What, you thought the Broncos would go undefeated?

In his bewilderment during last night’s first quarter, Peyton Manning looked as if he’d just stepped out of a retrofitted DeLorean and was trying to figure out what year it was.

Clearly, it wasn’t the next year after he played last, as it had always been before. That would have been 2011.

Just as clearly, the people around him were not the same as those he played with last. That team is gone.

The NFL’s Rip Van Winkle awoke to find himself in entirely new circumstances. And while he was gone, it was evident his opponents had been studying up. By the time he figured out he had morphed from the tricker to the trickee, he had thrown three interceptions in a first quarter for the first time in his career.

“We were able to disguise our coverages very well,” Atlanta coach Mike Smith said after the Falcons’ 27-21 victory dropped the Broncos to 1-1. “That’s something we said all week we’d have to do. You can’t give the quarterback a pre-snap read, and we were able to do that early in the ballgame. He made some throws we were able to convert, and make plays on the ball.”

When Manning last played, disguising coverages mostly meant showing blitz when you didn’t plan to blitz or the opposite, showing vanilla and then bringing the house. What Falcons defensive coordinator Mike Nolan did was more sophisticated. He disguised not merely the defensive play call but the defensive scheme as well.

Former quarterback and ESPN analyst Trent Dilfer called it a “walk-around, amoeba defense” that produced “a lot of brain clutter.” There was no base defense in position before most of those first-quarter snaps, just a bunch of guys wandering around.

“William Moore lines up as the (middle) linebacker, drops as the hole safety,” Dilfer said, referring to the Falcons’ strong safety, who made the first of the three interceptions. “Peyton Manning thinks he has a defined look at the snap; the look changes post-snap, (he) makes a big mistake.

“I think what you saw was Mike Nolan win the chess match and his players execute a scheme beautifully designed for Peyton Manning. They gave him these pre-snap looks, where Peyton usually wins, and then, as the ball is snapped, that look becomes totally different. Playing the game after the snap is much different from playing it before the snap and this is a guy that hasn’t played football in a year.”

That’s the most important fact to remember. For perhaps the first time since his rookie season in the league, Manning is actually behind the NFL learning curve, trying to catch up after spending a year undergoing multiple neck surgeries and undertaking a grueling rehabilitation process.

Nolan will not be the last defensive coordinator to try to take away his pre-snap advantage. In Week 1, Pittsburgh’s Dick LeBeau limited his disguises to the usual suspects: Where would safety Troy Polamalu be? Nolan’s walk-around scheme meant almost anyone could end up almost anywhere, and they frequently did.

Still, Manning eventually figured it out and brought the Broncos back to the point where a defensive stop with two minutes remaining would have given him and the offense a shot at a come-from-behind win. It didn’t happen, but the fact it was even possible after turning the ball over four times in the first quarter — Manning’s three interceptions and Knowshon Moreno’s fumble, awarded to Atlanta by replacement referees even after Broncos tackle Orlando Franklin emerged from the pile with the ball — showed how competitive the Broncos can be.

“You’ve got to remember, Peyton Manning’s a new quarterback in our system,” Broncos coach John Fox said. “He’s adjusting to teammates, adjusting to the things we’re doing. It’s not going to happen overnight. He’s just going to get better.  I think we learned a lot about our football team tonight.”

Much of what they learned was good, actually. The Falcons are an excellent team, a likely contender for the NFC title. Yet even after spotting them four turnovers, the Broncos ended up with more first downs (24-22), more total yards of offense (336-275) and a much better ground game (118 yards to 67).

Beyond the turnovers, Denver’s two most obvious weaknesses were the lack of a pass rush on Falcons quarterback Matt Ryan — he was sacked once — and an inability for the second week in a row to cover an opposing tight end (Tony Gonzalez had seven catches for 70 yards and a touchdown). But even those problems probably could have been overcome without the 4-0 disparity in giveaways.

“Those first three interceptions, he was flat out tricked by the coverage,” Dilfer said of Manning.

“Obviously, I’d like to have all three of them back,” Manning said. “Just three bad decisions. I’m sure when I see the film I’m sure I’ll see somebody open short, underneath, on a check-down. So I’d love to have all three of them back. But I’ll learn from them and I think our team will learn from them and I would hope to be better for it.”

Almost as compelling as the unfamiliar sight of a confused Manning was an excruciating performance by the crew of replacement referees, who were nearly as bad as the Broncos’ offense early on.

Although it’s easy to mock these refs, who were asked to fill in when the NFL locked out its regular game officials, it’s not their fault. These are referees from lower collegiate divisions most of whom would not even be candidates to form a new pool of referees if all the locked-out referees were suddenly fired. Such a pool would consist of Division I college refs, who can currently be found working Division I college games on Saturday afternoons.

Late Monday night, long after the game was over, Steve Young, the retired quarterback and ESPN commentator, offered a devastating but honest appraisal of why the NFL allowed the administration of its game to get as bad as it was at the Georgia Dome:

“I can say this because league officials have gone to sleep, so let me just go right at this. There’s a lot of people in the league that would rather break the (referees’) union. There’s a lot of people who don’t feel like officiating is on-field personnel; they feel like it’s a commodity.

“But more importantly, everything about the NFL now is inelastic for demand. There’s nothing they can do to hurt the demand for the game. So the bottom line is they don’t care. Player safety doesn’t matter in this case. Bring in Division III officials — doesn’t matter. Because in the end you’re still going to watch the game. We’re going to all complain and moan and gripe and say there’s all these problems. All the coaches will say it, the players will say it. Doesn’t matter. So just go ahead, gripe all you want. I’m going to rest. Let them eat cake.”

This is actually something to worry about. If the NFL doesn’t figure out that the integrity of the game requires referees with a clue, the chaos on the field in Atlanta will be replicated on gridirons across the country. In fact, it may get worse. At one point, the Broncos’ head coach found himself on the field trying to break up a scrum that looked about one short fuse from turning into a brawl.

By comparison, Manning’s bad quarter should cause very little concern. In fact, you could argue that by November, he’ll be thanking Nolan for helping bring him up to speed.

The four-time Most Valuable Player has been back for two games after missing a full season — an eternity in sports. He’ll adjust. It’s what he does best.