Ed Jaworowski clearly explains why my cast sometimes falls apart and sometimes works well. In "Trouble Shooting the Cast" he demonstrates a thorough understanding of the mechanics of fly-casting and goes from there to clearly pinpoint common casting mistakes. He has done his homework well. Jaworowski identifies and analyzes over 30 common casting problems and gives clear and concise explanations for their underlying causes. He explains the relationships between one problem and another. After dealing with the fundamentals of fly-casting, Jaworowski addresses special problem areas such as casting in the wind and casting shooting heads and weighted flies and leaders.
After studying "Trouble Shooting the Cast," I find that I starting to be able to dissect my (and other's) casting mistakes by just analyzing the movement of the fly line. For instance, Jaworowski clearly explains that line oscillations in my forward cast meant I had slack in the backcast or that the end of my fly line curves to the left or right because I had misdirected hand motion at the last instant of the forward cast. Now I am able to analyze each cast and know what I need to do to correct the problem.
The illustrations in the book are barely adequate, and could be a lot better. Actual photographs contrasting the correct and incorrect casting technique might have helped.
I agree with Lefty Kreh's assessment that Ed Jaworowski is the best fly casting instructor around.