Shakmaty Bereolos - The Official Chess Site of Peter Bereolos

9/30/18 - Bereolos-Burke, 2018 US Masters

After my first round upset there was no doubt I would have another GM opponent in Round 2 at this year's US Masters. I faced one of the many rising young stars of US chess, 17-year old John Michael Burke. This tournament was a great success for John. He was part of the large tie for first place, then held off his fellow 17-year old, Jeffery Xiong in the Armegeddon game to take the title.

I was relatively satisfied with the game I played against him. I felt like I was pressing for a bit, but that reversed when I couldn't play 25. a4 fixing his b-pawn, because of back rank problems. In an usual case where passive defense would have been the right solution, my active defense backfired when he calculated further than I did.

As a weird side note, this is not the first time I played John Burke in this tournament. Back in 1986, when the tournament was still known as the Midwest Masters, I lost to John Burke of Illinois in a painful finish after 34.Ra7

34...Ne5?? too focused on my own threats, I overlook a simple mate 34...Rf8 35.Nxd6 Nxd6 36.Rxd6 Rxb2+ 37.Kg3 c4 38.Rdd7 Rc8 39.Rxh7+ Kg8 and because of the Black pawns, White has nothing more than perpetual check. 35.Nf6 Nd3+ 36.Kg3 1-0

9/28/18 - Bereolos-Parry, 1998 The Living Legend

Here is another example of misadventure in R+2 connected passers vs R+1 from one of my own games. This game was against Michael Parry at The Living Legend tournament in 1998. The Living Legend tournaments were an annual event put on by the Chattanooga Chess Club to honor their senior member Rea Hayes who was born in 1915. Sadly, Rea is no longer with us, but his memory is still honored each year with the Rea Hayes Open.

To stick with the current theme, I'm just going to present the 7-piece portion of the ending. There is plenty to look at in the entire rook ending, but I'll save that for another post. With the Black pawn close to the White ones, White should be able to coordinate his king and rook to win the black pawn. After 42.Rxa6

46...Kd7 42...Rb2 43.Re6 Re2 44.Kg1 Kd7 45.Rf6! Ke7 (45...e4 46.h4 e3 47.Rf3 Ke6 48.Kf1!) 46.Rf2! 43.Rh6? I can't really explain this move. Why not the obvious king activation 43.Kg2! 43...Rb2 44.Kg1 Ke7 45.h4 e4 46.Rg6 Kf7 47.Rg4 e3? Black can hold the draw with 47...Rb4! 48.Kf1 (48.Kf2? e3+) 48...Kf6 49.Ke2 Rb3 cutting off the king, White can't win with the rook and pawns alone, somewhat analagous to the Thomas-Alekhine ending. 50.h5 Ra3 51.Rg6+ Kf7 52.g4 Rh3 48.Re4! After this White has no further troubles. 48...Rb3 49.Kf1 e2+ 50.Kf2 Kg6 51.Rxe2 Rc3 52.Re3 Rc2+ 53.Kf3 Rh2 54.Kg4 Rh1 55.Re6+ Kg7 56.Kh5 Rg1 57.g4 Kh7 58.Re7+ Kg8 59.g5 Kh8 60.Kg6 1-0

One big lesson from this ending. King activity is of massive importance in the endgame. White's non-sensical 43. Rh6? instead of 43. Kg2! should have cost me a half point. Black returned it with 47...e3? which let White free his king, after which the win was smooth.

9/26/18 - BCE-358, Reshevsky-Alekhine, AVRO 1938

I'll stick with the two versus one with connected passers theme for this week's BCE entry. Like last week, it is a Reshevsky game. This time versus World Champion Alekhine in the famous AVRO tournament of 1938, which some judge as the strongest tournament in history featuring the top 8 players in the world at the time

This ending has been heavily analyzed in the endgame books with Reshevsky missing a win prior to the BCE position. I want to just focus on the last move of the game where the BCE error occurs. In the following position, Alekhine played 63...Kb4 and the draw was agreed

In the revised edition, Benko stops here, as do Levenfish and Smyslov. Fine continues on with 63...Kb2 , which he calls folly. Minev is even harsher, calling it insanity. On the other hand, Dvoretsky says there is no reason for Black to play 63...Kb2, but he seems not to be losing even after that move . I'll point out that there is one way for White to go wrong after 64. h4 b1Q 65. Rxa1! Kxa1 66. g5 Dvoretsky's line beginning with 66. h5 is a surer way to go, but 66. g5 was Fine's line 66...Rh2 67. Kg4 Kb2 68. g6 Kc3 Here, if White tries to press his luck with 69. Kg5? attempting to advance both pawns, Black wins with 69...Ke5! 70. g7 Rg2+! 71. Kh6 Kf6! winning the g-pawn and the game.

9/25/18 - Aithmidou-Li, 2018 Batumi Olympiad

The Olympiad is off and running. Already in the first round some games caught my eye. The top seed US and second seed Russia both won their matches 4-0, but China only beat Morocco 3-1 as Mohamed-Mehdi Aithmidou (2244) pulled off the huge upset against super-GM Li Chao (2708) on the 4th board. This was a very interesting rook and pawn ending. I've looked at similar endings (Klein-Bereolos in June and Thomas-Alekhine earlier this month), which showed how subtle it could be to win with 2 connected passed pawns against one. Here, they entered the rook and pawn ending after 68...Kxd6

White's first two moves are the only ones to win, but are fairly obvious 69.Rg6+! Kc5 70.Rc6+! Kd4 71.b6 Ke4 72.c5 Ra2+ 73.Kg1 Rb2

74.Rc7? This looks natural, ready to walk the pawns home with b7-c6-Rc8, but should have cost White a half point. The route to victory was 74.Rc8! Rb1+ 75.Kh2 f3 76.Kg3! Ke3 77.Re8+! Kd4 and now the c-pawn queens 78.c6 Rxb6 79.c7 74...Rb1+! 75.Kf2 Rb2+! 76.Kg1 Heading towards the queenside doesn't help 76. Ke1 Rb1+ 77. Kd2 f3! with enough counterplay. 76...Rb1+! 77.Kh2 f3! 78.Kg3 Ke3 79.Rf7 The difference from putting the rook on the eighth rank on move 74 is shown by the variation 79.Re7+ Kd4 80.c6 Rxb6 81.c7 Rc6 stopping the pawn 79...Kd4! 80.Rf5 Ke4? 80...f2! 81.Kxf2 Rb3! is a positional draw.

The Black king stays on d4 or c4 to tie the White rook to the c-pawn. The Black rook stays on the b-file to prevent the advance of the pawns; either on b3 to prevent the White king from advancing up the board or safely on b5 if the White king comes over to the queenside. 82.Ke2 Kc4 83.Kd2 Kd4 84.Kc2 Rb5! 85.Rh5 Kc4!

81.Rf8 getting it right this time 81.Rf7? Kd4! would again be a draw since the c-pawn won't queen. 81...Kd5 82.Rc8 Rb3 83.Rc7 Ke4 84.b7 Rb2 85.c6 Rg2+ 86.Kh3 Rg8 87.Rf7 White will give his rook for the f-pawn, then the White pawns will queen. 1-0

9/24/18 - Bereolos-Wojtkiewicz, 5th Joe Sparks Open, 1989

I had originally intended my first meeting with Aleks Wojtkiewicz to be the next posting for my games versus GMs section. However, when reasearching the details from that time, I realized that Wojo was still an IM at the time. He didn't receive the GM title until late 1990. Still, since I had put in work annotating the game, and it fits in well with the endgame analysis I have been doing, I'm posting the whole game.

This game was pretty tragic from my point of view. From a balanced 4 Pawns Attack position, he began to drift and I achieved the e5 break without need of sacrifice. After getting a winning position, I let him muddy the waters a bit with a queen sacrifice, but was still winning. In some time pressure, I played a very loosening move that let him equalize. After giving the queen back and landing in a drawn ending, I played a dubious move on the last move of the weird 46/2 time control. Amazingly, the position was still a draw until a final blunder sealed my fate.

1.d4 Nf6 2.c4 c5 3.d5 d6 4.Nc3 g6 5.e4 Bg7 6.f4 0-0 7.Nf3 e6 8.Be2 exd5 9.cxd5 Bg4 10.Nd2 Bxe2 11.Qxe2 Nbd7 12.0-0 Re8 13.Qf3 a6 14.a4 Qc7 15.Nc4 Nb6 16.Na3 c4 17.Be3 Nbd7 18.Rae1 Re7 19.Bf2 Rae8 20.Kh1

20...Rc8 a sign of uncertainty, but the natural 20...Nc5 gets hit by the breakthrough 21.e5 dxe5 (21...Nd3 22.exf6 Nxe1 23.Qd1) 22.d6 Qxd6 23.Nxc4 Qc7 24.fxe5 Nfd7 25.Nd5 21.Bh4 Ree8 22.Re2 h6 23.Bf2 Nh7 24.Rd1 Nc5 25.Bd4 25.Nxc4 Bxc3 (25...Nxe4 26.Rxe4 Rxe4 27.Nxe4 Qxc4 28.Nxd6) 26.bxc3 Rxe4 27.Rxe4 Nxe4 28.Qxe4 Qxc4 29.Bd4 Nf6 looks about equal 25...Nb3 26.Bxg7 Kxg7 27.e5 dxe5 28.d6 Qd7 29.fxe5 Re6 30.Nd5 Rc6 31.Nxc4 Rxc4 32.Qxb3 Rc5 33.Qb6 Qxa4 34.b3 Qd4

35.Rxd4 White should win with 35.Red2 Qxd2 36.Rxd2 Rc1+ 37.Qg1 Rxg1+ 38.Kxg1 Re8 (38...Nf8 39.Nc7 Rxe5 40.d7) 39.Nc7 Rd8 40.e6; but the simplest win was likely 35.Ne3 Qxe5 36.Nf5+ Qxf5 37.Rxe6 fxe6 (37...Qxe6 38.Qxc5) 38.d7 35...Rc1+ 36.Rd1 Rxd1+ 37.Qg1 Rxd5!? trying to keep some complications 37...Rxg1+ 38.Kxg1 Nf8 39.Nf6 is killing

38.h4?! There is no need to weaken the g4 square and make this pawn loose. If white wants to make luft, then 38.h3 is the superior way to do it. The Black knight is returning to the game via f8 and d7, not g5. White doesn't need to rush to make luft and can instead target f7 in order to make Black give up a pawn in order to eliminate the pawns on e5 and d6: 38.Qf1 Nf8 39.Rf2 f5 40.exf6+ Kf7 41.h3 38...Nf8 39.Qb6 Nd7 40.Qxb7 Rd1+ 41.Kh2 Nxe5 thanks to the move h4, Black is back in the game. 42.Qxa6 Ng4+ 43.Kg3 Rexd6 44.Qxd6 Rxd6 45.Kxg4 Rd4+

46.Kf3?! It was time to head for the draw with 46.Kh3 Rd3+ 47.g3 Rxb3. I knew that was a drawn ending (I had even held it with ease against William Harris in the 1981 Master Challenge) but out of momentum I keep playing for a non-existant win. 46...Rxh4 47.Rb2 Rb4 48.Ke3 Kf6 49.Kd3 Ke5 50.Kc3 Rb6 51.b4 Rc6+ 52.Kb3 f5 53.b5 Rc1 54.b6 Kd6

55.Ka4? The final blunder. 55.Ka2! Rc8! 56.b7! Rb8! 57.Rb6+! was still good enough to draw 57...Ke5 (57...Kc5 58.Rxg6 Rxb7 59.Rf6 =) 58.Kb3 g5 59.Kc4 (59.Kb4 f4 60.Rb5+) 59...f4 60.Kc5 g4 61.Kc6 f3 62.gxf3 gxf3 63.Rb2 Kf4 64.Kc7 Rxb7+ 65.Kxb7 Ke3 66.Kc6 f2 67.Rb1 Ke2 68.Kd5 f1Q 69.Rxf1! Kxf1! 70.Ke4 and the White king is back in time 55...Kc6! 56.b7 Ra1+! now the White king has to block the rook's protection of the pawn and White is lost. 57.Kb4 Kxb7 58.Kc5+ Kc7 59.Kd5 Re1 60.Ra2 Re4 61.Ra6 Rg4 62.Ra2 h5 63.Ke5 Kc6 64.Rc2+ Kb5 65.Rf2 Kc4 66.Rf4+ Kd3 67.Rf2 h4 68.Ra2 f4 69.Rf2 g5 70.Kf5 Rg3 71.Ra2 Ke3 72.Rb2 g4 73.Rb3+ Kf2 74.Rb2+ Kg1 75.Kxf4 Rxg2 76.Rb1+ Kh2 77.Ra1 g3 78.Kg4 h3 79.Ra3 Rb2 80.Rc3 Rb4+ 81.Kf3 g2 82.Rc2 Kh1 0-1

Lessons from the ending are reruns from the game against Colding: 1. Forget what happened eariler in the game. 2. Don't forget to consider backwards moves (55. Ka2! and earlier 35. Ne3)

9/23/18 - Batumi Olympiad

The biennial chess Olympiad starts today in Batumi, Georgia. Team USA will field the same lineup (Caruana, So, Nakamura, Shankland and Robson) that brought home gold two years ago. Most of the top players in the world, with the exception of World Champion Magnus Carlsen will be participating.

I've always felt that because the Olympiad is so huge, many of the games do not get alot of coverage in the mainstream chess media. Therefore, I'm going to try to add games from this years Olympiad into my regular rotation of posts. While I like to focus on my own games, there is much to be learned from the games of others. I have been getting a little of that from my BCE posts, but those positions are well worn and much of it just serves as an education into chess history.

If I can figure out a good method of presentation, I may throw in some opening theory as well as examination of interesting endings.

9/19/18 - BCE-226, Fine-Reshevsky, Semmering-Baden, 1937

Position 226 is from one of Fine's own games, with Reshevsky holding a draw despite being 2 pawns down in a knight vs. bishop ending.

Semmering-Baden was a strong 8-player double round robin including 5 of the top ten players in the world per Jeff Sonas' estimated ratings. Keres was the winner a full point clear of an undefeated Fine. Reshevsky tied for third with Capablance.

The real curiosity about this particular error in BCE is that Reshevsky repeated the variation in his book of best games. Both annotators give the move ...Kf3 an exclamation point, which I found strange since it allows the g-pawn some freedom. In BCE, Fine says that White can't win unless he gets his king to f3 or h4. So maybe Fine was considering something like the following. I'll use the move numbers from the game; the BCE position occurs after 77. Nf5.

77...Bb6 78. Kf1 Now, instead of 78...Kf3, I like setting up the blockade with 78...Bd8 White can get his king to f3 with 79. Kg2 Bf6 80. Ng3 Bd8 81. Nh5+ Kg5! 82. Kg3 Bc7+! 83. Kf3 but Black his holding easily after 83...Kh4

I frequently discuss the lead up to the BCE position if it has interesting points. I'll skip that this time because the lead up is covered by BCE #234, which will be the subject of a future post.

9/16/18 - Colding-Bereolos, 1999 World Open

I previously posted the ending of my game with Ernest Colding at the 1999 World Open in the context of Bishop vs Pawns. While that fragment contained an interesting drawing mechanism, the critical points were in the preceding Bishop vs Knight ending after 53. Bxe4

Black should be winning, but it is much closer than I thought at the time. 53...Kf6 54.b4 Ke5 55.Bh1 c4? wasting a crucial tempo. Better is the immediate 55...Nf4! 56.bxc5 bxc5 57.a4 Ne2 58.Kb2 (58.a5 Nxc3) 58...Ng3 59.a5 Nxh1 60.a6 h2 61.a7 Nf2! 62.a8Q h1Q

63.Qe8+ Kf4! (else Qf7+) picks up the knight. 64.Qf8+ Kg3! and Black should win with his extra piece as the knight fork on d3 prevents White from winning the c-pawn. 56.a4 Nf4 in my original notes, I thought Black still had winning chances with 56...Ne7 but I don't see much after 57.a5 bxa5 58.bxa5 57.a5 bxa5 Somewhat incredibly, this natural capture makes the path to a draw much narrower. Black also draws without the capture with 57...Nd5 58.a6 Nc7 59.a7 Kf4 60.Kb2 Ke3 61.Kc2 b5!

(61...Ke2? 62.b5! and White wins in similar fashion to the next note.)

58.bxa5 Ne6 59.a6 Nc7 60.a7

The position resembles a study with the pieces shuffled off to the corners. It makes a good calculation exercise, Black to play and draw. 60...Kf4? Black can only hold the draw by going after the c-pawn from the other side 60...Kd6! 61.Kb2 Kc5! 62.Kc2 (there is no way for the White king to come up the queenside since 62.Ka3? Nb5+! and Black wins; or 62.a8Q Nxa8! 63.Bxa8! Kb5!

Black holds in a manner that is similar to the end of the game. The Black king shuffles between b5 and a5 to keep the White king at bay, while if the bishop comes to c6 to take away b5, then Kb6.) 62...Kb5! 63.Kd2 Ka4! 64.Ke3 Kb3! 61.a8Q? too impatient. White needs to first activate his King to keep the Black king from penetrating too deeply. 61.Kb2 Ke3 62.Kc2! h2 63.a8Q Nxa8 64.Bxa8 Ke2 65.Be4 Ke3 66.Bd5+-

Black is in zugzwang and must give ground.

61...Nxa8! 62.Bxa8! The position from the original post. Black has to play a bunch of only moves, but they are not at all difficult. 62...Ke3! 63.Kb2 Kd2 64.Bd5 h2 65.Bg2 Kd3! 66.Bh1 Kd2! 67.Bg2 Kd3! 68.Bd5 Kd2! 69.Be4 Ke3! 70.Bd5 1/2-1/2

Lessons from this ending: 1. Analyze your games without an engine first. After you have put your thoughts and anlysis down, then check it with an engine. That way you can discover holes in your thinking. 2. Forget the earlier parts of the game. This is always difficult. In this game I had been winning for a long time, but by the time 60.a7 was played it is obvious that Black is now playing for a draw. This was a time for strong calculation in order to hold the half point. 3. Don't forget about backwards moves. Another hard thing to learn, especially with the King in the ending. I'm pretty sure I didn't spend much time on 60...Kf4? going forward instead of 60...Kd6! going backwards. 4. Don't rush There was not going to be any way for Black to stop the White pawn, so he should have improved his worse piece with 61. Kb2 instead of promoting with 61. a8Q?

9/12/14 - BCE-226b, a curious position

In position 226b, Fine tries to generalize a blockading bishop holding versus a knight and 2 connected passed pawns. However, this example would have better served as an example of the agility of the knight when it further away from the edge of the board.

Fine quotes this game as Perenny-Lowenthal, 1851. A search of my database did not turn up the game. A position search didn't find anything either. Then, I searched for any games by Perenny and came up empty so the hunt was on.

Looking through other endgame books, I came across Pereni-Löwenthal, London 1851 in Averbakh. The different spelling of the names is not surprising since it was likely translated into and out of Russian. The bigger surprise is that the position is a mirror image of that found in BCE.

Considering the vertical mirroring, Averbakh gives the same game continuation as Fine, 1. Nb5+ Kc5 2. Nc3 Bd8 3. Ne4+ Kd4 4. Nd6 Bg5 5. Ka4 Bf4 Unlike Fine, Averbakh shows the win with 5. Nb7 like I have with 5. Ng7 on the corrections page.

London 1951 is famous as the first international tournament, and Lowenthal was one of the participants. However, there was no player with a name resembling Perenny or Pereni, so I kept digging.

The original source may be from 1849 issues of the French Magazine La régence: journal des échecs . In the July issue under the heading Position Curieuse(Curious Position) We have the BCE position.

This time the game is given with Loewenthal playing White (blancs) and Perenny playing Black (noirs). I wonder if at some point there was a mistranslation of blancs as Black. That wasn't the only difference. The next month they give the "solution" 1. Ng5+ Kf5 2. Nf3 Be8 3. Nd4+ Ke4 4. Nb5 instead of 4. Ne6 as per Fine and Averbakh (4. Nd6) 4...Bd7 etc. with the conclusion that I have roughly translated as The game is drawn, but Black must avoid a fork, and the Bishop should remain as much as possible on the c8-h3 diagonal. Well, this is further strangeness as 4. Nb5 places the knight en prise. Perhaps there was a typo in the notation and 4. G52(Nb5) should have been 4. G25(Ne2). That is still different from 4. Ne6, but the followup 4...Bd7 trying to blockade then makes more sense as 4...Bb5 like BCE would get forked by 5. Nc3+ and 4...Bd7 wouldn't make much sense versus 4. Ne6 because of 5. Nc5+.

That is as far as I've been able to trace back. I looked in some subsequent issues of La régence to see if there was a correction or letter, but didn't find anything. So there seem to be many mysteries around BCE-226b including who played White, where and when the game was played (Perenyi is a common Hungarian name and Loewenthal was also Hungarian, but the Wikipedia indicates that Lowenthal emigrated to America in 1949), what was White's 4th move, and how did Averbakh end up with the mirror image position?

9/7/18 - Becerra-Bereolos, 2004 Emory/Castle Grand Prix

I've added my 2004 game against Julio Becerra to the GM games section. Much like our game the following year this one was a fairly one-sided Ruy Lopez with some theoretical interest.

For the most part, I kept the analysis from my tournament report. However, I've added quite a bit with respect to the opening as the move I played (14...c6) in a topical line of the Zaitsev has arisen from the theoretical scrap heap in recent years. I think this variation is very representative of modern chess. Although Black's position looks a bit ugly to the human eye, the cold logic of the engine shows the precise path for Black. Thus, the move gets resurrected and Black has been holding his own in recent years even thoughts the overally statistics are still heavily in White's favor.

9/5/18 - BCE-356a, Thomas-Alekhine, Hastings 1922

Position 356a is a bit of a strange one. Fine cites the game Thomas-Alekhine from the 1922 Hastings tournament with colors reversed. In the introduction Fine states that he uses White for the superior side when the position does not refer to specific players. I guess the argument could be made that Position 356a does not refer to the specific game because while Fine reversed the colors, he did not change who had the move. Unfortunately for Fine, this position was zugzwang, so he effectively gave Thomas a pass which changes the evaluation from win to draw.

Hastings 1922 resembles the modern day Dortmund tournament with 2 local players (Thomas and Yates) facing highly ranked foreigners (Alekhine, Rubenstein, Bogoljobov, and Tarrasch). Alekhine and Rubenstein were a cut above the rest with 7.5 and 7 out of 10 respectively, while the others finished with minus scores

Thomas gave Alekhine a tough time in their 3rd round encounter. Alekhine shed a pawn but managed to get compensation. When Thomas blundered, Alekhine regained his pawn and the game entered a rook ending after 45. Rxe4

45...Rg1 46.Rc4 White could also consider keeping the Black king from getting active with 46.f5!? Rg5 47.Rf4 Kg8 48.b4 Kf7 49.Rc4 Rxf5 50.Rxc7+ Kf6 51.b5 Rxd5 Black has won a pawn, but White has avoided giving him connected passed pawns and should hold the draw after 52.b6 46...Kg6 47.Rxc7 Kf5 48.Rd7 Kxf4 49.Rxd6 Rg3 50.Rd8 g5+ 51.Kh5 Rxh3+ 52.Kg6 Ke5 53.d6 Ke6 54.b4 g4

55.d7? In the tournament book, Alekhine points out the draw 55.b5 g3 56.Kh7! clearing the g-file for the rook 55...g3 56.Rg8 Kxd7 57.Kf5 h5! 58.Kf4 h4! 59.b5 Kc7 60.Rg6 Rh2 61.Kf3 Kb7

This is the BCE position with colors reversed, except it is White to play and he is in zugzwang. Alekhine finished it off cleanly 62.b6 Ka6 63.b7+ Kxb7 64.Rg7+ Kc6 65.Rg6+ Kd5 66.Rg8 Ke6 67.Rg5 Kf7 68.Rg4 Kf6 69.Rg8 Kf5 70.Rf8+ Kg5 71.Rg8+ Kf6 72.Rg4 Kf5 73.Rg8 Ke5 74.Re8+ Kd4 75.Rg8 Kd3 76.Rd8+ Kc3 77.Rg8 Kd2 78.Ra8 Rf2+ 79.Kg4 g2 80.Ra1 Ke3 81.Kh3 Re2 82.Rg1 Kf3 83.Kh2 h3 0-1

9/3/18 - Men-Bereolos, 1993 Columbus Open

I was on the defending side of N+2 vs. B+1 against Boris Men in the 1994 Columbus Open. I had sacrificed a pawn in the opening a la the Marshall Gambit and had missed a drawing combination in the middlegame and a way to equalize eariler in the endgame letting him finally consolidate his pawn advantage. The position after 44.Nxf5+ is much worse for the defending bishop than in the Friedman-Bereolos game since here White has two passed pawns.

44...Ke6 45.Ke4 Ba4 46.Kf4 Kf7 47.h4 Kg6 48.c4 Kh5 49.Kg3! Bd7 50.Nd4 f5 51.Nf3? Winning is 51.Ne2! bringing the knight to the perfect square f4.

51...Bc6? Black needs to keep the bishop on the c8-h3 diagonal in order to meet knight moves with f4+ winning the h-pawn 51...Be6 52.c5 (52.Ne5 f4+!) 52...Bd7 53.Ne5 (53. Kf4 Bc6 tethering the White king to the knight 54. Ne5 Bb5 is similar, but not 54...Be4 55. Kg3! winning because 55...f4+ 56. Kxf4! hits the bishop and 55...Bd5 allows 56. Nd3! and the knight comes to f4) 53...Bb5! dominating the knight 54.c6 f4+ 55.Kh3 Ba6 returning to the diagonal via c8 52.Nd4 Bd7 53.Ne2! Correcting the mistake from move 51. 53...Kg6 54.Nf4+ Kf6 55.h5 Be8 56.h6?

There is no need for this push. The Black king is already tied to the pawn, so White should just walk his king to the queenside to push the c-pawn and collect the bishop. 56.c5 Bc6 57.Kf2 and there is nothing Black can do 56...Bf7 57.c5 Be8! 58.Nd5+ It's too late to come to the queenside now, but Black does need to take a little bit of care 58.Kf3 Kf7 59.Ke3 Bc6 and Black is ready for K-g8-h7xh6 but not the immediate 59...Kg8? which loses to some beautiful knight maneuvers. 60.Nd5! Kf7 61.Ne7!

61...Bd7 else Nxf5 62.h7 Kg7 63.Ng6! Kxh7 64.Nf8+! 58...Kg6! 59.h7 Kg7 59...Kxh7? 60.Nf6+! 60.Nf6

Knight + rook pawn on the seventh is a draw, so Black can sacrifice his bishop for the c-pawn. 60...Bc6 61.Kf4 Bb7 62.Kxf5 Bc6 63.Ke6 Bb7 64.Kd6 Ba8 65.Kc7 Bf3 66.Kd6 Ba8 67.Kc7 Bf3 68.Kb6 Ba8 69.Ka7 Bf3 70.Kb8 Bc6 71.Kc7 71...Bf3 results in 3 time repetition 1/2-1/2

Lessons from this ending: 1. Know your fortresses. Without knowledge of the N+RP on seventh Black might even resign since he is losing his bishop. 2. Be aware of tactics even in simple positions. You need to spot tricks like 61. Ne7! and 63. Ng6! from afar. 3. Look for ways to stop your opponent from making progress. The variations after Black's 51st move really illustrate this. When I had previously analyzed this game, I did not find the idea with ...f4+ which keeps the knight tied to the h-pawn. This theme also presents itself with the bishop tying the king to the knight after 53. Kf4 Bc6 and the domination of the White knight on e5 with Bb5 in several variations.