More Notes on Berger

Johann Berger, Theorie und Praxis der Endspiele (1890) systematically examines practical chess endings in a manner that ushered in the modern theory of the endgame. The book's availability has been enhanced by Google Books.

During my reading yesterday, some underpromotion exercises captured my interest. Berger credits Carl Ferdinand von Jaenisch as the composer. I played them out against Stockfish on my iPad and found the second one required some calculation to get the knight to its proper posting.

White to move

1.Rxg5+ Rxg5 2.fxg5 h2 3.g6 Kh3 4.g7 h4

White to move

White must underpromote to a bishop or knight to avoid stalemate. In this instance, a bishop is the better choice, but a knight can win.

Berger's second exercise from Jaenisch differs in the placement of two pawns.

White to move

1.Rxg5+ Rxg5 2.fxg5 h2 3.g6 Kh3 4.g7 h4

Now, while a bishop does not stalemate, it also cannot win. White must play 5.g8N.

5...Kg4

White to move

Berger's solution continues with 6.Nf6+. I played 6.Ne7, and the tablebases favor 6.Kxh2.

Preceding these studies, Berger offers a brief explanation of the square of the pawn. Following these, is a section on the opposition with several illustrative positions, culminating in this important one from Giambattista Lolli, published in 1763.

White/Black to move

White to move wins; Black to move draws. For some reason, I found the draw hard to believe, but I've practiced the position against students many times since learning it more than ten years ago. Winning with White to move is one one of my requirements for the Bishop Award in my Scholastic Chess Awards.