written by Dave Gomboc

Overview
As a chess player improving from 1700 (3 years ago) through 2000 (today) to 2300 (hopefully 3 years from now :-), I need software that grows with me. Rebel 8.0 is the only chess program I have seen that can adjust its rating strength to test yours. Complete with database capabilities, Rebel 8.0 is an excellent purchase for those who wish to maximize their computer as a tool to improve their chess.

Chess Engine
Let me state quite frankly: I will be surprised if Rebel 8.0 does not emerge at the top of the SSDF list. Strong tactics combine with solid positional knowledge (for a computer) to create an algorithm that plays many positions just as a strong human would. Rebel plays solid, unassuming chess.. but if you give it an inch it will try to take a mile! I especially enjoy playing 4 blitz games with it simultaneously. I can even set their ratings to 1300 before I begin, then show off to all my friends. Of course, at its top strength (Rebel estimates itself at 2461 on my Pentium 120 with 32Mb) the direction of the slaughter is reversed.

Features
As I made reference to above, Rebel 8.0 has some innovative features. There is a clipboard of four boards, so you can analyze various continuations, and see all of the positions simultaneously. This is a tremendous advantage when going over games. You can copy the position to one or more clipboards, then play out the various alternatives on each board. As an extension to this, Rebel will allow simultaneous play on the four boards! Fantastic.

An idea whose implementation has come is what Rebel refers to as "Power Analysis". If you want exhaustive analysis of a position, you can just set Rebel to "Analysis" mode and let it grind. What Power Analysis does is allow you to choose the continuations that it analyzes. For instance, if it's a question of who will be mated first, you can tell Rebel to look only at e5, g5, Nf5, Rdg1, Rh7, and Qh2. If I go for the weekend and leave it on Analysis, I might get to 14 or 15 ply before extensions. I'll get 18 ply when using Power Analysis, because Rebel doesn't waste time checking that a3 isn't the deep prophylactic move it might be. The programmers also considered allowing a moves to be removed from the search, but did not have time to implement it for Rebel 8.0. This would be a nice addition.

Are you 1400 and sick of getting crushed? Are you 2000 and feel like having a tough game but one you can win? With Rebel 8.0, it's very simple: you just type in the rating you wish Rebel to play at, and away it goes. I experimented with this feature. Unlike some other programs' failed attempts at dumbing down their programs, Rebel does a good job. At 1300 it would see the clear tactics, but would miss the in-between capture that nets it an extra pawn. At 1700 it would miss the stinger in a long series of tactical calculations. At 2000 it decided to attack my king but didn't concentrate enough on defence. And at 2450 I couldn't punch it out. It would fight for the slightest counterchances. This feature is one of the greatest things since sliced bread.

For those of you with Bookup, Rebel 8.0's EPD support allows you to use it as the chess engine. This is quite exciting due to Rebel's superior chess strength. Also, you can tell Rebel to show its top four candidate moves for any position, which is handy for analysis.

Database
I am not a game collector. Having said that, I found the database utilities built into Rebel 8.0 quite useful. The beta, at least, came with many games, complete with Elo rating of the participants. It's always interesting to look at a random GM game and try to guess their moves as you play through the game. You can pick out the games between two players, or the games played at a certain tournament -- even opening preparation is made simple. Rebel will also import ChessBase, NicBase, and PGN files; all the games from the Internet are yours to work with as well. With the recent explosion of chess information, you'll never be short of new gamescores to play through!

Searching can also be done by exact position. An improvement would be the ability to specify "White pawns on d5 and e4, White bishop on the h1-a8 diagonal", and have it scan through the database for games in which this occurs. Rebel is not quite ready to take on the big chess data vaulters yet.

Creating your opening books will be fully implemented in the release version. My opinion is that using a large game collection might be the easiest way. The company offers also offers large opening books specialized for Rebel. I have not tried these. I only know they are big.

Ease of Use
Rebel 8.0 is a DOS program, but don't let that scare you. It allows mouse control, and even has a "button bar" of common functions. You can choose to drag your pieces or click on initial and final squares. Colouring is completely customizable, though I found the defaults to be just fine. Having seen how Rebel Decade looks, my impression is that screen real estate is becoming harder to find! 640x480 is the resolution now: perhaps in future versions Rebel will need to move to 800x600 (or to Windows! :-)

Actually, at first I didn't find Rebel that easy to use, though now that I have tried it for a month I am comfortable with it. Perhaps this is because beta testers received the manual for Rebel 7.0 instead, as the new ones were not ready. The installation program is not very pretty, though it is serviceable enough. Prospective purchasers should note that Rebel 8.0 is copy-protected, but provides unlimited installs, so if you upgrade your hardware later and Rebel complains you can just reinstall the program. If the disk goes bad, the company will provide a free replacement.

The program has a customizable resign feature. You can decide yourself if you want it to give up when it's down a piece or if you want it to fight to the finish! You can also customize chess engine features such as hash size and aggression/solidity of play. There's even a simulation of different styles of chess players: the person who comes fresh to the board but wears out, the person who gets stronger the later it is in the endgame, and the person who goes out for a smoke now and then and loses some of their concentration. I'm not sure how useful these "Energy Level" settings are, but some people like them.

Did I mention that Rebel supports 5 languages?

Detractors
I don't expect any program to be perfect, and I'm sure you are wondering what is wrong with Rebel 8.0. Well..

Any menu option stops Rebel's analysis of a position dead in its tracks. I understand that if you change from "aggressive" to "solid" the evaluation will need to be restarted, but I see no need to restart after rotating the board so that the other colour is at the bottom. A research also happens at other weird times, i.e. after a forced mate has been found and a move has been played -- but dead is dead. Ed Schroder has told me there are chess engine related reasons for the general behavior. These are a couple of cases where there could be an exception to the rule.

Rebel will analyze (unattended) all the positions in a game, or test suites in a database, but it will not do the same for a block of games. Every time I grumble about this I remind myself that I am supposed to be doing the analyzing!

Some program options become unavailable when in a special mode, i.e. strength via Elo rating, or Simultaneous mode. One can't use position setup on a clipboard position: one must have the position set up on the main board, then paste it across. These restrictions should be eliminated where possible to do so.

The moves are displayed in figurine long algebraic only. I would like to see short algebraic, and I'm sure there are a few proponents of descriptive notation out there as well.

I wish that the close program icon in the top left corner required a double click. Perhaps I am in the minority here. I have hit it by accident a couple of times.

Finally, the program is a DOS program. This won't bother some of you, for others it will. My understanding is that Rebel will run well as a DOS application in windowed environments. Due to a display driver problem on my computer, I found myself exiting to DOS when using Rebel.

Summary
Rebel 8.0 helps me to improve my game. With the product I receive a strong opponent, analyst, and archivist. I know of no better program for the serious chess enthusiast.

Last update August 23,1996