Wednesday, December 4, 2019

The initiative

Older players will likely still remember the time when we could beat the best engines available. I never experienced that myself. I started to play regularly chess at the age of 14 and while I quickly improved, I never could catch up in the 90ties with the engines. From 2000 onward only topgrandmasters could still challenge a computer but around 2006 this also ended. After that the engines kept on improving at a steady pace. For an amateur it became increasingly difficult to detect the differences between the engines. Nowadays I see many chessplayers don't search anymore for the best engine and are satisfied with an engine of which they know that it can beat any human in the world.

It is indeed irrelevant to have the best of the best for just a blunder-check. Only a few will also try to discover the little nuances in a game. Today the top-engines have become so strong that they can find in the most complex positions very quickly the right track and beside can not only maintain an initiative stubbornly but also increase it methodically. Last summer I had multiple favorable positions in the Open Brasschaat of which I had no clue about what I should do. A first example is against the 15 year-old Marie Dgebuadze. After a small mistake of Marie I obtained a very nice position but then I didn't push through. The engine demonstrates with accurate play that I hesitated too long which allowed Marie to neutralize my initiative.

I couldn't achieve more than a draw at the end. However int he second example it went even more sore. If you check the rating of the 25 year-old Yago De Cuyper then you find out that I should win easily as +500 difference is a massive gap. Nevertheless during the game this wasn't the case at all. Again I get the upper-hand in the middlegame but also here I hesitate which allows my opponent to counter-attack. I was shocked especially when the engine showed me how a few moves were needed to convert my initiative into a clear advantage.

It was a miracle that I still won the final position but this has no relation with the initiative so would only digress us. More interesting is to check if there are some symptoms in my game which explain these failures. Why can't I maintain the initiative against these "weaker" players?

The question was raised to me if I don't practice sufficiently tactics. I did miss some hidden motives which caused me to not consider some moves. On the other hand at I maintain for some time already a 3100 rating which puts me at the top of the Belgian players so I don't think I am worse in tactics than others. I also got the advice to study more Dutch games so I get acquainted to common combinations in this opening. I have more than 20 years experience with the Dutch so I think that I can consider myself an expert in the Dutch. Therefore I do dare to claim that the examples shown are not standard at all.

No in both examples I hesitated to push my pawns on the king-side as there are always risks connected to it. I couldn't properly evaluate it so I chose to wait. Very often the apple falls from the tree by itself or you get a better and easier opportunity. In above games it didn't happen this time so I spoiled the advantage.

By the way I am definitely not the only one having this problem. Recently I was at the other side of the board sitting. The Belgian FM Roel Hamblok got a winning initiative in the interclub against me with a clever game-preparation but it wasn't trivial to convert it into a win. White hesitated to sacrifice any material and just chose normal developing moves which allowed me to fight back in the game.

I earlier warned in my article sacrificing for the dangers of it. You often are left empty handed when the attack doesn't win immediately. Correct sacrifices demand a high degree of precision to make them work. So I understand perfectly why Roel preferred to slowly build up his position instead of making some gambles. It did however let the initiative fade away.

The volatile character of an initiative only leaves a window of opportunity open for a limited time. Between 2300 and 2800 there is a big gap of playing strength. How you manage an initiative is definitely a key-element of it. Some books learn players to think out of the box and to look beyond the risks but likely talent has the final word.


Thursday, November 14, 2019

Which games to analyze? part 2

At the last Open of Touquet (France) the talented and young FM Sim Maerevoet told me that he should once store his scoorsheets digitally on his computer. I thought this was a remarkable statement. I am used to that older or lower rated players don't store their games in a personal database but I don't expect that from an ambitious player with virtually approximately 2400 fide.

It appears Sim barely or never analyzes his standard games with an engine. That is the opposite of how I work. Besides now I also start to wonder if my many hours of analyzing with engines is really useful as meanwhile Sim has 100 points more already then I have. On the other hand I can't imagine that I would get better results by playing countless hours of blitz and bullet at lichess like Sim does.

By the way I've being doing that in the past too and it didn't help me to improve but maybe it is related to the age of the person. Older persons make much harder progress than teenagers. Just maintaining their rating is already difficult. I am not doing so bad when I compare with my contemporaries. Maybe it is not very efficient to analyze games with an engine seriously but it definitely doesn't harm.

Nowadays most of my analysis is spent at deeply investigating the opening and sometimes I do get rewarded for it. In the last round of Open Brasschaat 2019 I used an idea which I had discovered in 2014 after some very extensive analysis made of the opening see my article fashion.
However I have to admit that such games are rare. It can take years before I can use some of my analysis and then they are often already outdated. This can be because the newest engine found some holes but also because new trends have popped up in games between grandmasters. Also I do notice that because of the exponential growth of my opening-analysis that I started to forget more often (see e.g. harakiri). In the last Open Brasschaat this was really annoying for me as I suffered from amnesia in 5 out of 9 games. Sometimes I just lost time but in 3 games also my opening went wrong.

I am sure it is much more efficient to read a new openingbook about an opening and immediately learn something about dozens of lines instead of just checking 1 line deeply. Still I do find it 100x more fun to discover 1 idea independently than read 100 new ideas in a book from somebody else. Maybe I should switch to watching dvds as reading books is not only hard work but it is also not easy to remember everything.

Analyzing middlegames is even more doubtful than openings. I spend about 1 hour at it for each game but I don't think that I learn something which can be used in another game. The positions are always very different which makes it almost impossible to find connections between them. Sometimes you also need to accept that we will never have the same tactical skills as the engines. In the earlier mentioned last round of Open Brasschaat I got a chance to become immortal by playing an absolutely insane combination. I showed it to other FM's but everybody agreed that such combination was alien.
Beautiful isn't it but I think the chance is 0% that I will ever be able to execute such combination in another game.

After the last standardgame of the most recent worldchampionship a journalist told Magnus Carlsen that the engine shows +2 after 25...b5. However Magnus answered coldly with "I don't care" see world chess championship game 12 carlsen offers draw in better position to reach tiebreaks. He is right of course because he has proven time over time that an evaluation of an engine doesn't have the last word about how chess will be decided between humans. Although I do use engines to define the quality of my games, I also realize that it is impossible to imitate an engine.

Nevertheless i do recommend analyzing your middlegames with an engine when you are still learning and improving a lot. This is especially important when you don't have access to a good coach. I estimate my chances would've been very slim that I would be today an FM if I had before never access at all to an engine. Today the return of analyzing my games deeply has been diminished a lot for me. I still do because chess is more than just playing games and winning rating. I also enjoy it immensely to discover combinations like the one above. I am interested in the truth so like to know what happened exactly in my games. Chess is not only a game for me but also science and art.

Endgames I consider more interesting to analyze properly. There are only a limited number of games reaching an endgame in which the result isn't fixed yet. You won't win much rating by studying deeply endgames. On the other hand endgames which are misplayed are often very painful. They often make a big difference in open tournaments especially at the end when the prizes are announced. Also endgames can often be categorized in groups. It allows you to formulate rules for a certain category. I gave an example of that in  my article exchange pawns when standing worse and at below endgame against the Belgian expert Sterre Dauw I spent quite some time to find out how things should be evaluated.
These type of rook-endgames in which 1 player has an extra lonely pawn at the other side of the board is something which occurs regularly in games. However even some FM's admit after the game that they had not idea how to evaluate such endgame correctly and even less which moves to play. I learned that it can depend from some small details like just 1 square difference of the h-pawn or king defines it it is won or only drawn. I also found it interesting to discover the concept of the 4th row line-up for the white pieces which allows the transfer of the king to the other side.

So experienced players won't gain much by analyzing their own games. It is more useful to track the latest trends in your repertoire and just play a lot. That is how the modern strong master is trying to further develop. Analyzing games is still useful for publication and archiving of course. Very likely this blog couldn't exist without it. The statistics of this blog prove that although many players don't have much time to analyze, they still like to look a bit deeper than just the shallowness of a game.


Tuesday, November 5, 2019

How much time do you spend at chess? part 2

The last 2,5 years I have supervised several times my son (and) daughter while they play chess-tournaments lasting multiple days. In those tournaments I am very often recognized by other players and then the first question I get is why I am not participating myself. Most parents able to play chess, also participate when the tournament-format allows it but I decided not to do. The reason is that too often I've seen small children looking annoyed after their quickly played games and are hanging around the unfamiliar playing-hall for hours without any supervision as their parent was still busy with its own game. Some of those children were only 8 years old and while most chess-players are nice people, there are also some very strange ones with whom I don't want my kids to have contact alone.

So as I wrote already a few times on this blog, I sacrifice a lot of my free time at sitting and waiting while my kids are playing chess. By reading something and chatting with other parents the time passes by more enjoyable but I also bring along my portable to continue the analysis of my own games. Such activity always attracts curious players. I also assume it creates some suspicion as with the current state of available electronic gadgets, you never know if it is not an effort to cheat. A couple of times an arbiter checked my portable to make sure I wasn't analyzing any running game.

When I am still analyzing on the second day the same game, the first dumbfounded questions arise from players. How deep do you analyze your own games? How much time do you spend at analyzing your own games?... However when I am after the 4th day still busy analyzing the same game, every spectator quits looking. Such analysis could be fine for correspondence-chess but that is not the kind of chess which a tournament-player is interested in.

In part 1 of How much time do you spend at chess? I wrote that averagely I spend about 4-5 hours of my personal time at the analysis of 1 of my games. That is an estimated time which doesn't take into account the number of hours processing time which my computers have used. In the same article I mention that my computer probably consumes 5 x more time. If I tell you that I only let my PC run during daytime while I am around then you understand that an analysis can last several days.

How many days exactly and what kind of analysis are made, seems interesting to once investigate. I knew that recently I mainly work at openings but there are big differences between the different games. We need metrics to get a proper view about it. Checking with a stopwatch the time used for each analysis made during multiple months is not a realistic approach but fortunately there exists an alternative called "Autosave.cbh" which generates acceptable results.

I assume most players never heard about this alternative before. What is "Autosave" and how would that ever replace a stopwatch? Some loyal and attentive readers of the blog should remember that I once used this word in the article the game preparation part 2. In that article I talked about databases which were part of the cockpit I use to analyze and one of those databases is "Autosave.cbh". I didn't elaborate about it at that time as it wasn't relevant for the article. Besides the name "Autosave.cbh" explains partly itself. The file saves something automatically.

Just like excel, word, ... also Chessbase takes care that regularly your work is saved to avoid losing everything when the system crashes. Such file is automatically created at the installation and you normally can find it in the directory Chessbase\MyWork see the screenshot here below.
So if your system crashes then often you can still find back your notation + analysis in the file "Autosave.cbh" and bring it back to your favorite-folder. Beside "Autosave.cbh" doesn't save only the most recent version but also earlier versions of your work. This allows you to restore something you erased and which you regret. Or as for this article I was able thanks to "Autosave.cbh" to check how many versions of the opening, middlegame or endgame were saved. 200 versions of just one game in "Autosave.cbh" were no exception for me. A glimpse about this excessive saving, you can see in below screenshot.
Timestamps I couldn't find of the versions but I believe it is fine to assume that each version covers approximately the same time-span. This was also shown when I compared 2 tournaments and divided the number of days used for analysis and the number of versions stored. The deviation was 11% so more than sufficient to make conclusions. The 2 tournaments which I used for the exercise were Open Gent and Open Brasschaat which I played last summer. The analysis of the games of Open Gent were finished the 28th of August which means it took me 27 days (I didn't work at it during the Open Brasschaat). The analysis of my games played in Open Brasschaat were finalized the 17th of October and that corresponds with 47 days of analysis (I didn't work at it when I had to play new standard games for interclub and clubchampionship). Eventually I was able to make a pretty detailed analysis of the number of days I spent at analyzing my 18 games.
Averagely it takes a bit more than 4 days of analysis per game but there are big variances between the games. I spent less than 1 day at my 4th round of Open Gent while the first round of Open Brasschaat took me more than 11 days.

Contrary to expectations, I notice nor the elo of the opponent nor the result of the game influence really the number of days. The time of the analysis is mostly related to the type of opening played. 80% of the time is spent at that phase which isn't such a surprise as I use a scientific approach to chess. You can't play successfully always the same opening without an in-depth study of it.

Openings which I never studied before, take a lot of my time to analyze properly. Nevertheless it doesn't mean that I neglect the other phases of the game. It seems that spending only 5% of the analysis at endgames is inadequate but how many players can claim they spend more than 4 days in the last 2,5 months exclusively at analyzing endgames seriously.

Yes I think this article once again shows that I am not the average player. Most players just play chess and spend only a couple of minutes to check any mistakes. Besides I do this kind of analysis already for more than 20 years. Over the years I have refined my working-methods and put much more emphasis at the opening.

Several international masters told me that they don't analyze their games so extensively as I do. Anyway I don't expect my students to do such analysis. You should only do that if you enjoy it. In a next article I want to discuss how useful this is for your own development. Is it more than just fun?


Friday, October 18, 2019

Pasword part 2

Recently I saw a tweet at twitter stating that “Kens password was hacked”. Apparently somebody had found in 2014 a unix passwordfile, from a very selected group of ITers (you can call them pioneers) and at that time already tried to hack the passwords (unix encrypts the passwords in such way that even admins or a superusers can't decipher them). There were some famous names like Ken Thompson, Dennis Ritchie , Brian Kernighan, Steve Bourne and Bill Joy. We talked about a team which defined in the years ’60 and ’70 the base of all our current ICT. If you would convert those names to topplayers that we would be talking about Steinitz, Tarrasch, Lasker, Reti and Nimzowitsch, no less.

That unix-file with passwords seemed very difficult to crack in 2014. The hardware wasn't as strong as nowadays. 20 words were revealed quite quickly but five resisted. The last man standing was… Ken Thompson, and his password was chess-oriented.

On this site (ken thompsons old unix password cracked) you can read the story. Encrypted unix makes his password “ZghOT0eRm4U9s” and it appeared eventually to be “p/q2-q4!”. In other words, his password was just “d2-d4!”.

Chess-oriented passwords are strong, and that is no surprise: Kens password contains letters, special characters in an apparently illogical sequence. Now that is a trick which I also use. The reason is simple because if you use as password “1.d4 f5 2.e4!”, then you only need to remember “Staunton”. I also remember that as a student in Oostende I logged on the PDP-11 with my name and “e4e5f4” as password.

There are several sites which allow you to test the strength of your password: 2 good sites are and Other sites give you guidelines about which characters you can add, but these two give an indication how long it lasts to crack your password. This indication largely depends on the speed of the computer and as the first site is more conservative (they think that hackers are very well equipped), I prefer to use the first one.

That “e4e5f4” doesn't survive a second (54 milliseconds), but this changes when you use the full notation: “1.e4 e5 2.f4” which requires already 600 years. With a few extra signs “1.e4! e5! 2.f4?” you increase it to 4 billion years. That is not bad for a simple to remember password - you only need to remember "kingsgambit".

Of course the more moves, the better; the French MacCutcheon (1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Lb4) lasts 10^48 years, without using exclamation-marks or question-marks. For people playing this line, it is simple but it is rather long so impractical to use. A rather short one is “Saveedra 6.c7-c8:T!” which  demands already 36 x 10^18 years of calculations, much easier to remember.

If you don't want to remember move-sequences, but rather prefer a chess-name as password, then I can recommend “Roman Dzindzichashvili” (42 x 10^21 years) or “Zurab Azmaiparashvili” (596 x 10^18 years). Have fun en keep it safe!


Monday, October 7, 2019


Having a son or daughter playing chess, requires a lot of patience from the parent(s). Especially when you accompany them to tournaments then you better realize in advance there won't be much time left to do other tasks. Besides as a parent you are mostly ignored by the chess-organisation. Often you are lucky to have a chair on which you can sit as I experienced several times at youth-tournaments that no separate space was provided for the companions.

Also you better try to do something enjoyable while waiting many hours as just sitting (like in the first picture of my article the memory) can be relaxing but surely won't be pleasant. Most parents are therefore armed against the hours of waiting. Some bring their computer to watch a movie. Others are writing a report for the job. I also see some parents gathering together to play cards or other games. I mostly belong to the group of readers so I bring a book, newspaper or some other literature with me.

Although in most cases I don't manage to read much in the end. I like too much talking to other people which probably also explains for a large part the existence of this blog. I don't have much trouble to start making a conversion with an unknown person and that has its advantages. This way you sometimes meet some really interesting personalities.

One example is the mother of Ines Dellaert. I had an enjoyable chat with her during Open Maastricht of 2018 and learned that she was trying to become one of the very first professional drone-pilots in Belgium. In Open Maastricht 2019 I met the papa of Matthijs De Groof. He started a couple of years ago together with his brother a company for gas-pressure-regulators see gasflowsolutions. He travels around the world to explain and sell his products. In the latest onjk an ex-professional-footballer joined my table. We had quite some fun because he was telling many anecdotes from the time he was still playing in the Dutch first division. Finally I want to conclude with the very congenial Alfred Olree with whom I was waiting every day at the same table for our children.

Alfred has an incredible rich life. Beside a very busy job as HR-officer, he is also father of 3 sons, married with (indeed) a Russian lady, youth-leader + director-member of the chessclub de drie torens and finally also has a beautiful passion for cats. Briefly there was enough to talk about for hours and even my wife paused her shopping for awhile to listen to all the stories. If it is about Russia and especially cats then she is interested. Besides it aren't just cats which Alfred has but the extraordinary magnificent Maine Coons. He already won many prizes with them also in Belgium.
Cats and chess, it sounds a weird combination but it happens more often than you probably think. There is even an opening named after the largest cat in the world. I mean the lion of course.

This opening has a very special history. Contrary to most other openings the lion wasn't invented by a grandmaster but by an amateur with the appropriate name Leo. According to archives Leo created the opening about 50 years ago and meanwhile many players have followed his footsteps. Particularly at amateur-level the system remains very popular till even today.

The system has some great assets compared to other openings. First it is an universal system so it can be applied against a wide range of setups. It also delivers excellent counterchances for black which allows to play for a win even against higher rated players. Finally it is very easy to learn which is of course handy for an amateur often not having much time to study chess at all.

Nonetheless the fact that the lion never became a mature opening at master-level in the last 50 years, should warn you that something isn't fully correct. That was last demonstrated in a game of my son which he played in the last onjk. If you have a name as Robin Van Leeuwen then you are almost automatically a fan of the lion but that doesn't mean necessarily you will score more points.
The lion was slaughtered without mercy in the game. Robin told us afterwards than he had never experienced such defeat before with his favorite opening. During the tournament there were beauty-prizes awarded and if I compare this one to the other winners then I am sure it would've made a good chance to win. However I didn't consider it honest to submit that game. I had shown to Hugo the whole idea in advance so including the sacrifice of the knight on e5. Very little creativity existed in the game.

At the master-level this sacrifice is well-known. Also I had met by coincidence the same opening in the most recent edition of Open Gent so I had just before onjk made some deep analysis of it.
I played this opening less accurately than my son without the knowledge of the analysis I made only later. The sacrifice on e5 is in my game less dangerous but black was aware about it so therefore didn't dare to play g5. However without g5 the lion becomes a little cat without claws.

Cats and chess doesn't sound like a good match to me. Still at home my cat often gets attracted by my chess-activities but does lose very quickly its interest. It is much more fun to have a nap on my warm belly instead of watching some boring pieces moving around.
Just try from this position to reach the computer without waking up the cat. I have to make the most funny movements to push a button and it is practically impossible to get the right position on the board.

Finally this isn't the most funny part of the story. Did you know that I am allergic for cats? Still for our cat I am his most favorite person in the house. I guess it is because I am the one daring the least to touch him. So why do I even have a cat at home? Well that is something you have to ask to the other inhabitants of our house.


Monday, September 30, 2019

To study openings part 3

Some people think chess must be doing great in Belgium as the new national champion Daniel Dardha is only 13 years old. However one swallow doesn't make a summer. If we look at other Belgian children below 14 then Daniel is 450 elo higher rated than the second one. We can't expect that Belgium will become a strong chess-county anytime soon based on just one very talented boy.

We lack well organised training-facilities for our Belgium youth to maximize their potential. There are many small initiatives which are mainly around a bunch of lower rated volunteers doing a tremendous job but that is not sufficient at all to fulfill all the requests. Many children live too far or simply are not aware about the existence of the classes. Besides those classes mainly consist of a basic training using the step-method (often only a few of them). It is a nice start but they lack practical knowledge of how to play a competitive game.

Mainly parents of foreign origin question regularly those training-methods. We have a lot of youth in Belgium with such parents (see memory) so naturally they compare between countries. Last I heard a father with Indian roots telling a coach that in his birth-country they start with endgames instead of immediately teaching tactics on a board full of pieces.

I think this is a clever remark from him as there are indeed many advantages to focus first at endgames. As there are less pieces on the board, it becomes much more easy to see the tactics. Also you get immediately a good feeling of how the pieces relate to each other in terms of value. Finally an advantage in an endgame is often more clear so it becomes more simple to distinguish wrong from right. 

However another recurrent critic I often get is that endgames are boring. Here we see the difference in life-philosophy between people of different origin. In Western countries we believe fun should be given absolute priority so we let children play as freely as possible. However in Eastern countries the educative aspect of chess is considered as the prime-goal. I see many immigrants force their children to play chess as they think it is important for their intellectual development. Fun is rather irrelevant which sometimes creates some sad situations in the class when children tell the chess-teacher that they don't like chess at all but are forced to sit and wait till the class has finished.

I think most people agree about openings that it makes no sense to learn streams of moves at beginners. It is enough to know how to develop pieces, occupy the center with one or more pawns and castle to bring the king into safety. You often hear about children spending too much time at openings while other facets of the game still contain big gaps. It would be much more efficient to focus first at those weak aspects of the game. So it makes definitely sense not to teach any openings during the methods of steps.

Therefore sometimes young players till even a rather high level know very little about openings. From which rating onward should we start looking at openings? Is it ok as 2200 elo rated player still not having any theoretical knowledge of the played variations? There exist indeed such type of +2200 elo players which just play openings based on common sense only (I am thinking of e.g. the phenomenon Ashote Draftian is Flemish champion).

In my article how many games should I play published earlier this year I clearly demonstrated with some examples from the chess-literature that studying openings in an important part of reaching masterlevel. Between a beginner and a candidate-master there is easily 1000 elo but from somewhere in middle (+-1800) I think it does make sense to slowly start building a repertoire. By the way I heard something similar recently from the Belgian IM Tom Piceu. Also he advised an ambitious +1800 player to start working at a repertoire when it appeared he was lacking any basic knowledge of the openings he was playing.

Nevertheless I was a couple months ago shocked to find out the repertoire of the British grandmaster Daniel Howard Fernandez. Daniel plays just like Vladimir Epishin a very wide range of openings (see my article jubilee) but there exists a big gap of concrete opening-knowledge between them. I had the impression of Vladimir that he is very familiar with his openings contrary to Daniel seeming to play just something which is often total nonsense. It is a mystery how you can become a grandmaster with such repertoire. Well he is tactically extremely strong so I guess that probably largely compensates it. Still I don't understand why he doesn't want to work more at his openings when you clearly have a lot of talent. In our mutual game of the past Open Gent I decided therefore to avoid as much as possible any murky positions containing lots of tactics.
I exit the opening with a large advantage but played it a bit too safe to keep it. I did manage to keep the position simple although that almost wasn't sufficient either to achieve the desired draw.

You would expect that such repertoire wouldn't stand a chance against stronger players. I also thought so until he blew our Belgian top-player Bart Michiels from the board with an awful opening. Black extracted a big advantage from the opening but in the middlegame got tactically completely outplayed. This clash eventually decided that Daniel later became the tournament-winner.
If you would like to play like Daniel then think twice before giving up studying openings. Daniel started to play chess at a very young age (in 2004 -9 British champion) and has traveled continuously around the world (Singapore, Australia, Europe, ..) He clearly got hardened by this tough life. So copying his approach to chess successfully seems very unlikely to me.


Thursday, September 19, 2019

Testing chess-engines

Till a couple of months ago I never bothered about testing chess-engines. I didn't see any value in it. I would never be able to achieve the same quality as the results CCRL publishes weekly. Besides such work is not cheap as you need to invest into hardware, electricity, floorspace,... On top most of those games played by engines are pretty boring. You better watch games of humans to see drama and creativity.

However as I mentioned in my last article, I had an open question for Leela. CCRL nor other sites give me an answer about how strong Leela would be in comparison with the classical engines when both use exactly the same type of hardware. That is a problem for me. I can install for free Leela on my PC but I only want to use it for analysis if I know the engine is one of the 2 strongest ones I possess. I am using that rule already for a very long time see my article of 2012 about how I analyze. Maybe some will consider this a bit silly but it assures me that my opponents will likely not have any better analysis.

So in the end I decided to do the testing myself. Then the next question is of course how to do this job quickly, accurately and as cheap as possible. I could use a set of puzzles but that is only one aspect of an engine. I rather prefer the engine to be tested by playing games but I can't/ don't want to miss my hardware for several months. A good compromise was found in a rapidmatch with the rate of 15 minutes + 10 seconds increment over 100 games. That should give a good indication of the playing-strength. At stake was a place in my top 2 engines so logically I chose Komodo 11 as its opponent for the match.

Then the next question is what do we decide about the openings. Do we give the engines full liberty of choice or do we select a number of positions which need to played out once from each side as TCEC does? The free choice is as we humans play our games but there are some disadvantages to that. The engines will likely play openings which are not part of my repertoire. The risk exists that they play very safe and we get an abundance of draws. Finally Leela will without an openingbook play almost exclusively the same moves in the opening so you risk to see several times the same opening/ game.

Therefore I preferred to let the engines start from a pre-defined set of openings. Which openings to choose is then the next logical question. It didn't take me long to find a good answer for it. I created a new database and injected a selection of 50 recently played games of myself. Next I removed in all games the moves beyond the 10th. The few duplicates which I got, were swapped by selecting a few other of my games. The final result was a nice mix of 50 positions in which some of them the balance was already broken. This way I avoided a too high number of draws. Besides the engines will only play openings which have occurred before in my practice which makes it of course more fun to watch the match.

Finally everything was ready. Via Fritz I activated the window to initialize the match as obviously I wanted to automate the whole process. First I selected Leela. Next Komodo11. I selected the right tempo and the last step was linking to my special database of 50 positions. After verification of all parameters I clicked ok and the match got off.
About 3 full days lasted the match. I let my PC run day and night but I did interrupt the process a few times to allow my PC cool down as around that time we were having temperatures around 40 degrees in Belgium. Anyway it was very easy to continue the match from the point where I paused.

The match was a big success which superseded the tests. First it became quickly clear both engines were very close of strength but also had a very different style. Often games got extremely interesting and besides played from openings all part of my repertoire. A number of times, I sometimes even together with my children, watched live 1 or more games. My children also regularly asked about the preliminary score as we all got attached to little Leela which despite the tactical handicap (more about it later) often managed to defeat the giant Komodo .

It made me want to have more of it so I decided to organize twice more such match in the next months with newer releases of Leela. For the 3rd match I decided to replace some of the openings. If in the 2 previous matches 4 times the same color won (so irrespective of the engine) then it seemed more appropriate to select some other opening to use as test.

2 matches were narrowly lost by Leela. The second match Leela tied with Komodo. I considered this a very unexpected and exceptionally good result on my modest computer definitely not optimal for Lc0. On the other hand the matches didn't give an answer on my original question. The scores were too close to know for sure which engine of the 2 was the strongest. Anyway this is not a disaster as now I got to know Leela very well in the 300 games. I got a pretty good idea when to use Leela for the analysis.

In my previous article we already got acquainted with Leela by looking at how the engine reacts in different types of positions but it is only by replaying her games that we fully realize how different the engine is compared with the traditional ones. So to conclude this article I made a selection of 3 games which demonstrate very well the strengths and weaknesses of Leela. This was not so easy as there was a very large number of beautiful games. I start with a fantastic game played from the Chigorin-variation of the Spanish opening (I covered the opening recently in my article statistics). Leela sacrifices very early an exchange and succeeds like a real boa constrictor to slowly suffocate black.
The extraordinary of this game is that there is no fixed center. The battle rages over the full board but black never gets a change to exploit the extra exchange.

A second game starts from a Dutch stonewall which I encountered in one of my games played end of 2017 against the Dutch IM Xander Wemmers see secret. In the game we see the advance of both rook-pawns which is very typical for the style of Leela. Next we see a magnificent demonstration of activity. Komodo doesn't understand at all what Leela is trying to do.
Leela plays this game as many others with an understanding of open lines, bad bishops which is much more advanced than Komodo.

If you have replayed the 2 previous games then you probably start to wonder why Leela didn't destroy Komodo in the match. Well tactically things got often completely wrong. A nice example is the next one in which Leela sees the combination 5 moves too late.
Fans of my blog will likely already recognized the link to my article the butterfly-effect. All the moves were already covered in that article so it was definitely a surprise to see them all executed on the board.

I got to enjoy testing of chess-engines via these kind of matches. A new match won't be for immediately as other work needs to done first. Besides Leela is building a new network from scratch and today it is still much weaker than the networks of a couple of months ago. It would also be nice for a next match to have by that time newer and stronger hardware.