Walsh’s first two 49ers teams won a combined eight games, but they were instantly among the NFL’s best at passing the football. Walsh mixed in weekly wrinkles and used so many formations that Los Angeles Rams linebacker Jack “Hacksaw” Reynolds fumed whenever the 49ers showed up on the schedule. Reynolds could peg most teams’ tendencies by watching a few weeks worth of game film. He had to watch 10 weeks of Walsh to get a feel for the 49ers, and even then he knew he’d see something new come game day.

Reynolds would later join the 49ers, gladly, and play on Walsh’s first two Super Bowl winners.

Walsh’s offense was so counter-intuitive that stodgier-thinking teams couldn’t, or wouldn’t, adjust. When the 49ers drove the length of the field for the winning touchdown against the Dallas Cowboys in the January 1982 NFC  Championship game, they remained in their base offense. The Cowboys, certain they would see extra receivers, refused to come out of their nickel defense. So Walsh ran sweep after sweep—mixing in one flanker reverse—and the San Francisco pulling guards had a field day clear-cutting their way through the 190-pounders in the Dallas secondary.

That game put the 49ers in their first Super Bowl — No. XVI at Pontiac, Mich. On media day the Tuesday before the game, scores of reporters were bused to the Silverdome to interview the 49ers. When practice ran long, those reporters found themselves cooling their heels — literally — in the sub-zero chill outside the stadium. Walsh, it turned out, was installing new plays. His brain was overflowing again, and there was no Dick Vermeil or John Ralston to stop him.

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Very little could stop Walsh during his time with the 49ers. He won three Super Bowls in his 10 seasons with the team, and that provided the thrust that put him in the Pro Football Hall of Fame.

But he also found success in two tenures as Stanford’s head coach. He served admirably as the 49ers general manager. He was a perceptive, if slightly uncomfortable, analyst on NBC for three seasons. He counseled quarterbacks and coaches as an independent contractor, and lent his voice to countless stories on the industry of football.

He left a legacy whose ripples extend from horizon to horizon. And countless blackboards that could tell the story of his genius, if only they could speak.