Victorious celebrations have been a regular event this summer for the Nationals, who are set up to challenge the Atlanta Braves and others in pennant races for years to come. (Toni L. Sandys/The Washington Post)

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.

“A lot of good things happened in that game,” Johnson said.

Long-term good things, he meant, which may impact the next 72 games. Jayson Werth took batting practice and declared himself ready to start playing at Potomac on Friday, putting his return ahead of any previous schedule. New backup catcher Sandy Leon, off the disabled list, got his first big-league hit. Soon he’ll get to show the arm that threw out 46 percent of base stealers in his minor league career, a Nats area of weakness recently.

The biggest ovation from 36,389 fans was for the return of star reliever Drew Storen, who pitched for the first time all season, had a perfect inning, retired red-hot David Wright and Jason Bay and unveiled a new diving sinker. If you need elbow surgery, Storen said, at least use the rehab time to perfect a new pitch. “I have extra mobility in the elbow now. I’m not death-gripping the ball as much and the two-seamer’s diving a lot more,” he said.

Finally, the team’s infield leader, all-star shortstop Ian Desmond, returned much earlier than some expected from the painful oblique muscle injury that has nagged him for six weeks. First at-bat, single to center.

“I had to represent the Goon Squad,” Desmond said about Johnson’s reserves, who went 6 for 9 with three runs scored.

The next 11 weeks figure to be a high-pressure honeymoon for the Nats, an extraordinary baseball anomaly that will almost certainly end next season. By then a major offseason free-agent addition may boost their chances, more talent may arrive from the minors, and no one will ever again say the word “shutdown” in the same sentence with “Stephen Strasburg.”

This is the first and last summer when the Nats will be far ahead of expectations and timetables, facing the July 31 trade deadline with as much concern for team chemistry as a mega deal.

They’re still at the innocent stage where it’s a big deal to see a potential young standout pitcher, Ross Detwiler, have a breakthrough in mound demeanor. Detwiler showed “a little bit of Gio out there,” he said of his grins on the mound in seven scoreless innings on Tuesday. “I was pressing too hard. Once you let all that go and get relaxed, then you have your best results.”

Here it all is on our plate — young team, learning process, first realistic pennant race — a story as sweet as summer corn for a town where winning baseball hasn’t been tasted in generations.

And here it comes, revving up this weekend four times against the Braves, each game important, yet probably not as vital as the trends developing just under the surface.

“Whoo, big deal,” Desmond said of the Braves series, his tone both serious and not. “It’s great. Play good clean baseball and it’s an opportunity to pick up some ground. But it’s July, still really early, too.

“We want that uncharted territory,” he said.

What’s that?

“September,” he said.

For Thomas Boswell’s previous columns, visit