Corresponding Squares

My quest to learn 300 chess positions in 60 days is proving time consuming. Most of the time that I could spare today was expended laboring to understand number 37. The first day was a review of some pawn endings that I know: positions 151-155 in Thomas Engqvist, 300 Most Important Chess Positions (2018). My quest is an effort to read all of this book in less than two months. On the second day, I reviewed some Paul Morphy positions that I know well. An obscure line in the Slav Defense captured my interest yesterday. Today, I went back into endgames with numbers 156-160 in Engqvist. Number 157 is a much analyzed study by Emanuel Lasker (some books employ the version published by Gustavus Reichhelm after Lasker and he discussed Lasker’s composition).

First, I set up Lasker’s position on my iPad and spent some time analyzing it. Then, I played against the engine, backing up and trying again when I failed. I have worked with this position in the past and knew the basic ideas, but have not developed well my ability to calculate the whole series of corresponding squares. Looking for help drove me into other books on the shelf. I confirmed that Jeremy Silman, Silman’s Complete Endgame Course (2007) lacks the position. I know that corresponding squares are mentioned early in Mark Dvoretsky, Dvoretsky’s Endgame Manual (2003) and the concept is trumpeted in Paul Keres, Practical Chess Endings (1974). I opted to check John Speelman, Endgame Preparation (1981) and was pleased with the instruction.

Speelman offers a digested version of what he found in Yuri Averbakh and Ilya Maizelis, Pawn Endings (1974), which I consulted later in the day. My process was to read some in Speelman, and then construct a position derived from Lasker/Reichhelm. First, I sought to find positions with Black to move that were winning for White. With all the pawns fixed as in Lasker’s study, I placed the Black king on a8. Where must I place the White king for the position to be winning if Black is on the move?

Black to move

Then, I repeated the process with Black’s king on b8. After several such efforts, I went back to Reichhelm’s version of the original study and played against the computer. Then, additional modifications and more play against the engine.

This version was one of the easier ones.

White to move

After many hours of play against the engine and study of several books, I have the sense that I am beginning to scratch the surface of this difficult position.

Schlage -- Ahues 1921: Historical Inquiry

A substantial number of chess endgame books present a position said to have been from a drawn game between Willi Schlage (1888-1940) with White and Carl Oscar Ahues (1883-1968). The game was played in Berlin in 1921, but no event is listed. Nor has a complete game score appeared. Schlage missed a win, as later pointed out by Ilya Maizelis.

White to move

From this position, Schlage started well, but his second move demonstrated that he did not discover the critical idea.

1.Ke6 Kc3 2.Kd6 

Maizelis pointed out that 2.Kd5! would have won.

2...Kd4 3.Kc6 Ke5 4.Kb7 Kd6 5.Kxa7 Kc7 1/2-1/2

As this ending appears in Mark Dvoretsky, Dvoretsky's Endgame Manual (2003), the position is on one of my pawn ending flash cards. Many of my students have tried to find the solution and then had it shown to them. When I encountered it this morning in Paul Keres, Practical Chess Endings (1974), I wanted to know more about the game. Searching for a game score took me down a rabbit hole of book after book. If no game can be found, then perhaps I can trace the analysis back to first publication.

It certainly did not originate with Jesus de la Villa, 100 Endgames You Must Know Workbook (2019) that a Wikipedia editor referenced. To the credit of the Wikipedia editors, Keres is also credited with presenting this ending.

Keres does not credit Maizelis, but Dvoretsky does. Chess Informant's Encyclopedia of Chess Endings: Pawn Endings (1982) has the position as number 65 and credits Maizelis with the solution.

My next step is the inquiry was Pawn Endings (1974) by Yuri Averbakh and Ilya Maizelis. An editor added to the text: "Maizelis was the first to point out the correct solution. so position No. 78 must be credited to him. Rabinovich indicated this in the first edition of his book, Chess Endgames, 1927" (26).

Happily, Mongoose Press brought out an English edition of the second edition (1938) of Rabinovich's text: Ilya Rabinovich, The Russian Endgame Handbook, trans James Marfia (2012). Rabinovich credits "I.M.", which he calls a pseudonym, with mentioning in the Soviet magazine 64 (1925, No. 6) that White's king "should move according to the most twisted, broken route" (as quoted by Rabinovich). Perhaps someone has access to old copies of 64 and can read Russian. I still have questions.