Stadium-building isn’t a zero-sum game. Soon — soon, surely — Arthur Blank’s pleasure palace will open, and then everybody presumably will be happy. The city of Atlanta, for having kept its NFL franchise downtown. The county of Cobb, for having lured a big-league team to the suburbs. Atlanta United, for not having to play in borrowed housing any longer. As we speak, there’s only one entity smiling and, behind closed doors, giggling. That’d be the Braves.

They left downtown in large part because they believed the mayor picked the Falcons over them. They broke ground on SunTrust Park four months after Blank and Co. turned the first shovels of dirt what will soon — soon, surely — be Mercedes-Benz Stadium. STP just opened on schedule, and it’s very nice. (Even the long-dreaded traffic hasn’t been dreadful.) MBS won’t be ready when it was supposed to be ready, which has become something of a trend.

The original target date for Mercedes-Benz Stadium was March 1, 2017, just before the start of the MLS season. That was soon amended, which was why Blank’s newborn soccer team had its baptism in a stadium built for (American) football more than a century ago. In the cold light of hindsight, it’s possible to fault Blank and Co. for getting ahead of themselves. Why not wait until 2018 to open play? Why impose a construction deadline that didn’t need imposing? Why render an expansion team a Georgia Tech tenant for most/all of Year 1?

But now, to borrow from the coach of the (American) football team that shares Bobby Dodd Stadium with Blank’s new toy, there are bigger fish to fry. The first scheduled event at Mercedes-Benz Stadium is now the Falcons’ exhibition game of Aug. 26. That’s nearly a month after Atlanta United was supposed to christen the place. More to the point, it’s a week before Alabama is set, perhaps tentatively, to play Florida State in Game 1 of the Chick-fil-A Kickoff. (Game 2 pairs Georgia Tech and Tennessee on Labor Day.)

It would be a major embarrassment for Blank, who suffered a public humiliation on the sideline of NRG Stadium in Houston on Feb. 5, if those high-profile college games are staged in the spurned and shuttered — but still standing, thank goodness — Georgia Dome. Blank, see, never liked the Dome. From the time he took ownership of the Falcons in February 2002, he had eyes on bigger and better. The lesson here: Even billionaires need to be careful in their wishing.

The forces of Blank insist MBS will be ready come August/September, but we’ve seen enough delays to know that this project hasn’t exactly been — to borrow a word from John Schuerholz, who’s doubtless chortling — seamless. The Falcons swayed the mayor and got their stadium and bulldozed two churches, but now the unloved Dome has become their “insurance policy,” to quote AMB Group CEO Steve Cannon. If a building could talk, the Dome would itself be chortling.

The Dome’s still-standing status is the leading indicator of how construction on its bigger and glitzier neighbor-for-the-moment is going. It was officially closed in March. Early projections held that it would be demolished in July. (That song from Joni Mitchell: “They paved paradise and put up a parking lot.” Not that the Dome was unpaved.) But the Blank folks didn’t announce a destruction date, which began to seem curious. It’s less curious today. They might yet have need of the place.

As we know, the owner who persists in the sideline promenade delights in the Grand Gesture. With its flowering-petal roof, Mercedes-Benz Stadium stands to be Blank’s grandest creation. That’s assuming the roof gets finished, and roofs are tricky. Montreal’s Olympic Stadium was supposed to be ready for the 1976 Summer Games. The stadium opened for those Olympics; the retractable roof was finished a decade later.

As Cannon told the AJC’s Tim Tucker: “We’re very confident that in June we’ll have that 100 percent certainty about the roof, the petal alignment and all of that.” But aren’t petals, by their very nature, delicate entities?

Could Mercedes-Benz Stadium open without a completed roof? Could Season 1 be staged under a closed roof, with the retractable part retrofitted after another round of construction in January/February 2018? Would the NFL, as has been rumored, schedule its first Sunday night game for MBS — with the Cowboys as visitors, no less — without “100 percent certainty” that the petals will cooperate? (The schedule is set to be released Thursday.) Will the franchise that couldn’t run out the clock in the Super Bowl suffer another timing malfunction?

Meanwhile, another professional team sits 12 1/2 miles up I-75. The Braves have no roof. They also have a functioning new stadium. They’re good to go. Heh, heh.