This book produced the absolutely most obedient dog I ever had. He could do anything by voice or signal comand. He was a loyal family pet & exceptional guard dog; even to the point of holding holding 2 guys who dared to whistle at my sister, until my father called him off. He was an unrelenting hunting companion & dedicated tracker going hours on a single trail. If you want a dog that is on par with the best military or police dog, this method will do it.