During the second Boston mayoral debate Thursday night, Kevin McCrea and City Councilors Michael Flaherty Jr. and Sam Yoon traded fire with incumbent Mayor Thomas Menino. The politicians rattled off statistics and references in rapid-fire fashion. What follows is an attempt to take a closer look at some of those statistics and references in an attempt to fact-check the candidates and give voters more context for the discussion.

• On schools, the challengers all attacked Menino for the high number of dropouts and families fleeing the city. Flaherty said 24,000 children had dropped out since 1993, Menino’s first year in office. McCrea said the city’s schools have 7,000 fewer students than they did 10 years ago. Menino countered that the dropout rate had actually fallen 33 percent during his tenure. He also said 10 percent more parents in Boston chose to send their children to public schools this year.

City officials say the dropout rate has actually dropped 35 percent under Menino, but their calculations appear to be misleading. The officials say they calculated their number by figuring the average annual dropout rate during Menino’s reign from 1993 to 2008, which they say is 8.2 percent, and comparing that number to the average dropout rate for the 13 years prior to Menino taking office, which they say is 12.7 percent. The percentage drop is 35 percent.

The problem with the Menino approach is that it sets up a false comparison and doesn’t really show what Menino has accomplished during his time in office. In 1993, Menino’s first year in office, the annual dropout rate was 7.6 percent. Since then it has gone as low as 7 percent, in 1995-96, and risen as high as 9.4 percent during both the 1998-99 and 2005-06 school years. In 2007-08, the dropout rate was 7.2 percent.

Those numbers would indicate the dropout rate hasn’t really changed that much under Menino, despite his tenure coinciding with statewide education reform and a massive investment in the city’s schools. As the website of the Boston Public Schools says: “The 9th-12th grade annual dropout rate in 2007-08 (7.2 percent) represents an 0.7 percentage points decrease from the previous year and is just slight above the low point of 7 percent (1995-96).”

 Natasha Perez, a spokeswoman for Flaherty, says the mayor’s 33 percent number is incorrect. “That was made up,” she said.

Perez said the dropout number cited by Flaherty during the debate came from a Boston Herald article, which attributed the information to the Boston Municipal Research Bureau. Calculations by CWunbound for the years 1994 through 2008, the only years that were immediately available, show 21,102 students dropped out. McCrea’s numbers came from school enrollment data. Menino aides had no immediate source for his claim that 10 percent more Boston parents are choosing Boston schools.

• Yoon was asked what he had personally done to reduce costs at City Hall. After reciting his mantra that the mayor has too much power, he said his contribution was holding a hearing in April in Codman Square on a report put out by the Boston Finance Commission that identified approximately $74 million in savings. “This is my attempt to bring fiscal responsibility to the city,” Yoon said. “It was pretty much squashed.”

The report by the FinCom recommended reductions in overtime across city government, but particularly in the police and fire departments. The report said police overtime in 2008 was $47.8 million, $17 million over budget. Fire overtime was $17.5 million, $5.3 million over budget. Other recommendations in the report included the elimination of several hundred high-paying city jobs, reduction of sick and injured payrolls, reform of school transportation policies, and abolishment of the Fire Department’s 69-employee fire alarm division.

A Yoon spokesman said the FinCom report has just been gathering dust, ignored by the Menino administration. The spokesman said Yoon’s use of the word “squashed” was a reference to the hearing Yoon had planned in Codman Square. The building selected for the hearing was not handicap accessible and the Yoon camp says the Menino administration effectively derailed media coverage of its event by arranging for a man in a wheelchair to show up and be denied admittance. Menino’s spokesperson denies any involvement in the incident. CommonWealth’s Michael Jonas reported that the incident showed the bitter flavor of the mayoral race.

Matt Cahill, executive director of the FinCom, said he didn’t think the Menino administration squashed his agency’s report. “I don’t think that’s the right terminology,” he said. Cahill said the administration has followed through in cutting overtime dramatically, about 20 percent in both fire and police departments. He said the administration is also exploring other suggestions in the report. “I wouldn’t expect them to do all of them,” he said.

• Flaherty said he would improve the city’s fiscal situation by collecting $66 million it is owed for  parking violations.

City officials don’t dispute the $66 million figure, but say it’s misleading. Tom Tinlin, the city’s transportation commissioner, said the $66 million is a snapshot of what the city is owed and described it as a number that goes up and down all the time. Overall, he said, the city has a 93 percent collection rate, meaning 93 percent of all fines for parking violations are collected. The rate is high because Bostonians are not allowed to renew drivers licenses if they have outstanding parking fines. According to the Transportation Department, Boston’s collection rate is one of the highest in the nation and compares favorably with San Francisco (84 percent), Philadelphia (75 percent), Detroit (51 percent), and Cleveland (34 percent).

Perez, Flaherty’s spokeswoman, said the city used to boast a higher collection rate than 93 percent. She expressed skepticism about whether the 93 percent figure was accurate. “They’ve been ticketing more and collecting less,” she said.

• Menino pointed to the city’s bond rating as evidence the city is well managed. He boasted that the city had saved $30 million because of the bond rating. Yoon said he wasn’t impressed with high marks from Wall Street. “I don’t care how well we do in terms of bond ratings,” he said.

Sam Tyler, executive director of the Boston Municipal Research Bureau, said the city’s AA bond rating allows it to borrow money at lower interest rates. But he said the good bond rating itself wasn’t responsible for saving $30 million. He said the city saved the money by refinancing its debt at lower interest rates, much as a homeowner refinances his mortgage to lower monthly payments.

• During debate over problems at the MBTA, Menino said he was a big supporter of the Indigo Line, a reference that may have been lost on some listeners.

The mayor was referring to the Fairmount line, sometimes called the Indigo Line. The Fairmount Line provides commuter rail service between South Station and Hyde Park. The mayor also mentioned a stop in the Ashmont section of Dorchester. Menino has pushed for more stops on the line to supplement existing MBTA service. Two stations in Uphams Corner and on Morton Street have been renovated and a new station is planned at Four Corners, at the intersection of Harvard and Washington streets. The Fairmount line does not go through Ashmont, where one spur of the MBTA’s Red Line ends.

• McCrea said city aides and City Council officials acted irresponsibly in handing out raises to top staffers last year retroactive to the previous year.

Details on the pay hikes were not immediately available, but city officials confirmed they were handed out. Dot Joyce, the mayor’s spokeswoman, said the raises of city aides were effectively rescinded when the mayor and his senior staff agreed to 3 percent pay cuts this year to avoid layoffs in the city workforce.