A book for the serious player only. Paul Keres was one of the stronger players that never won the world championship. He defeated about 8 or 10 world champs in his day, however.
This is a book that ostensibly reaches out to beginning chess players by including instructions on basic endgame mates. (However, I wish he could've devoted more time to the bishop and knight mate. That one is very hard!)
I picked this book up toward the end of my serious chess studies. Full disclosure requires me to admit that I did not finish it. However, this content is a must for anyone wanting to take their game to the next level. There are tons of book out there that discuss how to open a chess game but what do you 50 moves later when most of the pieces are gone? This book gives a detailed examination of likely endgame scenarios. The analysis is very detailed. It will probably take you a long time to complete this book. Once you do, you should have an advantage over many of the players out there (provided you continue refining your endgame prowess). A good knowledge of the endgame will also help you formulate your strategy (mid-game). This book is an excellent vehicle toward that end.