A long adventure for Washington and its Nationals begins this weekend with four games in three days against a strong Atlanta Braves team that likely will challenge the Nats at the top of the National League East for several seasons.

This is probably the start of an annual summer pennant-race ritual, an idea so novel in D.C. that, unless you’re Ted Lerner, you’ve only read about such things. The last time a D.C. baseball team was 16 games over .500 and in a pennant race this late in the season was during World War II, when talent was so scarce the St. Louis Browns had a one-armed outfielder.

“The Braves aren’t going anywhere,” Manager Davey Johnson said. “They’re all big games, but this is who we’ve got to beat.”

Maybe the middling Mets, melodramatic Marlins or flummoxed Phillies will join the NL East battle in various years. But the Braves and the Nats, two farm-system and fundamentals-first franchises, will be in each other’s faces for years. Barring catastrophic injuries, both teams already have their core pieces, plus enough prospects in their system and payroll flexibility to fill holes. The question isn’t how they’ll stay where they are now in the standings, but what combination of misadventures would prevent it.

So, Washington and its team are in the first stages of figuring out how to feel about a pennant race, prepare for it emotionally and cope with its mood swings.

“Don’t know, never been in one,” Ryan Zimmerman said.

“No idea. Let’s find out. Should be fun,” Michael Morse said.

“Every game is big. Don’t look ahead. One pitch at a time,” principal owner Mark Lerner said. “Or it drives you crazy.”

A pennant race is three months of sustained contradiction. On one hand, there’s the pressure of daily results, the constant knowledge that a hot or cold streak at just the right or wrong time can change the shape of a season.

The second-place Braves, now 3¹ / ₂ games behind, could leave D.C. in first place by a half-game over the Nats. Or the Nats, if they sweep, would lead the NL East by 7¹ / ₂ games on Sunday night, regardless of what any other teams do. Neither is a likely outcome, but it shows the stakes.

In addition, after the Nats meet the Braves, then the Mets three times next week, they play 18 straight games against losing teams. That’s opportunity.

On the other hand, especially in July and August, baseball for contenders is about process as much as it is about daily results. Just beneath the surface, which way are the vital components of the team trending? For example, on Thursday the Nats fell behind the Mets 9-1. Johnson symbolically surrendered, removing Ryan Zimmerman, Adam LaRoche and Bryce Harper to save energy. Gio Gonzalez left after getting just 10 outs. A chance to sweep New York, and knock them nine games back, close to Big Apple panic territory, was lost.

Yet the Nats were upbeat afterward and with reasons. They got 14 hits, lost 9-5, had the tying run in the on-deck circle in the eighth and ninth. Johnson got to use exactly the pitchers who needed work, such as Henry Rodriguez, while saving all his lefties for the southpaw-hating Braves.