This book is a must buy for tournament players who play the Pirc. Having gone through parts of this book I found the use to be typical for standard opening books. Although you have an obligitory introduction to each section that involves text, I found the conclusions to be fair, honest and reasonably thorough. What set the book apart from the rest is that it is from John Nunn. I feel that I can trust his opinions given his past work. It would have been nice and indeed enlightning, if John Nunn put in more text.

Content:
Nunn has selected 250 studies, checked them thoroughly using the best chess engines and annotated the positions in great details (approx. 75% of the book is just solutions). Majority of positions look like something that can happen in the real game, however, there are several "weird" looking setups. I consider myself very experienced in practical studies. I believe that solving clever practical study will improve your Endgame knowledge as well as enhance your calculation skills. I have constantly utilized studies in my personal training as well as with my students. I have to admit that the of the number of studies that I tried to solve from Nunn's book, almost all were very challenging and not as entertaining as I would expect.

Quality:
Certainly, this book is very high quality - both presentation and content. Nunn claims to have extensively check every study using the latest and strongest chess software available.

Who will benefit:
Composition/studies aficionado will enjoy this book. Also, extremely high rated player (GM or close strength) who run out of challenging studies to work on.

Overall:
I think that 99% of active players - from beginners through GMs will benefit much more from studying various Endgame books (including some of Nunn's own) then by studying this particular Nunn's book. The reason is that all good endgame books include practical studies and eliminate weird once, while mixing in some important theory. Also solutions are a lot more realistic and involve some strategic planning in addition to pure calculation that is common to studies. Thus you would improve your endgame skills and train calculation skills at once.

When I saw a title "Endgame Challenge" I was expecting a work similar to the book by John Hall with identical name. While not perfect, that book is one of my favorite Endgame exercise books. All of my students own it and utilize it a lot. In addition, you should have a good theory book - works of Fine, Averbach and Alburt (depending on your level) are among my favorite. Also, new book Fundamental Chess Endgames looks very interesting. I would also strongly recommend "Studies" CD from ChessAssistant.

Good luck!
Copyrighted by me!

This book is the worst of John Nunn. He can churn stuff out that is dry as sawdust. Perhaps the ultimate chess geeks can appreciate this. But I swear a computer could be writing this book. I have tried and tried again to read his books and they bore me into such a stupor that I contemplate giving up chess. On the other hand, this guy is a genius for getting GAMBIT up and running, and his Understanding Chess Move by Move is actually written by a human being! Having said all that, you should realize that I am not commenting at all on the substantive merits of this book--I am just saying, it is strictly technical stuff for hardcore chess geeks. There is NO personality here.

This book is probably most useful for players with ELO ratings above 1700.

When I was a Class C player I had a difficult time understanding the Sicilian defence. Black neglects development, and plays a move that immediately weakens d5. Nevertheless I found that a lot of my losses were indeed to Sicilians.

This book helped considerably to fill the void in my knowledge. Nunn gives an overview of each major variation (including some lesser played sidelines) and indicates the corresponding plans for White and Black. He backs up this discussion with game examples as well as some fairly deep analysis.

The book is not perfect. By trying to cover all major variations in one book, Nunn obviously sacrifices depth of analysis in some lines. For example the chapter on the Dragon variation could have used more depth. On the other hand, the Dragon variation alone has been the topic of entire books, so one can't fault Nunn entirely here.

Nunn's writing style is clear and concise and for the most part his analysis is objective. The book is easy to navigate and the binding is fairly sturdy.

The main benefit of studying this book is that one builds confidence in meeting the Sicilian defence. Although detailed analysis is given, inevitably the book will miss some lines that the player will encounter. Thus, the ideas behind the variations and the confidence to play the open sicilian are what I really gleaned from this book.

A good effort by Nunn. Not for beginners though. Additionally, the 3rd edition is out so I'm hoping that the third is as good as the 2nd.