Half-Way

The five positions from Thomas Engqvist, 300 Most Important Chess Positions (2018) that I worked through today were all familiar from endgame work I did with a student six months ago or so. Two--a simple Philidor Position and a Lucena Position--I have been teaching eighteen years. Although review, one position composed by Max Karstedt and published in Deutsches Wochenschach in October 1909 confused me slightly because Stockfish made a move that differed from the solution that I knew.

In my struggle with the difference, I made an inaccurate move that was still winning, except that I could not win it.

White to move

In Karstedt's solution, Black's rook is on h1. Hence, Rc6+ sets up a skewer if the rook is captured. Nonetheless, 7.Rc6+ is still the best move and after 7...Kd5, both Rc8 and Ra6 are winning with a shorter distance to mate after Ra6. If 7...Kb5, 8.Rc8 wins.

After some contemplation, I played 7.Rb1. The computer could have opted for the idea in Karstedt's study nonetheless: 7...Rg8+ 8.Kc7 Rg7+ 9.Kb8 Rg8+ 10.Kb7 Rg7+ 11.Ka6 Rg6+ 12.Ka5 Rg3 threatens mate if White promotes, so 13.Rb5+ Kd6 14.Kb6 Rg8 15.Ra5 and the pawn will promote.

Instead, Stockfish 16 played 7...Rxb1 and I spent the next ten minutes being reminded that I have not learned queen vs. rook well enough to succeed against software.

Today was the 30th day in my quest to race through this book at five positions per day instead of the recommended five positions per week. Even this relatively easy day added another item to my "to do" list that is growing because of this pace. Yesterday, three positions game me some difficulty and this morning I spend some time looking through the first few chapters of Yuri Averbakh, Rook v. Minor Piece Endings (1978). The endings of rook and pawn vs. bishop (chapter 3 in Averbakh) serve as an excellent supplement to some ideas that Engqvist introduced yesterday.

I have now completed the first 75 positions on the opening and middlegame, and the first 75 endgames in Engqvist's book. I am on schedule.