Credit: Justin Sullivan/Getty Images; MANDEL NGAN/AFP/Getty Images

They’re calling it The Debate of the Century. Hillary Clinton vs. Donald Trump. The 90-minute face-off that could, according to poll guru Nate Silver, tip the entire election — just a few point swing coming out of Monday night’s clash could hand Trump the lead after weeks of narrowing the polling gap … or it could push Clinton back out of Trump’s reach until November. As many as 100 million people might end up watching when the debate gets underway live at 9 p.m. ET. Here are eight things to look for:

1. Can they feign a convincingly pleasant handshake? It’s presidential debate equivalent of touching gloves in boxing, or bowing in karate — the pre-fight moment when two debate opponents cross the stage and have a friendly handshake, smile and exchange of unheard pleasantries. Except these two, best that everybody can tell, don’t like each other to a degree that transcends typical politics. Can Clinton and Trump keep it together enough to get through this classically fakey-fake moment of decorum that, in this case, will fool nobody?

2. Will the moderator fact-check Trump (or Clinton, for that matter)? Lester Holt faces perhaps more pressure than any moderator in modern history. He doesn’t want to add to NBC’s avalanche of criticism the way Matt Lauer or Jimmy Fallon did (though Fallon’s criticism was less fair) by not challenging Trump when they had a chance. On the other hand, Holt doesn’t want to seem like he’s fighting Clinton’s battle for her. Everybody will watch closely to see if Trump lies outright and then if Holt speaks up to be this debate’s Candy Crowley.

3. Will Trump stick to his rally tropes? We’ve heard them so many times: Trump was against the Iraq War, he’s gonna build a wall, he’s going to conduct mass deportation of immigrants, he thinks Obama wasn’t born in the United States. Trump’s rally tropes excite his fans but sometimes get reversed under direct scrutiny. Will he stick to his guns while in the spotlight (even for claims, like the birther movement and Iraq War issue, that are demonstrably incorrect)?

4. Can Clinton put her email mess behind her? Every time Clinton addresses this issue she seems to only dig the hole deeper. Can she give a satisfactory and candid answer without contradicting everything she’s already said?

5. Will Hillary have a coughing attack? The conspiratorial obsession with Hillary Clinton’s health could go into overdrive if one of her unfortunate coughing attacks occur during the debate. Sure, a cough wouldn’t mean anything, per se, about Clinton’s ability to govern, but it’s dreadful optics that could recall Richard Nixon’s sweaty performance in the 1960 debate.

6. Will Clinton quizmaster Trump? Trump has a rather shaky, Twitter-based grasp on world geopolitics, having notably fumbled before when claiming Russian President Vladimir Putin wouldn’t make a military move into Ukraine (even though he already did). Clinton could attempt to demonstrate Trump’s lack of knowledge by trying to corner him into giving a very specific answer on an important issue — the name of a country or world leader, for instance. If Trump flunks, it could be his Aleppo moment.

7. Will Trump hit below the belt? Trump has shown a willingness to “go there” with regard to Bill Clinton’s infidelities as a way to dig at Hillary. Could he bring up the Clintons’ marital woes on the debate stage and, if so, how will Hillary respond to that?

8. And that really just scratches the surface. We expect Clinton to hit Trump on not releasing his tax returns, to portray him as a Russian stooge, and to make a vote for Trump sound like opting for a nuclear annihilation. Whereas it’s probably a safe bet that Trump will make Clinton seem like a pawn for Wall Street or maybe hit her on Benghazi, and to brag about his wealth (and perhaps reveal his “secret plan” to defeat ISIS). The only certainty: From a political or entertainment perspective, this debate is a must-watch event.