The third and last presidential debate — held at 9 pm ET on Wednesday, October 19, in Las Vegas — will be moderated by well-known Fox News anchor Chris Wallace.

The 90-minute face off (no breaks) will cover debt and entitlements, immigration, the economy, the Supreme Court, foreign hot spots, and “fitness to be president” — topics selected by Wallace. After a town hall debate last week, Hillary Clinton and Donald Trump will return to the same format as the first debate; the questions will be written and posed by Wallace.

While this is the first time a journalist from Fox News will moderate a general election debate, Wallace is familiar with moderating Trump, having joined Brett Baier and Megyn Kelly for all three Fox News Republican primary debates (Trump only showed up to two of them).

The stakes are high for both candidates. Trump, who has been accused of sexual assault by multiple women and is trailing Clinton in the polls after poor reviews on his first two debate performances, has reinvigorated his claims that the election is rigged against him. Wallace was a tough moderator in the primary debates, once even telling Trump that his policy proposals “don’t add up.”

It won’t be a cakewalk for Clinton, either. As my colleague Andrew Prokop explained, “Fox viewers would very much like to see Clinton pressed on whether her email scandal, Benghazi, the Clinton Foundation, leaked information from John Podesta’s emails, her health, her ‘basket of deplorables’ comment, and so on make her unfit to be president.”

Wallace’s preferred style of moderating is controversial

Wallace, who anchors Fox News Sunday and has three primary debates under his belt this election cycle, has already articulated how he would like to be remembered after this third and final presidential face-off:

"If people say, 'it was a great debate and I don't remember you being there,' I will have done my job," he told Fox News.

It’s part of Wallace’s rather controversial idea of what role the moderator should play: Wallace has made it very clear that he does not believe it is the moderator’s role to engage with the candidates beyond posing the questions.

Wallace hasn’t always acted that way: During the Fox News debate in Detroit in March, he asked Trump to lay out specifically how he would close the deficit, before correcting him to say, “Your numbers don’t add up, sir,” and proceeding to display two graphics contrasting the facts with Trump’s math.

"I think it's literally the only time a graphic has gotten an ovation at a debate," Wallace said, reflecting on the applause his debate fact-check got. "It's kind of like what [Washington Post fact-checker] Glenn Kessler does — fact-checking a candidate — except I was doing it in real time in front of millions of people."

But when asked how he would counter Trump’s habit of stating outright lies during the third presidential debate, Wallace made it clear that he didn’t see it as his role to correct Trump’s false claims.

"That’s not my job. I do not believe that it’s my job to be a truth squad. It’s up to the other person to catch them on that,” he said in an interview with Howard Kurtz. “I view it as kind of like being a referee in a heavyweight championship fight. If it succeeds, after it's over people will say, 'You did a great job. I don't even remember you being on the stage.'"

As it turns out, a lot of fact-checking experts don’t agree with Wallace on this one.

“The danger of leaving it up to the candidates to fact-check each other is that it doesn’t necessarily bring us any closer to the truth,” Lucas Graves, a fact-checking expert at the University of Wisconsin Madison, told me before the first debate in September. He continued:

Politicians contradict each other constantly in speeches and commercials and debates, and the result usually isn’t very enlightening. The moderator is in a unique position to hold the debaters accountable by asking follow-up questions. That doesn’t mean they should hit a buzzer and shout "false" whenever a candidate seems to stretch the truth. But they can point to the research that’s already out there and ask the debaters to explain if they repeat a claim that’s been debunked over and over.

It will be important to watch whether Wallace will let the two candidates slide Wednesday night — or how baseless a claim will have to be for him to jump in.

Watch: Debates are broken and here’s how to fix them