While rival TV stations Tuesday night spent much of the night reporting Kasim Reed ahead of Mary Norwood in a very tight Atlanta mayoral race, WXIA-TV was telling a different story.

The NBC affiliate on its Web site and in updates on TV had Norwood as the vote leader for more than two hours. And at one point, while other TV stations and ajc.com had only 30 percent of the city precincts counted, WXIA claimed 70  percent.

How did they pull that off? The NBC affiliate used 80-plus employees and volunteers to visit as many of the 170 precincts as possible and collect vote totals before they reached the election offices. (Each person was assigned two precincts.)

In comparison, rivals relied on official tallies and/or the Associated Press. The Atlanta Journal-Constitution shared resources with WSB-TV (both owned by Cox Enterprises, which also owns ajc.com) to collect data directly from the Fulton and DeKalb election offices and the Fulton County Web site.

By law, precincts are supposed to post vote totals in a public place. WXIA staffers and volunteers were able to glean many numbers that way. But in about quarter of the cases, they couldn’t access the vote totals.

As a result, WXIA was not able to get tallies from all the precincts.

News director Ellen Crooke said she didn’t expect to get 100 percent of the precincts, but the station did collect broad enough sampling to give people a sense of how different parts of town voted. The station alerted the public online and on the air to the methods.

And since the station collected more results from precincts that favored Norwood, WXIA had her ahead until about 10:30 p.m. By then, the station was mixing in official numbers from precincts it couldn’t get totals from directly. The way the official tallies were coming out, Reed had a lead virtually the entire night, though that gap shrunk over time.

At 9:29 p.m. Tuesday night, the station did inform its Twitter and Facebook followers how they were compiling their data: “11AliveNews is independently gathering results with staffers placed at almost all … precincts.”

Currently, only several hundred votes separate the two candidates. Norwood is requesting a recount. Barry Garner, the director of registrations and elections for Fulton County, said official results won’t be ready until Saturday.

Garner said he had no issue with WXIA’s methodology but warned them of potential pitfalls. “People reporting from the precincts might transpose numbers wrong,” he said. “And unless they got someone to every single precinct at 8 p.m., they might not be able to get the numbers in every case.”

Crooke said WXIA did not have any problems with numbers collections but did suffer one major discrepancy, which had nothing to do with its collection process. The station assumed Fulton County wouldn’t include DeKalb County’s numbers. So as late as 11:24 p.m., the station, on its Twitter feed, had figures that double-counted DeKalb’s approximately 8,000 votes. By then, though, WXIA was accurately reporting a slim Reed lead.

Overall, Crooke proclaimed the project a “huge success.”

“Just because every other news organization in town has always done it one way doesn’t mean we can’t do it differently,” said Crooke, who has done similar election tallies at stations in Buffalo, N.Y., South Bend, Ind. and Louisville, Ky.

WXIA’s new computer map was able to show precinct-by-precinct breakdowns as the station received tallies, with red precincts for Norwood and blue precincts for Reed. “It allowed us to provide deeper analysis and insight that other stations couldn’t do,” Crooke said. “It was a huge undertaking but our whole staff came together.”

WXIA-TV, often third or fourth place at the 11 p.m. hour in ratings, tied WSB-TV for first Tuesday  night among 25-54 year olds. (It helped that Pres. Obama pushed back NBC’s popular reality show  ”The Biggest Loser” an hour, forcing NBC to pre-empt Leno.)

Steve Schwaid, news director at CBS affiliate WGCL-TV, said he would not follow WXIA’s lead. “It would never cross our minds not to use the official counting source for information,” he said. “An election is too important. There is no downside using actual results from official sources.”

Budd McEntee, news director at WAGA-TV, said he has had a reporter go to the election office in the past, but he never thought to station people at every individual precinct.

Both the Reed and Norwood camps found WXIA’s efforts admirably ambitious, though they did for a time muddy the waters a bit given what other news sources were saying.

““We knew it was going to be close, so we took it with a grain of salt,” said Roman Levit, the campaign manager for Norwood. “We treated it as just one more source of information.” But he did praise WXIA’s campaign precinct map as “a terrific innovation.”

Reese McCranie, a Reed spokesman, said it did create some concern for a short period of time given that WXIA had Norwood ahead for so long. “In the end,” he said, “we just relied on the Fulton County Web site.”