Thomas P. Christie was a mathematician at Eglin Air Force Base who collaborated with Boyd to develop the Energy-Maneuverability theory of aerial combat in the early 1960s. Christie provided the rigorous mathematical formalization that Boyd's intuitive insights required, creating the E-M diagrams and computational tools that made the theory actionable.
Christie later became head of the Tactical Air division in the Pentagon, where he protected Boyd and the Fighter Mafia, providing institutional cover for their advocacy work on the F-15 and F-16 programs. He went on to serve as the Director of Operational Test and Evaluation (DOT&E) at the Department of Defense under George W. Bush (2001-2005), where he continued to advocate for rigorous, honest testing of weapons systems — a direct continuation of Boyd's reformist principles.
Christie was one of Boyd's longest and most important professional relationships, spanning from the early 1960s E-M work through the reform movement of the 1980s and beyond Boyd's death.