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

10/7/20 - BCE-532, Capablanca-Tarrasch, St. Petersburg 1914

I'm back after a couple of week's hiatus with more BCE corrections. The ending in today's correction is somewhat technical in nature, but the game it comes from was one of the key results in Lasker's great comeback at St. Petersburg 1914. This game was played in the last round of the finals. In the previous round Lasker famously defeated Capablanca using the exchange variation of the Ruy Lopez. This brought Lasker to within a 1/2 point of the Cuban, who had entered the 10 round finals with a 1.5 point lead from the preliminaries. In the final round, Lasker crushed Marshall, while Capablanca blundered a piece early in his game with Tarrasch after 12...Rxe5

13.Rfd1 A case of the wrong rook. After 13.Rad1 the game continuation 13...Bg4 14.Qg3 Bxd1 15.Bxe5 would likely lead to a very small edge to White after 15...Nh5 16.Bxd6 Nxg3 17.Bxg3 Bxc2 18.f3 although Black should be able to hold a draw with 18...Rb8 intending Rb1 and relying on the bishops of opposite colors 13...Bg4 14.Qg3? White could maintain the balance with 14.Rxd6 Bxf3 15.Rxf6 gxf6 16.Bxe5 14...Bxd1 15.Bxe5 Qd2! With the White rook on a1 instead of f1, the mate threat prevents White from regaining his piece. Perhaps Capablanca had only considered 15...Qd8 16.Bxf6 Qxf6 17.Rxd1 when entering this line when White would have a clean extra pawn. Despite losing a piece, Capablanca managed to drag it out a long time, but the result was never in doubt. 16.f3 Nh5 17.Qf2 Qxf2+ 18.Kxf2 Bxc2 19.Rc1 Ba4 20.Bxc7 Rc8 21.Rb1 Bb5 22.Rd1 Kf8 23.Be5 Ke7 24.a4 Bc4 25.Rd4 Be6 26.Rb4 Bd7 27.Rb7 Ra8 28.Ke3 Nf6 29.a5 Ke8 30.Bd4 a6 31.f4 c5 32.Bxf6 gxf6 33.Rb6 Ke7 34.f5 Bb5 35.g4 Rd8 36.Kf4 Rd1 37.h4 h6 38.Rb7+ Kf8 39.Rc7 c4 40.g5 hxg5+ 41.hxg5 Rf1+ 42.Kg4 Rg1+ 43.Kf4 fxg5+ 44.Ke5 Re1 45.Kf6 Rxe4 46.Rxf7+ Ke8 47.Rg7 g4 48.Rg5 Bc6 49.Kg7 Bd5 50.Rg6 Re7+ 51.Kh6 Be4 52.Rxg4 Bxf5 53.Rxc4 Re5 54.Kg5 Bd3+ 55.Kf4 Rf5+ 56.Kg4 Rxa5 The one pitfall Black must avoid is ending up with only a bishop and the a-pawn. 56...Bxc4? 57.Kxf5! and the White king will reach a1 with a draw. 57.Rd4 Bb5 58.Kf4 Ra3 59.Ke5 Bd7 60.c4 Kd8 61.Rd2 Kc7 62.Kd4 a5 63.Rd3 Ra1 64.Kc3 Rc1+ 65.Kb2 Rh1 66.Rd5 a4 67.Rd2 Bc6 68.Ka2 Kb6 69.Rb2+ Kc5 70.Rb1 Rh3 71.Rg1 Kxc4 finally reaching the starting point of BCE-532 72.Rc1+ Kb5 73.Rb1+ Kc5 74.Rc1+ Kd6 75.Rd1+ Bd5+ 76.Kb2 a3+ 77.Ka1 Kc5 77...a2?! is the subject of the BCE correction. Tarrasch's technique is more to the point. 78.Rc1+ Bc4 79.Rg1 Rh2 80.Rg5+ Kb4 81.Rg1 Ra2+ 82.Kb1 Rd2 0-1 Capablanca resigned. He might have tried for some stalemate tricks with 83.Ka1 Bd3 84.Rg4+ Kb3?! [84...Kc3 85.Rb4 Rd1+ 86.Ka2 Bc4+ is a simple win] 85.Rb4+ Kc3 86.Rb3+ Kd4 87.Rxa3 although even here the poor position of the White pieces allows Black to win the R+B vs. R position.

9/23/20 - BCE-343, Seyboth, 1899

Today's BCE position is a theoretical rook ending that was first presented as a study. I was unable to find a link to the original presentation, but from the information in the van der Heijden database it appears that the mistakes were added by Fine. I found a couple of practical examples, one where the defender was successful and another where the same mistake given by Fine was made.

The first example comes from the 1964 World Student Olympiad, an event that no longer exists. Appropriately, the game is from match between two countries that no longer exist, the Soviet Union and Czechoslovakia. These teams finished first and second. The game Mnatsakanian-Janata had a couple of key moments before the position that is relevant to BCE. After 47. Kxf5

47...Rc5+? It appears Black can hold with 47...Rb8! which allows him to slow the advance of the f-pawn because he can check on the 6th rank after 48.Kg6 Rb6+! 48.Kg6! Rxb5 49.f5! Rb2 50.Rxc4 Rxh2 51.f6 Rf2

52.f7? Surprisingly, this move causes the White king to get overloaded. The win could have been had with some very accurate moves 52.Rxa4! Kh3 53.Ra5! g3 54.Rh5+! Kg4 55.Rg5+! Kh3 (55...Kh4 56.a4 g2 57.a5! Kh3 58.f7 Kh2 59.Kg7) 56.f7 52...Kh3! 53.Rxa4 g3! 54.Ra5 g2! 55.Rh5+ Kg4 56.Rg5+ Kh4! 57.a4 Rxf7! With the pawn still on f6 in the previous variation, Black doesn't have this resource as the White king would still guard his rook after a capture on f6. 58.Rxg2 Ra7! 59.Ra2 Kg4! 60.Kf6 Kf4! 61.Ke6 Ke4! 62.Kd6 Kd4! 63.Kc6 Kc4! 64.a5 Ra6+! 65.Kb7 Rh6! 66.a6 Rh7+! 67.Kb6 Rh6+! 68.Kc7 The position of the White rook on the second rank allows Black to hold after 68.Ka5 Rh5+! 69.Ka4 Rh6! since 70.Rc2+ Kd3! hits the rook 71.a7 Ra6+! 68...Rh7+! 69.Kd6 Rh6+! 70.Ke5 Rh5+! 71.Kf6 Rh8! 72.Ke7 Rh7+ 73.Kd6 Rh6+! 74.Ke5 Rh5+! 74...Rh8? 75.a7! Ra8 76.Kd6! Kb5 77.Kc7+- 75.Kf6 Rh8! 76.a7 Ra8! 77.Ke6

The White pieces are on slightly different squares, but the same defense as in BCE-343 works for Black. 77...Kc5! 78.Kd7 Kb6! 79.Rb2+ Kc5! 80.Ra2 Kb6! 81.Rb2+ Kc5! 82.Rb7 Rh8 83.Ke6 1/2-1/2 One of the two games Mnatsakanian failed to win in taking the Board 4 gold medal with 10/11.

The second example comes from a 2005 junior tournament in Slovenia. In Budihna-Ursic after 42...Kxb5

This should be an easy win for White with the Black king far from the action and a path for the White king into the Black structure 43.Kg6 Kc5 44.g5? This lets Black trade too many pawns. White wins by going after the g-pawn 44.f5 first securing the f-pawn 44...Ra7 (44...Kd5 45.Re8) 45.Re8 Ra4 46.Kxg7 Rxg4+ 47.Kxf6; Alternatively, White can even go directly for the pawn 44.Re8 Rd4 45.Kxg7 Rxf4 46.g5 blocking the g-file 46...fxg5 47.Kxh6! 44...fxg5 45.fxg5 hxg5 46.Re5+ Kd6 47.Rxg5 Ke6 48.Kh7 Kf6 49.Rg6+ Kf5 50.Rxg7 Rd1 51.h6 Re1?! This doesn't spoil the draw, but bringing the king closer with 51...Kf6 seems more logical. 52.Kg8 Re8+ 53.Kf7

53...Rh8? Black draws by getting checking distance with 53...Ra8 then 54.h7 Ra7+ (Reaching the mutual zugzwang position with 54...Rh8 also holds, but it is simpler to first drive the White king away from the pawn.) 55.Kf8 Ra8+ 56.Ke7 Ra7+ 57.Kd8 (57.Kd6 Ra6+ 58.Kd5 Rh6) 57...Ra8+ 58.Kc7 Rh8 54.h7! Reaching the mutual zugzwang position from the BCE correction 54...Ra8 55.Rg2 Ra7+ 56.Kg8! Ra8+ 57.Kg7 Ra7+ 58.Kh6 Ra8 59.Rg8 Ra6+ 60.Kh5 Ra1 61.Rf8+ Ke6 1-0

9/9/20 - BCE-250a, Englisch-Wittek, Vienna 1882

This week's BCE position is from the international tournament held in Vienna in 1882, which many consider the strongest chess tournament in history to that point. It was a massive 18-player double round robin won by Steinitz and Winawer with 24/34.

I wasn't really familiar with the two Austrian players in today's game, Berthold Englisch and Alexander Wittek. They both finished with plus scores with Englisch 7th on 19.5 and Wittek 9th on 18. Neither player appears to be a pushover. Englisch drew his two games with Steinitz and Sonos ranks him in the top 10 in the world at that time. Meanwhile, Wittek scored wins against both Steinitz and Winawer and Sonos has him within 100 rating points of both players.

In the BCE subject game, Wittek enjoyed the better side of a bishop versus knight ending after 36...Kf7

37.Bxh6 Temporarily restoring material equality, but the White h-pawn is doomed 37...Kg6 38.Be3 Kh5 39.Kd2 Kh4 40.Kd3 Kxh3? Keeping the White king out of e4 with 40...d5 would give Black great winning chances. The knight is ready to come to g6 to stop f4. 41.Ke4 Kg4 42.c4 Ng8 Annotations in Oesterreichische Lesehalle indicate 42...Kh5 as safer. Given some free moves, Black would play Kf6, Ke6 and d5, but after 43.f4 there are likely few winning chances for Black in the 4 vs. 3 ending. 43.f3+ Kg3 Allowing his knight to be dominated, but Black was obviously not keen on allowing the White king to penetrate after 43...Kh5 44.Kf5 so he goes on the counter attack 44.Bg5 The starting position of BCE-250a. A very interesting position. The Black knight is dominated, but this also freezes the White bishop. The activity of the Black king prevents White from simply collecting the knight. 44...Kf2 45.f4 exf4 46.Kxf4 Ke2 47.Ke4 c6 48.a4 a5 49.b3 c5 49...Kf2 should also draw as discussed in the correction link 50.Kd5 Kd3! 51.Kxd6 Kc2? Also losing is 51...b6? 52.Kc6 Kc3 53.Kxb6! Kxb3 54.Kb5, but Black holds with 51...Kd4! as shown in the correction link 52.Kxc5! Kxb3 53.Kb5! Kc3 54.Bd8? I think the simplest win is to create a passed pawn without releasing the knight 54.c5 Kd4 (54...Kb3 55.Kxa5) 55.c6! bxc6+ 56.Kxa5! although the more complicated lines given in Oesterreichische Lesehalle and by Fine beginning with 54.Kxa5 also win 54...Kd4? Black had to take the opportunity to activate his knight even though it is far from the action 54...Nh6! 55.Bg5! correcting his mistake and locking the Black knight up again. 55...Kd3 56.c5 Kd4 57.Bh4? 57.c6!+- wins as above 57...Nh6! not missing the second chance 58.Bf2+ Kd5! 59.Kb6 Nf5 60.Kxb7 Ne7! 61.Kb6 Nc6 62.Bg1 Nb8 63.Kb5 Nc6! 64.Bf2 Nb8 65.Bh4 Nc6! 66.Bf6 Na7+ 67.Kb6 Nc8+ 68.Kxa5 Kxc5 69.Ka6 Nb6 70.Bd4+ Kb4! 1/2-1/2

9/2/20 - BCE-382b, Levenfish-Botvinnik, 1937 USSR Championship, Game 11

At the time BCE was published, the 6th world champion, Mikhail Botvinnik, had not yet claimed the highest crown in chess, but was still one of the world's top players. Several of his endings appear in BCE including this week's.

Botvinnik won the Soviet championship in 1931 and 1933, but did not participate in 1934/35 nor 1937 and both times Gregory Levenfish was the winner (equal first with Ilya Rabinovich in 34/35). The reasons aren't completely clear, but in the fall of 1937 Botvinnik and Levenfish played a match for the Soviet Championship. The rules were a bit peculiar, especially in view of what happened in the negotiations for the Fischer-Karpov match, but the rules were that it took 6 wins to win the match, but if the match reached 5-5, the match would be declared drawn and Levenfish would retain the title. After 10 games, Botvinnik led 4-3 with 3 draws. In game 11, Levenfish was able to win a pawn when Botvinnik blundered on move 40 40...Rcc8?

41.Nd5+ Kf7 42.Nxf6 exf4+ 42...Kxf6 43.fxe5+ Kxe5 44.Rxd4 Rxd4 45.Rxd4 Rc2 46.Rd5+ Ke6 47.Rxb5 is worse 43.gxf4 Black should also have enough activity to hold after 43.Kxf4 Kxf6 44.Rxd4 Rxd4 45.Rxd4 Rc2 43...Nf5+ 44.exf5 Rxd3+ 45.Rxd3 Kxf6 46.fxg6 hxg6 The starting position of BCE-382b 47.Rd6+ Kf7 48.Rd5 48.Rb6 Rc5 48...b4 49.axb4 49.a4 Rc2 50.Rd2 Rc4 51.b3 Rc3+ 52.Rd3 Rc2 49...axb4! 50.Rd4 b3 51.Rd3 Rh8 52.Ke4 Rxh2! 53.Rxb3 Re2+ 54.Kd3 Rf2 55.Ke3 Rg2 56.Rb5 Rg1 57.Kd3 Rf1 58.Rb4 Rf2 59.b3 Rf3+! 60.Ke4 Rg3! 61.Rb5 Rg1 62.Rd5 Fine gives this move as 62.Rb4, which doesn't seem very logical blocking the advance of the b-pawn. It may have been Fine trying to cut out all of the move repetitions, but his line gives an opportunity for White to win with 62...Rb1 63.Ke5!, which did not arise in the game. 62...Rb1 63.Rb5 Kf6? As the correction link shows, Black should head the king towards the b-pawn with 63...Ke6. A key point of this ending is that with the kingside structure, it is very difficult for White to trade his b-pawn for the g-pawn. If the Black king gets in front of the b-pawn he can play Rg4 simultaneously attacking the f-pawn and defending the g-pawn. 64.Rb6+ Kf7 65.Rb8? This is the beginning of a strange sequence. I don't know what the rules for repetition were, but the position gets repeated several times with both players committing the same mistakes over and over again. Levenfish may have been trying to reach an adjournment while Botvinnik was trying to reach some drawn by repetition. White wins with 65.b4! as he eventually plays on move 73 65...Kf6? 65...Ke6 66.Rb6+! Kf7 67.Rb4? 67.b4! 67...Kf6? 67...Ke6! 68.Rb6+! Kf7 69.Rb8? 69.b4! 69...Kf6? 69...Ke670.Rb6+! Kf7 71.Rb7+? 71.b4! 71...Ke6! Curiously, Botvinnik shunned another repetition and finally played the correct move 72.Rb6+ Kf7? As shown in the correction link 72...Kd7! would hold the draw 73.b4! The fifth time's the charm! 73...Re1+ It's too late to go to the queenside as the Black king gets stuck on the back rank 73...Ke7 66.Ke5 Kd7 67.Kd5 Rf1 68.Rb7+! Kc8 69.Rf7! g5 70.f5! g4 71.Ke5 g3 72.Rg7 74.Kd4 Rf1 75.Ke5 Re1+ 76.Kd6 Re4 77.b5 Rxf4 78.Rc6! 1-0 The Black king can't support the pawn 78...g5 79.b6 g4 80.b7 Rb4 81.Kc7 g3 82.b8Q Rxb8 83.Kxb8! g2 84.Rc1 followed by 85.Rg1 and 86.Rxg2

Thus, Levenfish evened the score. Botvinnik struck back with White in Game 12, but Levenfish immediately recovered to win the 13th game and the match was drawn at +5 -5 =3.

8/30/20 - Bereolos-Sadorra, 2016 Kings Island Open

I'm not especially satisfied with my effort against Julio Sadorra at the 2016 Kings Island Open. While my attack should have yielded a draw, I think I played several second best moves in the middle game, which made the ultimate attack less strong. Compounding this, after the game turned, I did not put up much resistance. The move 34.Bc1?! is especially sour since I should have realized that avoiding a short term material loss was not worth the long term consequence of locking my rook out of the game.

8/26/20 - BCE-91c, Loyd-Winawer, Paris 1867

Today's BCE position is from the international tournament held in conjunction with the 1867 Paris World's Fair. The victory by Ignatz von Kolisch (+20 -2 =2) ahead of Symon Winawer and Wilhelm Steinitz propelled him to the top of Jeff Sonas' historical rating list. This isn't too surprising as there was not a lot of international competition back then and Sonas' entire list at that point only has 21 players, 13 of which played in Paris.

The only American player in the field was the noted puzzle creator Sam Loyd, who finished 10th. In today's game Winawer was trying to convert a pawn up rook ending with Black against Loyd. After 36.Ra2 he gave back the pawn to reach a "winning" pawn ending.

36...b5? The endgame concept of "don't rush" had not been introduced when this game was played. 37.axb5 cxb5 38.Rxa5 bxc4 The pawn ending should be drawn, Black could try to keep the game going with 38...g5+!? 39.hxg5 hxg5+ 40.Ke3 bxc4 since 41.Rxc5? dxc5 42.bxc4 Ke5 is a simple win for Black. White has to find 41.b4! when it seems that he has enough to hold after 41...Rc7 42.Ra2 (not 42.Rxg5? c3) 39.Rxc5! dxc5 40.bxc4! the starting position of BCE-91c 40...g5+ The tournament book agreed with Fine's assessment that Black was winning 41.hxg5! hxg5+! 42.Kxg5! 42.Kf3? Ke5 43.Ke3 f6 puts White in zugzwang 42...Ke5! 43.Kh6 Kxe4 44.Kg7? 44.Kg5 is the subject of the BCE correction, 44.Kh5 also holds the draw, but not 44.g5? Kf4 45.Kg7 (45.Kh5 Kg3 46.g6 fxg6+ 47.Kxg6 Kf4) 45...Kxg5 46.Kxf7 Kf5-+ as given by Fine44...f5! 0-1 The tournament book states that each side spent an hour which is somewhat shocking given that the time control was a leiesurely 10 moves per hour.

From the database, a little bit of French trivia. The players in the Paris tournament did not give a nod to their hosts, playing the French Defense (1.e4 e6) in only 4 games versus 100 games with 1.e4 e5, including today's subject game. The first time Winawer tried the Winawer variation (1.e4 e6 2.d4 d5 3.Nc3 Bb4) was a few rounds later, unsucessfully, against Steinitz. The winner of tournament, Kolisch, appears to have been the first to play the Winawer variation with Black in his match against Paulsen in 1861.

8/24/20 - TCEC Season 17 Superfinal, Games 19-20, Qb6 Sicilian

Games 19 and 20 of the Superfinal debated what is considered a sideline of the open Sicilian. 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Qb6 This and the related system with 2...e6 aren't the most popular variation of the Sicilian, but there is still a considerable amount of theory with close to 10000 games in the database. There is an older book by Ilic, and a more recent book by Grivas, who is one of the main practioneers. Even the Grivas book is 15 years old, but theory does not seem to have developed rapidly in this line. 5.Nb3 Nf6 6.Nc3 e6 7.Qe2

This was the starting position for the two game set. The engines went their separate ways here. 7...Bb4 Lc0 went for the move considered more solid 7...Be7 but then went for activity with a pawn sacrifice 8.Be3 Qc7 9.0-0-0 d5!? instead of steering towards the Hedgehog with 9...a6 This pawn sac is known in similar positions, but was a novelty here. 8.Bd2 0-0 9.a3 9.0-0-0 was the very latest from elite level human chess is the recent online rapid game between Carlsen and Gelfand in the Legends of Chess tournament. In the post-match interview, Magnus said he wasn't too sure about the theory as this is a line you never face and he thought that maybe 9.a3 was the main theoretical move. Still, it didn't work out too bad for him as he won in only 29 moves. 9...d5 10.e5 Nd7 11.f4 a6 (Magnus initial impression was that White was already after this and suggested 11...f6) 12.Qh5 Rd8 13.Bd3 and to me it feels like Black got a bad version of the Classical French. 9...Bxc3 9...Be7 is more popular here, but the text is more principled. 10.Bxc3 e5 11.0-0-0

11...Re8 Black would like to play 11...Rd8 intending ...d5, but White has the strong 12.Rd6 threatening Ba5 12...Qc7 13.Rxf6 gxf6 14.Qg4+ Kh8 15.Qh4 with a powerful attack in Adams-Knezevic France 1997. Ilic's suggestion of 11...Ne8 intending ...d6 and ...Be6 hasn't found many takers. Instead, human practice has turned toward; 11...a5 which seems much more useful than ...Re8 and has scored quite well for Black (63.6%) 12.f3 The assessment of 12.g4 d5 is likely critical, but Black seems to be holding his own here. Grivas gives 12.Qe1 keeping an eye on a5 as an alternative. Perhaps 12.h3 preparing 12.g4 is worth further investigation, keeping open the path for the White queen to the kingside. I only found one example, which ended in a draw after a long struggle starting with 12...a5 12...Rd8 13.Qb5 Now 13.Rd6 Qc7 14.Rxf6 gxf6 has lost its sting since the White queen can't quickly join the attack, but it seems like a kind of position where a neural net engine like Lc0 would still be able to prove long-term compensation 13...Qc7 14.Na5 a6 15.Qc4 d6 16.Nxc6

The first new move. 16.Bb4 was the previous try in Van Haastert-Safarli: European Club Cup 2018. Safarli is another GM who has played the Qb6 variation fairly regularly, so his games in this line are also worth study. 16...bxc6 White has the two bishops, but neither of them is doing much. Black has covered the weakness on d5, and is ready to complete his development with ...Be6, so the position is likely dynamically equal, but there is still play left. There was one further position a couple of moves later that I wanted to comment. 17.Qe2 17...Re8 18.Re1 a5 19.Qe3 Be6 20.f4 Nd7!?

A move which illustrates the difficulties of working with engines. I fed this position to fairly recent versions of Stockfish and Lc0 and they had the obvious looking 21.f5 as their 6th and 7th preference respectively, with only very slight advantage to White. I think this would be a very uncomfotable position to play as Black with the rediculous bishop on a2. Apparently, White can't immediately win it after 21...Ba2 22.b3 a4 23.Kb2 axb3 24.cxb3 Bxb3 25.Kxb3 Reb8+ 26.Kc2 (26.Ka2 Rxa3+ 27.Kxa3 Qb7) 26...d5 with a very strong attack for the piece. But even knowing that the engines evaluate the position as equal, over the board you will be constantly worried about the bishop getting trapped. Lc0 instead played 21.fxe5 and the game was eventually drawn after 153 moves, about 100 of which were the type of shuffling of pieces while avoiding 3-fold repetition that seem to be a characteristic of games between the top engines.

So, from the engine games, it looks like the Qb6 variation is doing fine and might give Black players an alternative to the steady diet of Najdorfs and Sheveshnikovs. Still, it seems that Black has to do some serious work before trying it as when things go wrong, they can end up in disasters as the games of Adams and Carlsen showed.

8/19/20 - BCE-294, Berger, 1888

BCE-294 is another endgame study by Berger that appears in his endgame book with colors reversed. That was likely Fine's source, Berger cites at as being from Songtagsblatte f. J. a. d. V. 1888. I'm not clear on what all those abbreviations stand for, from what I could find Songtagsblatte was a German newspaper.

As a study, this position is not great. There are a few pitfalls that White can fall into, but the fact that either of the obvious initial moves of pushing a pawn are winning takes away any athetic value. Fine seemed to trust Berger's analysis and did not recognize postions that transposed, evaluating the same position as both a win and a draw. Walter Korn analyzed the position in the December 20, 1955 issue of Chess Life under the title It's Confusion, Not Logic That Reigns, which seems appropriate. I think Benko did well to remove this example from the revised edition.

8/15/20 - Bereolos-Baugh, 1990 Pillsbury Memorial

Last month, the Hey position illustrated the fortress that a defender can put up against a knight and a rooks pawn when the rooks pawn advances to the seventh. I had previously shown this idea from my 1993 game against Boris Men. I had also utilized that knowledge a couple of years earlierat to rescue a half point from a lost ending against Christopher Baugh. After 33...Kxf4

White is dead lost. Black has a simple plan to use the h-pawn to distract one White piece on the kingside, then win on the queenside. 34.Kc1 h5 35.Kd2 Nf3+ 36.Ke2 h4 37.Kf2 h3 38.Ng3 h2?! There is no need for this advance. I now have some hope as it will be a draw if I can elimniate all the queenside pawns. 39.Kg2 a5 40.Ne2+ Ke3 41.Nc3 Kd3 42.Na4 b5? This is the move that costs the half point. There was still a win but it was considerably narrower than it needed to be. 42...Kc2 43.Nc5 b6 44.Nd7 b5 45.cxb5 cxb5 46.Nc5 Kb2 47.Nb7 a4 48.bxa4 bxa4 49.a3 Ne1+! 50.Kxh2 Nd3!

and the White knight can't get on a track to stop the pawn. 43.cxb5 cxb5 44.Nc5+ Kc2 45.Nb7 a4 46.bxa4! bxa4 47.a3 Kb3 It's too late to win with 47...Ne1+!? but it was a better practical chance as White still has to find a few more accurate moves 48.Kxh2 Nd3 49.Nd6 Kb3 (49...Ne5 50.Ne4 Nd7 51.Nd6 Kb3 52.Ne4!) 50.Nc8 Kxa3 51.Nb6 48.Nc5+! Kxa3 49.Nxa4 I offered a draw here, as a way to tell him that I knew it was a draw in case he didn't. He only punished this inappropriate offer by playing a couple of more moves. 49...Kxa4 50.Kh1! Kb4 51.Kg2 1/2-1/2

8/12/20 - BCE-213, Nimzowitsch-Tarrasch, Bad Kissingen, 1928

This week's BCE position is from a game between the two great rivals, Aaron Nimzowitsch and Siegbert Tarrasch, at the 1928 Bad Kissingen tournament. I've already talked some about that tournament, won by Bogoljubow. Nimzowitsch finished 5th on +1, while Tarrasch was next to last with -3. Nimzowitsch reached a pawn up ending, but with opposite colored bishops after 38.Bxe7

38...Kb7 Black could even start with 38...Bb5 39.Kh2 The starting position of BCE-213 39...c4? 39...Bb5 is the subject of the BCE correction intending 4 0.Kg3 Bf1 putting the pawns in the crosshairs. IM Gyula Meszaros gives another way to draw 39...f4 40.Bg5 e3 41.fxe3 fxe3 42.Bxe3 Bg6 43.c3 Bb1 44.a3 c4 45.g4 b5 46.Kg3 Kc6 47.Kf4 Kd5 48.Kg5 Ke6 49.Kh6 Kf7 50.h4 Bd3 51.h5 Bc2 52.g5 Bd3 53.b3 cxb3 54.Bc1 Be4 55.a4 (55.c4 bxc4 56.Bb2 Ke6 57.g6 hxg6 58.hxg6 Bxg6 59.Kxg6 c3 60.Bxc3 b2 61.Bxb2 Kd5 62.Kf7 Kc6) 55...bxa4 56.c4 Ke6 57.g6 hxg6 58.hxg6! Bxg6 59.Kxg6 Ke5 60.Bb2+ Kd6 61.Ba3+ Ke5 40.Kg3 Kc8 41.Kf4 Kd7 42.Bb4 Ke6 43.Bc3 Bd7 44.g3 b5 45.Kg5 Kf7 46.h4 Bc8 47.Kh6 Kg8 48.b3 cxb3 49.cxb3 f4 50.gxf4 Bd7 51.Kg5 Kf7 52.f5 Bc6 53.Kf4 Ke7 54.Ke5 Be8 55.Kxe4 Bc6+ 56.Ke5 Be8 57.Kd5 Bf7+ 58.Kc5 Be8 59.Be5 Bd7 60.Kb6 Kf7 61.f6 Be8 62.f4 Ke6 63.Ka6 Kf7 64.b4 Ke6 65.a4 bxa4 66.b5 1-0

8/5/20 - BCE-298, Rinck 1914

I'm back with more BCE corrections after a couple of weeks off. This week's BCE position is a study by Henri Rinck that appeared in Deutsche Schachzeitung in 1914. As I was unable to find any scans of that year's issues, I don't know if the error was in the original or added by Fine. To make up for a couple of weeks with no corrections, I'll give a bonus correction for a position from one of Benko's games that he added to this section in the revised edition of BCE.

The 1958 Interzonal tournament in Portoroz, Yugoslavia (in present day Slovenia) is best know for the fact that a teenage Bobby Fischer qualified for the Candidates Tournament. However, Benko beat Fischer in their head-to-head encounter and finished ahead of him to also qualify. Benko had a nice endgame save as Black against Hector Rosetto in round 2. After 47...Kd7

48.Rd4+? Handing Black a critical tempo. White should immediately go after the g-pawn 48.Rg4 Nh4 49.Rxh4 Rh1 50.Rg4 Rxh2 51.Kxb5 and wins 48...Ke6! 49.Rg4 Nh4! 50.Rxh4 Rh1! 51.Rg4 Rxh2! 52.Kxb5 The same position as the previous note, but the Black king is one square closer, which is enough to save the day 52...Kf5! 53.Rg8 Kf4! threatening to build a bridge with Rh5-g5, so White can't get his pawns moving yet. 54.Ka4 54.Kc4 Kf3 renews the threat to build the bridge. There is nowhere to hide by moving forward; 54.Kc6 Rh6+ 55.Kc7 Rh7+ 56.Kc8 Rh8 which should be a draw after 57.Rxh8 g1Q 54...Kf3! 55.c4 Rh1 56.Kb5 g1Q! 57.Rxg1 Rxg1!

This is the starting point of Position 609 in the revised edition of BCE. 58.c5 Benko also analyzes 58.a4 Rg8 59.a5 Rb8+? (Black needs to bring the king closer with 59...Ke4)60.Kc5! Rc8+ and White wins with 61.Kd5 (Benko's 61.Kd6? should be a draw after 61...Rxc4! 62.b5 Ra4! 63.a6 Ke4 (Instead of Benko's 63...Ra5? 64.Kc6 Ke4 which he abandons as a draw, but the winning method is well known 65.Kb6! Ra1 66.Ka7! and the b-pawn queens.) ) 58...Ke4 59.a4 Kd5 60.a5 Rg8 61.a6 Rb8+ 62.Ka5! Kc6 63.a7! Rg8 64.Ka6 Rh8 65.b5+! Kxc5 1/2-1/2

8/2/20 - TCEC Season 17 Superfinal, Games 17-18, Budapest Defense

At first I was going to pass over games 17 and 18, which seemed to be a weird sideline in the Budapest. Then, I read GM Sandler's raves about Lc0's play in the opening of this game and then noticed that both engines entered this sideline of their own accord and decided it merited further investigation.

1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 This was the starting position for this set of games 4.e3 I'm not aware that White is having any issues in the 4.Bf4 and 4.Nf3 lines, but both engines went for this modest pawn move 4...Nxe5 5.f4!?

I had once played this move, but in conjunction with 4.e4. In this particular position, I only knew the idea 5.Nh3 heading to f4 with more control over d5. The engines' idea seems to be that you can grab space, but not open the g1-a7 diagonal where a Black bishop can land. The setup is somewhat reminiscent of the Mujannah tabiya from the chess precursor game Shatranj.

The missing d-pawn doesn't seem to hurt White since the Black knights are far from the e4 square. There aren't a lot of games in the database with 5.f4, but White has scored a very healthy 72%. I tried it in an online blitz game and achieved a fairly easy win. White's structure gives him a nice space advantage and he still can pressure the d5 square. 5...Nec6 The earliest game I found with 5.f4 continued 5...Ng6 but it ended in a White win in Avram-Cramer 1968 US Open. The knight is still far away from influencing e4. 6.Ne2!? This was Lc0's novelty that got Sadler's praise. Stockfish went for more pedestrian development with 6.Nc3 and also got a nice position out of the opening, but Lc0 managed to hold a pawn down ending. 6...d6 One of the points of delaying the development of the queen's knight is to challenge the long diagonal after 6...g6 7.Bd2 Bg7 8.Bc3 7.b3 Bg4 8.Nbc3 Be7 9.g3 Bf6 10.Bd2 This move looks weird since earlier White was play involved trading the bishops on the long-diagonal. Now, Lc0 anticipates playing Nd5 and wants to grab the bishop pair rather than just exchanging bishops. 10...Bf3 11.Rg1 h6 12.Kf2 Bh5 13.g4 Bg6 14.Rg2 freeing g1 for the king. Despite all the moves that looked strange to the human eye, Lc0 has a very nice position, although Stockfish did manage to hold the draw. Overall, it looks like White has another variation to give Budapest players headaches.

7/19/20 - Bereolos-Kudrin, 1997 Chicago Open

I remember being quite frustrated by my loss against Sergey Kudrin in the 1997 Chicago Open. I knew I should be losing such an equal position, even against a strong player. My major mistake was making exchanges that improved his position. As the tide turned, I didn't put up maximum resistance either. However, the story ends on a good note as a scored 2 wins and a draw in the last 3 rounds to tie for 10th and collect what was my largest prize ever.

7/15/20 - BCE-94, Brinckmann-Rubinstein, Budapest 1929

This week's BCE correction is one of Rubinstein's classic pawn endings. I'm not sure why Fine tried to improve on Rubinstein's clear and logical play in this one.

The 1929 tournament in Budapest was fairly strong, although it was missing Alekhine and Bogoljubow who were playing their world championship match. Capablanca won convincingly with an undefeated 10.5/13 over second place Rubinstein a full point behind. Rubinstein's opponent in this game, Alfred Brinckmann finished near the bottom with 4 points.

In the game of interest, Brinckmann had an extra pawn after 59...Kxe6, but he is dead lost.

Black has all the advantages: there are a bunch of White pawns stuck on the same colored square as the bishops, the Black king is more active, Black has more space with a potential breakthrough on the queenside with b4 and d4, and the extra White pawn is a worthless doubled pawn that Black soon recovers. Rubinstein brought the point home smoothly. 60.Bd4 g6 61.Be3 Kf5 62.Kc1 Bf4 63.Kd2 Kxg5 64.Ke2 Kg4 65.Bxf4 Kxf4! 66.Kf2 The starting position of BCE-94 66...Ke4 66...Kg4 is the subject of the BCE correction. 67.Ke2 g5 68.Kf2 d4 69.cxd4 Kxd4! 70.Ke2 b4! 71.Kd2 b3! 72.c3+ Ke4! 73.Ke2 Kf4! 74.Kf2 Kg4 75.Kf1 Kg3 76.Kg1 g4 77.Kf1 Kh2! 78.Kf2 Kh1! 79.Kg3 Kg1 80.Kxg4 Kxg2! 0-1 White gets to the queenside first, but Black's advanced b-pawn carries the day 81.Kf4 Kf2 82.Ke4 Ke2 83.Kd4 Kd2 84.Kxc4 Kc2 85.Kb4 Kxb2 86.c4 Kc2 87.c5 b2 88.c6 b1Q+

7/8/20 - BCE-229a

This week's BCE position is a continuation of last week's. Fine moves the pawn back a couple of squares and claims the position is still a draw. Hey's analysis in Deutsche Schachzeitung was followed up by some discussion that I assume came from Schlecter, as he was the editor. It was noted that in the ending of K+N+h vs. K, pushing the pawn to h7 too soon is a mistake and that was likely the cause of White not winning. The following positions and analysis are then given, which lay out the winning method for BCE-229a. First, Hey's position with the pawn on h6 instead of h7.

1.Ne6 Bh4 2.Nc5 Bd8 3.Nb7 Bc7 4.h7 when it is mate in 2. Next, it is shown that having the king on g8 makes no difference.

1.Nf5 Bf4 2.Ne7+ Kh8 3.Nc6 Bc7 4.h7 again with mate in two.

A more modern take on this position, which adds more preliminary play is the following study by Andrei Zhuraviev in 1995, which took a special first prize in the Jan van Reek 50th jubilee composing competition.

I'll just give the main line. You can refer to Issue 121 of EG for analysis of alternatives. 1.Nf3! Ke6 2.Kg5! Kf7 3.h6! Bd6 4.a4! a5 5.Kf5! Kg8 6.Kg6 Bf4 7.Nd4! Bd6 8.Nc6 Bc7 9.Ne7+ Kh8 10.Nf5 Be5 11.Ng7 Bd6 12.Ne6 Be7 13.Nd4 Bd6 14.Nf3 Bf4 15.h7 1-0

7/4/20 - TCEC Season 17 Superfinal, 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 Superfinal, 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 Superfinal, 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 Superfinal, 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 Superfinal, 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 Superfinal, 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.

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Stats since June 1, 2006