it's in the background like that.

I must confess, however, that I was eager to try out Chess Tiger and the Chess Partner GUI to see what Rebel's new home would look like.

Chess Tiger, Chess Partner

I can't say all that much about the strength of Chess Tiger versus other computers. Part of the reason for this is that I have only one computer so using Auto232 to pit programs against each other isn't an option for me. I also don't play over the Internet with a computer. Based on results of computer-computer matches played by other beta testers, both Tigers are extremely strong and will likely be near the top of the SSDF list (although I think Century will be near the top too).

I am looking forward to seeing how Gambit Tiger does versus other programs after more games are played. I think Christophe has created something unique here that plays a mean game of chess and is fun to watch too!

In regard to my own games against the Tigers, I found them hard to play against because unfortunately you can only weaken them by reducing their time to move. Hopefully that aspect of the program will be improved in future releases.

The Chess Partner Windows interface seems quite good to me. There is a lot of flexibility in configuring the interface for your own personal tastes - whether for online play, analysis, playing games, etc.

The interface does allow Analysis Include and Exclude, but to me its implementation is not as smooth as Century's. You don't select moves by making the moves on the board like you do in Century. Instead you must select from a list of possible moves, which I found less intuitive. Also, once the analysis starts you can't simply add or subtract moves. I hope some of the functionality of Century's approach can be added to Chess Partner in future updates.

For me, a great feature of Chess Partner is that you can have one of the Tiger engines analyzing a position while another external engine is analyzing the same position. I caught a couple of the Kramnik-Kasparov games live, and it was exciting to have both Gambit Tiger and Century simultaneously analyzing the games move-by-move.


I think the Rebel 11 CD is an exceptional value because in one package you get:
  • Three extremely strong and varied engines in Century, Chess Tiger and Gambit Tiger;

  • The feature-packed Chess Partner interface;

  • Century's easy-to-use DOS interface, which still has some features not found in other Windows interfaces; and

  • The tremendous customer support of Ed, Chistophe, and Lex.

I would like to thank Ed, Chistophe, Lex, and the whole team for a great beta testing experience.