The combat system of legendary commando trainer W.E. Fairbairn is much different than has been taught in the post-war West—better, more stress-proof, and more ingeniously systematic than even many Fairbairn aficionados appreciate. In the 20th century, no one shaped hand-to-hand combat more than Col. W.E. Fairbairn, the Shanghai policeman who trained Allied commandos and spies in “gutter fighting.” Fairbairn never fully documented his training system—the underlying calculations and instructional regimen that made it so chaos-proof. But in truth, his abbreviated, hard-hitting system works better, degrades less under extreme stress, and is more ingeniously integrated than even Fairbairn’s post-war popularizers understood. Using wartime documents and the modern psycho-physiology of predation and emergency, scientist Dmitry Samoylov shows that Fairbairn’s system is subtler, more ingenious, and more effective than previously thought. He presents the fullness of Fairbairn’s system—the tactical thinking hidden “under the hood” of the techniques and the training methods for applying them in crisis—and corrects common misunderstandings about how Fairbairn applied and taught his method.