written by Jeroen Noomen



REVIEW REBEL 9



In this review I would like to present the new Rebel 9 chess 

program of Ed Schroder. As the opening book maker and member 

of the Rebel-team I am of course a little biased, but still 

I think that Rebel 9 has so much to offer, that every chess-

enthusiast has to admit this is a very professional product

containing a lot of extras and presenting the top of playing 

strength of today, concerning chess programs.



Doing a review is not so easy as it would seem. Every single

buyer of a chess program has his own preferences: One likes 

beautiful features, the other is only concerned about playing 

strength, while the third is mainly interested in analytical 

options and large databases. To present all the options of 

Rebel 9 is simply impossible for me: There are so many, that

if I would have to describe them, it would take me a whole 

book to write about them....  



Therefore I will mainly concentrate on the points that are

interesting from my point of view. This can hardly be called

a full description of all possibilities, but on the other hand

you can share my thoughts and opinions in the question 'what 

does Jeroen Noomen find attractive in the Rebel program'. 



1. The opening book

-------------------

I'm sure everyone would predict I would start this preview 

by mentioning the opening book. Since 1989 I have been making 

opening books for chess programs of Ed Schroder. It all started 

in 1989 with the famous Mephisto Polgar, after which there 

followed the HG550 module for Mephisto MM 5, Mephisto Risc 1 MB,

Gideon and finally Rebel 6, 7, 8 and 9. It's interesting to 

watch the growth of the books I made: The Risc 1 MB had 40 KByte

of opening theory, now we are approaching the 400 KByte mark, 

thus the Rebel 9 opening book is nearly 10 times bigger compared

with the Risc 1 MB!



What is important in a good opening book? Well, from my point 

of view a good opening book should contain:



* All important, often played and popular variations like the 

  Ruy Lopez, Sicilian, King's Indian, Slav Defence etc.

* Good knowledge about sidelines, dubious variations and 

  anti-computer lines.

* Not only a wide variety of alternatives, but also long 

  variations, like f.e. the Marshall gambit in the Ruy Lopez (60 

  ply are possible here!).

* Additional analysis, improvements proposed by strong grandmasters

  and own analysis (you might be surprised when I tell you that 

  all books on  openings contain many many mistakes, that would be 

  fatal when you would copy them without checking!)

* All novelties and improvements that are played in the games of 

  the world's strongest players.



I am very proud of the result of the Rebel 9 opening book. In my 

opinion it is the best opening book there is (and people say I am

a very modest guy!). No other program knows so much about the 

Sicilian defence as Rebel 9. It is also an expert in the Semi Slav 

defence, the Marshall gambit and Saitzev variation in the Ruy Lopez,

the fashionable  9 b4 in the main line King's Indian, and many many

more. This all has been made in a period of 8 years and I am sure 

that the Rebel 9 opening book can deliver grandmasters quite some

frights......





2. The playing strength

-----------------------

How strong is Rebel 9? Incredibly strong! It has such a balanced 

strategy that you can surely call Rebel an 'allround' chess program. 

It plays dynamic positions very well, puts pressure on the opponent, 

is tactically strong, has a lot of positional understanding and if 

this all is not enough, it will give you a tough time in the endgame. 



Maybe the most underestimated quality of Rebel 9 is its capacity of 

launching King's attacks. On the Rebel homepage you can find several

games in which Rebel 9 shows its feeling for sacrificing material 

in order to hunt the enemy king. If you castle on opposite wings, be

sure that Rebel is going for your king.....



That chess programs are strong tacticians is generally known. But 

the so called 'brute force' strategies and 'null move' technique are

leading nowhere. Chess is not merely a game of calculating. Knowledge

is getting more and more important, because it doesn't matter if a 

program sees a tactical shot in 2 seconds or in 30 seconds. Rebel 9 

has a lot of knowledge, because of which it is able to play strongly 

in many types of positions. Fast calculators are helpless in closed 

positions, in which they move their pieces like zombies. 



Not Rebel: it knows how to handle blocked centers and wing attacks.

The most striking example was the game of Rebel against IGM Larry 

Christiansen (AEGON 1996), in which the American grandmaster tried 

the Benoni Wall, but got completely outplayed.



In Computer Schach und Spiele, the leading German chess computer

magazine, it was confirmed that Rebel is a tough opponent for all 

chess programs, simply because it plays all types of positions well.



Therefore I don't think the results of the Rebel program in the last 

4 AEGON tournaments can be called a surprise: Rebel was simply the 

most balanced chess program, scoring 4 times in a row excellent results.



The secret? Not difficult: What type of opening or strategy the human

players used, Rebel was always able to show its allround capacity. 

The anti-computer strategies didn't work.....



In general I would describe the playing style of Rebel dynamic, 

aggressive, positionally sound, with a good feeling of piece-activity

and king's attacks.



The endgame is very strong, especially the passed pawn evaluation and

the cooperation between king and remaining piece(s).



3. The evaluation

-----------------

Maybe a surprising aspect to mention. But when I compare the 

evaluation of positions by Rebel 9 with other programs, I come to the

conclusion that Rebel has by far the most reliable evaluation. 



There is a tendency in other programs to overestimate aspects like weak

pawns, activity of the pieces, space. This often leads to evaluations

of more than +1, that are not very reliable in my opinion. 



Rebel's evaluation is much more modest and nearly always close to the

truth. And you can see in Rebel's games that it is exactly this good

evaluation that makes Rebel such a strong program: It never under- or

overestimates its chances, because its guideline is a very safe and

positionally sound evaluation function!



One aspect that I would like to add, is the evaluation in King's 

attacks. Try a position in which one side has an insecure King and you

will see that Rebel's evaluation will do the trick: Smoke out the King,

try to get it into the open field, smash the defensive pawnwall and so

on. I have never seen so many great attacking games by a chess program,

following up a straightforward plan. Rebel's king safety evaluation is

simply the best there is!



In general I find the evaluation of Rebel in most positions very 

reliable, because of which I do all analytical work of my own games 

with the help of Rebel. And I can assure you that analysing with the

help of Rebel improves my own play, because it not only shows my 

tactical failures, but also helps to evaluate unclear positions, of

which I am not sure whether they are good or bad for me.



4. Analytical support

---------------------

As I said I do a lot of analytical work with Rebel: To check my 

own games, to check analysis of grandmasters and to check theoretical

articles and novelties. Another strong point of Rebel 9 is, that it 

supports players who use a chess program to analyse in an optimum way.

For me the next features are the most important:



a) The history of Rebel's thinking process. When Rebel 9 is 

    changing its mind about the best line, or goes up one ply, it shows

    both in the lines under the chessboard. In this way you not only 

    have the main line to watch, but you can also see why certain moves

    are rejected and which moves Rebel 9 likes. This is by far more 

    valuable than only one main line!



b) The possibility of including and excluding moves from Rebel's 

   thinking process. If you want Rebel 9 to analyse only one move or a

   couple of moves, simply use the 'Analysis include' option. Execute 

   the moves Rebel 9 has to analyse on the chessboard and Rebel will 

   only take these moves into consideration. Very handy if you are 

   f.e. hesitating between two different moves. Rebel skips the other

   moves from its list, because of which the analysis is going much 

   deeper in the same time. The same goes for 'Analysis exclude'. 

   Execute the moves that Rebel 9 should NOT analyse on the board and

   Rebel is going for the second best option. I like this much better

   than a next-best option, because you can exclude more moves this 

   way, without the necessity to press the next-best button over and

   over again.



c) The special analysis levels. You can play every move you like, 

   Rebel 9 is just analysing the new position. In this way you do not

   play AGAINST Rebel 9, but WITH Rebel 9! Very easy to handle, play 

   through the game you just played and Rebel shows you what has gone 

   wrong. With the arrow-keys you play forward or backward and can 

   try a new alternative. Very user-friendly and ideal for analysing

   games!



d) The way Rebel 9 is showing its thinking process. There isn't 

   only a main line and a score of the position, but Rebel 9 will

   also indicate when a move is going to get a better score (by 

   putting a '+' in front of the move) or a worse score (a '-' is 

   displayed). If the next ply is still going to take a lot of time,

   you already know if the score will be much better or much worse

   than the score that is given at the moment! Furthermore Rebel 9

   shows its theoretical knowledge by displaying all the alternatives

   it knows from the given position. If it is still 'in book', you 

   always know which moves are theory and which are not.



e) You can have Rebel 9 analyse a game from the white side, from

   the black side, or both. Put Rebel 9 on f.e. the 3 minute per 

   move level and go to sleep. Rebel will evaluate every move you

   made and show you its alternative (when Rebel 9 is disagreeing

   with your move). When you wake up, all this information is 

   stored and by moving through the game, you can see exactly 

   where things went wrong. No need to move pieces, no need to do

   anything, just go to sleep and Rebel 9 does the job for you.

   In this way you can even analyse a whole database, f.e. with

   the last games you played.



5. Database options

-------------------

Rebel 9 is delivered with a large database of (grandmaster)games

and a lot of options to search in the database. You can search

for names, moves and text, but also by means of a certain pattern.

I like very much the way the games are presented: If you enter

the database and put the cursor on a game, the theoretical 

position and the position after the last move is shown on two 

small chessboard at the right! Very nice. IF you want, you can 

have an overview if a game, in which Rebel 9 shows you the most

important positions in the game on small chessboards and analyses

these positions as well! Below every position the evaluation is 

given, so that you can see exactly what happened in this game: f.e. 

First white had the advantage, then it passed to black. But black

blunders and white took advantage of this. 



You can analyse databases, form your own databases, skip games,

add games and so on. Why not get rid of those notation forms, 

lying in your desk for more than 5 years? Simply add all the 

games you've played to your personal database and all is stored

in the computer! And Rebel 9 can analyse this database, you can 

play through your games very easily and if you put the Analysis

level 'on', Rebel analyses the game while you are playing through

it. And that is not all: All your games are stored and classified

by the ECO-index, so you can see what openings are going very 

well for you and which ones need a little repairing.



6. Other extras

---------------

The autoplay function is the most striking new function in 

Rebel 9. You not only have the option to choose 4 different chess 

programs (Rebel Decade, 7, 8 and 9) but you can also let them 

play against each other! On any level you want, blitz or 

tournament, easy level or whatever you want. One of the best ways

to use this, is when you have f.e. an adjourned game at the club

you're playing at.



In the evening you come home, put the position in Rebel 9 and

choose two programs to play against each other from that adjourned

position. Take a slow level, f.e. 10 minutes a move and activate

the autoplayer. Then you go to sleep and the next morning Rebel 9

shows you how the game should/could continue.



Of course you can do a lot of additional analysis next evening, 

but you are better informed about the adjourned position than 

your opponent, that's for sure...



I also like the option to play 4 games simultaneously. Often I

lose 3-1 or something, but it is nice to play 4 games at the 

same time against the same program. Rebel 9 follows the rules 

for simultaneous play exactly, as soon you have played a move, 

you can't take it back.... So watch your steps!



7. Conclusion

-------------

Rebel 9 is a great chess program in my opinion. It gives you a 

huge amount of features, plays very strong and provides you with 

all the help at analysing games and positions. It can be used 

for training by strong club players, for correspondence chess, 

for any player who wants to improve his/her game of chess. 



It is not only a joy to play AGAINST Rebel 9, but also to play

WITH THE HELP of Rebel 9. It helps you understand chess, analyse

your games, show you where you went wrong and provides you with

database options to store your own games.



True, I am a member of the Rebel-team and of course positive

about this product. But our main goal is to give you a fine 

chess program that encourages you to play chess, to learn more

and to help you. And everybody can see for himself if he agrees

with my statements or not. I like Rebel 9 very much and I hope 

you will enjoy it as well!



Jeroen Noomen