Col. John (Richard) Boyd (USAF) (January 23, 1927 - March 9, 1997) was a fighter pilot and military strategist of the late 20th century whose theories have been highly influential in the military and in business. He was know as "Forty-Second Boyd" for his ability to beat any opposing pilot in aerial combat in less than forty seconds.
He was the creator of the Energy-Maneuverability, or E-M, theory of aerial combat, as well as the chief architect behind the F-15 and F-16 fighter planes. One of his six "Acolytes", Pierre Sprey, similarly developed the A-10 project.
A popular anecdote credits Boyd for largely developing the strategy for the invasion of Iraq in the first Gulf War. Boyd was called to Washington, D.C. in the weeks preceding the war, to develop the plan under the supervision of the then Secretary of Defense Dick Cheney.
In a letter to the editor of Inside the Pentagon, former Commandant of the Marine Corps General Charles C. Krulak is quoted as saying "The Iraqi army collapsed morally and intellectually under the onslaught of American and Coalition forces. John Boyd was an architect of that victory as surely as if he'd commanded a fighter wing or a maneuver division in the desert."
Boyd's key concept was that of the decision cycle or OODA Loop, the process by which an organization reacts to an event. According to this idea, the key to victory is to be able to make decisions more quickly than one's opponent.
Boyd actually never wrote a book on military strategy. The central work encompassing his theories on warfare consists of a several hundred slide presentation entitled Discourse on Winning & Losing and a short essay entitled "Destruction & Creation".