19 May 2024

Distraction

This morning’s tactics session as suboptimal. After solving the first one correctly, I did so poorly that I dropped my rating 98 points from 3038 to 2940. I continued to solve with increased determination, ending at 3004. The last exercise, which I solved correctly in 4:59, offers a case study in distraction. How often do we focus on one area of the board, completely oblivious to what else is happening somewhere else.

I spend most of five minutes trying to make something work on the queenside, noting the threatened knight fork if my queen strayed. I looked at the contact between the bishops. In the last few seconds after expending so much time looking at unproductive lines, I noticed Black’s fatal problem on the kingside and executed the simple mate in two.

15 May 2024

Self-propelled Pawns

For several years, I have used the term "self-propelled pawns" for two connected passed pawns in rook endings. I do not know whether I made up the term or read it in a book. Nonetheless, it is usually fairly easy to win such positions. Reuben Fine, Basic Chess Endings (1941) wrote, "connected pawns always win unless they are blockaded" (317).

During the 25% off sale earlier this week, I took the plunge and upgraded from ChessBase 15 to ChessBase 17. The new version lacks a feature that I regularly use: endgame keys. However, the help files suggest a different method of finding particular types on endings: similar endgames under report (see image).

I tried the new method this morning and was not surprised that Megabase 2024 contains many thousands of games with two connected passed pawns in rook endings. Naturally, I started looking for games when the stronger side failed to win. In most cases, the ending was misplayed.

I had the position above a year ago in a 16 minute game on Playchess. I finished the game checkmating my opponent 20 moves later using 3 seconds per move or less on all but five moves. 9 seconds was the longest.

I do not have access to the time per move nor time remaining for those games that were drawn, although winnable. Even so, perhaps the errors are instructive.

Black to move
This position was reached in a game played in 1998. Black, rated 1355, played 69...f4 and the game was drawn after 70.Rf8. 69...Kg4 would have been my choice and Stockfish confirms that Black is winning.

In a game played in 2003 between two 1500s, the two pawns plus rooks ending was reached on move 47. Black made progress advancing his pawns over many moves. Even here, after 87.Rd5+, Black was winning.

Black to move
87...Rd3 88.Rxf5 Rf3+

This move throws away the win. 88...e3 was the only way to keep the win in hand.

Black to move
Black, rated 1598, spoiled the win with a move that reminded me of a position from Kling and Horwitz (1851) and posted as "Elementary Technique" a month ago.

62...Re5+

I would have played 62...Re1, which is one of several winning moves.

63.Rxe5 fxe5 64.Kxg5 and drawn.

White could have erred with 64.Kxe5, when the idea in Kling and Horwitz would secure the win for Black.

The final example is from a 2010 game between two stronger players in the championship of Chili.

Black to move
55...Kg8

There is nothing wrong with the move in the sense that it does not spoil the win. However, 55...h4 can be played. However, 56.Ra7 forces Kg8. 57.Rg7+ Kf8 58.Rh7 Ke8 and this line begins to resemble the game as played.

56. Rg7+ Kf8 57.Rh7 Ke8 58.Ke6 Kd8 59.Kd6 Kc8 60.Kc6 Rc4+ 61.Kd5

Black to move
61...Rc7 spoiled the win, which is not entirely simple. Tablebases assure us that 61...Rf4 leads to checkmate in 42 moves. Black's king is still cut off, though.

White found 62.Rh6! and a draw was agreed.

Exchanging rooks leads to an elementary winning pawn ending, while 62.Rh8 allows the Black king to become active.






14 May 2024

Easy Exit

This morning in an online 10 minute game, I knew I had an advantage, but suffered a failure of confidence without a clear checkmate. I forced a draw. The rating difference was such that the draw lifted me 6 points.

I had Black

White to move
32.a6

While replaying from the diagram against Stockfish, the machine played 32.Qc6. A queen ending was reached after the subsequent moves: 32...Ng3+ 33.Kh2 Ne2 34.Rxe2 Qxe2 35.Bc1 Qd1 36.Qc5 Qxb3 37.Bd2 h5 38.Bxb4 Rb8 39.a6 Rxb4 40.a7 Ra4 41.Qc8 Kh7 42.a8Q Rxa8 43.Qxa8

Black to move
Analysis diagram

My failure to convert the advantage in this ending highlights an area that deserves some study.

Returning to this morning's game.

32...Qe1+

32...Ng3+ is better.

33.Kh2 Qg3+ 34.Kg1

Black to move
At this point, I knew that I had an advantage and spent 58 seconds looking for a clear path forward. 

34...Qe1+

I opted to force a draw.

34...Ng5 created threats, but did not force matters towards a favorable conclusion.
I missed the option of returning to a previous position and easily winning White's rook. To wit, 34...Qe3+ 35.Kh1 Ng3+ 36.Kh2 Ne2 and White must give up the rook to stop checkmate.

The same situation would have occurred after 32...Ng3+

After the rook exchanges itself for the knight, Black's queen forks bishop and pawn.

White to move
I had no difficulty winning this position against Stockfish in my second battle with the silicon beat today.



30 April 2024

Inspired by Ruy Lopez

This morning I had a familiar position although the opening moves were not anything I recall playing before. The position was familiar because it had the same critical elements (pattern) found in a game Ruy Lopez played in 1560 and that appears in my book, Checkmates and Tactics (2019). The exercises in this book are those I've been using with scholastic chess players since 2006 as part of my award curriculum.

I had White in the 10 minute game.

1.e4 e6 2.c4 c5 3.Nf3 d5 4.exd5 exd5 5.d4 dxc4?! 6.Bxc4 Bg4?

Bad pins often backfire.

White to move
7.Bxf7+ Kxf7 8.Ne5+ creates a discovery against the bishop as well as forking king and bishop.

8...Ke8 9.Qxg4 Nf6 10.Qe6+

The game is continuing along the path shown by Lopez.

10...Qe7

White to move
11.Qc8+ Qd8 12.Qxd8

I considered 12.Qxb7, which Stockfish prefers, but reasoned that Lopez's combination was good enough to give me a clear advantage.

12...Kxd8 13.Nf7+

What we have of Lopez's game ends with this fork.

13...Ke8 14.Nxh8

My opponent made me play all the way to checkmate. Along the way, I won the other rook through another combination.

White to move
24.Rxe6

24.Rxb7+ is simpler and better.

24...Kxe6 25.Nc7+ Kf5 26.Nxa8

It's not often that I get to fork both rooks with my knights in the same game.

Lopez's game started with a King's Gambit Declined. His opponent is given in ChessBase Mega as Giovanni Leonardo da Cutri (spelling and name sequence differs from source to source).

1.e4 e5 2.f4 d6 3.Bc4 c6 4.Nf3 Bg4

The bad pin.

White to move
This position is number 21 in Checkmates and Tactics, available through Amazon both in print and Kindle versions. It is the third exercise in my Bishop Award set.

6.Bxf7+ Kxf7 7.Nxe5+ Ke8 8.Qxg4 Nf6 9.Qe6 Qe7 10.Qc8+ Qd8 11.Qxd8

Lopez's move is best, which differs from my game.

11...Kxd8 12.Nf7+





27 April 2024

Active King

In a ten minute game this morning, I struggled most of the game for equality. When my opponent erred in opting for a rook ending, rather than knight vs. bishop when his passed pawn likely would have cost me my bishop, I knew my drawing chances were good.

Then, while reviewing the game, I was surprised to see that a move that assured the draw was deemed an error by the website's game analysis feature.


Let's look at the critical position with normal diagrams (White on bottom).

White to move
I played 47...Kxf4, reaching an easily drawn ending that neither side should have difficulty playing.

This position, however, is winning for Black.

47...Rb2+ 48.Kf1 (Kg1 likely transposes) 48...Kf3

Leaving the f-pawn alone while creating mate threats was completely off my radar, perhaps because I knew there was no forced checkmate. The threats, however, gain something.

49.Kg1 Rb8+ 50.Kh2 Kf2

White to move
White is forced to move the rook and cannot attack my g-pawn.

51.Rh8 Rxb7 52.Rh6 Re7 

Black keeps mate threats alive.

53.Kh1

Black to move
Two of the roads that lead to victory from here are:

a) 53...Re6 54.Rh2+ Kg3 55.Rg2+ Kxf4 finally capturing the f-pawn!
b) 53...g5! 54.Rh2+ (54.fxg5 Kg3 and White must give up the rook to avoid checkmate) 54…Kf3

White to move
Black's g-pawn is untouchable due to the mate threat.

55.Rb2 Re1+ 56.Kh2 g4

I would have known that I was winning had I foreseen that I could reach this point.

It was good to draw a 2000+ rated player, but there was an instructive missed opportunity that I hope to remember.



24 April 2024

Three Blunders

In a ten minute game online, I struggled to get any advantage whatsoever against the Scandinavian Defense. Pieces were exchanged to lead to a rook ending with most of the pawns still on the board. Then rooks were exchanged. At the start of the pawn ending, there was some calculation needed because all of the pawns could move. I had White.

White to move
36.c4 e4+ 37.dxe4+ dxe4+ 38.Ke3 bxc4 39.bxc4

Black to move
39...Ke5??

This move was the first serious error of the game. 39...a4 was necessary. However, some calculation is needed to see that White gets no where after 40.Kd4 h5 (only move, and easy to miss) 41.c5 e3 42.Kxe3 (White could also opt for a queen ending that should be drawn with 42.c6 e2 and both pawns promote--Black's first; White's with check) 42...Ke5 43.c6 Kd6 44.h4

Black to move
Analysis diagram
44...gxh4 is the only move that holds the draw. 45.c7 Kxc7 46.gxh4=

Back to the game as played.

40.a4+- h5 41.g4 h4

White to move
White is in the driver's seat with a clear advantage and a clear plan. Sacrifice the passed pawn in order to penetrate on the kingside with the king and create another passed pawn. Promote it.

42.c5 Kd5 43.c6 Kxc6 44.Kxe4 45.Kf5 Kb4 46.Kxg5 Kxa4

White to move
47.Kxh4??

This seemingly obvious move throws away the advantage. Now both players get queens and White's extra pawn has no chance to advance.

47...Kb5 (or Kb4) 48.g5 a4 49.g6 a3 50.g7 a2 51.g8Q a1Q

White to move
Analysis diagram
47.Kf4! was the only winning move, but I did not consider it. Only after a quick and superficial glance at chessdotcom's computer analysis did I discover my error and begin the day's endgame lesson. The graph shows a brief moment of equality after I gained an advantage.

Play might have continued: 47...Kb4 48.Ke3 a4
If 48...Kc4 49.Kd2+-
If 48...Kb3 49.g5+-
49.Kd2 a3 50.Kc2 Kc4

White will eventually win Black's a-pawn and then return to the kingside with an easy winning pawn ending. Or, if Black tries to hang on to the a-pawn, White's g-pawn queens.

My blunder in a complex position was answered by the worst move of the game. My opponent placed his king where it would be in check when my g-pawn promoted.

47...Kb3??

The third and decisive error. The rest was easy.

White to move

48.g5 a4 49.g6 a3 50.g7 a2 51.g8Q+ Kb2 52.Qxa2 Kxa2 53.Kg5 Kb3 54.h4 Kc4 55.h5 Kd5 56.h6 Ke6 57.h7 Kf7

One square short.

58.h8Q 1-0

21 April 2024

Kling and Horwitz Defense

Questions arose while going over Ending 56 in Jesus de la Villa, 100 Endgames You Must Know: Vital Lessons for Every Chess Player, 4th ed. (2015), 129-132. Although de la Villa indicated that moving the king to the long side is an error while defending against a center pawn, his analysis showed that Black could hold. In one case, Black's king was on the long side while Black's rook harassed White's king from the short side. De la Villa was quick to point out that this plan fails against a c- or f-pawn, although it works against a center pawn. The technique, according to de la Villa is called the Kling and Horwitz defensive technique.

Curious, I dug into the newest endgame book on my shelf: Bernhard Horwitz and Josef Kling, Chess Studies and Endgames, updated and ed. by Carsten Hansen (2024). Quite a few endgame books were pulled from my shelf over the next few days as I studied the positions, analysis, and terminology.

First, I sought the original position in Kling and Horwitz. It was not a simple matter to find a position with any of the technique that de la Villa showed in 100 Endgames. I looked elsewhere for some clues to why the technique is dubbed "Kling and Horwitz".

Grigory Levenfish and Vasily Smyslov, Rook Endings, trans. Philip J. Booth (1971) credit Josef Kling and Bernhard Horwitz with the following position that is a win with White to move, but a draw if Black has the move.
Aleksandar Matanovic, Encyclopedia of Chess Endings, vol. 2 offers the same position flipped with Black's king on f7 and the other pieces on the d-file. It also is credited to Kling and Horwitz. Searching for the position in Kling and Horwitz, Chess Studies, or Endings of Games (1851) is a futile quest. The position appears no where in that book. Nor does Horwitz and Kling, Chess Studies and End-games (1889) offer it.

Sam Shankland, Theoretical Rook Endgames (2023) favors the term "long and short side defense", but does indicate it is also known as the Kling and Horwitz defense (27). Shankland also deploys the term, “botched Philidor defense” (27).

The position in Levenfish and Smyslov differs from one reached in analysis by Francois-Andre Philidor only in the significant placement of the defending king on the long-side of White's pieces. Philidor's analysis intended to show the pitfalls of the weaker side failing to maintain the rook on the sixth rank.

White to move
Philidor, Analyse de jeu des Echecs (1777)
1.e5 Rb6

Philidor asserts that if Black deserts the sixth rank with the rook before White pushes the pawn to the sixth rank, then White wins. In a variation, he attempts to show the necessity of the sixth-rank defense beginning with 1...Ra1. Philidor's variation bears some attention because, as has been shown by several writers, 1...Ra1 is not the error that Philidor thought. While the sixth-rank defense in his main line in simple and unbeatable, the positions in the variation have practical significance. It frequently occurs in play that a textbook Philidor position cannot be reached, and yet there are still ways to draw.

2.Kf6

Black to move
A position similar to this one is often presented in discussions of the Philidor position when it is the stronger side's turn to move. Black can no longer achieve a third- or sixth-rank defense because the pawn will block the check with an unstoppable mate threat.

However, Black can check from the rear. Philidor asserts that this defense fails if the stronger side plays it correctly.

2...Rf1+ 3.Ke6 Kf8

3...Kd8 does indeed lose.

4.Rh8 Kg7 5.Re8

According to Philidor, this is the only move that assures the win. In fact, as engines now confirm, the position has remained drawn the whole time.

5...Re1 6.Kd7

Black to move
6...Kf7??

No less than seven alternatives would have held the draw: Kg6, Re2, Re3, Re4, Rd1+, Rb1, Ra1.

7.e6+ Kg7

Philidor also offers 7...Kf6 8.Rf8+

8.Ke7??

After this error, Black can again hold the position. White’s rook needed to move from in front of the pawn to d8, c8, b8, or a8. The last seems most principled as it denies Black access to the a-file.

8...Re2??

From this point on, Philidor's analysis correctly shows how White wins.

8....Ra1 was necessary. With the king on the short side and the rook on the long side, Black is able to hold the draw either checking the king from the side or repositioning the rook behind the pawn to prevent its advance.

Jesus de la Villa explains the technique well using a position that he apparently composed.

Black to move
There may be worse places for Black's rook, but perhaps no worse ones where a draw is still possible. De la Villa writes, "I have deliberately chosen an unfortunate position for the black rook in order to illustrate all the problems that may arise" (129-130). He emphasizes that with a center pawn, placing the rook behind the pawn can hold a draw, "even if the defending king is forced to the long side" (129). In his analysis, Black's king is not forced to the long side, but rather moves there deliberately so that de la Villa can best illustrate the drawing technique even when there are difficulties.

Nine moves into his analysis, the position in Levenfish and Smyslov is reached.

1...Rf1 (Rf2, f3, and f4 all work, too) 2.Kd6 Re1

"This is the K&H 'trademark'. The rook stands behind the pawn to prevent its advance", according to de la Villa (130).

3.Ke6 Kd8 (Kf8 is the correct way to proceed, but this "error" is not critical).

4.Rh8+ Kc7 5.Kf6 Kd7

This important move was missed by an online opponent of mine a few months ago, allowing me to show my handling of the Lucena position.

6.Rh7+ Ke8

Returning to the promotion square should always be part of the weaker side's defensive strategy.

7.Ke6 Kd8 8.Rh8+ Kc7 9.Re8

"The only serious attempt to make progress" (De la Villa, 131). The position is similar to the one where Philidor wrote, "This is the only move which can assure you the game" (Analysis of the Game of Chess, 1777, 279).

Black to move
9...Rh1

Black prepares side checks from the short side.

10.Rf8 Re1

The rook returns to behind the pawn.

De la Villa's analysis ends here. Levenfish and Smyslov carry it one move further.

11.Rf2 Kd8

The position in Levenfish and Smyslov and after the ninth move in de la Villa appears in a variation in Dvoretsky's Endgame Manual (2003). Missing from Dvoretsky is credit to Kling and Horwitz. In fact, Dvoretsky gives the ideas without crediting any endgame theorists or composers from the past. With the 5th edition (2020), however, credit is given to Max Karstedt. I have not confirmed that the 3rd and 4th editions do not credit Karstedt because I do not have them at hand, but my hunch is that this bit of information represents Karsten Mūller's editorial contribution.

The Karstedt Maneuver 


Ilya Rabinovich, The Russian Endgame Handbook, published in the Soviet Union in 1938 credits Karstedt and does not mention Kling and Horwitz. Yuri Averbakh, Comprehensive Chess Endings, vol. 5 Rook Endings was first published in 1984 in Russian, then in 1987 in English translation. Averbakh writes about this position:

Black to move
"Philidor thought that ... Black could draw only by 1...Rb6, and that any attempt to attack from the rear--1...Rb1 would lose. But Karstedt showed that this is not so, and later analysis by Berger, Cheron and Rabinovich basically confirmed his conclusions" (123). Having spent some time studying Rabinovich's analysis before I found this statement by Averbakh, I created with some help from Stockfish the analysis of Philidor's discussion that I present above.

Inasmuch as Kling and Horwitz's work is readily available both the originals digitized and accessible through Google Books and through Carsten Hansen's new republication of the later text, which wholly absorbs the 1851 text, I am satisfied that the term, "Kling and Horwitz technique", is an error.

If I could locate Max Karstedt's original analysis, I could be certain that the "Karstedt maneuver" is the correct term. However, Kartsedt left us no books. He did compose about 150 studies. None of those available in Harold van der Heijden's Endgame Study Database show this technique. Karstedt is not well-known. There is a Wikipedia article about him that offers a references to a secondary publication: Siegbert Tarrasch's book on the 1906 Nuremburg tournament. A few copies are available, but not at a price I'm willing to pay. This secondary reference is Wikipedia’s source for an article by Karstedt that is said to have his appeared in "German Weekly Chess" (presumably Deutsches Wochenschach).*

A date of 1897 is given for Karstedt’s correction of Philidor in several texts, but reference to an original source appear in none of the chess books I checked. My best clue as to where to look comes from Siegfried Hornecker, "The Unknown Soldiers I", ChessBase News (30 May 2020). Hornecker cites Die Schwalbe (February 2018), where Günter Büsing states that Karstedt wrote for Deutsches Wochenschach and Deutsche Schachblätter. This makes the Wikipedia reference possibly accurate. Although some issues of both of these periodicals can be found online, the 1897 edition of Deutsches Wochenschach is not available, and the other periodical began in 1906. With access to the 1897 issue of Deutsches Wochenschach, I would expect to be able to locate an article by Karstedt. It would be an interesting read.

Lacking appropriate primary sources, I might choose to trust Rabinovich, Averbakh, and Müller. Alternately, I might consider the term Karstedt maneuver speculative.

Whatever name is employed, it is worth learning. For that, Jesus de la Villa and Sam Shankland both offer exceptional in-depth analysis.


*Wikipedia shuns any work that appears to be “original research”, and hence has a built-in preference for a secondary work that mentions Karstedt, such as Tarrasch, over anything Karstedt may have written. I’m not certain whether there is a preference for translated names of publications, or whether this is simply sloppy editing.






15 April 2024

Elementary Technique

Josef Kling and Bernhard Horwitz, Chess Studies, or Endings of Games (London, 1851) was one of the earliest books to emphasize chess endings. It was written in English descriptive notation, so even the presence of a free digital version does not make it particularly accessible to today’s chess players. Happily, Carsten Hansen has brought out a new edition containing the text of the 1851 edition, an expanded edition Horwitz was preparing when he died, and thorough analysis of their work. Hansen’s edition is published as part of his Alexander Game Books Classics series, available through Amazon.

A position in the original 1851 edition will serve as part of my lessons with young chess players this week, as it offers some elementary instruction in techniques that every chess player needs.
Kling and Horwitz note the beginner’s tendency to prematurely push a pawn—something I’ve observed in many hundreds of youth games over the past couple of decades. They note that rooks can be forced off the board, leading to an easily won pawn ending. When I played it against Stockfish, I reached a position that is also reached when playing the first and most elementary position in the book.

After the moves given by Kling and Horwitz, 1.Re3+ Rxe3 2.fxe3, Black is in zugzwang. Black loses because required to move. Were it White’s move, the game would be drawn.

Black to move
2…Kxe3

This move is marginally more testing than 2…Kxg3. In both cases, White will employ the same technique to bring the remaining pawn close to promotion. But, with the g-pawn, there will be stalemate dangers that do not surface while trying to promote the e-pawn.

Here, again, the beginner must learn not to hastily push the pawn. Rather, White’s king must work its way in front of the pawn to control the key squares.

3.Kg2 Ke4 4.Kh3 Kf5 5.Kh4 Kg6

White to move
The beginner’s game begins to improve when they learn to move the king in front of the passed pawn. Such placement is as vital for the defender as for the stronger side. 

6.Kg4 Kf7 7.Kg5 Kg7

Black, seizing the opposition, puts up the most stubborn defense. Now, and only now, White may advance the pawn. In this case, that takes the opposition from Black.

8.g4 Kh7

White to move
Once beginners have learned to curb the tendency to push the pawn too soon, and have learned the concept of gaining the opposition, the next step is to understand that opposition is only a means to an end. Here, taking the opposition fails to make progress. White must perform an outflanking maneuver to gain control of one of the key squares—f7, g7, h7.

9.Kf6 Kh6 10.g4+ Kh7

This is the first position in Kling and Horwitz, Chess Studies.

11.Kf7 Kh8

White to move
Now, White must be wary of the stalemate danger.

12.Kg6

12.g6 would leave Black no legal moves, ending the game with a draw.

12…Kg8 

White to move
13.Kh6

13.Kf6 does not spoil the win, but the game must return to the same position for another opportunity to play the correct move.

13…Kf7

The engine opts for the longest distance to mate. While testing students, I choose 13…Kh8 so they must show that they understand that pushing the pawn works here. 14.g6 Kg8 15.g7 Kf7 16.Kh7.

For my beginning students, we are likely to continue all the way to checkmate.