Presidential debate: Ten obscure facts on the great debate
There may be the most talked-about and over-analyzed presidential debate in history.
So our Washington correspondent has tried to come up with ten facts you may NOT know about the encounter that could change America (and the world).
1. It's taking place at Hofstra University, on Long Island, outside of New York City. The college is named after a early 20th century lumber entrepreneur.
2. The university is allowed to fill 300 seats. Each campaign can allocate 400 seats.
3. Hillary Clinton has been practicising the last two nights at a hotel near her New York home, finishing rehearsals at midnight.
4. In her practice sessions, her aide Phillipe Reines is playing the rôle of Donald Trump.
5. Mrs Clinton can claim to be the most experienced debater in American presidential history. She has done 38 mainstream TV debates, including her primary, Senate and Presidential races.
6. The debate host is Lester Holt, NBC's main anchor. His passion is the bass guitar.
7. On social media, Trump is easily winning against Mrs Clinton. He has 11.7 million followers on Twitter; she has a mere 8.9 million.
8. Trump says his biggest fear is being over-prepared. He's not using a lectern in practice and is refusing to do full-scale 90 minute rehearsals.
9. Trump has no-one in particular playing Hillary in the prep sessions; he is just kicking around ideas and answers with staff.
10. 100 million Americans are expected to tune in. That means around 224 million won't be. The other big draw is Monday Night Football on ESPN. The TV game is the Falcons v. the Saints.