Regression-tests

It took me about 20 years when I finally started to build a proper opening-repertoire. I often wondered afterwards why I waited so long with it. Not only I played far too long bad openings (which I probably still partly do because I am still playing the Dutch Defense) but in most games I really had no clue what I was doing during the opening. I still hope to play a lot of chess in the future but those 20 years are gone and won't return.

20 years or even longer ago nobody told me that I should study openings. The Belgian FM Gunter Deleyn told me just before the lockdown this year that in his younger years it was outrageous to consult books about openings. This would be doping and an insult to chess which should be a pure intellectual fight between 2 humans. Times have changed clearly. Nowadays I read often about coaches spending a lot of time at openings even at a very early stage of development.

So only around 2013 I finally started to study openings seriously. I guess it was a mix of elements which convinced me to do. First I experienced a couple of debacles in the opening see e.g. an article of 2012: an expanded repertoire for black which opened my eyes. I realized that I was nowhere with my repertoire. Yes I did know already a few things about openings at that time but it was totally insufficient to meet the repertoire of a master. Besides also the quick technological developments forced me to undertake actions if I didn't want to lose ratingpoints. More and more of games were inserted into the databases. Meanwhile stronger engines were often showing how bad my openings were.

In 2016 I wrote on this blog for the first time about the changes I made to my approach of selecting openings see to study openings part 2. In that article I described mainly the methods I used but also that the results came very (too) slowly. In 2016 I had studied about 100 openings deeply. Today this number has increased to 300 (the definition of an opening I use is that it concerns a position of which you can find about 100 games in the megadatabase in which at least one of the 2 players has minimum 2300 fide-elo).

I don't know how many openings I should still analyze before I have covered my complete repertoire. I guess it is possible to calculate the exact number by writing some script which connects an opening-tree of your repertoire to a megadatabase but I already know in advance that the answer won't make me happy. I am sure that I am not even at the midpoint. Nonetheless this doesn't mean that I can't profit already from my work in progress. My database of +300 openings analyzed very deeply is an oasis of killer novelties and ideas. I very often use them in my games and I am not only talking about refutations of specific lines but also about surprising the opponents.

Naturally the research of the openings also lead to many changes of my repertoire. Many lines were dropped and replaced by (hopefully) better ones. Readers following this blog for years will probably still remember my articles part 1 and part 2 of the Dutch steps in the English opening. However it aren't only old openings which are erased from my repertoire. Also of the +300 deeply analyzed openings which I made in recent years (between 2013 and 2020) already 60 of them are again obsolete. This also means that the analysis I made for those openings isn't relevant either anymore for my repertoire. 

This I regretted as I spent a lot of time at it. Initially I thought this is something I have to accept till I realized maybe it is possible to try to revive some of the old analysis by checking it after x-years with more recent and stronger software+hardware. The idea of regression-tests was created. I call it regression-tests because the terminology is already known in the IT-world. When new software is added to older software (e.g. for a new release) then a good developer will not only test the new software but will also make sure that the new software didn't impact the functionality of the old software. Very often we see some changes did corrupt the code of the old software. In the jargon used by the developers this is called regression-tests.

Meanwhile I am already for 4 years doing regression-tests on some openings which were earlier removed from my repertoire. It is always nice to have an old opening back into the repertoire. The experience is never gone and getting more flexibility (choice between old and new) is always useful in practice. However till now the results of those tests were very disappointing as I wasn't able yet to resurrect any old opening. Sometimes I do manage to discover a small improvement of a sub-line but it never leads to a re-evaluation of the complete system. A nice example is one of my most recent regression-tests I made of the opening 1.d4 f5 2.Bf4.

[Event "MT-Preinfalk (SLO)"] [Site "ICCF"] [Date "2017.09.30"] [Round "?"] [White "Zugrav, Wolfgang"] [Black "Staroske, Uwe"] [Result "1-0"] [WhiteElo "2574"] [BlackElo "2530"] [PlyCount "61"] [EventDate "2017.??.??"] 1. d4 f5 2. Bf4 Nf6 3. e3 e6 {(Black is an expert in the Dutch Defense and plays the opening against the strongest correspondence-chess-players. I notice that after this game Uwe changed his repertoire and played next time g6. The French grandmaster Adrien Demuth convinced me by his book 'The Modernized Dutch Defense' to try however d6 as the critical mainline with g6 is very difficult to play for black.)} 4. Be2 {(In 2019 I thought based mainly on this game that Be2 is the strongest continuation in this position. However after regression-tests made in 2020 on the occasion of my game I played in the 4th round in Prague this summer, I am not anymore sure that Be2 is the best. I have found quite some annoying lines with the bishop at d3.)} 4... Be7 5. c4 O-O 6. Nf3 b6 7. Nfd2 Bb7 8. O-O c5 9. Nc3 d6 {(A game played between the engines Topple and Pirarucu in 2020, showed me an interesting alternative which maybe restores this line.)} (9... cxd4 10. exd4 Bb4 11. Qb3 Nc6 {(The engine-game continued with Qe7 but Stockfish and Leela show an interesting concept here.)} 12. d5 Bxc3 13. dxc6 Bxd2 14. cxb7 Bxf4 15. bxa8=Q Qxa8 $13) 10. h3 Ne8 {(A top-correspondence-game played in 2018 seems to indicate that cxd4 is stronger but even then it is not a walk in the park for black.)} 11. d5 e5 12. Bh2 Nd7 13. a4 g6 14. a5 Nb8 15. axb6 Qxb6 16. f4 e4 17. Bg3 h5 18. Be1 h4 19. Ndxe4 fxe4 20. Nxe4 Bc8 21. Bh5 {(This is correspondence-chess of the highest level. This can never be achieved by humans unless they already analyzed it in advance at home with an engine of course.)} 21... gxh5 22. Qxh5 Bf5 23. Bc3 Qc7 {(Accepting the third piece-sacrifice leads to a forced mate.)} (23... Bxe4 24. Qg4+ Kf7 (24... Kh7 25. f5 Bf6 26. Qg6+ Kh8 27. Rf4 Ng7 28. Rxh4+ Kg8 29. Qh7+ Kf7 30. Bxf6 Kxf6 31. Rxe4 Kf7 32. f6 Rg8 33. Re7+ Kxf6 34. Re6+ Nxe6 35. Rf1+ Nf4 36. Rxf4+ Ke5 37. Qf5#) 25. Qe6#) 24. Qh8+ Kf7 25. Ng5+ Bxg5 26. Qh5+ Kg8 27. Qxg5+ Ng7 28. e4 Bh7 29. f5 Rf7 30. Rf4 Nd7 31. Rxh4 {(A fantastic game.)} 1-0

Online I notice that the popularity of this opening has gained enormously. If I look at my personal database of my online played games then I encountered it already in more than 500 blitz-games. Naturally I was curious what the new book of the Serbian grandmaster Nikola Sedlak: Playing the Stonewall Dutch would tell us about this line.

Only 1 page in the book I was able to find about this opening which is a disappointment. This is a huge difference compared to the 38 pages !! in the book The Modernized Dutch Defense which I already announced in my article chess position trainer part 3. I believe 38 pages were absolutely necessary for this line so I feel that Nikola has underestimated this in his book.

For a more elaborated review of Nikola's book I refer to a comment which i wrote on chesspub. Anyway this article is about regression-tests so I don't want to digress a lot about this one specific opening.

So let us return to the regression-tests and try to understand why there are very few interesting results. First I believe it is important to know that the old analysis on which the regression-tests are executed, are averagely made about 5 years ago. In 2016 I wrote in my article raise of the machines part 2 that the strongest engine improves at a rate of about 55 elo per year without taking into account the hardware. With the introduction of neural networks we see that this trend hasn't flattened, at contrary. In other words we can estimate that the level of my analysis has improved with at least 200 elo over the last 5 years and probably it is even much more.

Nonetheless we see that this increase of playing-strength has rarely (never say never) refuted any of my old refutations. I don't have a conclusive explanation for it but I do have a theory based on my daily work with the best engines. 5 years ago the engines were already extremely strong (much stronger than our current world-champion Carlsen) so the quality of the analysis I made at that time was already very good (this is very different compared to analysis made by humans in the era before engines existed). If 5 years ago an engine discovered that a line is bad then I notice that the best engines of today can't fix this anymore.

The increase of playing-strength of the new engines is mostly concentrated into the discovery of new much more complex refutations of positions which were before considered still fine. That is also the reason why last year I wrote in my article computers achieve autonomy part 2 that many dubious openings are disappearing from grandmaster-practice. More and more openings/ lines are theoretically at a dead end and those doors don't open anymore.

Finally I want to add that we should not despair about chess. The engine closed many doors but at the same time also opened many new ones. Every day I find new and beautiful lines. So it is mainly a matter of let go some old lines and be ready to adapt the repertoire when you discover something doesn't work anymore.

Brabo

The chess-microbe part 3

While the French Open of Cappelle La Grande (end of February) was still running, it already became clear to me that the corona-virus wouldn't be a joke despite at that time the news was still minimizing the dangers of it. However I was also at that time still hopeful that we could quickly beat the virus. China was able to do it so I assumed that Europe and definitely Belgium with a much higher average standard of life should manage this too. Meantime we know that this didn't happen.

We failed as we didn't want/ weren't able to impose the draconian measurements necessary to exile for sure the corona-virus. Economical as well as individual interests blocked an efficient strategy. As a consequence after 6 months we still are dealing with the threat and it seems that it will be like that till a good vaccine is sufficiently spread among the population.

Of course people are fed up of it by now. Virologists and policymakers keep telling up to hold on to the strict hygienic regulations but people aren't willing to do anymore. Against all advice still 3 million Belgians traveled abroad last summer. After months of a complete stop of chesstournaments, I also notice more and more clubs restart (small) otb-tournaments. In other words more and more people are willing to take bigger risks which unfortunately we also find back in the increase of infections.

Playing chess physically is not without risks. The Belgian championship organized in Bruges went fine without new infections (a.f.a.i.k) but there are no guarantees which was proofed by the recent outbreak of covid-19 after the Spanish teamchampionship despite they used many strict hygienic measurements like face-masks, gels... We still don't know much about which risks are exactly connected to an action. Avoiding any contact is the only rule which protects us for sure. It is therefore no surprise that many players dropped out of the Spanish individual championship (which started just after the Spanish team-championship) although the authorities tried to reassure the participants that there wasn't any threat anymore.

Myself I avoided any contact for a longtime. I was definitely afraid of becoming ill. However slowly I also got to miss more and more my old social life. In the first months I was able to fill the freed time with other activities but this came harder over time. You can't clean your house forever and my garden has never been so nice before. I analyzed my games of Cappelle La Grande for 2 months but at some point this ends of course. I teached my family the games Catan, Rummikub and Risk but after a while they got fed up by losing against me all the time. I am fanatic in any game I play and I understand it is no fun for others when I self-learn all kind of advanced strategies by looking up on youtube how experts are playing.

In my article online chesstournaments I also mentioned that I started to play a lot of online chess but that obviously couldn't compensate my needs. More and more I was not knowing anymore what to do in my free time. For convenience I focused myself on my job. I didn't take any holidays for half year and chose to work long days in the office until I was contacted that I really had to share my planning for the annual holidays. Initially I had the idea to wait with it till this corona-crisis would have passed but this clearly wasn't an option anymore.

Legally I had still 6 weeks of holidays to take before the end of the year. Last month of the year is always very busy so management was pushing to not wait any longer with taking up the holidays. However I really didn't like the forecast of a staycation of several weeks next to my door at all. Eventually I made a difficult decision. My fear for covid-19 wouldn't dictate anymore what I should do or not.  Playing chess makes me happy and for that I was willing to take some risks. So beginning of July I started to look for a chess-tournament to play during my holidays in August.

The Belgian championship in Bruges was of course the closest for me but as I explained in my previous article it was not an option for me as I can't wear the obligatory face-masks for hours due to my skin-allergy. However there existed not many tournaments where you can play without face-mask. I couldn't find even find any tournament in the neighboring countries like Netherlands, France or Germany. Out of sheer necessity I looked further away from home. I considered tournaments in Swiss and Austria but in the end I was attracted to a tournament in Czechia (Prague): 9 rounds of classical chess (same time-control as we have in our Belgian interclub) with the playing-hall in the hotel where we could stay. Face-masks weren't obliged. 1000km so still manageable by car (as I didn't like the plane with a face-mask), 2 rating-groups so my children would also get interesting opponents. After some hesitation I accepted but immediately I also realized that there were no guarantees.

This became quickly evident when a second corona-golf started. Each day we approached the tournament, the situation became less clear and more complex. Till the last minute I was doubting to go or not and probably any smart person would've cancelled it as the things which we had to endure were definitely unusual to say the least.

First Prague became quickly an orange zone which means a lot of covid-19 infections but not yet that much to forbid people going to it. Next my own province Antwerp was hit by a dramatic increase of new infections. For Netherlands we even were a red zone so forbidden territory. Then a week before the tournament of Prague would start, the Czech government announced that you need to wear face-masks in all inside-events with more than 100 people. This I didn't like so I contacted the organizers of the tournament to cancel my participation (at that time there were already +250 participants confirmed). However they told me that this rule isn't applicable for sportsmen when they do sport. Chess is in Czechia considered as sport contrary to e.g. in Belgium. I didn't feel fully convinced by their statement but it appeared to be the truth.

However my biggest setback happened 2 days before we had to leave. My wife became ill and had a running nose with low fever. We immediately decided that she had to take a corona-test. This also means the rest of our family had to be in quarantine till we were sure that the result was negative. However the Friday of our departure we still didn't receive the result of the test and waiting any longer would mean that we would miss at least the start of the tournament. I guess most people in this situation do miss the start but here you are dealing with a desperate and fanatic chessplayer. I convinced my wife to stay home and that it was ok that I would travel alone with my 2 children to Prague. She had to call us during the drive from the moment she knew the results. As we would be the whole time in the car, there was no risk for others. However it also meant that if her test would be positive that we would immediately return and the adventure would be over.

Fortunately a couple of hours after we left home, the message arrived that my wife had only a cold so no covid-19. As a Russian she doesn't have the immunity against the wet Belgian climate which means each year she has several times a cold. Resting and sleeping is in such periods the only she can do but this way I was alone the whole week in Czechia with my 2 children. If it wouldn't have been about covid-19 then I surely would've invited another player (adult) as all reservations were already made.

As this wasn't enough excitement also another obstacle arrived 1 day before the start of the tournament. Suddenly Germany required from Belgians of the province Antwerpen that they should show a negative covid-19 test otherwise we had to first quarantined for 14 days.  Now I had decided in advance to make an overnight-stay in the beautiful German city Dresden (at 150 from Prague) so I could drive the last kms next day quietly. However it is impossible to get such test done in less than 24 hours. I called the hotel where we would sleep and explained the situation but they had not yet heard about this new regulation. Ok but the next day things could be different. In the end I took the risk and thought in worst case we will sleep in our car.

Fortunately things didn't escalate. In Dresden nobody cared about the new rule and happily accepted our euros which allowed us to visit the center and close an enjoyable first day of our holidays. The next day we already left early in the morning to Prague. My next worry was that we didn't have yet a vignette which is obligatory for driving on the Czech highways. So the first tank-station I found, I looked for it. This was also a bit stressful as I don't speak Czech and my poor German was first not understood.

The remaining 100 km went at last fine thanks to my GPS. Only at the hotel I still was struggling a bit to find a safe place for my car. Once that was done, I finally could register myself for the tournament and the hotel (so same location). A kind man helped us in English and comforted us everything was in order with the rooms and the subscriptions. As the first game would start only at 16h we still took the opportunity to rest a bit in our room. More than 300 chessplayers (50% more than last year) were participating. Even a Norwegian +2600 player joined us despite only a first prize of 500 euro (which he didn't even win). I am obviously not the only one having missed classical chess during the last couple of months.

9 rounds of "real" chess. I enjoyed every minute of it and I noticed many thought similarly about it. There was also a lot of youth, much more than usual. I guess it is because youth is more corona-resistant. Anyway it was the first time that I felt old. 7 of my 9 opponents were much younger than me: 12 years, 13 years, 14 years old.... Besides these young players all had ratings between 2000 and 2100 and already conquered several national youth-titles. You understand that this is not a tournament where you are going to win a lot of ratingpoints but I didn't care as just playing was much more important.

Anyway against the 3 youngest ones I scored 2,5/3 so the loss of 20 fide had rather to do that I was playing a bit too slow (this is always the case after having not played classical chess for a long time) and also that I encountered in each of my 9 games openings in which I had little or no experience. In at least 4 games I had a very bad position out of the opening and sometimes I was only able to make a draw by proposing some tactical draws.

This means I have now again for weeks of analyzing work at home which I enjoy a lot. Playing tournaments like that is much more for me than just the time sitting at the board. I also took the time to visit the beautiful center of Prague. Here I noticed a plus-side of the corona-crisis as everywhere it was very calm. It must have been ages ago that you could stand in front of the famous astronomical clock in the heart of Prague during mid of the summer at daylight with so few people around.

I can also recommend the Madame Tussauds-museum in Prague if you are with children. The dolls are looking lifelike and people told me afterwards that they are exceptionally good compared to other Madama Tussaud-museums. Sometimes I did have to explain to my children who some of the stars are as naturally they don't know the ones from long before they were born.

Freddie didn't make a problem of my anti-corona-pose.

To play a tournament oneself and at the same time take care of 2 children isn't easy but I managed. Warm meals were available in the restaurant of the tournament and fortunately this was ok for my children. We also had a supermarket at a couple of hundred meters away from the hotel in which we could buy a lot of extra snacks and drinks.

For the return I decided wisely not to stop anymore in Germany. I wanted to visit Leipzig but expected that by that time the new regulation would be much stricter for Belgians coming from the province Antwerp. I noticed not one single Belgian at the way back. In less than 9 hours we were back home from Prague thanks to the German highways.

Once I arrived home, I immediately contacted our familydoctor to undergo a corona-test. This is not mandatory for people coming back from Prague but I considered playing chess in a hall with more than 300 players not wearing face-masks as a high-risk behavior (I was still afraid of course).  Personally I didn't do any handshakes and always wore a face-mask when I wasn't playing but most players didn't care at all about corona. This was especially clear when I met my opponent of round 4. A young muscled man with some tattoos was clearly upset when I didn't want to handshake before the game and I feared a few seconds that he would punch me on the nose.

[Event "Open Prague 4th round"] [Site "?"] [Date "2020"] [Round "?"] [White "Narr, K"] [Black "Brabo"] [Result "1/2-1/2"] [ECO "A80"] [WhiteElo "2110"] [BlackElo "2281"] [PlyCount "136"] 1. d4 {(My opponent arrived 20 minutes late. He was a young muscled man with tattoos and was clearly upset when I didn't want to handshake. He didn't accept my face-mask as an excuse and I feared for some seconds that he would punch me on my nose.)} 1... f5 2. Bf4 {(I couldn't find any games of my opponent against the Dutch in the database.)} 2... Nf6 3. e3 d6 {(Earlier I always played e6 here but last year I concluded that black can't fully solve all his opening-problems if white plays the strongest moves. Nevertheless the Serbian grandmaster still recommends it in his recent book about the stonewall. On the other hand d6 is recommended in the book "The Modern Dutch" of the French grandmaster Adrien Demuth. Still I took a risk as I had never studied it .)} 4. Nc3 {(To put the knight in front of the c-pawn looks silly but theory considers it as interesting.)} 4... e6 5. Qf3 Qe7 {(Played after a long thought obviously with the idea to play a quick e5. The more quiet Be7 is definitely also playable.)} 6. e4 e5 7. dxe5 dxe5 8. Bd2 Nc6 {(Initially I thought this is a mistake but the engine shows it is still ok. Anyway fxe4 would've been much more easier and safe.)} 9. Bb5 fxe4 10. Bxc6+ bxc6 11. Nxe4 Bd7 $6 {(Only here I commit a mistake. Mandatory was Bb7 and castle long after which my activity compensates sufficiently the broken pawn-structure.)} 12. Ne2 Qf7 13. O-O Nxe4 14. Qxe4 Qd5 15. Qe3 Bc5 16. Qc3 O-O $6 {(It is hard to criticize such logical move but I agree with my best engines that the refined Bg4 is more accurate after which white's pieces are cooperating less harmoniously.)} 17. Be3 Bd6 18. Ng3 Be6 19. Rfd1 Qc4 20. Qxc4 Bxc4 21. b3 Be6 22. Ne4 Rfd8 23. f3 a6 24. Kf2 h6 $6 {(Bf5 is here a bit stronger to attack the knight on e4 as well as the pawn on c2.)} 25. Rd2 $6 {(During the game I already wondered if Rd3 isn't a bit stronger to create the option of Rc3.)} (25. Rd3 $1 Be7 26. Rc3 Bd5 27. Rd1 Kf7 28. Ke2 $18) 25... Kf7 $6 {(The computer plays a5 with the idea to find counterplay after white answers a4 via c5. It is a risky plan but better than waiting passively.)} 26. Rad1 Be7 27. Rxd8 Rxd8 28. Rxd8 Bxd8 {(The exchanges make the defense not easier but black has little choice. This should be winning for white but white was lacking time. He is now missing the 20 minutes that he was late at the beginning of the game.)} 29. Ke2 Be7 30. Bc5 Bd8 31. Kd3 $6 {(After Kd3 I am not anymore so sure that white can still win. The engine therefore rightly first recommends g4 to discourage my next move of the game.)} (31. g4 $1 Bd5 32. Ke3 Ke8 33. Bb4 {(Or first c4 and then Bb4.)} 33... Bf7 34. c4 Bg6 35. Nc5 $18 {(My strongest engines don't manage to hold this position for black but technically it is still a lot of work especially for a practical game.)}) 31... h5 32. Be3 Be7 33. Bc5 Bd8 34. Be3 Be7 35. Bg5 Bd6 36. c4 Bf5 37. Kc3 Ke6 38. Be3 Kd7 39. c5 Be7 40. Kb4 Kc8 41. Ka5 Kb7 42. Nd2 $2 {(The engines don't like it that black gets the opportunity to play Bd3 but despite the high evaluations of h3 and Kb4 I can't find a clear win for white.)} 42... Bf6 $2 {(The computer defends actively with Bd3. However I don't see how Bf6 can be punished although I admit black will still suffer for some time.)} 43. Kb4 Kc8 44. Ne4 Be7 45. Bd2 Bxe4 {(This is not an easy decision. My engines still show a clear plus for white but I can't see any breakthrough for white.)} 46. fxe4 g6 47. Bh6 Bf6 48. Be3 Be7 49. g3 g5 50. h3 $6 {(The evaluation drops after this move but after the 'stronger' g4 i think it is also a fortress.)} 50... g4 51. h4 $6 {(After this move Leela gives equality but also hxg4 is a fortress.)} 51... Kb7 52. Kc4 (52. Bg5 $4 Bxg5 53. hxg5 h4 54. g6 hxg3 55. g7 g2 56. g8=Q g1=Q $19) 52... Bf6 53. Kd3 Kc8 54. Bf2 Be7 55. b4 Kd7 56. Kc4 Bf6 57. Be3 Ke6 58. Kb3 Kd7 59. Ka4 Kc8 60. Ka5 Kb7 61. Bh6 Ka7 62. Be3 Kb7 63. a4 Ka7 64. Bg5 Bg7 {(With only 5 minutes remaining it is never too late to play a wrong move.)} (64... Bxg5 $4 65. hxg5 h4 66. g6 hxg3 67. g7 g2 68. g8=Q g1=Q 69. Qc8 $18) 65. Be7 Kb7 66. Bg5 {(We both looked at the bishop-sacrifice but it doesn't work so finally white stopped pushing for a win.)} (66. Bd8 Bh8 67. Bxc7 Kxc7 68. Kxa6 Bf6 69. b5 Bxh4 70. gxh4 (70. Ka7 cxb5 71. axb5 Be7 72. b6+ Kc6 73. b7 Bxc5+ 74. Ka8 Bd6 $19) 70... cxb5 71. axb5 g3 72. Ka7 g2 73. b6+ Kc6 74. b7 g1=Q 75. b8=Q Qa1#) 66... Bh8 67. Bd8 Bg7 68. Bg5 Bh8 1/2-1/2

3 days after the test (it is no fun getting a stick deep in your nose) we all got back fortunately negative. Still we were asked to stay in quarantine for 2 weeks as such tests are not giving an absolute verdict. Meanwhile this period has passed. The chess-microbe has won from the corona-virus. However I also realize that next time it can be the other way around. Such adventure is definitely not to be recommended and you really need to be a fanatic chessplayer to uberhaupt do such risky things.  So I am mainly thankful of being able to tell you here this story. It gave my a lot of pleasure but I will only look it up if better and safer alternatives aren't available.

Brabo