What were the seminal offenses/defenses of each decade?

Inspired by this post, remember the definition of “seminal” when answering. Think of it (as it was in the original post) as The Great Gatsby was to books in the 1920s as X was to offensive/defensive schemes in Y. Here are my picks. Add your own: 1900s – 1910s: Single-wing. 1920s: Notre Dame Box. 1930s:…

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