- REBEL 9.0 Reviews -

written by Moritz Berger

Rebel, 9th iteration


This is an abridged version of a 3 times longer, more detailed review which you can find on the Computer Chess Reports web site (see for subscription details). The CCR version of this review will probably appear here after Christmas, but of course not the CCR reviews of competing products ... I will also post results (games and scores) of a 40 game match Fritz 5 vs. Rebel 9 on the CCR site in a few weeks, please note that there are already many impressive autoplayer results vs. the usual suspects (Hiarcs, M-Chess, Genius, ...) available on the Rebel homepage.

Just for fun

The funniest feature I ever saw in a chess program is the so called Energy level: You can configure Rebel to either get stronger, weaker or play at random strength during each game. Imagine your opponent getting drunk, waking up slowly or just playing cat and mouse with you.

With the new release, Rebel 9, you can also completely skip opening theory (since your goal might not be to learn opening theory but to get a good game without those annoying theoretical blunders in move 3 …). "Shuffle book" will jump to an arbitrary end-position in the programs own theoretical opening book, of course this might not prevent you to lose in 3 moves, it will only look less silly in the move list when it says "move 20" than "move 3".


In my experience, Rebel offers the most advanced database part of all DOS chess playing programs (not counting e.g. TASCbase).

If you want to improve, you will want to have some elementary statistical information available about your performance. There are in fact a number of such functions you can use for broad surveys of certain topics, not only on your own games.

• Player vs. Player (Kasparov-Karpov)

Database:GAMEBASE *** Match Kasparov-Karpov ***

Name Tot Score + ½ - Perc Old Oppo New

Kasparov 895 581.5 - 313.5 352 459 84 64% 2780 2639 2717

Karpov 1100 665.5 - 434.5 343 645 112 60% 2740 2644 2656

Player 1 - Player 2 Score + ½ - Perc

Kasparov - Karpov : 161.0 - 146.0 53 216 38 52%

Rebel allows you to enter a rating for both players every time you save a game. You will find ratings for many players in the Topbase on the Rebel Bonus CD. But Rebel (via the dbutil program on the Bonus CD) also offers you database maintenance functions that even ChessBase doesn’t have: You can globally replace player names by one variant with standardized spelling, ensuring proper results if you search for them (e.g. replace all names that contain "Nimzo" by "Nimzowitsch" (German spelling)). This capability is extended to also insert default ELO values for each player and, last but not least, this process can be automated via a list of Names and ELO numbers.

Rebel 9 now also offers search for material (useful for endgame studies or to learn e.g. the best strategy of queen vs. 2 rooks) and positional search (e.g. exchange sacrifice Rook on c8, useful if your memory is like a sieve and you want to find a game where you remember only one motive). Duplicate elimination is also possible (but not aggressive enough, IMO).

To be fair, I should also mention that Rebel doesn’t allow complex queries like ChessBase. My recommendation would be to either buy ChessBase or use Rebel 9 to perform a broad query on a big database, resulting in less than 8000 games which is the game limit in the freeware ChessBase light (available at Then you can perform more sophisticated queries on the result by exporting them to ChessBase.

Very important here is the fact that Rebel 9 now also supports .PGN databases directly. Unfortunately, PGN databases are not accessible with the more sophisticated functions and basically allow simple save and retrieve operations (probably because of performance considerations). Talking about performance: ChessBase is also much faster except when you search on player names, Rebel doesn't support theme and opening key trees etc. So after you get addicted to computer chess with Rebel 9, be prepared to spend even more money for ChessBase for serious database quests...

Analysis and advice

Besides the usual "think forever and I look at your favorite line of play and evaluation", Rebel offers more sophisticated Analysis include and Analysis exclude options. Both work by entering the respective modes, then making some moves on the board.

Rebel not only gives an game overview of various stages of the current game on several miniature boards, it now also evaluates each position and displays a score below the board, allowing you to quickly spot crucial stages in the game and jump there by clicking on the respective board.

In the database list, Rebel displays some kind of ECO position (i.e. after leaving theory) for the currently selected game together with the final position for which there's an Evaluate button to evaluate it. I found this highly useful for browsing a database of autoplayer games and spotting interesting openings or endgame motives.

Licensed to kill

After observing several strong (~ FIDE ELO 2200-2300) human players under "tournament conditions" (and on a real chessboard) against all top programs (Rebel, Fritz, Genius, M-Chess, Hiarcs, CM5k, Chess System Tal, Crafty) I believe that Rebel is the strongest program against humans at the game / 30 minutes to 60 moves / 30 minutes time controls I tried on my Pentium 100 and 166. Rebel’s performance at the yearly AEGON man-machine tournaments remains consistently high during the past 4 years, this seems to support my impression.

According to Mark Young, Rebel on P2/300 has reached a 2700+ standard rating on ICC, the highest rating in the history of this chess server. I hope this doesn't frighten you from buying the program ;-)

More chess than you can stand

This somewhat pathetic phrase refers to the Bonus CD is included with Rebel 9. To suggest added value, Ed Schröder also sells this as a separate product... Despite the fact that most will buy the Bonus CD together with Rebel 9 to maximize product synergies.

I will not repeat the detailed description you can find on the Rebel homepage, it is a very nice collection of highly useful stuff and adds tremendous value to the Rebel 9 package.

Cobwebs and dust

The bad news is of course that Rebel 9 is still a DOS application. Rebel crashes NT 4 SP3 down to a blue screen, so even trying to start it under NT is not recommended (the install also hangs under NT). The flip side of the coin is that Rebel fully supports Auto232 autoplayer, Chess232 and Mephisto chess boards (don’t know how well the TASC support works).

If you accept the fact that Rebel is still a DOS application, it’s user interface works surprisingly well, especially the user interface design of the database part and online help is much better than in the Windows chess programs I know (Fritz, Genius). Tutorials that describe common tasks also are a big usability plus and compensate for the lack of an extensive printed manual.

Put or call?

If you want the most feature complete DOS chess playing program, you absolutely ought to buy Rebel 9. I highly doubt that the competition will ever reach this functionality under DOS, I guess they will all very soon make the transition to Windows where the race will start anew.

The wealth of features, chess material, no copy protection, extensive support via Internet and strong chess playing engine give compelling reasons to buy this product even if you’re a Windows user.


I am rather fond of this product. As a Windows NT user I would slightly prefer Fritz 5, as a Chess232 chessboard user (which is more important chess-wise) I give Rebel 9 the nod. Roughly three quarters of my needs are satisfied by this product - I consequently would rate it a strong 8/10.

Trick or treat

Top 10 things I like


1. Excellent chess playing engine
2. Extended Autoplayer 232 and Chess232 support
3. Good bread and butter database capabilities and then some (statistics, auto-rename, double elimination, …)
4. No copy protection, excellent database and opening book update service via free Internet Bonus subscription
5. .PGN, .EPD support, .CBF, Nicbase import, Bookup analysis and import/export of e-mail chess-forms, opening book import from Genius, Fritz 4 and Chessmaster
6. Ingenious shuffle book option
7. Overnight book analysis, pre-analyzed extensive theme books available via Rebel 9 homepage for registered users
8. Outstanding help system, extensive tutorials
9. Analysis options, presentation of evaluation details
10. Playing-strength adjustable to suit everybody’s needs: auto-increase, decrease, randomize, ELO-rating-level, 3 global strength levels

Top 10 things I hate


1. DOS program, doesn’t run under NT
2. No nested variants in game score
3. Doesn’t support .CBF (only via import) and .CBH (not at supported at all) database formats (although here ChessBase is to blame for not making these formats publicly available …)
4. Limited opening book annotation symbols (only play or not play)
5. Learning weightings are not user-editable
6. Way too inflexible timing options, no Fischer clock, no move increment, no adjustable time odds (different time controls for computer and opponent), no adjustable e.g. 37 moves / 43 minutes level.
7. Rebel .mvs books cannot be edited, there’s no way to convert the rebel.mvs main book to an editable .rbm file.
8. Some hotkeys (e.g. Alt+P -> Alt+Q) have changed from previous releases.
9. If you access the menu bar, the chess engine is halted and has to be restarted on the current position. Still annoying even for Rebel veterans like me.
10. Impact of learning function is not even remotely explained (a well kept competitive secret by the programmer). At least I know that it's some kind of book learning, but it's not adjustable and doesn't take into account opponents strength and time controls (the latter being idle speculation by myself in the absence of tangible information).

Top 10 reasons to upgrade (besides the top 10 things I like)


1. Greatly improved database handling (!!!)
2. Tons of study material (chess problems, games, opening books) and utilities on Bonus CD
3. Book learning and pre-analysis capability
4. Direct .PGN file support (no conversion necessary)
5. Improved chess engine
6. Analysis exclude option
7. Search on pattern, search on material
8. Improved game overview with evaluation scores
9. Build in autoplayer (available engines: Rebel 7,8,9, Decade)
10. Extensive set of chess material and utilities on Bonus CD