Embraced most enthusiastically by the Marine Corps, Boyd's theories were critical to development of strategies that helped the United States win the Persian Gulf War of 1991; carried into the private sector, they've been adopted and adapted by businesses such as Toyota, General Electric and Wal-Mart.

Coram, whose book "Boyd'' was three years in the making and reached bookstores last month (2002), is a veteran reporter and pilot. He argues that Boyd may have been the most important student of warfare since Sun Tzu, the Chinese scholar whose 2,400-year-old essay, "The Art of War,'' is still a touchstone for military officers.

"Sun Tzu gave you a rulebook,'' said Mike Wyly, a retired Marine colonel who helped spread Boyd's ideas through the Corps. "What Boyd said is way more applicable in actual thinking about tactics and strategy.''

Boyd built on Sun Tzu's teaching that the surest way to victory is to so confuse the enemy that he is rendered unable to fight. He read voraciously, simultaneously studying human behavior and the history of warfare, in particular battles in which outnumbered or ill-equipped forces defeated enemies who seemed clearly superior.

He concluded that successful commanders managed to think and act ahead of their foes. In a briefing titled ``Patterns of Conflict'' and delivered over the years to hundreds of military and civilian officials, he broke decision-making into a continuous four-step cycle -- observe, orient, decide, act -- and demonstrated how the successful commander wins by ``getting inside the loop'' to disrupt and ultimately paralyze his opponent.