They gave it the ol’ college try. Alas, this is professional football, where the bottom line matters more than the purity of effort. The Atlanta Falcons led by 17 points at home on a day when winning would have put them in the Super Bowl, and they lost. There’s your bottom line.

“It was definitely our game to win,” cornerback Dunta Robinson said. Then: “It was our game to win, and we didn’t win.”

They led 17-0 one play into the second quarter and 24-14 at the half. They’d been so good that a guy (i.e., me) who’d picked them to win by 10 points felt like applying for a genius grant. In one half, the Falcons gained 297 yards against a San Francisco defense that features six Pro Bowl selections. For one half, they’d done everything they wanted to do.

They did next to nothing afterward. The Falcons wouldn’t score again. Said center Todd McClure: “I felt like we were unstoppable that first half. We just didn’t get it done.”

Put more precisely, they didn’t keep doing it. They allowed a run-based offense working with a quarterback making his ninth NFL start to extract his team from a massive hole, much as they’d allowed Seattle’s Russell Wilson to override a 20-point deficit a week earlier. But this, as we know, is what the Falcons do: They dominate a game only to stop dominating, and usually they win anyway.

Said left guard Justin Blalock: “We put ourselves in that situation all the time, ad nauseum. I don’t want to say we took it for granted that we were going to score … “

But how could they not believe, even after the 49ers nosed ahead 28-24? San Francisco had left 8:23 on the clock; against Seattle, these same Falcons had needed only 23 of the remaining 31 seconds. One more Matty Ice drive, one more great escape: Hello, Bourbon Street.

On cue, here they came. They caught a sliver of a break when Harry Douglas’ diving third-down catch was allowed to stand, prompting Niners coach Jim Harbaugh to trash his headset. And then it was third-and-four at the 10 and Roddy White was open at the 5, but linebacker Ahmad Brooks – making like Alabama’s C.J. Mosley on the final play of the SEC championship game – batted Matt Ryan’s pass away.

Fourth-and-four: Ryan threw for White again, this time over the middle, and linebacker NaVorro Bowman played through White to knock it down. There was contact, but was it a penalty? Even White said: “You’re not going to get that call there.”

And then the 49ers were doing as the San Francisco Giants had done in this town in October 2010: Celebrating a playoff victory that might well have gone the other way. But there are no do-overs in pro sports: You seize your chances or you watch the other guy play for the big prize.

It would be wrong to deem this an out-and-out choke: For the final 44 minutes, the 49ers were clearly the better team. But the Falcons should not have let San Fran be the better team, not after that start: They had a fat lead in their building and they wasted it.

We saw Sunday that the Falcons, for all coordinator Mike Nolan’s sleight-of-hand, weren’t quite good enough defensively. They thought they could induce Colin Kaepernick into throwing interceptions, but he threw nary a one. (By way of contrast, the more seasoned Ryan made two second-half turnovers, including a fumbled shotgun snap.) Instead Kaepernick kept finding the ridiculously open Vernon Davis, who had almost as big a game as Seattle tight end Zach Miller had enjoyed against these defenders.

The point being: For as far as the Falcons came this season, they aren’t quite a finished product. The 49ers stopped the Falcons’ offense when it mattered; the Falcons’ defense couldn’t do the same.

“I’m proud of the coaches and players,” owner Arthur Blank said. “We’ll be back.”

Surely they will. Winning at this level isn’t easy. The 49ers, lest we forget, messed up their NFC title game against the Giants last January. But these Falcons had so much to gain by winning Sunday, and they’d gotten the start they needed. It was all going right until it went wrong.

Said Ryan: “We played well most of (the) plays. They just made the four or five plays they needed to win the ballgame.”

To say the Falcons still don’t know how to win in postseason ignores the obvious: They beat Seattle. To say they still haven’t mastered the art of finishing in January is self-evident. Two games, two flying starts, two lost leads, one giddy victory and now a crushing defeat. “We needed to do something to finish,” Robinson said, but all that ended Sunday was another Atlanta team's dream.

Further reading: The 49ers' early error, grand Julio and the new Thrillerdome.