ATLANTA — Of course, it was too easy. Here, it almost always is.

All the Atlanta Braves needed to do to capture their first World Series championship in 26 years was win one last game at home, in the stadium where they had already gone 7-0 this postseason. And in the first inning of Game 5 on Sunday, when Adam Duvall whacked a sinker 377 feet for a grand slam, it seemed like Atlanta — city and namesake suburban baseball team alike — had found the where-were-you-when moment it had been seeking for decades.

Of course, it was too easy. Truist Park’s final game of 2021 ended not with a championship roar that had been building since the first inning, but a loss, 9-5, to the Houston Astros in Monday’s first minutes.

“It’s not over yet!” one of Atlanta’s chronically upbeat stadium announcers shouted after the final out.

But, Atlantans knew in the middle of a spectacular autumn night, it could have been. They, in fact, say it should have been. They say it almost instinctively, the situation and the script almost a perverse rite of life in Georgia.

“We knew we had a long, long way to go in that game and anything could happen,” Brian Snitker, Atlanta’s manager, said. “It would have been great if we could have kept adding on. We just weren’t able to do that.”

Whenever Atlanta’s road trip concludes in Houston, where Game 6 will be played on Tuesday night, Snitker’s overachieving team will return home with one of two unshakable markers for history: as a World Series champion, or as the seventh team to lose it all after leading, three games to one, in a best-of-seven series.

Atlanta knows something about sacrificing such a daunting margin: The Braves did it last year in the National League Championship Series, losing to the Los Angeles Dodgers, the eventual World Series winners. (Atlanta beat the Dodgers in this year’s N.L.C.S.)

“It taught us to never take our foot off the gas, and everybody in that clubhouse understands that,” Will Smith, Atlanta’s closer, said of that episode ahead of Game 5.

Atlanta has good reason to remain upbeat besides a good team and a 3-2 series lead: It has not lost consecutive games since mid-September, Max Fried is expected to start at Minute Maid Park on Tuesday and no team has won the World Series on its home field since 2013.

The foreboding thought, though, is the notion that maybe this team will prove to be too much like the 19 Atlanta baseball teams that reached the postseason since 1991 and didn’t win a World Series than like the one team that did, in 1995.

Atlanta’s professional sports teams, after all, long ago mastered the art of civic disappointment and, sometimes, heartbreak.

Although the Atlanta United won the M.L.S. Cup in 2018 and the Campeones Cup in 2019, the Hawks, in the N.B.A., have gone 63 seasons without a title. The Thrashers, the former N.H.L. team, existed for 12 seasons and made the playoffs once.

And then there was the debacle in the Super Bowl that ended the 2016 N.F.L. season — played in Houston, of all places — when the Atlanta Falcons enjoyed a 25-point lead until the final three minutes of the third quarter and still managed to lose to the New England Patriots.

But the subject of consternation here has most often been a baseball franchise that, thanks to the era of TBS and Ted Turner, is more a Southern team than an Atlanta team (or a Cobb County team). Its résumé from the 1990s and 2000s glimmers with N.L. East titles, occasional pennants and six Hall of Famers — four players, a manager and a general manager — but only the one championship.

It is true that this World Series has gone better than Atlanta’s last one, in 1999, when the Yankees swept. It is true that, with two wins, Truist Park now has more Atlanta World Series victories in it than Turner Field had. It is true that Atlanta still has two more chances.

The team’s hope is that baseball’s recent history, not Atlanta’s long one, will guide the rest of the series after the Commissioner’s Trophy was won at a neutral site in 2020 because of the coronavirus pandemic.

The last team to claim a World Series at home was the 2013 Boston Red Sox when they toppled the St. Louis Cardinals in six games after trailing, two games to one.

In the last 20 years — for many of them, the All-Star Game determined home-field advantage in the World Series — seven teams have won the title at their home park: the 2001 Arizona Diamondbacks, the 2002 Anaheim Angels, the 2006 St. Louis Cardinals, the 2008 Philadelphia Phillies, the 2009 Yankees, the 2011 St. Louis Cardinals and that Boston team in 2013.

There are some perks to home-field advantage, which Houston enjoys in this series because of its superior regular-season record. Some are apparent, like familiarity with the playing surface, with how balls bounce off the outfield wall and even with the music. (Minute Maid Park was also, infamously, the hub of the Astros’ sign-stealing scheme.)

“You saw how loud this place got these three days,” Marwin Gonzalez, who served as a pinch-hitter for Houston in Game 5, said before the American League champions left Atlanta. “That gives an extra bounce.” He added, “For us going back to Houston, we gave ourselves a chance to go game by game and to get the Game 6.”

But the 2019 World Series, in which the Astros played the Washington Nationals, stands as some of the clearest evidence that home-field advantage is overstated and makes little difference in performance, mostly because the road team won all seven games.

And despite the weight of a 108-year World Series title drought, the Chicago Cubs overcame any challenges of playing a decisive Game 7 on the road and beat Cleveland in 2016.

Snitker said he would have preferred to win at home, where, before and during Sunday’s game, the plazas and streets around the ballpark, the center of a mixed-use development called the Battery, overflowed with Atlanta fans. But, he added, “I’ll take it anywhere.”

“I don’t care where we’re at,” he said. “If we win the World Series, it doesn’t matter where it is. I’d have loved to have done it in front of our fans. Hopefully, we can do it the next couple of days.”

Maybe so. Quite possibly so.

But there were signs everywhere of what could have been on Sunday. Inside the park, cases of beer and Champagne earmarked for a championship celebration sat unopened. Outside, the Battery was a graveyard for empty cups, beer cans and pizza boxes.

Atlanta had missed another opportunity. All it could do, again, was wait and brace and hope.