Falcons President and CEO Rich McKay assured the world this week, via an NBC Sports interview, that the Mercedes-Benz Stadium roof will open and close like a carp’s mouth by late August. Or words along those lines.

The Prez’s message was stridently upbeat, reassuring even, given the delays that have accompanied the grand notion that a team whose ceiling is ever-expanding requires a roof to match.

The world’s most complicated cover – what Michelangelo would have done with the Sistine Chapel if only he had a wrench instead of a brush – will be functioning by the Aug. 26 Falcons-Cardinals exhibition game, McKay flatly stated. Finally, a concrete assurance amid the doubts.

Taking him at his word, there follows the question: So, will the roof be opened or closed for the grand unveiling?

You’d like to think all concerned are very open-minded on this subject.

Let’s hope it’s a fine late-summer day and evening in Atlanta, and there’s the first open-air professional football game played in this city since the Falcons beat Seattle on Dec. 15, 1991. A little fresh air never hurt anyone.

Beyond the preseason, there will linger the question of just how much that retractable roof will get retracted. Will the roof be opened enough to justify all the added expense and stress that went into its construction?

History has shown in the case of the other three retractable-roof NFL stadiums, the roofs are closed about two-thirds of the time. And, of course, always closed in the case of other big events that require environmental certainty.

The last Super Bowl was played in Houston’s convertible stadium. The temperature was fairly mild that night, with a 20 percent chance of rain and a 100 percent chance of heartbreak by the end. The roof stayed tightly closed. At least as I recall – the details of that one got a little blurry.

In fact, every Houston home game that season was under a roof. It is just too easy to default to comfort.

Atlanta’s weather is somewhat less liquid than Houston’s, so any strict comparison is not reliable.

But, human nature being what it is, will fans prefer their heads shaded and their air conditioned unless the weather happens to be absolutely perfect? And perfect is a state that nature so rarely adopts.

And what of the competitive considerations? Might not the Falcons and their sporty offense lobby for controlled, predictable conditions over the chaos of a random breeze? There is no better laboratory for offensive innovation than a stadium with fake grass and a tight lid.

Holding in the noise rather than allowing to seek the clouds also is a proven benefit to the home team. And this particular home team loves its stadium noise, sometimes too much.

ESPN’s Jon Gruden has opined: “Every time I’m in a retractable-roof stadium, I wonder why it’s closed.” But the voices for football in the raw are few.

If Arthur Blank’s place pops the top on half its games, that would be a small miracle. Befitting the roof itself.