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.