I've been practicing jiu jitsu for a year. We have worked a lot on Oomoplatas and Gogoplatas, that's where I learned about the rubber guard. There is also a large focus on MMA at my dojo, so I picked this book up and started reading it. A couple pages in I knew this was a great book, and it really is. One of the first series of techniques you learn is the Lockdown, Whip up and the subsequent sweeps from Half Guard. Let me tell you, I train with 2 Colorado amateur MMA title holders and I have got them with these moves every time. I am very impressed with the style and the thought that was put into this book, truly genius. I wouldn't say this book is the end all be all, but it is a great addition to anyone's game. I continually roll with people of all different skills, sizes and abilities and I utilize the techniques in this book very often. Another book I've checked out is BJ Penn - Mixed Martial Arts: The Book of Knowledge, again another solid addition to anyone's game.