San Francisco 49ers legend Bill Walsh's "West Coast Offense,” a term applied to the high-percentage, passing-first offense he birthed in Cincinnati and brought to the Niners, where the Pro Football Hall of Famer won three Super Bowls during the 1980s — remains a foundational piece of the NFL landscape.

Walsh's deep coaching tree roots reach far and wide, and include the likes of Cowboys head coach Mike McCarthy, legendary former Seahawks head coach Mike Holmgren and current Chiefs head coach Andy Reid. But the offense remains very much his, no matter how many iterations emerge.