Great men get a lot of air time, and often deservedly so. But sometimes a great man doesn't get the recognition he deserves. In John Boyd's case, he worked for an organization (the US Air Force) that deemed his work as classified. He didn't suffer fools, no matter how powerful they were, and thus made a lot of enemies who didn't want to give him credit. As a result, few people know who he is. I was blown away by his accomplishments, as told in Robert Coram's book Boyd.
Boyd was not only naturally gifted both physically and mentally, but he added to his abilities as he got older by constantly pushing outward the boundaries of his knowledge. The discoveries he made as a young pilot were remarkable in themselves; he turned dogfighting (air to air combat) from what was deemed to be an art (pilots either have the skills or they don't), into a science; by inventing/perfecting a number of manoeuvers, he put American pilots at a distinct advantage despite sub par aircraft.
But Boyd exceeded his early accomplishments with his later work, as he developed methods that would help design superior fighters, and further designed a process that can be used to improve any operations process. (For more on this, see OODA Loop, which was designed for war but is also cited in other fields including business.)
Unfortunately, the military is not exactly an organization that prizes independent thinking. Boyd had to expend considerable energy fighting the system. Military leaders, private contractors and politicians would have a lot to lose if Boyd continued to demonstrate the folly of their thinking, and they would do their best to shut him down. Fortunately for the military, which is likely far better off thanks to Boyd's work, Boyd didn't shy away from any fight. As such, he helped inspire a number of people (known as Boyd's Acolytes) to improve the functioning of the military from within.