Shakmaty Bereolos - The Official Chess Site of Peter Bereolos

Games versus GMs

Welcome to my chess page. This is mostly random thoughts and analysis in the form of a chess diary with other sections of the site slowly developing. A lot of the content will come from my own experience. There are two reasons for this. One, so I can use this site as a self-improvement tool. Two, so you the readers will have content that is not found on other chess sites. Follow the link to the left to reach my annotated games against grandmasters. Send me comments and ideas

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Corrections to Basic Chess Endings

7/4/20 - TCEC Season 17, Games 15-16, Modern Tiger

Games 15 and 16 of the Season 17 Superfinal featured a variation of Modern Defense that is a favorite of Swedish GM Tiger Hillarp-Persson, who has written two books on it: Tiger's Modern and The Modern Tiger. Game 16 was the more important game theoretically and from the match perspective. Stockfish scored the first of only two Black wins in the match, although that result had nothing to do with the opening. 1.e4 g6 2.d4 d6 3.Nc3 a6!? The starting position for this set of games. Tiger usually completes the fianchetto before playing this move. It ends up transposing after the next move.

4.Be3 Stockfish played the more aggressive 4.f4 in game 15. 4...Bg7 5.h4 A typical scenario in many fianchetto openings. Black has to decide if he wants to ignore the advance, play ...h6 with the intention of meeting h5 with g5, or Stockfish's choice to immediately stop further advance of the h-pawn 5...h5 This is the most popular move, but White has scored the best against it. It was Tiger's first choice in his first encounter against h4 back in 2003, but he now considers it dubious. His preference is to ignore the pawn with 5...Nf6, but he also played 5...h6 in one game 6.Nh3 Tiger gives White the edge after 6.Nf3 Bg4 7.Qd2, but Black could also play 6...Nf6 or 6...b5 which are typical in the variations without the advance of the h-pawns 6...Bxh3!? An interesting concept. Black surrenders the bishop pair, but now the White king can only castle queenside where Black will have more space. It also takes away an attacking piece from White's kingside attack. I thought it might be a unique concept by Stockfish, but Svidler had played this move in a French League game against Meier in 2009 7.Rxh3 Nd7 8.Qe2

A novelty from Lc0, but I don't really understand the point. 8.Qd2 as played by Meier seems much more natural, not blocking Bf1 although Svidler had few problems after 8...c5 9.0-0-0 cxd4 10.Bxd4 Bxd4 11.Qxd4 Ngf6 and a draw was agreed.

The remainder of the game was a weirdly mirror to game 12. This time it was Lc0 that self destructed. The position was fairly stable after 42...a4

Black's weak e-pawn is easy to defend and offset by White's f-pawn. Stockfish was already sitting on a 0.00 evaluation, but Lc0 gave itself a very small winning percentage. The machines began one of their maneuvering sequences with lots of Kg7-h7 and Ka2-Ka1 as well as back and forth moves by the rooks and queens. The only progress Lc0 made was to advance its f-pawn by one square and after that there were points where Stockfish offered the e-pawn for the f-pawn including after 81...Re8

As at the other times where White could take the e-pawn, Lc0 declined to do so here.instead opting for 82.f5?! 82.Rxe6 Qxe6 83.Qxe6 Rxe6 84.Rxe6 Rf7 is an equal ending. I think this situation is a bit different than what happened in Game 12. There, Stockfish had a large negative evaluation of its position, and giving up a pawn didn't change the evaluation much. Here, Lc0 gives itself a very small advantage, which is reduced by the pawn sacrifice, but still positive, whereas allowing the 50 move rule would reduce the win probability to zero. 82...gxf5 83.Rd1 Black should still have a small edge after 83.Rxe6 Rxe6 84.Qxe6 Qxe6 85.Rxe6 Kg7, but this should also be drawn. The text move kicked off another long sequence of shuffling. Lc0 steadfastly refused to regain the e-pawn, but Stockfish did not show any progress and it looked like the game would be drawn by the 50 move rule after 129...Rfa8

Three more random moves and the game would be drawn, but Lc0 decided to give another pawn with 130.g6? which Stockfish happily took 130...Qxg6, although even here, Stockfish did not come off of its evaluation of 0.00 until a few moves later. 131.R5e2 Kh8 132.Qd7 R8a7 133.Qb5 Qg8 134.Rh2? Even here White could take the e-pawn 134.Rxe6 Rxe6 135.Rxe6 Qxe6 136.Qb8+ Kg7 137.Qxa7+ and the Black king is too exposed for Black to win 134...Ra8 Now, Stockfish finally registered an advantage to Black. Strangely, Lc0 had predicted this move when playing 134.Rh2, but still gave itself the better chances, but now it also swung the advantage in Black's favor. After urther adventures Stockfish began announcing mate on move 172 and brought home the point after 196 moves.

7/2/20 - McEntee-Bereolos, 2008 Billy Colias Memorial

Another example of trying to use a dark square grip in the Benoni as compensation for a pawn is my game against Tim McEntee in the 2008 Colias Memorial. After 46.Kxe2

46...Ke5 The attempt to activate the rook doesn't work 46...Rc5 47.Rb3 Rxa5 48.Rxb7 Ra2+ 49.Ke3 Rxg2 50.Rd7 47.Ke3 g5 48.Rb3 f5

This move weakens the sixth rank,but it is already weak enough for White's purposes if Black waits passively, although he has to find a few good moves to break down the defense 48...Rd7 49.c4 Rc7 50.Kd3 Rd7 51.c5 dxc5 52.Kc4 Rc7 53.Rb6 Now, Black has no play as the king raid is too slow Kf4 54.Rh6 Kg3 55.Rh7 Kxg2 56.e5 Kxh3 57.e6 Kg3 58.d6 49.exf5? After this Black has no problems 49.Kd3! seems to give White excellent winning chances. Even working with the engines, I've been unable to find a good defense. The Black king is surprisingly vulnerable on e5. It is a quite logical move, White intends simply c4-c5, but I think sometimes the opposition is so deeply ingrained that players are hesitant to give it up. Some attempts

a) 49...f4 does nothing to stop White's plan and even cuts off an escape route for Black's king. White wins 50.c4 Rg7 51.c5 dxc5 52.Rb6 c4+ 53.Kxc4 Rc7+ 54.Kd3 Re7 55.Rg6;

b) 49...fxe4+ doesn't fare much better 50.fxe4 and here in addition to c4-c5 White also has the idea Rb2-f2-f5# 50...g4 51.Rb2 gxh3 (51...Rg7 52.Rf2; 51...g3 52.c4; 51...Rf7) 52.Rf2;

That seems to leave c) 49...g4 as probably best, but then 50.exf5 is a much better version than the game since after 50...gxf3 51.gxf3 Kxd5 (on 51...Rf7 the engine comes up with the hard to find 52.f4+!? when taking either f-pawn allows the White king to d4 to support c4-c5 and 52...Kxd5 transposes to the main line) White has 52.f4 stopping the king's return to e5 52...Rf7 53.c4+ Kc5 54.Rb6 Rxf5 55.Ke4 Rf7 56.f5 Kxc4 57.Rxd6 and White is winning;

49...Kxd5 50.f4 Rf7 51.fxg5 Rxf5 52.Rxb7 52.g6 Rg5 52...Rxg5 53.Kf2 Rf5+ 54.Ke2 Rg5 55.Kf2 Rf5+

56.Kg1?! Attempting to keep the game going because he is up a pawn. Tim's fighting spirit is commendable, but there is no real justification since the Black king is so active. White should just acquiese to a repetition with 56.Ke3 Rg5 56...Kc4 57.Rb4+ Kxc3 58.Rxh4 d5 58...Rxa5 lets the White king participate in the defense 59.Rh6 d5 60.Rc6+ Kb2 61.Kf2 d4 62.Ke2 59.Rh6 d4 60.Rxa6 d3 61.Rd6?! It's simpler if White keeps the a-pawn 61.Rc6+ Kb3 62.a6 d2 (62...Rd5? 63.a7!) 63.Rd6 Kc2 61...Rxa5 another try is 61...d2 62.a6 Ra5 63.Kf2 Rxa6 64.Rxa6 d1Q but White sets up a fortress with 65.Ra3+ Kc2 (65...Kd2 66.Ra2+!) 66.Rf3 although Black may have some practical chances here as his king has crossed over the third rank 62.Kf2 d2

63.g4? Stopping a check on f5, but White should force the Black king in front of the d-pawn before advancing his own pawns 63.Rc6+ Kd3 64.Rd6+! Kc2 65.Rc6+ Kd1 66.g4 and the game should end in a draw 63...Ra1! 64.Rc6+ Kb4 65.Rd6 d1Q 66.Rxd1 Rxd1 67.h4 Kc5 68.Kf3 Rd4 69.h5 Kd6 70.h6 Ke6 71.h7 Rd8 0-1

7/1/20 - BCE-229, Hey, 1913

BCE-225 is another position presented as a study that was based on an actual game. Oskar Hey describes it in correspondence to Deutsche Schachzeitung as coming from a consultation game at the Neuberger Schachklub between Kahl and Bpahler against Fick and Hey. In this position, the bishop needs to be able to defend both the a-pawn and prevent the knight from delivering mate on f7. Hey treats it as a corresponding squares problem giving the squares the bishop must occupy for each positioning of the knight. The additional subtlty, that was missed by both Hey and Fine is that White has a waiting move, Kh6. However, unlike last week's rook vs. bishop duel, here the bishop generally has more than one square it can be on for the defense, which allows Black to hold. They key is that either the squares must be connected or Black has to be able to give check when the White king goes to h6. That latter point is why the BCE line fails. Hey gives 3 squares the bishop can be on when the White knight is on c5: d6, g3, and d8. From the first two squares, Black can meet Kh6 with Bf4+, but from d8 the only check is on g5, which drops the bishop. Since Black cannot reach the other two defensive squares from d8, he is in zugzwang.

The only other position Hey got wrong was with the knight on d2, where he says the Black bishop should be on e3 or e7, both of these get mated fairly quickly 1.Ne4 is #3 vs. Be7 and 1.Nc4 is #6 vs. Be3. From d2, the forward knight moves are to b3, c4, e4, and f3. The common defensive square against Nb3 or Nc4 is Bc7 and the common defensive square against Ne4 or Nf3 is Bf4. That indicates against Nd2, the bishop can be on any square along the b8-h2 diagonal except c7 or f4.

6/26/20 - TCEC Season 17, Games 13-14, Modern Benoni-Classical Main Line

My plan of looking at openings from the TCEC Superfinal has hit a bit of a hiccup in that I am not even through 1/6th of the openings played and already the Season 18 Superfinal has begun (again with Lc0 and Stockfish squaring off). Nevertheless, I think I am going to persist with the Season 17 openings and try to finish that off.

While the Taimanov and Modern Main Line get all the attention these days, the Classical Main Line is still of quite a bit of importance if for no other reason that many Black players only play the Benoni via move orders that avoid those two dangerous tries. The Classical Main Line was featured in Games 13 and 14. Although Lc0 extended its lead in game 14, I found Stockfish's play in the opening a bit strange. Lc0's defense in game 13 probably won't inspire many backers, but is of more importance theoretically.

1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.Nd2 This move orderavoids Black's options with ...Bg4. 7...Bg7 8.e4 0-0 9.Be2

The starting position for this set of games. 9...Na6 Stockfish chose 9...Nbd7 which can lead to similar positions if Black carries out the maneuver ...Ne8-c7, which Stockfish attempted. However, it never completed that maneuver nor did it get in ...Re8, which is almost always a part of Black's plan. 10.0-0 Nc7 11.a4 Re8 12.f3 b6 Petrov choses 12...Nd7 as his main line in his GM Repertoire book calling it a modern line. Indeed, it has been played by Gashimov, Topalov, and Ivanchuk in this century. Those names are usually pretty good endorsements, but the move dates to the 1950s when it was played by Tal. There is also a Fischer game from 1968 with this move. 13.Nc4 Ba6 14.Bg5 h6 Watson said he didn't find a way for Black to equalize after this move and Petrov gives it a ?! mark. Both authors prefer 14...Qd7 15.Be3 Bxc4 16.Bxc4 a6 17.Qd2 Kh7 18.Rab1 Rb8 19.b4 b5 20.axb5 sometimes White does not insert this exchange and continues 20.Be2 20...axb5 21.Be2 Nd7

Lc0's novelty. Previously 21...c4 was played. I agree with Petrov's description of this type of position (he didn't include the exchange on b5) as passive and generally unappealing. Lc0's move is much more dynamic and more in the spirit of the Benoni. Black sacrifices a pawn, but takes over the dark squares. This probably isn't enough to interest Black players in the line, but is a good example of resources the engines find he positions where humans might slowly get ground down. Stockfish took the pawn 22.bxc5 Nxc5 23.Nxb5 Nxb5 24.Bxb5 Re7 but then didn't demonstrate any convincing plan against Black's dark-square grip, trading all the way down to an ending with the light-square bishop against the knight, which offered no chances despite the extra pawn.

6/24/20 - BCE-485, Kling, Horwitz, Campbell, Healey, and Zytogorski

BCE-485 is an interesting duel between rook and bishop. BCE and several other sources I found cite the position as coming from The Chess Player's Chronicle, 1856. However, the position shown there is

with the caption Black has the move; White cannot win. This Chess study is founded on a position occuring in a game of Mr. Zytogorski. The full game seems to be lost to history.

The earliest publication of the BCE position that I found was in 1890 in Berger, which is likely where Fine got the position. Berger also references the position as coming from The Chess Player's Chronicle, even citing the page number that the above diagram occurs on. In the text, he describes that the game ended in a draw, but that later joint analysis by the five players in the headline discovered a way for White to win. For completeness, here is the main line in Berger, which starts from the BCE position.

1.Ra7 1.f6+? is the subject of the BCE correction. This was apparently the game continuation, when 1...Kg6! 2.Ra3 leads to the first position above. 1...Bg8 2.Ra8 Bd5 3.Ra5 Bg8 4.Ra7 Bd5 5.Kd6+ Bf7 6.Ke5 Kg8 Fine chose 6...Kh6 as his main line 7.Kf6 Bd5 8.Ra3 Bb3 9.Ra8+ Kh7 10.Ke7 Bd5 11.Ra3 Bb3 12.Kf8 Kh6 13.f6! Kg6 14.f7 Bc4 15.Ra7! Kf6 16.Ke8! a1Q 17.f8Q+ 1-0 Despite working well in advance of tablebases, with the exception of Black's last desperate promotion (White mates in 17 after 16...Bxf7+ where 16...a1Q leads to mate in 9), the 19th century analysts managed to find both the fastest winning line for White and the move of longest resistance for Black.

Benko deleted the example in the revised edition, but kept Fine's text about the win being difficult against an advanced pawn.

6/20/20 - Bereolos-de Firmian, 2005 Kings Island Open

I've posted notes to my game against Nick de Firmian in the opening round of the 2005 Kings Island Open. I had given very light notes to it at the time, but have expanded on them now. It was a fairly one sided game, but the recapture decision on move 20 is instructive. My scoresheet indicates I only spent one minute on this move, so I was instinctiviely trying to improve my knight and not concerning myself with his. The difference between White's unstable Nd4 vs. Black's rock Ne5 gives Black a large advantage. In fairness, the game was played at a faster time control (G/75), but the fact that I hardly paused here makes me wonder if I would have played any differently with more time.

6/17/20 - BCE-600a, von Guretzy-Cornitz, 1864

Analysis of the ending queen vs. rook plus pawn dates all the way back to Cozio and Philidor in the 18th century. Kling and Horowitz added to the theory with some studies in their books in the middle of the 19th century. The next leap forward was by Bernhard von Guretzky-Cornitz in articles in Neue Berliner Schachzeitung in 1864. Fine used four of Guretzky-Cornitz's positions in BCE. One of these was the subject of a previous correction. Unlike that instance, Guretzky-Cornitz had the the assessment correct for this one, but slipped up in the analysis. Fine only included the main line, but Guretzky-Cornitz did consider the saving 5...Rc2

However, after 6.Qb5+ he only considered 6...Kc1? Black has to stay on the short side of the pawn with 6...Ka2 or 6...Ka1 (but not 6...Ka3? 7.Qb1! Rc3 and now White triangulates 8.Kd6 Rc4 9.Kc6 Rc3 10.Kd5 returning the move to Black and putting him in zugzwang. 10...Ka4 11.Qb2 forces the rook away from the pawns defense and 10...Rb3 11.Qc2 is no better.

Benko decided to remove this example for the revised edition, leaving only Fine's introductory text But if the White King can manage to attack the Pawn (as a result of a favorable initial position due to prior exchanges) the game is won. I thought this was an odd comment from Fine since the variation he presents begins with 1.Ke4 removing the attack on the pawn.

6/10/20 - BCE-388, Alekhine-Euwe, Berne 1932

Alekhine and Euwe played a number of rook endings of interest that appear in BCE. We've seen some from their World Championship matches previously, today's position is from the tournament in Berne 1932. This event was a combination international tournament and Swiss championship. The foreign players dominated taking the first six spots led by the World Champion, Alekhine, with a dominant 12.5/15 performance a full point clear of Euwe and Flohr. Euwe managed to hold their individual encounter despite being a pawn down in a rook ending after 36...Rxg5+

37.Kf3 The starting position of BCE-388 37...Ra5 37...Rf5+ is the subject of the BCE correction 38.a3 Fine shows that 38.d5 is also too slow. Black is able to grab enough pawns and get his own pawns rolling in sufficient time to hold the draw. 38...Rb5 39.Rd7 Kg7 40.Rxa7 Rxb2 41.Re7 Kf6 42.Re2 Rb3+ 43.Re3 Rb2 44.h4 Another try is 44.Re8 Fine's long variation appears correct leading to a draw as the rook on e8 is not very well placed. 44...Rd2 45.Ke4 Rxf2 46.Rb3 Re2+ 47.Kd5 Re6 48.Rc3 Ke7 49.Rc7+ Ke8 50.a4 g5 51.hxg5 Rg6! 52.Rb7 Rxg5+ 53.Kc6 Rg6+ 54.Kc7 f5! 55.d5 Rg7+ 56.Kxb6 Rxb7+ 57.Kxb7! Kd7! 58.a5 f4! 59.a6 f3! 60.a7 f2! 61.a8Q f1Q! 62.Qc8+ Ke7! King in front of the pawn is a general rule of thumb for the defender in queen + pawn versus queen, but here the king would be driven out of the defense after 62...Kd6? 63.Qe6+ Kc5 64.Qc6+ Kb4 65.d6 and White should win 63.Qe6+ Kd8! Here king in front is necessary, otherwise Black gets squeezed away after. 63...Kf8? 64.Kc7 Qc4+ 65.Qc6 and the pawn advances 64.Qd6+ Ke8 65.Qc6+ Kd8! 66.Qd6+ Ke8 67.Kc7 Qf7+! 68.Kb8 Qd7 69.Qe5+ Kf8 70.d6 Kf7 1/2-1/2

6/7/20 - TCEC Season 17, Games 11-12: French Winawer

I likely would have skipped over games 11-12 of the TCEC match since it featured a sideline of the Winawer variation that is not really on the cutting edge of theory 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 b6

However, since Lc0 won game 12 in a 180 move marathon to even the score, it bears some attention. Stockfish again seemed to display some weaknesses in a closed position. After 19.Rh3

As in game 9, Stockfish chose to seal off the queenside with 19...a4 20.Nd3 c4 21.Nf4 b5 22.a3 Again, I'll speculate that Stockfish might be overweighing the fact that White has a "bad" bishop. Here, Black's bishop isn't much better. White eventually managed to trade the bishops after 42.N2xh4

White is undoubtedly better, but the question is how to make progress since Black has the f-file completely covered. Lc0 first widened the beachead on the kingside by bringing its king up and playing g5. 55.Kxg5

From here, Lc0 didn't demonstrate any winning idea, shuffling its pieces back and forth until 87.Rf2

Despite playing 32 moves, if we compare this to the last diagram, the White pieces could have achieved this configuration in as few as 9 moves. It seems like Black might be able to reach the drawing haven of the 50 move rule. However, Stockfish seemed to blow a fuse here with 87...b4?I don't have any good explanation for this move. Why shed a pawn for nothing when your opponent is just shuffling back and forth? I ran a version of Stockfish out for a long time and was surprised to see this move slowly bubbling its way to the top . I think the explanation is that Stockfish is evaluating that it is lost here, but like Lc0 doesn't have a convincing plan for White. So all of its choices are scoring about the same including b4 since after 88.cxb4 it is still hard to figure out how White wins. I don't know if it was absolutely necessary, but Stockfish allowed a trade of rooks 97...Qxe8

This began another series of shuffling culminating in 123.Ka2

Here, Stockfish again made Lc0's job easier by allowing a queen exchange with 123...Kd8?! 124.Qg5+ Qe7 125.Qxe7+ Kxe7 and after another 55 moves, Lc0 finally brought home the point. With the queens off, the White king can be much more mobile and he eventually penetrated via b4. Of course none of that would have been possible if Black hadn't needless given up his b-pawn. A very strange game!

6/5/20 - Rudolph-Bereolos, 1979 US Open

Another pawn ending from my early days of playing. I played the pawn ending correctly this time, but there were a few hiccups in the transition. This was from the US Open in Chicago against Alexey Rudolph, who is known these days as WIM Alexey Root. After 31.dxe4

Black has a rather useless extra doubled pawn. White's domination of the f-file gives full compensation. 31...Rc7 31...Qd4+!? is a computer move that should also be equal after 32.Kg2 Qc4 but it seems a bit reckless to leave f6 unguarded 32.Rxc7 Qxc7 33.Qf6 Qg7 34.Qxg5 The pawn ending after 34.Qxg7+ Kxg7 is drawn as there is no way for either side to penetrate. However, there is nothing wrong with regaining the pawn. It might even seem that White is a tad better because her queen is more active, but the White king is too exposed and there are numerous routes for Black to activate his queen: down the f-file as happens in the game, down the d-file, or via either the h6-c1 or a7-g1 diagonals. 34...c4 35.Qd8+ Kh7 36.Qd5 a6 37.Kg2 Qf6 38.Qd1 Black also makes some progress after 38.Qd2 Qh4 39.Qe2 Qg5 38...Qf4 39.Qf3? 39.Kh3! Qxe4 40.Qd7+ Kh6 41.Qd8 and it seems that the Black king cannot escape perpetual check

39...Qd2+? 39...Qxf3+ 40.Kxf3 Kh6! 41.Kg3 Kg5! wins as Black has more waiting moves on the queenside. Ironically, capturing the pawn on g5 on move 34 is what gave Black this opportunity as otherwise the Black king would not have a route into the White position. 40.Qf2? Qd6? again 40...Qxf2+ 41.Kxf2 Kh6! 41.g5 Resealing the kingside, now there shouldn't be too much left 41...Qe6 42.Kg3 Kg7 43.Qd2 Kf7 44.Qd8 Qe7 45.Qd2 Qc5 46.Qd7+ Qe7 47.Qd5+ Qe6 48.Kf3? 48.Qxe6+ is a simple draw

48...Qxd5! 49.exd5 Ke7! 50.Ke4 Black has so many spare tempi on the queenside it doesn't matter if White waits a move before going to e4 50.Ke3 Kd6 51.Ke4 b4 52.c3 (52.a3 c3-+) 52...a5 53.cxb4 axb4 54.a4 b3-+ 50...Kd6! 51.b3 The other pawn moves aren't any better 51.c3 a5 52.b3 cxb3 53.axb3 a4-+; 51.a3 a5 52.b4 (52.b3 b4 53.axb4 cxb3!) 52...axb4 53.axb4 c3 54.Kd3 Kxd5 55.Kxc3 Ke4 56.Kd2 Kd4-+ 51...cxb3! 52.axb3 b4 53.c4 bxc3! 54.Kd3 Kxd5 55.Kxc3 e4 56.Kd2 Kd4 57.Ke2 e3 58.Ke1 Kc3 59.Ke2 Kxb3 60.Kxe3 a5 61.Ke4 a4 62.Ke5 a3 63.Kf6 a2 64.Kxg6 a1Q 65.Kh7 Qa7+ 66.Kg8 Qg1 0-1

6/3/20 - BCE-321, Karstedt 1896

BCE-321 is a theoretical position that Fine references as being from Rabinovich. However, Rabinovich cites the analysis as coming from Berger and Karstedt, so that is likely where the error originated. The Encyclopedia of Chess Endings cites the position as a study by Karstedt from Deutsches Wochenschach in 1896, so that is what I am taking as the original source. Unfortunately, I was unable to find a scan of that year's issues to check for sure. ECE also indicates that the position is drawn with the White rook on b3 or b1. However, a separate ECE entry with the rook on b4, also attributed to Karstedt, is shown to be winning for White

1...Rc6 2.Kb5 Kc7 3.a7! Rb6+ 4.Ka5! Rxb4 5.a8Q! and unlike the positions with the rook on b3, b2, or b1, here Black does not have a check on the a-file to pick up the new queen.

5/29/20 - TCEC Season 17, Games 9-10: Leningrad Dutch

Games 9 and 10 in the TCEC Spuperfinal were both drawn. The starting position was a sideline of the Leningrad Dutch. 1.d4 f5 2.g3 Nf6 3.Bg2 g6 4.Nf3 Bg7 5.0-0 0-0 6.c4 d6 7.Nc3 e6

This is quite uncommon compared to 7...Qe8, 7...c6, and 7...Nc6 Sandipan and Reindermann seem to be the main practitioneers. However, the move does have historical pedigree. Botvinnik used it (with neither side yet castled) trailing by two points late in his first match with Tal. Although Tal won the game, he did not consider it to be a bad continuation in his book on the match. 8.Re1 I don't know if this move was still part of the proscribed opening moves or if both engines selected it. Tal played 8.Qc2 with the idea of preventing Ne4. 8...Ne4 When Stockfish was Black, it opted for the immediate 8...d59.Qc2 d5 Sandipan and Reindermann both played 9...Nxc3 in this position. I think the opening debate can be closed here. If transposing to a Stonewall is the best Black has, then the idea doesn't seem very promising. Black would never play g6 in a Stonewall and he has wasted a move by playing d5 in two moves.

There were a few other positions of note later in the game that I think show the engines still have some weaknesses in closed positions. 10.Bf4 c6 11.e3 Nd7 12.Rac1 Qe7 13.b3 Re8 14.Be5 Nxe5 15.Nxe5 Bd7 16.Ne2 Rac8 17.c5 Ng5 18.f4 Nf7 19.Nd3 g5 20.h3 Kh8 21.Qc3 Rg8 22.Bf3 Bf6 23.Kf2 Ra8 24.b4 Rg7 25.a4 Rag8 26.Rh1 Be8

Here, Stockfish uncorked the absurd 27.a5?!Certainly no human would remove the possibility of a queenside breakthrough with b5. Perhaps its evaluation function gave a plus for forcing one more Black pawn on to the light squares. 27...a6 28.Rcg1 Nd8 29.Qb2 Qf8 30.Kf1 Qe7 31.Kf2 Qf8 32.Rh2 Qe7 33.Qa1 h5

Likewise, here it looks like Stockfish again saw the opportunity to fix another Black pawn on light squares with 34.fxg5 Rxg5 35.h4Black's position is somewhat of a Stonewall player's nightmare with the light squared bishop trapped behind the pawns. But White doesn't have any pawn breaks, and the pawn at h5 is easily covered (bad bishops guard good pawns). 35...R5g6 36.Nef4 Rh6 37.Rhg2 Kg7 38.Rf1 Kf8 39.Qe1 Bf7 40.Qd1 Rgh8 41.Kg1 Ke8 42.Ne5 Qc7 43.Nfd3 Kf8 44.Qe2 Kg8 45.Qf2 Be8 46.Be2 Nf7 47.Qf4 Nxe5 48.Nxe5 Qg7 49.Kf2 Bd8 50.Rfg1 Bc7 51.Ke1 R8h7 52.Kd2 Kh8 53.Rf2 Bxe5 54.Qxe5 Qxe5 55.dxe5 Rg7 56.Bf3 Bd7 57.Ke2 Rgg6 58.Rff1 Rh7 59.Kf2 Rg8 60.Rd1 Rg6 61.Rh1 Kg8 62.Kg2 Rh8 63.Be2 Kg7 64.Kf2 Kh6 65.Bf3 Rhg8 66.Rhg1 Be8 67.Rc1 Rh8 68.Rcd1 Bd7 69.Rd4 Ra8 70.Rd2 Rag8 71.Rd3 Rd8 72.Rdd1 Rdg8 73.Be2 R6g7 74.Rd4 Rg6 75.Bd3 Ra8 76.Bf1 Rgg8 77.Rh1 Kg7 78.Be2 Kh6 79.Rdd1 Rac8 80.Ra1 Rcf8 81.Rhd1 Rg6 82.Kg2 Rfg8 83.Kf2 R6g7 84.Rg1 Rg6 85.Ra3 R6g7 86.Rb3 Kg6 87.Kg2 Re7 88.Rd3 Kh6 89.Kf2 Rg6 90.Ke1 Re8 91.Rd4 Rh8 92.Bf3 Rb8 93.Kf2 Rbg8 94.Be2 R6g7 95.Rg2 Rg6 96.Bd1 Ra8 97.Kg1 Rgg8 98.Kh2 Rac8 99.Rg1 Rb8 100.Kg2 Rg7 101.Kf2 Rbg8 102.Be2 Be8 103.Bf3 Bd7 104.Rdd1 Rg6

Human players would have arranged to repeat the position 3 times long before getting here. I didn't really try to check to see if one side or the other was avoiding the repetition. If Stockfish's contempt setting was high, I think it would avoid repetition as long as it didn't significant change its evaluation. So if it saw two moves both at 0.00 it would chose one that did not repeat for a third time. On the other side, from what I understand of the AI engines, they evauate the position in terms of win probability. So Lc0 might be seeing the position as 99.99% drawn with 0.01% chance of winning. The option that would repeat the position for a third time would make it 100% drawn, so it chooses something else to keep the miniscule winning chance alive. In this position, Stockfish showed that it may have a sense of humor as the move it selected to enforce the 50 move rule was 105.Be4 1/2-1/2

5/27/20 - BCE-349a

Just a short BCE post this week. Fine seems to have made up this position in order to illustrate a stalemate defense, but the defending side has an alternative. Benko decided to completely remove this flawed example from the revised edition. He could have considered using the tragicomedy the Dvoretsky showed in his Endgame Manual from the game between Joerg Hickl and Stephen Solomon in the West Germany-Australia match at the 1988 Olympiad. After 63.Kg4

Black indirectly defended his g-pawn with 63...Rb3? The right idea, but he needed to move the rook further with 63...Rb1 or 63...Rb2. Now, the White king is short of squares 64.Rg8+! Kf6 65.Rf8+? 65.Rg6+! is the stalemate trick. The game was adjourned here. Black sealed 65...Kg6? Black is winning after 65...Kg7, but decided to repeat moves and work the win out at leisure with his teammates. He was quite fortunate that his opponent resigned without resumption! 0-1?

5/24/20 - Bereolos-Moradiabadi, Land of the Sky XXX

GM Elshan Moradiabadi has become a fixture at the annual Land of the Sky tournament winning or tying for first in all but one of the last seven editions. The year he didn't come out on top was 2017, when he was nicked for 3 draws. I almost made it 4, but lost a long ending where the assesment changed from draw to win several times.

5/20/20 - BCE-224d

Endings with a bishop and two connected passed pawns are generally won for the attacking side unless the defender can set up a blockade. Without a blockade, about the only chance is if the attacker has a rook's pawn that queens on the opposite color of the bishop. However, with care, as shown in the correction link, the attacker can avoid allowing the knight to sacrifice itself for the knight's pawn.

In practice, even strong players can get it wrong. Former US Champion Lubomir Kavalek managed to hold the ending twice. First, at Las Palmas 1974 against Guillermo Garcia, after 51...Nxc5

52.h4 Nd3 53.Bb5 Nf4 54.Bc4 Nh5+ 55.Kf3! 55.gxh5? Kf6! and Black will get to the corner. The presence of the extra h-pawn makes no difference. 55...Nf4 56.g5 Nh5 57.Bf7 Nf6 58.g6? 58.Bg6 takes away f5 from the Black king and White is ready to advance the h-pawn. 58...Kf5! 59.g7 White might have thought that this position was zugzwang. 59...Ng8! 1/2-1/2 The bishop blocks the pawn's advance after 60.Bxg8 Kg6

Even a World Championship Candidate was not immune. In Portisch-Kavalek, Montreal 1979 after 57.Kxe4

57...Nf6+ 58.Kd4 Nd7 59.Bd6 Kf5 60.Bc7 Ke6 61.Bxa5 Kd6 62.b4? 62.Bd8 Nb8 63.Kc4 Nc6 64.Bb6+- is similar to the winning variation in the Garcia game, the a-pawn is ready to roll 62...Nb8! The White pieces are on unfortunate squares, Black threaten the fork Nc6+ followed by the capture of the b-pawn. 63.Kc4 63.b5 doesn't stop it 63...Nc6+! 64.bxc6 Kxc6!= 63...Nc6! 64.Kb5 Nxb4! 65.Kb6 The king reaches the corner after 65.Bxb4+ Kc7 66.Bd6+ Kb7!= 65...Nd3 1/2-1/2 In order to stop the Black king from getting to the corner and not allow the knight to capture the last pawn, the White king gets stuck in front of the pawn. 66.Bc3 Kd7 67.a5 (67.Kb7 Nc5+) 67...Kc8 68.Ka7 Nc5 69.Bd4 Na6 70.Be5 Nc7=

5/13/20 - BCE-62a, Breyer-Nyholm Baden, 1914

This week's BCE position is a pawn ending from the gambit tournament held in Baden 1914. All games were required to begin with a gambit (not including the Queens Gambit). Under such conditions it isn't surprising that the famed attacking player Rudolph Spielmann emerged on top with 12.5/18.

Guyla Breyer is well known to chess players for his contributions to the hypermodern school. His opponent in this game, Gustaf Nyholm, was one of the first great Swedish players, winning matches for the national championship six times between 1917 and 1921. The subject game started as an Evans Gambit, although Nyholm declined it. After an exchange of queens with 36.fxe4

Here, Nyholm made a very risky pawn sacrifice 36...Ke7 This move was severely criticized in Gregor Marco's Viennese chess journal Wiener Schachzeitung where it was given no less than 3 question marks. I think that is a bit extreme given that Black can still hold the draw after the text. Nevertheless, I agree that it is a high risk move that doesn't have much chance of reward, so the clearer path to the draw would be the line 36...c5 37.Nd3 c4 38.Nc5 Ke7 39.e5 f6 40.exf6+ Kxf6 41.Kf2 Bd5 42.g3 Ke5 37.Nxc6+ Kd6 38.Nd4 Ke5 39.Nxe6 fxe6 40.Kf2 Kxe4 41.Ke2 Kd4 42.Kd2 The starting position of BCE-62a. Black has regained his sacrificed pawn and has the more active king, but the outside passed c-pawn gives White the winning chances. 42...g5 42...h5 is the subject of the BCE correction. Marco indicates the text as the losing move, but that comes one move later. 43.c3+ Kc4? The queen ending should be drawn after 43...Ke4! 44.g4 Kf3 45.c4! e5 46.c5! Kf2! 47.c6 e4! 48.c7 e3+! 49.Kd3 e2! 50.c8Q e1Q! 44.g4 Kd5 45.Kd3 Kc5 46.Ke4 1-0

5/9/20 - TCEC Season 17, Games 7-8: Frankenstein-Dracula Variation

Stockfish took the lead with a win in Game 7 of the TCEC Superfinal. Games 7 and 8 featured a complex exchange sacrifice in the Vienna game. 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Qh5 Nd6 5.Bb3 White can avoid the coming madness with 5.Qxe5+ 5...Nc6 Likewise, Black can bail out with 5...Be7 and 6...0-0 6.Nb5 g6 7.Qf3 f5 8.Qd5

The starting position. Black has to cover f7 with his queen, which involves the loss of Ra8. Black's compensation is better development and more space 8...Qf6 Theory and practice have both favored 8...Qe7 which was Stockfish's choice as Black in Game 8. However, the database actually shows Black with a slight plus score after Qf6 and it is also the choice of all 3 engines on ChessBase's Let's Check including a version of Stockfish. On today's chess24 broadcast of the Online Nation's Cup, at around 2:20:00 Jan Gutafsson briefly talks about the variation in relation to the Firouzja-Aronian game calling it fun, but better for White. I did notice when he played the moves on the board, he played the queen to f6.

In game 8 after 8...Qf6 9.Nxc7+ Kd8 10.Nxa8 b6 Lc0 also made an unconventional retreat with its queen 11.Qd3 (The more frequently seen moves are 11.Nxb6 and 11.d3) It seems as maybe the engines have determined that White will end up losing time with his queen in any case, so they do it on their own terms. 9.Nxc7+ Kd8 10.Nxa8 b6 11.Qf3 Lane considers the line with Qf6 to be dubious and gives 11.Nxb6 axb6 12.d4 Nxd4 13.Nf3 Bb7 14.Qxd4 exd4 (White can't play into this line with the queen on e7 because this move would be check) 15.Bg5 claiming a more pleasant ending. In the few games in practice, Black has done fine here with 3.5/5, so it isn't that clear cut. Black has two bishops for compensation and there are not open lines for the rooks. The only high level game to reach this position continued in similar fashion, although White didn't spend the tempo to take on b6 11.d4 Nxd4 12.Nf3 Bb7 13.Qxd4 exd4 14.Bg5 Qxg5 15.Nxg5 Bxg2 16.Rg1 Bxa8 17.0-0-0 Bg7 was prematurely agreed drawn in Sulskis-Motylev 2000 Linares Open. 11...Nd4 I don't really grasp the point of this move rather than continuing to develop with 11...Bb7 12.Qh3 Based on how the game eventually continues, one may wonder about immediately sending the queen back home with 12.Qd1 The problem is that the long diagonal is still a bit soft, for example 12...Bb7 13.f3 Qh4+ 14.g3 Qh5 15.Kf2 Ne4+ 16.Kg2 Ng5 and White's position is falling apart. The text defends g2. 12...f4 another strange one. I would again prefer 12...Bb7. Other engines like 12...g5 to try to further harrass the White queen. 13.c3 Nc6 14.d3 h5 15.Qf3 g5 16.Qd1 Now, White has completely undeveloped, but Black has wasted a lot of time with his knight maneuver and still has to pick up Na8. Stockfish ended up converting the extra exchange in a long ending.

5/8/20 - Timmel-Bereolos, 2020 Land of the Sky

I've only been able to play one tournament so far this year, the annual Land of the Sky tournament in Asheville. In the opening round I played a rook ending against John Timmel that shared some similarity to Tsay-Ippolito. After 27.Ne3

27...Nxb2 When envisioning this position from afar, I had intended 27...b5 trying to keep up the pressure, but when we got here I saw that he could answer with 28.c4 and I didn't think Black had much. So instead, I won the pawn even though it should lead to a draw. At least my knowledge that Ippolito had managed to win his game gave me some confidence that there could be problems for White. 28.Rf2+!? Before capturing the knight, White gives Black a choice on which way to go with his king. 28...Kg8 This decision was partially driven by the fact that I knew from studying Tsay-Ippolito that one of the key ideas for White is to attack the kingside pawns before so Black passer is too far advanced. Instead, 28...Ke8 29.Rxb2 Rxe3 30.Rxb7 Rxc3 31.Rg7 g4 32.Rg5 Rc1+ (32..c4 33.Rxh5 Rc2 34.h4 gxh3 35.Rxh3 c3 36.g4 Kf7 (36...Rc1+ 37.Kg2 c2 38.Rc3 and the Black king has to defend against the g-pawn.) 37.Kf1 Kf6 38.Ke1 Kg5 39.Kd1 and White wins the c-pawn.) 33.Kf2 Rc2+ 34.Ke3 should be fine for White, but as in the game, White should not play 34.Kg1? when 34...c4 would be decisive. 29.Rxb2 Rxe3 30.Rxb7 Rxc3 31.a4 I thought the simplest was 31.Rb6 threating both Rxa6 and Rg6+ which shows that Black's Kg8 didn't really do what he intended. 31...Rc1+ 32.Kf2 Rc2+ 33.Ke3= g4 34.Rxa6 Rxh2 35.Rc6 Rg2 36.Kf4 31...Rc1+!? seeing if I could improve the rook's position before pushing the pawn 32.Kg2 Rc2+ 33.Kg1?! and it paid off. The h-pawn isn't really worth leaving the king trapped on the back rank. 33.Kf3 Rxh2 34.Ra7 picks up the a-pawn and White should draw without trouble. 33...c4 34.Ra7?! This move doesn't really do much. White should immediately get behind the pawn with 34.Rc7 The best try for Black seems to be 34...c3 35.h4 g4 as there are a couple of pitfalls for White 36.Kf1 It should be noted that there is no passive defense with the extra a-pawns on the board. (36.Kh1? Rc1+ 37.Kg2 c2-+) The Black king then comes over to d8 then up to d3 threatening to move the rook. To prevent this White would check on the d-file with his rook, which let's the Black king cross the c-file and pick up the a-pawn. 36...Kf8 (36...Rc1+ 37.Ke2 c2 38.Kd2 Rg1 39.Kxc2 Rxg3 40.Rc5 Ra3 41.Rxh5 Rxa4 42.Rg5+ and Black doesn't have a good way to make progress) 37.Ke1 Ke8 38.Rc5 (The immediate 38.Kd1? gives Black a critical tempo 38...Rd2+ 39.Kc1 Rd3 40.Rc5 Rxg3 41.Rxh5 Rg1+ 42.Kc2 g3 43.Rg5 g2 ) 38...Kd7 39.Kd1 Rd2+ 40.Kc1 Rd3 41.Kc2 Rxg3 42.Rxh5 Rg1 now this isn't check and White has enough time to construct a defense 43.Kxc3 g3 44.Rg5 g2 45.Kb2 34...c3

35.Rxa6? He's left it very late, but the draw was still to be had with a long series of only moves 35.Rc7! Rc1+ 36.Kf2! (36.Kg2? c2-+) 36...c2 37.Ke3! (37.Ke2? Rh1-+) 37...Re1+ 38.Kd2! Rh1 39.Kxc2! Rxh2+ 40.Kd3! Rh3 41.Ke4! Rxg3 42.Kf5! h4 43.Ra7! h3 44.Rxa6! h2 45.Rh6! Rg2 46.a5! g4 47.a6 g3 48.Kg4 Rg1 49.a7! 35...Rd2 0-1Black promotes his pawn with ...c2 and Rd1+

5/6/20 - BCE-453, Capablanca-Lasker, St. Petersburg 1914

This week's BCE correction is from the famous tournament at St. Petersburg 1914. Legend has it that Tsar Nicholas II first bestowed the title Grandmaster on the 5 finalists: Lasker, Capablanca, Alekhine, Tarrasch, and Marshall. The tournament was a great triumph for World Champion Lasker who managed to overcome a 1.5 point deficit to Capablana by scoring 7/8 in the double round robin finals to take home the 1200 ruble prize. From what I could find about conversion rates and inflation, that might be around $15,500 today.

Today's game is one of Lasker's two draws in the finals. Capablanca pushed for a long time in the ending, but could not overcome Lasker's defense. After 28...Rb2

Capablanca won two pieces for a rook 29.Rxb5 Rxb3 30.Bd2 Bc5+ 31.Rxc5 Nxc5 32.Nxc5 Rb2 33.Be3 The starting position of BCE-453 33...Re2 34.Bf2 f6 35.Kf1 Ra2 36.g4 Kf7 37.Ne4 h6 38.Kg2 Ra3 39.f4 Rb3 40.Ng3 Ra3 41.Nf1 Rd3 42.Ne3 Rc3 43.Kf3 Ra3 44.f5 Ra2 45.Nd5 Rb2 46.Nf4 Ra2 47.h4 Ra5 48.Bd4 Fine now uses the sequence 48.Ne6 Rb5 49.Ke4 Rb2 50.Bd4 Rb4 51.Kd5 Rb1 to skip ahead to the position after Black's 72nd move. 48...Ra3+ 49.Be3 Ra5 50.Nh5 Ra4 51.Ng3 Kg8 52.Ne4 Kf7 53.Bd2 Ra1 54.Bc3 Rf1+ 55.Nf2 Rc1 56.Bd4 Re1 57.Ne4 Rf1+ 58.Bf2 Ra1 59.Kf4 Ra4 60.Bc5 Rc4 61.Kf3 Rc1 62.Bf2 Ra1 63.Kf4 Ra4 64.Kf3 Ra3+ 65.Be3 Ra5 66.Nc5 Ra1 67.Ne6 Ra3 68.Ke4 Ra4+ 69.Bd4 Rb4 70.Kd3 Rb3+ 71.Ke4 Rb4 72.Kd5 Rb1 73.g5 hxg5 74.hxg5 fxg5

75.Nxg5+ 75.Nxg7 is the subject of the BCE correction. Karpov and Zaitsev analyzed the ending for the Encyclopedia of Chess Endings in Position 1007 and do mention the variation 75...g4? 76.Nh5! although they only give it !? 76...Re1 77.Ng3 with clear advantage to White. They attribute this line to Minev. Today, thanks to the tablebases, we know White is winning. 75...Kg8 This position is also analyzed in the Encylopedia as Position 997. It doesn't give an annotator, so I don't know if this was still Karpov and Zaitsev, or one of the editors. There are a few variations of interest in that analysis, which I quote below. 76.Ne6 Rd1 76...Rb7? 77.Bxg7! 77.Ke4 77.Nxg7 Rxd4+! 77...Kf7 78.Ng5+ 78.Bxg7 Re1+! 79.Kd5 Rf1! 78...Kg8 79.Ke5 Re1+ 80.Kf4 Rf1+ 81.Kg4 Rd1 82.Nf3 Rf1 83.Be5 Kf7 84.Kf4 Kg8 85.Ke4 Rd1 86.Ng5 Re1+ 87.Kd5 Rd1+ 88.Ke6 Re1 89.Nh3 Rb1 89...Rh1 90.Nf4 Rg1? 91.Nh5! g6 92.f6 +- 90.Nf4 Rb6+ 91.Ke7 Rb5 92.Ng6 Rb6 93.Bd6 Ra6 94.Ke6 Rb6 95.Ne7+ Kh7 96.Nc8 Ra6 97.Ne7 Rb6 98.Nd5 Ra6 99.Nc3 Kg8 100.Ne4 Rb6 1/2-1/2

5/3/20 - Tsay-Ippolito, 2019 US Masters

A few days ago, I heard the sad news that the 2020 US Masters is the latest event to be cancelled because of the coronavirus. However, we still have games from last year's event to analyze. An example with the rook in front of the extra outside passed pawn where White managed to win occurred in the game between Vincent Tsay and Dean Ippolito. The rook ending began after 34...Rxa2

35.Rxe6 Rxa4 36.Rc6 Ra2 37.Rxc7 a5 38.Ra7 An important difference from the BCE example is that the defending king is confined on the back rank. Still, I don't think this should be enough to be decisive. 38...a4 As we will see, g4 is a key move in White's defense, so Black could try to prevent it with 38...h5!? If White sits and does nothing, he will lose as in the game, but it appears he can switch to a side defense a la Vancura and hold 39.h3 a4 40.Re7 a3 41.Re3 with the key point being that the Black king is cut off from the queenside so White can just shuffle with Kh1-g1. The only way for Black to make further progress is 41...Ra1+ 42.Kg2 a2, but then 43.Ra3 is an easy draw. 39.Kg1 g5 Black could restrict the White rook with 39...a3 then if the Whtie rook leaves the a-file Black makes a queen with Rb2, a2, and Rb1+ Still White seems to have a path to a draw with 40.g4 g5 (Allowing the white pawns to advance by bringing the king over immediately doesn't seem to help 40...Kf8 41.h4 Ke8 42.Kf1 Kd8 43.Ke1 Kc8 44.Kd1 Kb8 45.Ra4 Kb7 46.Kc1 Kb6 47.h5=) 41.Kf1 Kf8 (The Black rook can check at various points as the White king journey's to the queenside. However, this eliminates the idea of Rb2/a2/Rb1+ so Black needs to follow up with ...a2 after the check in order to keep the White rook tied to the a-file, otherwise White can take the h-pawn with an easy draw. Checking when the king is on f1 doesn't help as the king hides on h3 41...Ra1+ 42.Kg2 a2 43.h3 and White doesn't have any weaknesses for the Black king to attack.) 42.Ke1 Ke8 (Likewise here, 42...Ra1+ 43.Kf2 a2 44.Kg2 and 45.h3) 43.Kd1 by now it is obvious that the White king is getting to the queenside first, so Black doesn't have anything better than trading a for h, but the resulting 2 vs. 1 position doesn't cause White trouble because the Black king is cut off. 43...Ra1+ 44.Kc2! a2 45.Kb2 Rh1 46.Kxa2! Rxh2+ 47.Kb3 Rh4 48.Kc3 h6 49.Ra6 Kf7 50.Kd3 Kg7 51.Ra4 h5 52.Ra7+! Kf6 53.gxh5 Kf5 54.Ke3= 40.h3 Perhaps the first step in the wrong direction. 40.g4 followed by bringing the king across draws similar to the above. Maybe White wasn't sure about the 2 vs. 1 positions so he avoids ...Rxa2 40...a3 41.Kh1? I guess White thought he had a fortress and could defend passively. There was still time for 41.g4 41...h5! Now, Black is winning.

42.Ra5 It's too late for 42.g4 Black fixes the weakness on h3 with 42...h4! 43.Kg1 Kf8 44.Kf1 Ke8 45.Ke1 Ra1+ now this check puts White on the wrong foot as the Black king wlll be close enough to the queenside so Black can keep the ...a2 move in reserve since White isn't in time to capture the g-pawn with his rook 46.Kf2 Kd8 47.Kg2 Kc8 48.Ra5 Kb7 49.Rxg5 Ra2+! 50.Kf3 Rh2! 51.Ra5 Rxh3+ 52.Kg2 Rg3+ 53.Kh2 Kb6 54.Ra8 Kb5 55.g5 Kb4 and Black wins. White can also try running the king to the queenside without pushing a kingside pawn, but thanks to the two tempi White squandered Black can win with very accurate play 42.Kg1 g4 43.hxg4 hxg4 44.Kf1 Ra1+ 45.Kg2 Kf8 46.Ra4 Ra2+! 47.Kf1 Ke7 48.Ke1 Kd6 49.Kd1 Ra1+! 50.Kc2 a2! 51.Kb2 Rg1! 52.Kxa2 Rxg3 53.Ra5 Ke6 54.Kb2 Kf6 55.Kc2 Re3! 56.Kd2 Re7 57.Rb5 g3 58.Rb3 Rg7! 59.Rb1 Kg5! 60.Ke2 Rf7! 61.Rf1 Rf4! -+ 42...Kf7 43.Ra6 Ke7 44.Kg1 Kd7 45.Kh1 This passive defense is hopeless because of the weakness on g3. Black slowly brings the king in to win g3. 45...Kc7 46.Kg1 Kb7 47.Ra4 Kb6 48.Ra8 Kb5 49.Kh1 Kb4 50.Rb8+ Kc4 51.Ra8 Kd3 52.Kg1 Ke4 53.Ra5 g4 54.Ra8 Kf3 55.hxg4 Kxg3 56.Kf1 hxg4 57.Ra5 Ra1+ 58.Ke2 Kg2 59.Ra8 g3 60.Ra7 a2 0-1

5/2/20 - TCEC Season 17, Games 5-6: Kings Indian Mar del Plata

In games 5 and 6 of the TCEC Superfinal, Lc0 and Stockfish debated one of the big main lines of the Classical Kings Indian. 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5 7.0-0 Nc6 8.d5 Ne7 9.Ne1 Nd7 10.Nd3 f5 11.Bd2 Nf6 12.f3 f4

The starting position for this pair of games. Back in the early days of computer chess the engines didn't handle these types of closed positions very well. They would often realize the danger in Black's kingside attack far too late. Of course, they have much improved in that area. 13.c5 In the game Stockfish was White, it went for 13.a4 which has only been played at high level in correspondence chess, perhaps showing the influence engines have had there. That game did return to somewhat familar waters after 13...g5 14.b4 h5 15.a5 Now the standard regrouping is Rf7, Bf8, and Rg7. Lc0 instead went for 15...Kh8 16.c5 Rg8 I don't really understand why this should be an improvement as the bishop will still need to move to clear the g-file and from g7 the rook can also help in the defense of the queenside by protecting c7. 13...g5 14.Rc1 Ng6 15.Nb5 Older books by Nunn and Gallagher argued that White had nothing better than to insert 15.cxd6 at this point 15...Rf7 The point of White's previous move is that he can sacrifice a piece after 15...a6 16.cxd6 axb5 17.dxc7 which Gallagher called speculative back in 2004. In practice, White has scored heavily in the database (+12 =4 -1) 16.Ba5 b6 17.cxd6 cxd6 18.Be1 a6 19.Nc3 a5 20.a4 This move was introduced by Giri in his blindfold game against Grischuk at the 2011 Amber tournament. I don't fully understand the point, especially in conjunction with White's next move. Bf8 is generally part of Black's plans and a4 gives him the time to execute it. Compare this to the immediate 20.Nb5 and if we follow the course of the game 20...g4 21.fxg4 (Kotronias only looks at 21.Rc6) 21...Nxe4 22.Rc4 Nf6 23.Bf3 e4 24.Bxe4 Bxg4 25.Bf3 Bxf3 26.Qxf3 Ne5 27.Nxe5 dxe5 28.d6 Rc8 White has 29.Rc7 with some pressure. 20...Bf8 21.Nb5 Giri played 21.Nf2

21...g4 Technically, the novelty in this game, but the idea is known in similar positions. In a couple of games that had reached this point, Black prepared the advance with 21...h5 and was successful in both games 22.fxg4 Nxe4 23.Rc4 Nf6 24.Bf3 e4 25.Bxe4 Bxg4 26.Bf3 Bxf3 27.Qxf3 Ne5 28.Nxe5 dxe5 29.d6 Rc8 30.Rc6 now on 30.Rc7 Black can take on d6 30...Bxd6 with the tactical justification 31.Rxc8 Qxc8 32.Nxd6 Qc5+ 30...Rxc6 31.Qxc6 Nd7 Black has stabilized the queenside situation. Stockfish eventually reached an ending with 2 pieces against a rook that I thought might have some winning chances, but Lc0 held the draw.

4/29/20 - BCE-368

We saw in the Kasparov-Karpov ending that the defending side has drawing chances with 3 vs. 3 on one and a passed a-pawn even when the attacking rook was behind the pawn. When the rook is in front of the pawn, winning chances are even more difficult. BCE-368 is an example of this. Generally, with a rook in front of the a-pawn, White needs some weaknesses in the Black position in order to win. At first sight, it looks like f5 and h5 provide those weaknesses. However, it turns out that the f5 pawn is largely irrelevant and h5 can be defended. White does have a winning try that was not mentioned by either Fine or Benko. In the first round game of the 1996 Pardubice Open the following position arose in the game Pcola-Hybl after 50...Kg7

51.h4!? this aims to prevent the ...h4 resource that is seen in the correction link 51...gxh3+? 52.Kxh3 f4 Black may have thought he was leaving White with a and g pawns, which would be a draw, but White dashed that hope with 53.f3! fxg3 54.Kxg3! and White wins by pushing the f pawn as we saw in the Shamkovich-Liberzon game. 1-0

Black does better not to capture en passant. In the Albania-Rwanda match at the 2008 Olympiad, the diagram position above arose in the game Guxho-Ngendo after 39...Ra3

40.h4!? Ra2 41.Kf1 Kh7 42.Ke1 Kg7 43.Kd1 Kh7 44.Kc1 Kg7 45.Kb1 Ra5 46.Kb2 Kh7 47.Kb3 Kg7 48.Kb4 Ra1 49.Kc5 Kh7 50.Kd6 Kg7 51.Ke5

51...Ra5+? The simplest defense was 51...Ra4 preventing Kf4. Losing the f5 pawn is not of importance here as after 52.Kxf5 Ra5+! White can't make progress despite his two extra pawns. Black checks on a5 if the White king goes after the kingside and along the b-file if he goes to b6 or b7. White can get the opposition in the pawn ending, but even this is drawn. 53.Ke6 Ra6+ 54.Kd5 Ra2 55.Kd6 Ra6+ 56.Kc5 Ra2 57.Kb6 Rb2+ 58.Kc6 Rc2+ 59.Kd6 Ra2 60.Rc8 (on 60.Re8 Black checks the king away before taking the pawn 60...Ra6+!) 60...Rxa7 61.Rc7+ Rxc7 62.Kxc7 Kf6 63.Kd6 Kf5 64.Kd5 Kf6 65.Kd6 Kf5 and the attempt to outflank loses after 66.Ke7? Ke4!-+; White can also try 52.Ke6!?, but 52...Ra6+! is similar to the previous line 52.Kf4 Now Black is in zugzwang. He needs to keep the rook on a5 to meet Kg5 with f4+, so he makes the only move with his king that doesn't lose immediately. 52...Kh7 He could also have tried the trap 52...Ra4+!? when White wins with 53.Kg5! but not (53.Kxf5? Ra5+! with a draw as we saw above) 53.Rf8 pointing out the problem with Black's king move, now White harvests the Black kingside 53...Rxa7 54.Kg5! Kg7 55.Rxf5 Ra6 56.Kxh5 Ra4 57.Rf4 1-0

4/25/20 - TCEC Season 17, Games 3-4: Sicilian Scheveningen

There has been one high level chess event that has been completed despite the current lockdown. The Super Final of the 17th season of Top Chess Engine Championship (TCEC) between Stockfish and Leela Chess Zero (Lc0) completed this week with Lc0 taking the 100-game match +17 =71 -12. I hadn't really paid much attention to engine chess tournaments before although I of course had looked at the Alpha Zero versus Stockfish games. However, I have heard some people comment that these games should be studied because these are now the best players on the planet. The estimates of the ratings of Stockfish and Lc0 are in the upper 3400's.

One of the criticisms of the first Alpha Zero games against Stockfish was that they were played under conditions that were not optimal for Stockfish. The TCEC is a more neutral competition where all the engines are running on similar hardware. This is a bit more difficult now with the neural net programs like Lc0, which are GPU based versus traditional engines like Stockfish which run on the CPU. The TCEC tried to deal with that issue this season a bit by separating the preliminary rounds into CPU and GPU divisions.

One element that is unique to TCEC is that the games do not start from the opening position. Instead, 50 different opening positions are selected and each side gets a chance with each color. This makes it an interesting crucible for opening theory. I'm going to do some surveys of some of the openings from the match and see how they compare with human practice.

The first decisive games came early, in games 3 and 4, where White won both games from a sideline in the Keres Attack of the Sicilian Scheveningen. 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 In the 14th game of their second match , Kasparov tried to avoid the Keres Attack against Karpov with the move order 4...Nc6 5.Nc3 d6, but Karpov all the same threw the g-pawn forward with 6.g4 5.Nc3 d6 6.g4 An early thrust of the g-pawn is common in modern chess, but it was quite sensational when Keres introduced it against Bogoljubow in 1943. This move has really put players off of playing the Scheveningen variation. 6...a6 Should this move, which was Petrosian's frequent choice against the Keres Attack, be given a dubious mark? Since 2010, in games where both players were rated at least 2400, White has scored a commanding +16 =6 -4. The most common move is 6...h6 which Kasparov played against Karpov in the first game of their first match. That was the only time Kasparov played the traditional Scheveningen in a World Championship match. 7.g5 Nfd7

This was the starting point for the TCEC match. 8.Be3 The most common move, this was Lc0's choice. Negi recommends 8.Bg2 trying to discourage ...b5. Stockfish went for the more restrained 8.a3 when Lc0 decided to do without ....b5 and developed with 8...Nc6. 8...b5 9.a3 Bb7 10.f4 The only high level game I found with this move was a rapid game where Amonatov deafeated Artemiev. The text move makes quite a bit of sense as attacking the Black structure with f5 is thematic in these positions. The most common move is 10.h4 when Negi suggested that Black is fine after 10...Nc6 11.Nxc6 Bxc6 12.Qd4 Rb8 intending to trade queens with ...Qb6. This got played in the second game of a recent Banter Blitz match between Carlsen and Grandelius. Neither player mentions Negi's book, so I think they were on their own. Carlsen mentions that he is a tempo up on the h3 Najdorf which we can see by looking at a line like 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.h3 e6 7.g4 b5 8.g5 Nfd7 9.a3 Bb7 10.Be3 Nc6 11.h4 I think this offhand comment by Magnus pinpoints why ...a6 against the Keres Attack is out of favor. Who really wants to give White an extra tempo in the Najdorf? Grandelius mentions the idea of trading queens, but after 13.0-0-0 he changed his mind and went 13...a5 perhaps out of respect for the World Champion's endgame prowess. Unfortunately, Carlsen blundered a few moves later, so the game lost theoretical interest, although he still hung on to draw. On a historical note, the earliest game in my database in this line is Fischer-Najdorf from the 1960 Olympiad. There Bobby chose 10.Qd2. 10...Nc6 11.Rg1!?

The novelty, Amonatov captured on c6. At first this move might seem a bit obscure, but it takes the rook off of the diagonal from Bb7, gives extra protection to the g-pawn in preparation of f5, and also allows for a rook lift Rg3 which can give extra defense to the queenside. Stockfish itself also chooses 11.Rg1 giving White a large advantage, over +1.4. I find this interesting because presumably Stockfish was playing the moves it thought best for Black after 8.Be3, but Stockfish chose 8.a3 when it had White. A couple of versions of Stockfish on Chessbase's Let's Check rate that move around +1.0.

I do have one experience in this line. At the start of our sophomore year Billy Colias and I played a 5-game match to determine who would start the year as first board for the Munster High School team, which Billy won 3-2. In the third game, I abandoned my normal 1...e5 and played this variation of the Scheveningen. From the first diagram, the game continued 8.Be3 Nc6 9.h4 Qc7 10.Qd2 Nde5 11.f4?! Nxd4 White can't recapture either knight beause of the fork on f3. Billy found a way out with 12.0-0-0 and Black can't hang on to his extra piece. I grabbed a pawn and exposed his king with 12...Nxc2 and eventually lost a long game. Trying to hold the piece with 12...Nef3 13.Qf2 e5 doesn't work as after 14.Nd5 Qa5 15.Kb1 White is going to play c3 and one of the knights falls. A reasonable alternative is 12...Ndc6 13.fxe5 Nxe5

I think the reason I don't often play the Sicilian is that I would rate this position as clearly better for Black. He has an extra pawn, no weaknesses, and a beautiful outpost for his knight on e5. He might be able to grab the bishop pair with ...Nc4 and White has an isolated e-pawn. For compensation White has a small lead in development and more space on the kingside. Yet Stockfish gives the Black advantage as only -0.29 after 14.h5

4/24/20 - Andrews-Bereolos, 1996 Music City Grand Prix

One of my earliest games against Todd Andrews featured an ending with 3 connected passed pawns versus a rook. After 31.g3

Black is a pawn down, but his active rook gives some compensation 31...h4? Trying to attack White's kingside, but there is a flaw. It was better to activate the king with 31...Kb7 32.Rd1? 32.gxh4 Bxf4 White has a surprising way to guard h2 with 33.Be5 Now, the rook ending doesn't look too good for Black 33...Bxe5 34.Rxe5 Rxb2 35.h5 Rb4 36.Rf5, but the passed h-pawn is going to cause Black problems even if he keeps the bishops on the board 32...h3 Even though Black temporarily loses another pawn with this move, the Black pawn on h3 is very useful in confining the White king to the back rank and Black's problems are behind him. 33.Bxb6 axb6 34.Rxd6! Rg2+ this thematic idea appears several times in the ending. Black poses White the choice of protecting or abandoning his h-pawn 35.Kf1 35.Kh1?! doesn't make a lot of sense here as 35...Rxb2 36.Kg1 Rg2+ repeats the position except that White has dropped his b-pawn. 35...Rxb2 36.Rd8+?! better is 36.Rf6 as the text just activates the Black king 36...Kb7 37.Rd7+ Kc6 38.Rxf7 Rxa2 39.Kg1?! White is really skating on thin ice after this move. There is not much problem making a draw with 39.f5 Rxh2 40.f6 Rg2 41.Rg7 Kd6 42.Rb7 Rxg3 43.Rxb6+ Ke5 44.f7 Rf3+ 45.Kg1 Rxf7 46.Kh2= 39...Rg2+!? With the idea of putting the rook on the other side of the b-pawn before advancing it. 40.Kh1 White doesn't want to admit his previous move was wrong, but moving the king to the f-file would prevent the black rook from stopping the f-pawn so the pawn race should end in a draw 40.Kf1 Rxh2 41.Rh7 b5 42.Rh6+ Kc5 43.Rh5+ Kc4 44.f5 b4 45.f6 b3 46.Rh4+ Kc3 47.f7 b2 48.Rb4! Kxb4 49.f8Q+! and White will give perpetual check 40...Rd2 41.Kg1! b5

42.Rh7? The only way to draw is 42.Rf8! to get the rook to b8 before the b-pawn becomes too far advanced Black can again try 42...Rg2+!? 43.Kf1! (43.Kh1? b4 44.f5 b3 45.f6 b2 46.Rb8 Rd2 47.Kg1 Rd1+! 48.Kf2 b1Q 49.Rxb1 Rxb1! 50.f7 Rb8 -+) 43...Rxh2 44.g4 (44.f5? Rh1+! 45.Kf2 Ra1 46.Rh8 h2! 47.Rxh2 Ra2+! 48.Kg1 Rxh2 49.Kxh2 b4-+) 44...b4 (now on 44...Rh1+ 45.Kf2 Ra1 White has 46.Kg3) 45.Rb8 Kc5 46.f5 Kc4 47.f6 Rh1+ 48.Kf2 h2! 49.Kg2 Rf1 50.Kxh2 Rxf6=; 42...b4! 43.Rxh3 b3! 44.g4 b2! 45.Rb3 Kd5! The White pawns get far enough advanced to draw after 45...Kc5? 46.f5 Rd1+ 47.Kf2 b1Q 48.Rxb1! Rxb1! 49.f6= 46.Rb4 Now on 46.f5 the Black king is close enough to slow the pawn's advance 46...Ke5! 47.Rb5+ Kf4! (but not 47...Kf6? 48.h4 Rd1+ 49.Kf2 b1Q because of the zwischenzug 50.g5+!) 48.Rb4+ (48.f6 Rd1+! 49.Kf2 b1Q 50.Rxb1 Rxb1! 51.f7 Rb8) 48...Kg5-+ 46...Rd1+ 47.Kf2 b1Q 48.Rxb1 Rxb1!

The White pawns need to be one rank further advanced in order to draw 49.Kg3 Ke4 50.f5 Rb6 51.Kh4 Kf4 52.Kh5 Ra6 53.h4 Rb6 54.f6 Rxf6! 55.g5 Ra6 56.g6 Kf5 57.g7 Rg6 0-1

4/22/20 - BCE-301, Euwe-Capablanca, Karlsbad 1929

This week's BCE position is another game from Karlsbad 1929. This time two World Champions are featured, but neither held the title at the time of this game. As mentioned last week Capablanca was half a point short of Nimzowitsch's pace. He lost 2 games in the event after going +30 -1 =36 from 1926-1928. Euwe finished tied for 5th with a +3 score. Their game is actually featured in two BCE examples. BCE-398 starts with the position after 39.Rg6

39...Kc5 40.Rxh6 Kd4 41.Kf3 a5 42.Kf4 a4 43.Rh5? Fine's main line of 43.Rh3 wins as White saves many tempi versus the game line. 43...Ra6 44.Rd5+ Kc3 45.Rd1 a3 46.Kf5 a2 47.f4 a1Q 48.Rxa1 Rxa1 49.Kxf6 The starting position of BCE-301 49...Ra6+ 50.Kf5 Kd4 51.e5 Kd5 52.g3 Ra8 53.Kf6 Ra6+ 54.Kf5 Ra8 1/2-1/2

4/18/20 - Palatnik-Bereolos, Chattanooga 1997

I've uploaded my annotations to my 1997 game against Sam Palatnik from the final round of the Living Legend tournament. This was the 2nd year that the Chattanooga Chess Club held an event to honor their senior member, Rea Hayes. This was during the time that Palatnik was the Tennessee GM in residence and it was not unusual for him to participate in a 1-day event. Despite getting a reasonable position from the opening, I don't think I gave him too much trouble. This game is a good lesson in good pieces versus bad pieces.

4/17/20 - Shamkovich-Liberzon, Moscow Jubilee 1967

One of the big steps forward in chess information was the pubication of Chess Informant beginning in 1966. It's symbolic system allowed players around the world to read annotation by the world's best players without language barriers. The 5th volume introduced the Combinations and Endgames section, and today I'm going to look at one of the rook endings from that issue.

The Moscow Jubilee tournament in October 1967 was part of the celebration of the 50th anniversary of the Russian Revolution. Unlike the very strong international event held in Moscow earlier in the year, this one was an all-Soviet affair. It was pretty strong with 8 of the 12 participants holdig the GM title. 3 of the other 4 went on to become GMs, the sole exception being Gennady Ageichenko. However, Ageichenko is inspirational in that he finally made the IM title at age 69! Lev Polugaevsky and former World Champion Vassily Smyslov tied for first with undefeated +5 scores

The opponents in today's game were two of the first grandmasters to emigrate from the Soviet Union. Vladimir Liberzon became Israel's first GM and played top board for them in several Olympiads. Leonid Shamkovich eventually settled in the US and was a frequent participant in the US Championship. Neither fared great in the Jubilee tournament. Shamkovich had -1, while Liberzon withdrew with illness after scoring 2.5/8. However, their encounter did produce a rook ending that is worth study. Judovic gave light notes in Informant #5. Keres analyzed the game in depth in the March 1968 issue of Chess Life. Finally, Müller and Konoval analyzed it using tablebases. So there wouldn't seem to be much to add, but there is a critical positions right at the start of the rook ending. White had an extra pawn after 46.a4

46...Bd4? After Keres' suggestion of 46...Bc3 Black is probably objectively holding, but White can still press for a win. Instead, Black tries to take refuge in a rook ending, but it is losing for Black. 47.Bxd4 Rxd4 Without the h-pawn, this is a textbook win for White by advancing the a-pawn to the seventh then pushing the f-pawn. The question is if the h-pawn makes a difference. 48.a5! The analysis in Informant and by Müller and Konoval did not start until after this critical move. White can't start with the rook move 48.Ra8? Rg4+! 49.Kf3 (49.Kh3 Rf4 50.Kg3 Rg4+; 49.Kf1 h4! 50.f3 Rf4 51.Kf2 h3 52.a5 h2 53.Kg2 h1Q+ 54.Kxh1 Rxf3!=) 49...Rg1! 50.a5 (50.Rh8 Ra1) 50...h4! 51.a6 h3! 52.a7 h2! 53.Rh8 (53.Rf8+!? Kg7 54.Rg8+!? Kf7) 53...Ra1! 54.Rxh2 Kg7; Preventing the rook check with 48.f3? doesn't help either 48...h4 49.a5 Ra4 50.Ra8 Ra2+ 51.Kh3 Ra3 52.Kg4 Ra4+ 53.f4 h3 48...Rg4+ Keres shows that Black is a tempo short if he tries to trade the kingside pawns 48...h4 49.Ra8 Rd2 50.a6 h3+ 51.Kxh3 Rxf2 52.a7 Ra2 53.Rh8! 49.Kf3 Ra4 49...Rg1 50.Ra7+! Kg6 51.a6 h4 52.Ra8! Ra1 53.a7 Kg7 54.Kg4+- 50.Ra8 Kg6 51.a6 Kg5 52.Ke3 Judovic's variation is the simplest way to win 52.a7 Kh4 53.Kg2 Ra2 and now a trianglualtion to put Black on move 54.Kg1 Ra1+ (Keres also shows that the tougher defense with 54...Kh3 also fails 55.f4! h4 56.f5! Ra5 57.f6! Ra6 58.f7! Rg6+ 59.Kh1! Ra6 60.Rg8+-) 55.Kh2 Ra2 56.Kg2 Ra1 57.f4 and wins in similar fashion to the game. 52...Ra3+ 52...Kh4 53.a7! Kh3 54.f4! Ra3+ 55.Kd4 Ra4+ 56.Kc5 Kg4 57.f5! Kxf5 58.Rf8+! Kg4 59.a8Q Rxa8 60.Rxa8! h4 61.Kd4! h3 62.Ke3! h2 63.Rg8+ Kh3 64.Kf2! h1N+ 65.Kf3! and Black loses his knight 53.Ke4? 53.Ke2 Kh6 54.a7 Kh7 55.f4 h4 56.f5 h3 57.Kf2! and the White king gets in front of the h-pawn

53...Ra4+? With the White king cut off along the third rank, Black can retreat his king and use his h-pawn for counterplay 53...Kh6! I'll flaunt the Nunn Convention here and award this move an exclam (53...Kg6 also holds the draw). I think too often these days and declare moves blunders based on the engine. Over the board, I think it is incredibly hard to find this king retreat, especially since only two moves earlier the king advanced with the idea of sheltering in front of the h-pawn. 54.a7 Kh7! (not 54...Kg7? which allows the White pawn to advance to f6 with check 55.f4! h4 56.f5! h3 57.f6+! Kh7 58.f7! h2 59.Rh8+! Kxh8 60.f8Q+!) 55.f4 h4! 56.f5 h3! 57.f6? h2! 54.Kf3? Blocking the f-pawn costs White precious time. He should have repeated the postion with 54.Ke3; Keres' suggestion of 54.Ke5? fails for the same reason we saw on the previous move 54...Kh6! (instead of 54...Ra5+? but it is not surprising that he missed this as he let move 53 pass with no comments. ) 54...Kh4! 55.Ke3 Ra3+ 56.Ke4 Ra4+ 57.Kf5 Ra5+ 58.Ke6

58...Kg4? Judovic gives 58...Ra4? an exclam with no further analysis, but Keres shows that White wins with 59.a7! Neither annotator shows the drawing line 58...Kh3! 59.a7 h4 60.f4 Kg4 61.f5 (61.Rg8+ Kxf4 62.a8Q Rxa8! 63.Rxa8! h3=) 61...Ra6+! 62.Kd5 Kxf5 63.Rf8+ Kg4 64.a8Q Rxa8! 65.Rxa8! h3 66.Ke4 h2= 59.a7! Ra6+ 60.Ke5 Keres shows one last trap White could fall into with 60.Ke7? Kh3 61.f4 Kg4! and the White king is too far afield to help in the coming rook vs. pawn ending. 60...Ra5+ 61.Ke4 Ra4+ 62.Ke3 Ra3+ 63.Ke2 Ra2+ 64.Kf1 Kh3 on 64...Ra1+ White can hide his king with 65.Kg2 which would not have been possible if Black had played 58...Kh3 65.f4! Ra5 66.Ke2 Ra2+ 67.Kd3 Ra3+ 68.Kc4 Kg4 69.Rg8+ Kxf4 70.a8Q Rxa8 71.Rxa8! h4 72.Kd3 h3 73.Ke2 1-0

4/15/20 - BCE-403a, Bogoljubow-Maroczy, Karlsbad 1929

This week's BCE position is from the 1929 Karlsbad tournament, which was Nimzowitsch's greatest triumph with 15/21 half a point clear of Capablanca and Spielmann. The two big names involved in this game finished in the middle of the pack. Bogoljubow was 8th at +2, while Maroczy was =12th at -1.

I have Nimzowitsch's book on the event, but he did not cover all the games and this one was omitted. Other sources are still a few years from being in the public domain, so I didn't have any other analysis to compare my notes with. There was an interesting moment right at the transition into the rook ending after 32...Rd8

33.Rb1 33.Ke3!? exd5 (White wins the pawn ending after 33...Rxd5? 34.Rxd5 exd5 35.Kd4 Ke6 36.h4!) 34.Kd4 and it seems that the black pawn is much more vulnerable on d5 than on e6. 33...Rxd5+ 34.Ke3 Rd7 35.Ke4 Kf6 36.Rb3 Rc7 37.Rc3 Rc6 38.Kd4 b6 A somewhat instructive moment. Black dissolves White's weak pawn in order to activate his rook. It doesn't look like White has much of a plan, but look what can happen if Black tries to just sit passively 38...Rc7 39.a4 Rc6 40.a5 a6 (40...Rc7 41.a6 bxa6 42.c6) 41.Rb3 Rc7 42.Rb6 and White will press further with c6. 39.a4 bxc5+ 40.Rxc5 Rd6+ 41.Kc3 Rd1 42.Rb5 42.Ra5 Rf1 43.Rxa7 Rxf2 transposes to the game 42...Ra1 43.Ra5 The starting position of BCE-403a 43...Ra2 44.Rxa7 Rxf2 45.Rh7 h5 46.a5 Fine's main line with 46.g4 is a simpler way to draw. 46...Rxg2 47.a6 Ra2 48.a7 Kg5 49.Re7 Kh4 50.Kb3 Ra1 51.Rxe6? 51.Rc7 is the subject of the BCE correction 51...Rxa7! 52.Rxg6 Kxh3! 53.Kc2 Rd7! 54.Rg5 h4 55.Rg1 Rd4 56.Kc3 Rg4 57.Ra1 Kg2 58.Kd3 h3 0-1

4/11/20 - Wagner-Bereolos, 1997 Kings Island Open

Mark Wagner is another one of my once a decade opponents. I've previously discussed the endings I played against him in 2007 and 2019. Our first meeting, in the second round of the 1997 Kings Island Open reached a materially even knight ending after 40...Nxe8

Black is very slightly better here because he will be able to create an outside passed pawn on the queenside with ...d5. Still, this isn't much. 41.h5 gxh5 42.Nxh5 d5 43.cxd5 Nc7!? provoking the d-pawn forward in the hopes that it will become weak. Another try is 43...Nd6 44.Ng3 Nxb5 45.Nf5 Nc3 46.Nxh6+ with similar play 44.d6 Nxb5 45.d7 Ke7 46.Nf6 Nc7 47.Ng8+? 47.f4 b5 48.Ne4 Kxd7 49.Nxc5+ Kc6 50.Nb3 Kd5 is equal 47...Kxd7 48.Nxh6 Compared to the variation after 43...Nd6, Black is well ahead since he has already collected the d-pawn 8...Ne6 49.Kg3 b5 50.Nf7 Nc7? Black should win with 50...Kc6 with the idea of pushing the c-pawn. Black's pawns are much faster than Whites: 51.f4 c4 52.dxc4 bxc4 53.f5 Nc5 54.Kf3 c3 55.Ke2 d3+ 56.Kd1 c2+ 57.Kc1 Nb3+ 51.g5 Ke6 52.Nd8+ Kf5 53.Nf7 b4 54.f4? 54.Nd6+ likely leads to a draw as 54...Kxg5 is met by 55.Ne4+ and 56.Nxc5 54...Nd5? Black should take control of d6 with 54...Nb5 when he should be winning 55.Nd6+ instead Black has to waste a tempo because of the check 55...Kg6 56.Nc4 b3 57.Kf3 Ne3

58.Ke4? A complete breakdown. White could draw with either knight retreat 58.Nd2 b2 59.Ke4 Nf1 60.Nb1 Ng3+ 61.Kd5 Ne2 62.Kxc5 Nc3 63.Nd2= or 58.Nb2 Kf5 59.Ke2 Nd5 60.Kd2 Nxf4 61.Na4 Ne6 62.Kc1 Kxg5 63.Kb2 Kf4 64.Kxb3 Ke3 65.Kc4= Kd2 66.Nxc5 Nxc5 67.Kxd4! 58...Nxc4 59.dxc4 b2 60.Kd5 b1Q 61.Kxc5 Qf5+ 62.Kxd4 Qxf4+ 63.Kd5 Qxg5+ 64.Kd6 Qd8+ 65.Kc6 Qc8+ 0-1

4/10/20 - Shen-Furline, 2019 CCCSA Fall IM

Another endgame that was key in Christopher Shen's IM norm performance in the Charlotte Chess Center's Fall IM tournament came in the very first round against Jacob Furfine. Shen appeared well on his way to victory with an extra exchange after 48.fxe3

It seems clear that Black does not have sufficient compensation. All the Black pawns are weak and the White pawns are safely on the opposite color of the Black bishop. The position is open enough that White should be able to penetrate with his rook and/or king. Black's only trump is the passed b-pawn. Having said all that it would seem that White's win should just be a matter of technique, but after analyzing it quite a bit, the win is not at all easy. 48...Bb5 Black uses some tactical nuances to activate his bishop before pushing his pawn. It turns out that the White pieces are not on perfect squares. 49.Rf2 49.Rf5?! only allows Black to activate his king. 49...Kg6 50.Rf2 (50.Rxd5?? Bc6 or 50.e4? Bd3 are the tactical points) 50...Bc4 51.Rb2 b5 52.Kg3 Kf5 53.Kf3 Ke6 54.Kf4 Kd6; Sending the king over to stop the b-pawn doesn't seem to help much either 49.Kf2 Bc4 50.Ke1 b5 51.Kd2 b4 52.Kc2 Ke6 and the White rook is stuck preventing penetration by the Black king via f5. 49...Bc4 50.Rb2 b5 51.Kg3 Ke6 52.Kf4 Bd3 53.Rb3 Bc4 54.Ra3 Kd6 55.Kf5 55.Ra6+ Kc7 (55...Ke7 56.e4 seems to be easier as the Black king is cut off) 56.Rxf6 b4 57.Ke5 b3 58.Rf2 Kc6 59.e4 dxe4 60.Kxe4 Kb5 61.Ke5 Kb4 62.d5 Kc3 63.Rf3+ Bd3 64.d6 b2 65.d7 b1Q 66.d8Q and the engine claims a win for White, but this could be a quite difficult position to win in practice. This is a long and difficult variation, but creating a passed d-pawn with e4 seems the only way to break down Black's defenses 55...Kc6 56.Kxf6? Now the Black king gets too active. There was still time to return to the previous variation with 56.Ra6+ Kb7 57.Rxf6 b4 58.Ke5 b3 59.Rf2 56...b4 57.Ra1 Bd3 58.Ra4 Kb5! 59.Ra8 b3 60.Rb8+ Kc4 61.Ke5 Be4 62.Rc8+ Kd3 63.Rb8! Kc2 64.Rc8+ Kb1 65.Rb8? 65.Kf4 b2 66.Kg5! Bf3 67.Rb8 Kc2 transposes to the game 65...b2! 66.Kf4

66...Kc2? Black is winning with 66...Kc1! 67.Kg5 (67.Rxb2 Kxb2! 68.Kg5 Kc2 69.Kxh5 Kd3) 67...b1Q 68.Rxb1+ Bxb1! when is king is one square closer to e3 than in the the next variation. 67.Kg5! Bf3 Now if Black promotes, the White king returns in time to protect e3 67...b1Q 68.Rxb1! Kxb1! 69.Kxh5! Kc2 70.Kg5 Kd3 71.Kf4! 68.Rc8+ Kd2 69.Rb8! Kc2 70.Rc8+ Kb1 71.Rb8 Be2 72.Rb7 Kc2 73.Kf4 Bd3 74.Kg5 Be2 75.Kf4 Bc4 76.Rxb2+! Kxb2! 77.e4! dxe4 78.Kxe4! Kc3 79.d5! Be2 80.d6 Bg4 81.Kf4 Kd4 82.Kg5! Ke5 83.d7! 1/2-1/2

4/8/20 - BCE-396b, Steinitz, 1885

The first World Champion, Wilhelm Steinitz, also composed a few studies. Today's BCE position was first published in 1885 in The International Chess Magazine, which Steinitz editied. I was unable to find a digitized version of the 1885 volume. Fine's analysis in BCE matches that of Berger in position 267 of Theorie und Praxis der Endspiele, but I can't tell if that Steinitz' solution or if Berger added elaboration.

The position is somewhat similar to Tarrasch-Johner except that here Black captures the a-pawn and leaves White with a kingside pawn which can be stopped. In that game, Black collected all the kingside pawns, but White should have won with his a-pawn.

4/1/20 - BCE-185b, Duras, 1906

Like his contemporary Reti, the Czech grandmaster Oldrich Duras excelled at both over the board play and at chess composition. Over the board, Sonas has him peaking at #4 in the world in 1909 behind only Lakser, Rubinstein, and Capablanca. He won a special prize for the study that is the subject of today's BCE position. Fine cites it as 1906-07, which is strange for a study. I'm going with just 1906, the date that is shown in both the van der Heijden database as well as Southerland and Lommer's 1234 Modern End-Game Studies, which Fine cites as one of his sources. Both of those list the study as being published in Bohemia, but I was unable to find digitized copies of that periodical online to confirm the date. Neither of those sources give the mistake in BCE, so that may have been an addition by Fine. The study is very deep and beautiful, yet clearly of practical value as well. I'll just give the main line

1.Ba3! Kc4 2.Be7! f3 3.Bd8! Bxh2 4.Bb6! Kb5 4...g4 is the subject of the BCE correction 5.a6! g4 6.Bf2! Bc7 7.b8Q+ Bxb8+ 8.Kb7! Ka5 9.Bh4! Kb5 10.Be1 g3 11.Bxg3! Bxg3 12.a7! f2 13.a8Q! f1Q 14.Qa6+! Kc5 15.Qxf1! 1-0

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