Too often, trading systems that looked good last year, in an advertisement, or during computer back-testing, lose money as soon as you start trading them. This book explains why that happens, and gives detailed techniques for developing systems that will be profitable.
I expected much more from this book, that is somewhat simple.
Author points to many basic subjects regarding developing a framework for testing strategies to trade, like doing statistical tests, measuring success with an objective metric, applying monte carlo methods, emphasizing correctly that only out-of-sample tests matter and such.
The book is bloated with AmiBroker screens/code, maybe useful for teaching absolute beginners on how to use the software, but nothing is treated in-depth here.
It could be a useful book for beginners, but even then, there are better options for that case, like Kevin Davey or Tomasini book.