While Tiger Woods has spent a career lacking a true rival, he's used an assortment of adversaries to his advantage. Golf Digest Contributing Editor Tom Callahan touched on this in his book, In Search of Tiger: A Journey Through Golf with Tiger Woods, in a passage about Woods and his mother, Kultida: "If you cross them, you are dead. They are like Joe DiMaggio that way...Tida never forgives, Tiger seldom does; neither of them ever forgets. They revel in paybacks for the rest of their enemies' lives." Any slight -- even those imagined or innocuous -- does not go unnoticed. Hence the Nixon-like enemies list Woods has developed through the years. Here is a partial list: