Mark Hatmaker is a highly regarded coach of professional and amateur fighters, law enforcement officials, and security personnel. He is the founder of Extreme Self Protection (ESP), a research body that compiles, analyzes, and teaches the most effective Western combat methods known. He is the author of the No Holds Barred Fighting series, which includes More No Holds Barred Fighting, No Second Chance: A Reality-Based Guide to Self-Defense, The Ultimate Guide to Conditioning and Boxing Mastery, and The Ultimate Guide to Submission Wrestling. He lives in Knoxville, Tennessee.