If you have read the fun*dart*men*tals review, I can only say this book is very different. But it's also a great dart book, and to me both books are equal good. Kari has a completely different approach than Frank. He is a Finnish research scientist, and he has made the first deep scientific study on darts. The Dart Book is the result of it. But if you think that such a scientific book would be impossible to read you are definitely wrong. It's clearly understandable with a certain but good sense of humor.
The main part of The Dart Book is a table of optimized play for the game of 501. Kari has calculated the best target for the first, second and third dart for every point standing in a 501 game. The results are given for beginner, average, expert and pro level according to the statistical spray of darts for each player class, and targets are optimized for the best winning percentage calculated as far as 15 darts ahead!
In addition to this most valuable information Kari has done more research on the physics of dart throwing, and he is an advocat of the dart game Mawari. The Dart Book is one of the few sources for the rules of this interesting game.
I can only recommend this book for everyone who plays dart seriously. There is only one problem, and tragically this is the availability: The Dart Book is sold out, and Kari is waiting for a second print. If you are lucky to get one of the few copies still out there, buy it. You won't regret. And if you can help Kari in achieving this second print, I'm sure you won't regret, too.