This is article #21 in a series covering the origins of football’s terminology. All are available under the Terminology tab above. My book, Hut! Hut! Hike! describes the emergence of more than 400 football terms. FeDefensive football has grown far more technical and strategic over the years. Before the 1950s, most football books written by coaches had numerous chapters covering the offense and one or two addressing the defense. Coaching defense primarily consisted of tackling drills and other individual techniques, while defensive strategy consisted of little more than changing the defensive alignment.