Saturday, March 13, 2021

Modelgames part 2

I am a big believer in using modelgames, and it is no coincidence that many opening- and repertoire-books / courses use modelgames. These are games that give me an aha-experience about an opening or middle-game (and an endgame by exception). More objectively defined, they meet a number of criteria. The first is that the games show a clear plan, and (secondly) the annotator explains this well. Where are the priorities, what must / is not allowed, which pieces to keep, and where to put them. It is also important whether the played line belongs to my opening repertoire (preferably).

I recently ran into one more, and it was a blitz for the first time, but the few lines of comment Daniil Dubov added were enough to slightly sharpen my weapons against the London (an opening that has recently been promoted as an universal weapon on the Internet. ). I had already found that “normal” Queen-Indians against the London work fine, but the few tips from Dubov (don't play d7-d5, Re8 and Bf8 are fine, and don't do too much too soon, because white players only want black to play actively), are the few anchors a player of my level needs to get far in the middle game.

Because of those very good analysis (also in the middle-game), Mauricio Flores Rios (Chess Structures: A Grandmaster Guide) is such a great book. One example: his commentary on the game Grischuk-Zhong (Shanghai 2001)  is so clear and simple that I have already been able to play it. It was a completely different chess than I usually played: instead of looking at a few lines and thinking “it will work”, I was now more likely to see which piece belongs where, and stick to the plan consistently.

Perhaps not a model-game, but excellently analyzed, I found the French game Parma-Hecht played at Bamberg 1962. For me not a model-game, because black wins (and I do not play the French), but the insights that Hecht puts down in his book Rochaden Schacherinnerungen are very interesting. Now that I am making the transition from model-games to excellently analyzed games, I have to say that Fischer's 60 Memorable Games contains much better analysis than Kasparov's MGP1, for example. Not because there are quite a few mistakes in Kasparov's book (and more than in Fischer's I think), but because Fischer explains it very clearly, while Kasparov too often gets lost in concrete lines, without explaining the game on the board. In the short period that the Evans Gambit was in my repertoire, Fischer's games against Celle and Fine were my model-examples. And when I brought a center-gambit to the board, Tartakover-Reshevsky, from the 1937 Stockholm Olympiads was my lead-game (alongside Zatonskih-Ipatov; only recently did I discover XieJun-Flear, which would have been a nice third). In that game White risks too much and he is lost after the opening, but in all the years that I played C22, nobody came to the refutation of Reshevsky. Only in correspondence-chess did I once meet Dd7 on move 13 (instead of 13… Dc8, but actually just as good) - that turned out to be a nice draw.

Often, classics can pass for modelgames. As Morphy treats Duke Isouard's Philidor in the Paris Opera, it is certainly worth remembering. And as already described here in this blog, giants like Botvinnik also stood on the shoulders of giants (Lasker, Capablanca, Rubinstein, Alekhine), and they interpreted the former exemplary played openings in a new way to play out certain positions. It is no coincidence that someone like Gelfand often refers back to Rubinstein. His Positional Decision Making in Chess is full of it. Also games of worldchampionships (or matches in general, because often the same openings are brought out) are often a good source to take a certain way of playing as inspiration. This is certainly not to say that only top-games can serve as an example (see “my” model-games). Games that usually do drop out are tactical slugfests; usually you don't get classic brilliant games appear on the board. You should already be able to execute a double bishop sacrifice (remember Lasker-Bauer and Nimzowitsch-Tarrasch: we also stand on the shoulders of giants for the middle-game). And although I have not yet managed to reenact anyone such as Steinitz-Von Bardeleben (you have to be crazy as a black player), “classic opening disasters” are possible (how many black-players have lost in a few moves in the Levenfish-Dragon, because after f4 they played Bg7 after all?).

Tartakover (° 1887, +1956) gave a remarkable example of a model-game in his book of best games. At the beginning of his career (which ran from 1905 to 1954, so exactly 50 years) his talent had not yet fully matured, but he knew all his classics and achieved a considerable playing-strength relatively early: he won Nuremberg 1906 and became shared third-fifth in Vienna 1907.

In his games against Vidmar and Dus Chotimirsky he used a variant that Lasker had introduced a few years before, with one of his monumental games, namely the one against Napier, who played the game of his life against the worldchampion.
[Event "Karlsbad-01 International Masters"] [Site "Karlsbad"] [Date "1907.08.31"] [Round "9"] [White "Tartakower, Saviely"] [Black "Dus Chotimirsky, Fedor Ivanovich"] [Result "1-0"] [ECO "B72"] [Annotator "Surmont,Yves"] [PlyCount "111"] [EventDate "1907.08.20"] [EventType "tourn"] [EventRounds "21"] [EventCountry "CZE"] [SourceTitle "HCL"] [Source "ChessBase"] [SourceDate "1999.07.01"] [SourceVersion "2"] [SourceVersionDate "1999.07.01"] [SourceQuality "1"] {[%evp 0,111,41,41,48,22,22,-18,28,28,28,28,101,73,89,41,41,6,40,21,37,-3,-2, -39,5,13,13,13,57,57,57,2,-12,20,15,-22,77,77,90,95,162,149,269,289,289,289, 303,275,275,275,275,275,275,275,275,286,356,356,356,356,364,241,285,285,290, 290,675,265,265,265,263,232,225,229,218,217,238,238,243,228,232,232,232,232, 226,236,235,191,194,199,208,216,218,244,366,381,384,385,536,560,569,571,663, 678,688,710,729,780,760,784,1090,1120,29993,29994]} 1. e4 c5 2. d4 cxd4 3. Nf3 Nc6 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. Be2 {A seemingly innocent move, however holding some punch: a quick push with g4 becomes possible (and such twists are even possible in Philidor-esque positions).} 7... O-O (7... d6 8. h3 O-O 9. Qd2 Bd7 10. g4 a6 11. g5 {This is the aha moment of this line: with f3 the knight can jump comfortably to h5, and stand there for a longer period of time and stop the white attack. Now the diagonal of the bishop is free, just Bxh5 follows Nh5 and Black's position collapses.} 11... Ne8 12. h4 Rc8 13. h5 Na5 14. hxg6 hxg6 15. O-O-O {and although it seems as if white is much quicker, it was still an exciting game, which Tartakover was able to finish smoothly despite everything.}) 8. Qd2 d6 {Today, almost everyone here plays f3, but Tartakover is also on the shoulders of giants. In Vienna 1905-06 he had already opposed such a position against Vidmar and won, but that game also relies on a very important model-game, namely Lasker-Napier (Cambridge Springs 1904). His own game against Vidmar he enthusiastically describes as the perfection of the ideas of the latter game.} 9. h3 Bd7 10. g4 Rc8 11. g5 {Same as in the match against Vidmar: Nh5 is not possible and black is left with a passive position.} 11... Ne8 12. h4 Ne5 13. h5 Nc4 14. Bxc4 Rxc4 15. hxg6 fxg6 16. O-O-O Qc8 17. f4 e5 18. fxe5 Bxe5 19. Nd5 Rf7 20. Rdf1 Rg7 21. b3 {and from here on the engines don't like the position anymore for black.} 21... Rc5 22. Nf3 Bc3 23. Nxc3 Rxc3 24. Bd4 Rc7 25. Bxg7 Nxg7 26. Qh2 Nh5 27. Nd4 Bc6 28. Qxd6 Bxe4 29. Rh2 Ng7 30. Rf4 Rd7 31. Qe5 Bf5 32. Nxf5 Nxf5 33. Rc4 Qd8 34. Qe6+ Kg7 35. Kb2 Qe7 36. Qxe7+ Rxe7 37. Rc3 Ne3 38. Rd3 Ng4 39. Rh4 h5 40. gxh6+ Nxh6 41. c4 Nf5 42. Rg4 Kf6 43. c5 g5 44. b4 Kg6 45. b5 Kh5 46. Rc4 g4 47. c6 bxc6 48. bxc6 Rc7 49. Rd5 Kg5 50. Rcc5 Kh4 51. Rxf5 g3 52. Rc4+ Kh3 53. Rh5+ Kg2 54. Rd5 Kf3 55. Rd3+ Kf2 56. Rc2+ 1-0
It was remarkable that he also used this approach successfully with black: against Swiderski in the B-tournament of Ostend 1907 he managed to do exactly the same against the too cautious approach of white.
[Event "Oostende Masters"] [Site "Ostend"] [Date "1907.06.22"] [Round "28"] [White "Swiderski, Rudolf"] [Black "Tartakower, Saviely"] [Result "0-1"] [ECO "A28"] [Annotator "Surmont,Yves"] [PlyCount "40"] [EventDate "1907.05.16"] [EventType "tourn"] [EventRounds "29"] [EventCountry "BEL"] [SourceTitle "HCL"] [Source "ChessBase"] [SourceDate "1999.07.01"] [SourceVersion "2"] [SourceVersionDate "1999.07.01"] [SourceQuality "1"] {[%evp 0,40,43,-23,-15,-19,-33,-24,-12,-6,-29,-29,-33,-46,-29,-65,-27,-54,-26, -34,-10,-20,30,13,13,-6,14,-27,-18,-51,10,8,15,-3,10,15,30,-32,-4,-166,-169, -387,-431]} 1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. a3 d5 5. cxd5 Nxd5 6. d3 Be7 7. g3 Be6 8. Bg2 h6 9. O-O Qd7 10. Bd2 {and yes, this is just a dragon with swapped colors, so why not use that same plan too?} 10... g5 11. b4 g4 12. Ne1 h5 13. Rc1 h4 14. e3 hxg3 15. fxg3 Nxc3 16. Bxc3 Bg5 17. Qe2 f6 18. Bd2 O-O-O 19. d4 {a blunder which loses the game, but black was already better.} 19... Nxd4 20. Qf2 Nb3 0-1

So yes, I think you can learn something from a good game showing a good plan. That may even be a “master-against-amateur” game for me, but that is for another time.


Saturday, March 6, 2021

Data-mining in chess

Data-mining is a technique used to find patterns (correlations) in large amounts of data. This is not only useful for commercial companies, for example, who want to know whether they can still use their chessboards for their current target group of old grey men, or if they may need to tap generation Z. It is not immediately about finding first-order relationships, but second- and even third-order relationships can also be useful.

This blog has already shown numerous examples of thorough research, but I think the host of this blog would certainly have gotten results faster here and there, with a more advanced search-engine, to find patterns, news, profit twists, original statements in a more automatic way.

What we can do today with the Chessbase's filters is already fun - and Chessbase is slowly moving towards more functionality, but we are not there yet. Chess Query Language (CQL), which makes much more possible on pgn databases, is a further step, but there are limits to that too. To do real data-mining on chess games, * all * details of the game should be known: not only all moves, but also all pawn-formations (on each move), all positional features (such as double rooks, bishop-pair, immobilized piece, ...), all maneuvers (fake-sacrifice, knight on the edge, ...) and all threats (smothering mate, fork, ...), but also the reflection-times used (impact of time-scarcity!), all data of the players, ... Only then is an uniform check possible, such as the relationship between a won rook endgame (due to threat of switching to a won pawn-endgame, elo-strength, opening, game-progress and e.g. the age of the players.

The question is, of course, whether such a thorough analysis can add anything. Maybe to identify general trends, but in my opinion certainly not to help with game-preparation. Even if you find out that your opponent plays his knight-endgames badly, you are not going to play a second-choice move in the middle-game just to get into a knight-endgame, I think.

Chessbase already shows relations between the opening-line and the endgames that typically result from it, and that in itself is very useful. But I got the idea of ​​data-mining when I accidentally discovered a very large win-percentage in an opening-variant at computer-games years ago. The position just after the opening was the same, but white won almost all matches. It concerns this line:
[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "?"] [Black "?"] [Result "*"] 1. e4 e5 2. d4 exd4 3. Qxd4 Nc6 4. Qe3 Nf6 5. Bd2 Be7 6. Nc3 d5 7. exd5 Nxd5 8. Qg3 Nxc3 9. Bxc3 Bf6 10. Bb5 *
My database of CCRL-games consists of 38 games with this variant. Black wins 3 of them, there are 11 draws, so White wins 24 (!). The problem in the position is that many engines entered the sequence: 10… Qd5 11.Bxf6 gxf6 12.Bxc6 + Qxc6 13Qg7 Ke7 14.Qxh8 and White usually won. Well, I have to admit that the ratings were usually respected, so this was also an example of statistical coincidence. Such a filter exists already in Chessbase: on a selection you can check which variants (ECO-codes in particular) score the best (something that also allows Lichess to do with your own games).

Several points are illustrated with this example: 1) there are still very nice things to be found in computer-databases; 2) always interpret the results of a filtering (it's not because a variant that Walter Browne often lost is bad, because Browne was a notoriously time-trouble-addict) - you also have this problem with computer-games: some engines have a better time-management algorithm, or are tactically better than the opponent if the reflection-time becomes very short.

Regarding statistical coincidence, I would like to add this: once - in the distant past - Fritz and Junior played a real “computer candidate match”. Professor Enrique Irazoqui organized the match in Cadaques (The gospel according to Enrique Irazoqui). The intention was to select a “challenger” to play a match against Kramnik in Bahrain in October 2002 (see Brains in Bahrain and 32-bit op 64 velden). There was a lot of controversy, because Fritz and Junior were handpicked by Chessbase, and other engines (Rebel, Hiarcs, Shredder and other (sub-) toppers from that period, were simply ignored). Junior started that match with 5 wins over Fritz, but Fritz straightened the match over 24 games and won the play-off. The games themselves can hardly be found on the internet, but the reports are fortunately still there: twic339Kramnik versus Deep Fritz 2002 and games.onlinesupplement2.

In other words, if the sample-size of these games had not been 24 games, but only six or twelve, the result of the match would have been different. There was already a lot of discussion during the match about the settings of Junior and Fritz, to explain the 5-0 start, and even more so when Fritz drawn the match- let alone had this happened in a match between two people. Hence the criticism of the ever-shorter World Cup matches: players no longer take any risks, because once in the lead in a match over 12 games, for example, then it is only goalkeeping (which was once Fischer's great criticism of a match) with a fixed number of games). Many World Cup matches (and long tournaments) have shown that, for example, fitness is also an element that carries over into the strength of a player. For example, Rubinstein was a diesel, while other players just weakened if it took "too long". But now we are already a long way from the starting-point.