Washington Nationals first base coach Davey Lopes, left, talks with center fielder Ben Revere during a spring training game in Viera, Fla. (Katherine Frey/The Washington Post)

On a sunny and windy morning on the back fields of Space Coast Stadium, Davey Lopes gathered the Washington Nationals’ position players at home plate. For the next 40 minutes, he led them through detailed instructions on base running — at each base. The spry 70-year-old jogged around first base a few times to demonstrate how to better run to the bag and take leads.

“Don’t think any of this is insignificant!” he shouted.

That morning, everyone felt like a student, including Manager Dusty Baker and the rest of the coaching staff, General Manager Mike Rizzo and special assistants Dan Jennings, Bob Schaefer and Steve Arnieri. Class with Lopes and his four-plus decades of baseball experience was in session.

“He’s probably the best first base coach of all time — easily,” said left fielder Jayson Werth, a Lopes disciple from their time together with the Philadelphia Phillies. “You can win a lot of games through base running and base stealing. Over the course of the season, I think he has tremendous value. It’s going to be the little things here and there, but that’s the stuff that wins you games.”

Previous manager Matt Williams pushed the Nationals to improve their base running in 2014, but injuries undermined that in 2015. In 80 attempts last season, the Nationals stole 57 bases, fourth fewest in baseball. But the Nationals hope this season will be different with the guidance of Lopes, whose 557 career steals rank 26th all time.

“The guy knows what he’s talking about, and he knows how to convey his message,” said Baker, who played with Lopes on the Los Angeles Dodgers in the 1970s and 1980s. “He’s a fun-loving guy, but he’s a no-nonsense guy. And Davey is the best. He sees things that other people don’t see.”

As offensive production declines, base running allows teams to maximize their opportunities. But despite some fluctuations, stolen bases totals have generally declined over the past two decades. Last year, teams stole 2,505 bases, the lowest total since 1994.

Lopes believes World Series champion Kansas City’s success with speed, contact and stolen bases has become a model for other teams.

“It’s fun,” Lopes said. “It’s cool to watch. Baseball, let’s be honest now, is kind of boring to watch unless you grow up in it. Run production is down. Pitching is becoming more dominant. You’re trying to get a new group of fans that is coming into the game. You have to get something that’s appealing, something that is quick. Most quick action games are more interesting to watch than games at a turtle pace.”

Lopes is urging the Nationals to be more aggressive on the bases and trying to rid them of the fear of mistakes.

“You’ve got to play with a certain attitude,” Lopes said. “You can’t take anything for granted. [Tommy] Lasorda used to say, ‘We can always get truck drivers to try. I want you guys going to bat four times and running hard four times.’ I think we, meaning baseball people, kind of accept how the game has changed and the aggressiveness is not there as much.”

The Nationals pursued Lopes for years, Rizzo said. He was the first base coach under Frank Robinson in 2006. With the Nationals again, Lopes is also reunited with close friend Baker. The team has big hopes for Lopes and his teaching.

“He brings a lot more to the table than just base running,” Rizzo said. “His presence and aura in the clubhouse and the way he interacts with the players is second to none. The base running is important. Especially in the game of offensive efficiency, that extra 90 feet is vital. Any time you go first to third or second to home or grab a base with a ball in the dirt, it’s vital to scratch out extra runs.”

To Lopes, base running success is more mental than physical. He wants the same aggressive two-strike approach used at the plate at first base. He doesn’t want any jogging to first base on a single. He wants to always put pressure on the outfielder. Leave the at-bat at the plate and focus solely on running when on first.

Once at first base, Lopes will share pitchers’ delivery time and any clues about their movements that predict what they will do. Even when he was a player, Lopes was always known for his sharp eye. In 1985 he stole 47 bases with the Chicago Cubs and was caught only four times — at age 40.

“I was blessed with that [eye],” he said. “How it happened, I don’t know. I’d look at guys when I was playing and noticed little things. When I was playing, the only computer you had was your brain, which is probably better than most anything if you use it right.”

The Nationals have the ability to improve their base running this season. Ben Revere, Michael A. Taylor and Trea Turner are the fastest players on the team, but Bryce Harper, Anthony Rendon and Danny Espinosa are threats, too. Lopes has encouraged the Nationals to make their mistakes in spring training, but the results have shown already: They are 24 for 26 in stolen base attempts.

“Just knowing that he has our back in those situations, steal a bag and get thrown out, we’ll get it done and get better the next time,” Harper said. “Very comfortable with him and very excited to have him at first base with us and being able to pick his mind.”

Lopes stresses that speed isn’t everything. Werth, who has the third-best stolen base percentage of all time at 86.6 percent, was part of the World Series-winning 2008 Phillies who pressured opponents with aggressive base running thanks to Jimmy Rollins, Shane Victorino and Chase Utley, other efficient base stealers.

“You have to be aggressive,” Lopes said. “Just like you have to know the repertoire of the pitcher, you have to know the arms of the outfielders. What kind of arms do they have? How do they come to the ball? The angles they take to the ball? I won’t be doing too much changing in the physical stuff, like how they set up and all that kind of stuff. My job will be to change the attitude and the mentality.”