After Day 1 of petitioning in 2001, the campaign of the city’s public advocate, Mark Green, triumphantly announced that it had successfully gathered the 7,500 signatures required to secure a place on the Democratic primary ballot.

Despite his rapid and effective gathering of signatures, Mr. Green was ultimately defeated by Mayor Bloomberg. Four years later, almost a week after the start of petitioning season, none of the campaigns has made an announcement about securing thousands of signatures at record speed. That doesn’t mean the campaigns of the three Republicans and the four Democrats vying to be elected mayor aren’t taking the process seriously. On the contrary, many of the campaigns have hundreds of volunteers walking through neighborhoods and positioned at subway stations throughout the five boroughs. They are, however, keeping under tight wraps the details of their quests for signatures and the exact number they have secured.

“It’s very cloak-and-dagger, the petition drive,” the campaign spokesman for Rep. Anthony Weiner of Queens, Anson Kaye, said when asked about his candidate’s petitioning strategy.

Mr. Kaye said the Weiner campaign had hundreds of volunteers out in the streets and would have no trouble collecting the requisite number of valid signatures. Indeed, he said the campaign would probably have enough signatures by yesterday and would have more than enough by mid-July, the deadline. But Mr. Kaye said he didn’t want to get far beyond the basics: that the petitions were being carried by volunteers, supporters, and some political organizations, and that a nationally known field guru who worked for Senator Kerry in Iowa, Michael Whouley, is running the operation.

On the subject of petition strategy, by far the most secretive of the campaigns was that of Mr. Green’s 2001 Democratic runoff rival, Fernando Ferrer, the former Bronx borough president. His campaign spokes woman, Jennifer Bluestein, would not utter a word about petitioning to The New York Sun.

Another candidate from Queens, Thomas Ognibene, who wants to run against Mr. Bloomberg in the Republican primary, wouldn’t say how many people he has out on the streets or what neighborhoods they’re targeting. He said he has good reason to keep quiet because the Bloomberg camp is flooding his own neighborhood and following his volunteers.

“Every time we go somewhere, the mayor sends 500 people there,” he said. “It’s hard to compete with somebody who can spend millions of dollars to do this operation.”

A spokesman for the Bloomberg campaign, Stuart Loeser, said the campaign does have hundreds of people carrying petitions, but he said the campaign had not just swooped into Mr. Ognibene’s territory in Queens.

“We’ve swooped into communities across this city,” Mr. Loeser said. “If he thinks it’s only in his community, it’s because he hasn’t been anywhere else. He hasn’t seen that we’re everywhere else.”

Mr. Ognibene also noted that someone from the Bloomberg campaign had actually knocked at his door in Queens, asking for his signature of support for the current mayor.

“I think it was just to make a statement, something cutesy,” he said.

A professor of election law at Fordham University, Jerry Goldfeder, termed that kind of petitioning tactic “psychological warfare petitioning.” He said it’s completely legal.

Mr. Goldfeder laughed when asked why some petitioning strategies are being kept under wraps.

“I have no idea,” he said. “I don’t know what the secret is.”

He said there are plenty of signatures to go around, particularly among Democrats, and he said the speed with which candidates collect signatures is not of utmost import.

“The purpose of petitioning is to demonstrate support in order to get on the ballot,” he said. “The only reason to get as many signatures as you possibly can as quickly as you can is a voter can only sign for one candidate in a particular race. … You get signatures quickly in case somebody signs more than one, you’ve gotten the first one.”

Although the legal purpose of petitioning is to secure a place on the bal lot, the campaigns are looking at it through different lenses.

The Gifford Miller campaign sent out a press release this week, boasting that the City Council speaker has won support from more than 28 community clubs, labor unions, and political organizations. The campaign expects to collect more than 100,000 signatures, far more than the law requires, as a method of reaching out to New Yorkers.

“This will be an unprecedented grassroots effort built on the overwhelming amount of support that Gifford Miller has won throughout the city’s community groups, political clubs, and Democratic county organizations,” Mr. Miller’s spokesman Reggie Johnson said.

The director of field operations for the campaign of C. Virginia Fields, Luther Smith, said it was actually a positive that the Manhattan borough president has not won the kind of institutional backing that some Democratic rivals boast of.

“I feel really lucky,” he said. “I think most candidates, especially borough-wide and citywide candidates, they rely on getting support from the county organizations. Once they do that they just sit back and relax. They don’t have to think about it.”

Had Ms. Fields won support from one of the county Democratic organizations, Mr. Smith said, he could sit back, drink a Coke, and wait. Instead, he said, the campaign has recruited volunteers from across the five boroughs. The Fields campaign has also reached agreements with a number of candidates running for City Council, who are putting Ms. Fields’s name on their petitions as well as their own.