Inside Tim Walz’s playbook—as a high school football coach

Under the bright lights of the Metrodome, Mankato’s magical turnaround—from a program that had gone winless just a few years earlier to the precipice of a title—was on the verge of going up in smoke.

Then came Mankato West’s salvation: a perfectly positioned defensive back, ready to change the game. He snatched the ball out of the air on the 7-yard line for a title-winning interception.

In that moment, Mankato West coach Rick Sutton turned to his No. 2, the mastermind of the team’s defense. His name was Tim Walz. And 25 years before he appeared on the 2024 Democratic ticket as the party’s nominee for vice president, he was Mankato West’s defensive coordinator—and a state champion.

“It was one of those moments that you can’t describe unless you’ve been in it," Sutton remembers. “Big, big bear hug."

These days, Walz is better known as the No. 2 to presumptive Democratic presidential nominee Kamala Harris, who this month tapped the now governor of Minnesota to be her running mate. The appointment marked the latest step in a stunning rise for the 60-year-old, who has gone from teacher to politician to vying for the vice presidency.

But that wasn’t the first time in his career that Walz has been tapped to help rally support behind an unexpected contender.

“I picture Tim Walz jumping 3 feet in the air with both fists fully extended yelling," says Dan Clement, a former West Mankato linebacker. “He was the best cheerleader we had."

Walz grew up playing football in Nebraska, where he later became a teacher and coached at Alliance High School. There he quickly built a reputation as someone who got the most out of available talent. Rocky Almond, the basketball coach, said his forte was “getting kids to play a lot harder and a lot better than they thought they could."

That’s also where Walz began to shape his football philosophy. The school ran a 4-4 defense—meaning four linemen and four linebackers, an aggressive setup that focuses on thwarting the running game. Walz, who coached the linebackers, came to believe in the 4-4 so much that it would later form the core of his playbook when he designed his own defense in Mankato.

“We were a run oriented offense at that time and focused on stopping the run," says Jeff Tomlin, the coach at Alliance. “We were definitely blue collar."

This being the Midwest in the 1990s, everyone played old-school, blue-collar football. Running games were everything—“We didn’t have quarterbacks back then," former Mankato West linebacker Seth Greenwald jokes. If a team didn’t have a strategy to thwart the run, it was asking to get trampled every week.

Which is exactly what was happening to Mankato West. When Walz and his wife moved to her home state of Minnesota in 1996, the football team needed all the help it could get.

That season, the Scarlets went winless. Things were so miserable that for the first six weeks, they didn’t score a single touchdown. Reports of Mankato West’s futility, however, have been exaggerated. Walz said earlier this year that the team suffered through a 27-game winless streak. Sutton insists it wasn’t that grim: They actually went 1-26.

So Walz knew he needed to do two things for Mankato West: teach geography and fix the defense. Only the latter required him to educate a bunch of teenagers on beating offensive linemen.

While Walz’s playbook wasn’t overstuffed with different plays, it relied on the type of complex signal-calling that still exists in the college game today. He also focused on technical details, like teaching players how they could follow the movement of offensive guards to anticipate where a run play was headed.

Not only did his playbook tell players where to be, it also laid out which techniques were appropriate. According to a 1998 Mankato West playbook reviewed by The Wall Street Journal, the Scarlets’ defense had 234 variations they could run on any given play, from “BASE, LOOP, COVER 3" to “SMACK, TWIST, COVER 2."

“We are all then KEYING THE BALL to get off on the snap and get 11 to the ball in a bad mood!" page 10 of the playbook says.

The improvements led to high expectations for the 1999 team, which featured a talented senior class, many of whom would go on to play college football at schools such as the University of Minnesota. They had gone from doormats to being ranked 10th in the state’s Class 4A, the division for the second-largest group of schools.

Then the season actually began—and it looked utterly disastrous. Through West Mankato’s first six games, the team was 2-4. At that point, the players knew that if they lost another game, their hopes were kaput.

“Coach Walz and the whole coaching staff, they didn’t blink," Greenwald says, “It reached a point where eventually the players didn’t either."

The coaching staff was right. The Scarlets went on a roll and kept on winning, all the way to the 35-28 thriller in the state championship—an epic that saw the team return a 93-yard punt for a touchdown. In the years since, the school has grown into a powerhouse. But the 1999 season marked Mankato West’s first ever football title.

What no one could have predicted was that Walz’s coaching tenure would someday become a talking point on a national campaign. This week, it even prompted some gentle ribbing from Walz’s Democratic allies. Michigan Gov. Gretchen Whitmer couldn’t resist using his experience as an excuse to bring up her Detroit Lions’ pair of victories over Minnesota’s NFL team last season.

“Maybe he should help out the Vikings," she said, “after we smoked them twice last year."

—Kristina Peterson contributed to this article.

Write to Andrew Beaton at andrew.beaton@wsj.com and Joshua Robinson at Joshua.Robinson@wsj.com