POLITIFACT ON FIRE!

SUMMARY: We mark the final week of the campaign by highlighting some of our favorite Pants on Fire ratings from the past year. We're filling our home page with all Pants on Fire ratings.

When we launched PolitiFact in the summer of 2007, we realized that sometimes it wouldn't be enough to call a statement False. We needed an even lower rating for the most ridiculous falsehoods. But what to call it?

Kevin McGeever, an editor at our sister site TampaBay.com, came up with the idea: Pants on Fire.

Initially, we thought we'd primarily use the rating for our lighthearted items. Our first Pants on Fire went to Joe Biden for his claim that "President Bush is brain-dead." We studied medical journals about the definition of brain death and wrote a tongue-in-cheek article that said Dr. Biden had not performed the proper diagnosis for brain death. He had not done a cerebral blood flow study or examined Bush to see if he had an oculocephalic reflex.

Many readers got the joke, but many did not and they continue to send us quizzical e-mails. (Reply to all: We were kidding!) In the same spirit, we also gave a Pants on Fire to Bill Richardson for invoking God on why the Iowa caucus should come first in the nominating season, and Rudy Giuliani earned one for claiming "I'm probably one of the four or five best-known Americans in the world." (We used Google searches to determine that he lagged behind the Clintons, Tom Cruise, Angelina Jolie and Oprah, among others.)

But we soon realized there were lots of serious claims that were so over-the-top wrong that they deserved the rating. So we gave one to Mike Huckabee for claiming that most of the 56 signers of the Declaration of Independence were clergyman ( actually, only one was ) and we gave one to John Edwards for threatening to take away Congress' health care plan if lawmakers didn't approve his universal health care. (The president doesn't have that power over Congress. )

We don't award Pants on Fire ratings very often. In total, we've awarded 49 since we launched on Aug. 22, 2007, accounting for 6 percent of our Truth-O-Meter rulings. McCain has gotten seven, Obama has received two.

Chain e-mails have received the most Pants on Fires — 13. (Indeed, the chain e-mails have the worst record for accuracy of any source we've checked. Nearly half of their claims are False or Pants on Fire .) They include the bogus list of books that Sarah Palin supposedly wanted to ban , the fake receipt that supposedly showed Michelle Obama ordered $400 in lobster and caviar from a New York hotel,  and the distorted Bible verses to suggest that Barack Obama was the Antichrist .

The 2008 election has been the most fact-checked campaign in American history. Between our 750-plus items, and dozens of articles published by our friends at FactCheck.org and other news organizations, the presidential candidates have been challenged about their accuracy more than ever before. But despite all that, the candidates are still stretching the truth and, in some cases, spreading outright falsehoods. As we look to the next phase of PolitiFact, we expect we'll still find plenty of times to call them Pants on Fire .