Fruit, the alternative to Crafty

Interview with Fabien LETOUZEY, programmer of Fruit by Frank Quisinsky.
April 5, 2005


1. Frank Quisinsky - Fruit and the free sources of Fruit will give me some material for an interesting interview with you. I believe many of the Gladiators, Winboarders, Chessbaslers, others wait of this interview and in my opinion it's the right time to make it. Means that we all must cope with the strong Fruit and we all have to build an own opinion about a new situation the amateur chess area have now. Let us start harmless Fabien?! How old are you, what is your job / profession and how long are you working in chess programming?
I am 33. I am working part-time in a small company that installs networks. This means I have a lot of free time but also that I have little budget if at all for things like travelling or buying a new computer.

I don't remember exactly when I wrote my first chess program, perhaps 5 years ago. I created a "xannprog" account on FICS, so it's possible to find out exactly when that was. More importantly, I had been (and still am) writing programs playing other games (Othello and draughts then, now also Awari and some more) before. See for instance the freeware Othello program "PilOth" for Palm-compatible devices.

2. Frank Quisinsky - In the first times you made your program free available we can read a lot from yourself in WinBoard forum. Fruit was a big topic and I am thinking on the first great times we have with WinBoard. Each new engine was a celebrated hero in WinBoard forum. Times have changed Fabien. Today we have a lot of engines and different groups of users which try to go an own way. The amateur chess area isn't strong as in the years before because we don't work hand in hand. But your engine is each time special topic users like. I believe the near from yourself to users could be the reason. What is your personal wish to the group of others programmers? Perhaps more interesting messages to programming and other computer chess related topics! I believe this point should be important for you and your own ideas. Your sources are free available, you can't cower the ideas you have with the note you give us with your public sources!
I became an "official" community member only in 2004, but I did not get the impression that time had changed. As I recall, all happened exactly as you described.

Amateur computer chess as I see it is not a global research project, but rather the meeting of different people each with his own goals. In particular, engine authors are only ONE part of the community. What would they be without testers and public tournaments?

The community has become relatively large, probably because of Internet. It is only natural that some "side groups" have emerged. CCC is a rendez-vous point, but in my opinion the topic is too general for our needs. There are too many posts for people who are not on-line regularly to follow.

I don't think the creation of separate fora is a big problems. It allows more people to participate (e.g. for those who can't or don't want to speak English) and if an interesting exchange takes place somewhere, one can post a reference to it in other places. It may look a bit strange but I think it's working well. It still feels like everybody knows everybody, which is reassuring.

I leave it to you whether amateur chess is not as strong as before (whatever "strong" means), as I was not here to see it for myself. It is not at all the impression that I am getting though. I do believe that there are more exchanges nowadays, especially in the form of additional software (anything that is not an engine).

I don't know if Fruit was really a special topic before Toga appeared. There is no reason why it would be more important than other engines. I don't think I am especially close to users, for instance I can't remember a feature that I included to please one of them. Instead I have the feeling that the majority was attracted by engines that specialise in attacking the king, not quite my cup of tea ... In other words I have always considered Fruit's playing style as a handicap regarding popularity.

I think highly of most programmers because each of them contributes in some way: helping others, giving their point of view, bringing "side" software, etc ... That's the vast majority. The only ones I am not interested in are those who never communicate. They release and that's all; no difference with most professionals. One person that deserves a special mention is Tord Romstad. I think he has been very influential in the last two years, and this has little to do with open source. Among the new generation, Alessandro Scotti is promising!

Many people might think that programmers discuss techniques less and less, but it is simply more and more difficult to post about something really new/different. The new generation of programmers can find many answers by digging into fora archive section.

I can't hide my ideas, but I did not claim I had any of interest either. I prefer to think that I have "principles"; I follow them, whether good or bad. I expect that anybody who had a look at the source code failed to find anything "special" he was looking for ... Perhaps the real idea is that the components in an engine might not be as important as the glue that is tying them (don't look for too much deep meaning in this sentence though).

3. Frank Quisinsky - I was thinking a long time about your project. All isn't clear for me and sometimes I think much of this what you do is inconsistent. Fruit supported "only" the UCI protocol. You search the way to WinBoard forum and you develops an adapter / converter (Polyglot). Under WinBoard itself the users have now the possibility to used UCI engines with Polyglot. Why you don't support the Winboard protocol directly? Why you prefer the UCI protocol? Why you develop such a tool?
I certainly don't think of myself as being inconsistent, so let's explain. Allow me to answer in a different order, first things first:

The choice of UCI is based on software-design principles that are not easy to explain. It's a programmer's thing really, I don't expect engine users to understand. Let me give you a clue though: think about young WinBoard engines that you have tried; how many handled pondering ... without bugs??? Another clue might be that surely, Stefan Meyer-Kahlen knows a lot about good programming, right? So trust him if not me, UCI is good for programmers because it leads to fewer bugs in the code...

At the same time there is no usable UCI interface on Linux, the system I am using. Yes I know of Jose but it is slow and does not allow engine matches. The only interface is XBoard, WinBoard's Unix cousin. This means I had to write a separate program to link Fruit to XBoard and translate both ways: PolyGlot.

Note that although PolyGlot was born as separate software due to a programming principle for engine development, other people can benefit from it as well (including on Windows and Mac OS). Soon after its first release UCI engines were allowed in (all, I think) public tournaments using WinBoard-related software, an important event.

Nowadays the decision to support either protocol or both is entirely the programmer's and hardly has an impact on users. I agree that adapters are not easy to use (although it's possible to write additional software to easily configure them, any candidate?), but of course there are only smart people in our community :)

Now regarding my "choice" of the WinBoard forum.

My opinion is that I did not choose that forum, it's the forum that chose me. It sounds megalomaniac but read on ...

I had sent beta-version source code to Dann Corbit, who built an executable and posted messages on CCC and the WinBoard forum. CCC was reaction-less (which is OK with me), but there was a "large" amount of action on the other one to the point I was invited there so that I could react. I answered the questions as only seems natural, and never really left the forum afterwards. It became my new "house" (I had regular access to Internet at that time). It was then I understood that CCC was about computer chess alright, but not AMATEUR computer chess.

After the release of PolyGlot there was another reason for me to use the WinBoard forum: using PolyGlot makes sense mainly in conjunction with WinBoard, since most other GUIs are UCI-compatible. It was therefore the best way to contact PolyGlot users.

Now a precision for the readers of this (Arena) forum: "WinBoard" forum is mostly a misnomer, it really is about amateur computer chess in my opinion. At least that's my use of it. As far as I know, UCI is not considered off-topic in the forum, so there's no need to shy away. I would say the same thing regarding other GUIs (see for example the AEGT sub-forum).

Sorry for the long explanation, I hope that you are now convinced that I am only PARTLY inconsistent :)

4. Frank Quisinsky - The first I do Fruit 2.0 was available is to read your text file. This can be a provocation to Arena but with much intelligence from you?! Linux is the topic. Arena isn't compatible to Linux and after all what I read you must be a big supporter of Linux. Honest, I like the Linux idea. Martin Blume will try Linux support later and he doesn't change this opinion but at the moment he is looking and searching for information about it. I think the time is good for Linux. Today enough strong programs are available for Linux. What is the reason for you to prefer?
First I don't think I am a high supporter of Linux. It is the better choice for my own use, but this does not mean anything for others. In particular I recommend against trying it if one does not know what he is doing. In fact my favourite operating system is Mac OS, but does not work on PCs.

My wish to see "Arena for Linux" was genuine but should be seen in general terms: any program that has the same functionality as Arena is fine with me, it does not have to be exactly the Arena software.

Let me state clearly that it is very difficult to write portable software that has a graphical interface. There are solutions like Java but they bring their own set of "side effects" like slow down and not looking natural in the host OS (e.g. I guess Java programs on Windows don't look exactly the same as native applications). Porting GUI-less software like chess engines is much easier. Therefore I know that porting Arena itself would not be a piece of cake for Martin. On top of that Arena is written in Delphi, a Windows-specific language.

In all fairness I should not ask for an Arena-like program to be written on Linux, but rather do it myself and make it available to others. It is a huge amount of work though (as you know) and my own needs are not large enough to justify such effort.

Frank, you could post on CCC to obtain reactions from potential users on this topic.

The reason I chose Linux used to be technical. Windows 95 is in my opinion the worst piece of software ever written, and I never considered using it (bless you if you survived it). With Linux I could write my own bugs without wondering who crashed first in case of a problem ...

Nowadays the technical matter is less important, thanks to MicroSoft adding standard techniques in his NT series (Windows 2000 and XP are part of the NT family). However there is another reason for me not to use them: the feeling of freedom. When I use Windows to access Internet from cybercafes, I have the feeling that the machine is remote-controlled by big-buck companies. I am sure you all know what I am talking about.

In any case there is no question that by not using Windows, I lose access to 95% of chess GUIs, engines etc ... But I place my own freedom higher than this!

5. Frank Quisinsky - Before we speak about Fruit, the main topic of this interview, I have to ask you about the following! For some months I have different contacts to Sylvain RENARD. Sylvain is member of the French chess federation, programmer of Capture and helped in organizations for the French computer chess events in Massy. In one of the mails he has written he gave me the following comment: Is Fruit a French program Frank? What's this, nobody know the French programmer better as Sylvain RENARD! The group of French programmers are very strong. All the French programmers know each others in person. One of the strongest groups the computer chess are having today. Perhaps the strongest and your name are unknown? What is the reason for it? Why you don't have interest to support this group of French programmers and why you never played a French-ch. Honest, if I am programmer I would search the way to this fantastic group of persons!
In fact my name is not completely unknown to some of them. Years ago the authors of AnMon and Dragon visited a computer-Othello tournament I was participating in. Bruno Lucas and I also exchanged a few emails after the release of Fruit 1.0.

You need to know that I have spent the last two years in England (I now live in France again), and travelling for those events was never considered. On top of that I have little interest in participating in tournaments. I much prefer coming as a visitor (yes I have tried both, in other games). Lastly my budget seldom leaves me room for travelling at the moment.

6. Frank Quisinsky - Let us talk about Fruit. Before you released Fruit 2.0 I missed your interesting messages in chess fora. The answer must be your now famous work on the latest version of Fruit 2.0. I am sure you are working in the latest half year each day on the sources from Fruit 2.0?
It's true that I spent a lot of time on Fruit in October to December 2004. You would be surprised, however, how little of it really affected the level of play.

In Fruit I try to mix development time between improving the program (which does not make me a better programmer, my goal) and cleaning up the code. The latter takes considerably more time without any visible difference.

Only one addition between versions 1.5 and 2.0 is important: the pawn-shelter bonus in the evaluation function (something most other engines have always had). It probably did not take more than two hours to code. More generally, features that have made a difference since Fruit 1.0 were mostly a matter of one or two week-ends at most. The only other main addition is history pruning, but I think it has a small impact, if at all.

Testing is another story though, there I am greatly in-debt to Joachim Rang and Robert Allgeuer. For instance, Robert pointed out that ETC (Enhanced Transposition Cutoff) seemed to hurt Fruit in several versions. I had been using it in versions 1.0 and 1.5, and its removal might be an important decision for Fruit 2.0. The heuristics in itself looks harmless enough and I could not find a bug in my implementation, but complex interactions might be responsible for a drop in strength. In any case, my point is that part of the strength increase between Fruit 1.5 and 2.0 is not even related to me at all!

7. Frank Quisinsky - I do not understand enough from chess programming to go in detail about your sources. Perhaps someone else can create such an interview with you about this (I would like to read it). After all I read from others it would appear that your sources are very clean and easy to understand. The complete situation in amateur chess area goes in the next round. I hear the sources of Crafty have good comments but to are too complicated. The sources of Pepito are interesting and the sources of Phalanx are not easy to understand. If I look at the available results of Fruit your engine is around 100 ELO stronger than Crafty. 100 ELO more and the result would be the same playing level as Gandalf, Junior, Hiarcs and Fritz. is this all an own work or do you get help from other programmers for such a fantastic work? To write a strong program is one point of view but to make the sources public as well is ingenious!
You are right to point out the distinction between comments and clarity of the code. Any experienced programmer will confirm that the source code of Fruit was NOT designed for public release, but rather is given "as is". In particular, there is hardly any comment at all!

The clarity of the code is only due to my programming style and not at all with potential readers in mind. Clearer code leads to fewer bugs. It's an interesting characteristic of programming that one needs years of experience to learn how to AVOID complicated things.

More concretely, in chess that leads to slightly-slower programs (say 25% lower NPS) that are easier to modify. For example Fruit spends a lot of time scanning board squares to evaluate mobility. I know several faster ways I could compute the same thing. However none of them would allow me to easily modify the mobility feature later.

I should also explain why Bob's code is "less readable" in my opinion. This has nothing to do with poor programming style. Bob has a considerably superior programming experience than I have, and he obviously knows what he is doing. Simply, Crafty's code is full of speed tricks. There is no doubt that it is very fast. Activate both futility pruning and delta pruning in Fruit (Crafty is using both features), and see Fruit's "real" NPS for yourself. Note that these features reduce node count and are slightly beneficial overall, proving once again that NPS is not everything.

So this style is better for Bob (stronger engine than naive code) but perhaps not as good for readers. It is probably unavoidable for "old" programs. I am convinced that Fruit would look the same if I worked on it for many years. However I have as principle to rewrite projects from scratch every few years, both to try new ideas and to accommodate with ever-changing programming style.

I am sorry to say that whether an engine is someone's "own work" makes little sense to me, although I understand that tournament directors would like a clear yes or no.

The reason is that all engines, whether amateur or commercial, share most of the techniques. Alpha-beta (of which PVS, NegaScout and MTD(f) are only derivatives), iterative deepening, check extensions, null move, etc ... are shared by most and have been published, mostly by researchers, some of them more than 30 years ago! Sure there are many different ways to represent the board and pieces but it only affects speed, which rarely amounts to more than a few dozen Elo Points.

There is one component that so far is distinct in each engine (although some older ones were probably "inspired" by Crafty): the evaluation function. But there again the evaluation features are hardly ever very original: the principles of sound chess play can be found in hundreds of books. It's hardly a secret that rooks should be placed on open files, something that Fruit does not even know (though rook mobility partly emulates this piece of knowledge).

So what is left for improvisation? A lot of course, otherwise all engines would be equal. But say in terms of quantity of code they don't represent so much. Among this "lot" I think there is a large place for things that cannot be extracted: programming style and ways of linking engine components, making them work together. Not something that most would consider as a "chess-engine technique" like null move.

OK let's stop here and do a little sum up with Fruit in mind: I can't think of a search feature in it that was not described before. Ditto for evaluation terms (except perhaps a few drawish-endgame rules that activate in one game in a hundred). There are specific principles that I follow in Fruit that gives it a personality somewhat (like never truncating the PV and making sure that mate-depth claims are always correct), but they probably have no impact on strength at all and could even hurt a little.

Can I claim that I have written it all on my own? "Yes", I typed all the code myself. Without help??? Certainly not, hence my point: "it makes no sense".

Sorry for the dramatic style ... One positive point now: instead of seeing engine authors competing against each others, I see them as cooperating (mostly indirectly) and making progress together, since they have so much in common, whether they want it or not.

My opinion anyway ...

Something (hopefully shorter) about publishing source code in my case. It has nothing to do with a plan to get help or anything. It is a perfectly natural thing to do for anybody who is NOT using Windows. It allows users of less well-known systems (I can cite many) to use the program. It also serves as a description of the techniques I have chosen, since I don't have the time to intervene in most forum discussions. People can find ideas (with no guarantee) or simply discover a "different" programming style. Last but not least, some programmers can gain the confidence that no special "secret technique" is needed to reach that level and that they should follow their own ideas. It's about freedom.

8. Frank Quisinsky - Before we go into detail on the effects of such strong free sources, I have a question that I would like to ask. What programming techniques are required to write such a strong engine Stefan Meyer-Kahlen has. Do you have any ideas to make your Fruit another 100 ELO stronger? I think you are the right person for such a question and perhaps you can go in detail in your answer. I am not able to make this question any clearer. My programming knowledge isn't good enough.
Regarding the techniques to reach the level of Shredder: if I knew, I would (/ would not) ... (fill in the blanks). Also, those who know keep it for themselves (and sometimes go commercial). Let's state what I GUESS instead:

I used to think that using heavy forward pruning (not counting null move) was the key. Although all commercial programs seem to use one form (recall I can't use any of the top programs, even amateur ones, since they run only on Windows), I don't believe it's the main difference between amateurs and professionals anymore.

In fact the necessary techniques might not be algorithms at all, but planning/development techniques!

E.g. in Fruit 1.0 I started with an outrageous "I know nothing" evaluation function. Then instead of adding dozens of common evaluation terms, I watched games and chose a few that "seemed" important in those games. It seems to work very well for me, but it might apply only to evaluation.

When the engine's level is already high, the inclusion of a strong player into the development team probably becomes necessary.

The importance of serious testing has been stressed in the last few years, for example the popularity of EPD testing has gone down. There is a place for it, but not as a measure of strength.

Something that I think is very important for development is consistency! A chess engine is not just a bunch of heuristics put together. I say this because it seems a common misconception. I believe a chess engine should have a design (e.g. development "rules"), a hidden personality if you want. In particular search and evaluation should work together.

Now about making Fruit stronger. Let's not talk about a 100-Elo strength increase, that is too much to expect in one go.

I believe I can easily get 50 more Elo points, after that I don't know. Maybe Toga is already a proof of that. Note that "easily" does not mean "quickly", but rather "with little effort".

This is partly due to the design in Fruit that I have not yet achieved (things I planned from the beginning I still have not tried/added). Also, the "method" of fixing things that look wrong in games (as opposed to making popular additions and see what happens) has done well so far. So I have no reason yet to think that it should suddenly fail to work. Of course it will fail, eventually. I am only say 1800 Elo so my ability to recognise errors is necessary limited.

In the case of Fruit 2.0, I would focus on "holes" in the evaluation function. Simply some features I have not put there at all, because they did not look urgent enough. Scoring king attacks is probably a priority, and there are endgame mis-evaluations I am not happy with.

Regarding the search I would go the other way around: try to remove as many features as possible. E.g. if extending single replies to check does not gain much, I would prefer to remove it to simplify the code. Note that since Fruit 1.0, history pruning has been the only big change.

Unfortunately my interest in working on evaluation is very low because I don't learn anything in the process and I cannot apply the same changes to games other than chess. For this reason I cannot promise important future development on Fruit.

To end on a positive note, It's also possible to make progress without any development: by simply tuning existing features. This is why I leave technical UCI options in release version.

9. Frank Quisinsky - The various opinions about free sources are quite diverse. In my opinion the amateur chess area is clearly stronger than the commercial area because there are many people are working in it. Given time their results will be better thn the work from professionals. It is very important that we build a team and don't divide ourselves into many different channels. You make the amateur computer chess area very strong with your free sources and a new era will be the result. Commercial programmers have to produce new ideas, in the latest years the amateurs do it and this is the reason that the commercial chess have in my opinion a big problem today. The latest secrets from the commercial programs will be known in the next 1-2 years. Possible those amateurs are on the fast line. This all can be positive and negative Fabien. We need a strong commercial area, an organized selection. What do you await from commercial companies at the moment? Perhaps better 3d boards :-)
There are MANY amateur engines and the number keeps increasing. I agree that some of them are bound to become strong.

However I don't want the readers to think that Fruit is going to be especially important for the future of computer chess. I think that my contribution will mostly affect the design of new engines through confidence and not help improving already strong ones.

Now about amateurs vs. professionals.

There should not be a problem at all because amateurs want to enjoy themselves and commercials use marketing techniques to sell their products.

The buyer will see ChessMaster in the local shop or Shredder on chessbase.com but not amateur engine XXX hidden in the download section of a site he is never going to visit (because not advertised).

On top of that amateur-chess enthusiasts DO buy most top engines, regardless of how strong List is.

Because of this, I don't see a problem in the current situation. We can enjoy ourselves without conflicting with the market of others.

I can imagine a positive impact of strong amateurs for engine buyers though: I am still surprised to see that apart from Shredder, all top engines use private protocols (if I understand correctly). If amateurs give more power to customers like the right to ask for features, is it such a bad thing? Another way of seeing it is that as long as the big guys don't make a move toward users, it doesn't look like they are in such a difficult position don't you think?

In the end, it's freedom of life vs. freedom of commerce. I leave it to philosophers what is right and what is wrong.

Now for those who think that releasing open source is has a special impact on the market (which I disagree with), think about the following events:

- discussing techniques in fora (exchanging ideas)
- writing tools for amateur authors (e.g. testing software)
- writing a free GUI (guess what I'm thinking about?)

10. Frank Quisinsky - The time after Crafty! Perhaps the right title for our interview? What do you think about the name of this title?
I much prefer a title like "An alternative to Crafty". There is no need to try to replace Crafty. Crafty is a large program, with many advanced features. It supports the xboard protocol natively and uses its own opening book. These conditions are important for use on non-Windows platforms. I think that Crafty is available as part of most Linux distributions! It is also used in game research: when somebody wants to show the results of a new technique he has to implement it in Crafty, so that others can replicate the experiment.

However I feel it is important that new programmers don't look at Crafty as a Holy Grail (as they used to do a few years ago). I think the main reason why amateurs have been making big progress in the past few years is that they don't try to follow Crafty anymore.

Note that Bob is not responsible for this. Perhaps the lack of communication in the mid nineties was. Now sources of information are plentiful.

Crafty is one way, not THE way. Fruit is not THE way either, you must find your own way (sorry). That's my message.

11. Frank Quisinsky - I will not speak about Fruit copyrights but about the result of your free sources. The situation is confused for users. We have Fruit on our hard disk and a new program call Toga. The programmer of Toga used your sources and after the first impressions by testers Toga is around 40-60 ELO stronger as Fruit. After all I understand it's for you OK that others used the Fruit sources. What can we, the users, await now?

Perhaps the following constellations?

A. You await from other programmers which used your sources a mail with information about possible improvements from YOUR code. You try to public after your own check a new version of Fruit. From version to version Fruit will be stronger? This can be the end of commercial computer chess! A "new" formatted team can created an ELO giant in a short time.

B. It's not important for you what others do and you work on your program with your own ideas. With other words you ignore possible improvements from the programmer of Toga.

C. All is wrong Frank, I have the following idea!
A. was certainly not my intention, I had B. in mind. Expecting others to improve my own program AND taking all the benefit for me would truly be a horrible way of thinking.

12. Frank Quisinsky - Honest, the users await your answer of Toga. Do you release in the new future a new version of Fruit, perhaps with the idea the programmer of Toga have?
At the moment I am working on a non-chess project and I don't know for how long. When I start working on Fruit again it will require a lot of testing, even if I just add Thomas' ideas more or less verbatim. In other words, nothing is going to happen in the next few months!

Now, when the time comes I am not even sure I will want to make exactly those changes, even though they might easily bring me 50 Elo points. I have a clear picture of what I want in Fruit, and what Thomas has done might or might not fit my design (e.g. the order in which I want to add new features).

I hope this will help tournament organisers to make their decision. If they want precisions, they should ask ...

13. Frank Quisinsky - A new and interesting tournament will be organising by a user. The user added Toga in this tournament because Toga seems to be stronger as Fruit. You are disappointed about it? In my opinion I have to play with the original and this is Fruit. I am thinking on my own ATL-2 tournament!
Let's be honest, if Toga replaced Fruit in all events I would feel weird :) Why would a project I am NOT associated with lead to that situation?

However: Fruit 2.0 got enormous attention in January 2005 (no doubt more than it deserved, which lead to disappointment of some it seems). The level of this version is known and not going to change. The soon-to-start next rounds of AEGT and WBEC will say more about the level at relatively slow time control, and CEGT is already well advanced.

I think it's fair enough that other more-recent engines now get attention as well. At the top, there are new promising versions of DanChess, Glaurung, Pro Deo, SlowChess Blitz, SOS, Spike, Zappa and others that need extensive testing. Toga might or might not be added to this list depending on what each tester is trying to achieve. If it's at the expense of Fruit 2.0 then so be it, I will wait for the results with interest anyway.

In any case, let us not forget that tournaments belong to their director(s). I will neither try to intervene nor complain. If they need information to make their decision, they should feel free to ask.

14. Frank Quisinsky - Thanks for your answers Fabien. My opinion about free sources is to 65-70% positive. I am thinking on Dr. Gabriele Müller which used sources from Crafty without to public this information. I have bad experience with it and this is the reason for only 65-70% I will give. I think the commercials have to collect persons with new ideas. Today we have to make the commercials strong or the free area doesn't have an animation! If the commercial not able to make it we have to help. Fruit will be a long time an interesting topic. You gave us a lot of material for interesting discuss and for a nice time on the chessboard. I wish you a lot of success with Fruit and I hope to see your program in one of the next French computer chess events. This is the personal wish I have.
Thanks to you for precise questions, and to readers for (hopefully) tolerating my long answers. I don't think clones are that much of a problem, as they are easy to spot. If needed, amateur authors will be there to give a hand. Let's also see how the reaction to Toga is going to evolve ...

15. Frank Quisinsky - I have much fun with my ATL-2 tournament. Fruit will be added later. I will wait of your answer to one of my questions. Interesting for the group of users is the playing style of Fruit. Do you prefer tactical or positional engines? I don't give Fruit a look in detail by myself but I will do it with the ATL-2 games. Perhaps you can write a little bit about the playing style you prefer.
My ideal for a style would probably be Capablanca-like: solid, avoid having weaknesses, don't attack without preparation, wait for the opponent to make mistakes, convert to favourable endgame whenever possible. However I need to add a lot of knowledge to make such a style possible. In particular pawn-structure and endgame-plan knowledge (that is not easy to explain to a computer).

Regarding Fruit's actual playing style: I will leave that for others to comment on.

Frank Quisinsky - THANKS FABIEN, this was perfect for me!
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