In this book Euwe showed the historical progression of theory through annotated games. The Development of Chess Style was first published in 1968 and Euwe's writing style is somewhat dry and formal, but what is important is his explanation of chess style and theory.
His chapter on Steinitz is a clear, no, brilliant, presentation of Steinitz' theories. Euwe's annotations are clear and concise and lower rated players cannot help but benefit from them.
This edition has benefited a lot from updating by GM Dr. John Nunn. Nunn has added footnotes and made some major corrections to the annotations that have enhanced Euwe's presentation. Nunn also converted the book to algebraic notation. Nunn rewrote the chapter on the Soviet School and added new chapters on Fischer, Karpov, Kasparov, Anand, Kramnik and Topalov. He discusses their styles, contribution to theory and added annotated games. Unlike Euwe, he spices things up with a little humor, but does not get ridiculous to the point of being flippant.
On the down side, guys like Louis Paulsen who was a pre-Hypermodern whose play actually gave birth to some of Steinitz' theory and Adolf Anderssen is pretty much ignored. Euwe, a modest man, also ignores his own contributions to chess, giving only scant examples from his play. In what I find as a rare tribute, Euwe gives attention to contribution to theory by Flohr and Bogoljubow not exactly major players when it comes to cintributing to the development of chee, but apparently, Euwe thinks they had something significant to offer.
Euwe's opinions are sometimes at odds with other authors. Euwe, while clearly admiring Lasker, claimed that it wasn't possible to learn much from him. Reuben Fine, on the other hand, claimed that chess players are Lasker's pupils. It should be pointed out that Andrew Soltis attempted to clarify Lasker's importance in his excellent book, Why Lasker Matters. Nobody pays any attention to Lasker today, but Soltis shows how "modern" Lasker was. He took risks when necessary, made positional sacrifices, knew when to transition into the ending, used psychological evaluations of his opponents to his advantage and was often more concerned with making practical moves than the theoretical best.
What does this book do for the improving player? It will help in understanding of the concepts that today's chess is built upon. The 61 games teach the fundamentals of positional play. Development, mobility, the center, king safety, weak squares, pawn structure, Q-side majority, open files, two bishops, material advantage are the building blocks by which superior positions, usually culminating in tactical fireworks, are built. The best part is that you absorb all the information on what today is a neglected area on a way that is actually fun and painless. You'll enjoy the book and at the same time pick up a knowledge of positional play that cannot hurt your game, only help it. It's also cheap compared to a lot of chess books on the market these days and they don't have half the substance. Love this book.