John Boyd was known as “Forty-Second Boyd” throughout the Air Force because of his promise to beat anyone in simulated air-to-air combat in forty seconds or less. He was taken up on his offer many times and never lost. Boyd turned his natural combat skills into teaching tools for his fellow pilots, coining his famous Energy-Maneuverability Theory, which completely changed the way fighter pilots fought. His theory was even employed in the future design of aircraft, allowing manufacturers to design planes that had great maneuverability. His theories changed tactical fighting forever.