How do we know if we can beat the bookmaker? That's easy: just look at our bank balance. But how do we know if we've not just been lucky? More specifically, how do we know that someone who says he can do it, and who is selling his "expertise," can keep doing it again and again, through talent, skill, and hard work? This book examines the techniques available to answer that question, to identify those qualities, and to help the reader find value for money in an industry that appears to be largely built on trust and the influence of chance; to uncover the truth about sports tipsters and ultimately how to find the best tipsters--the "Black Cats."