This book, by Sylvain Galibert, is aimed mainly at grapplers, but contains concepts useful to those who prefer punching too.
Principles are ideas which lead to success.Principles and Concepts for Martial Arts, Sylvain Galibert
Galibert begins by defining what a principle is, and swiftly moves on to what is essentially a reference list of principles he’s noticed and how/why they are useful. He says himself in the foreword that if you’ve been around martial arts for any length of time you’re unlikely to find anything truly new or groundbreaking in the book.
That is true, but at the same time having them all clearly explained and laid out next to each other, with examples, does make it easier somehow.
I did find that, not being a judoka or BJJ practitioner, many of the examples were unfamiliar, but a quick youtube search usually solved that problem.
This book isn’t one to sit and read all in one go, like you would a novel. It’s more of a thinking book. Read a section, and then spend some time thinking about how that principle applies to techniques that you know. Think about how applying this principle could work for you, with your particular body type and martial art.
We have plenty of time for thinking at the moment, with dojo training suspended due to Covid-19. Don’t waste the time!