Contestant's knowledge of roman numerals wins him $20,000

As Bart Simpson once said, when would you ever need to use roman numberals?

As Bart Simpson once taught us, roman numerals can save your life.

Well, Jeopardy contestant Ken Jennings used them to win n $20,400 playing in a single category, and boy, is it impressive.

The category called "initials to roman numerals to numbers" sounds mind-bendingly complex - they give you a clue to someone's name. Taking the initials of that name, you turn them into roman numerals, and then express those in regular numbers.

So "Prime Minister of Britain" would be "David Cameron" (DC) - or 600 (500+100).

But Jennings doesn't just know this - he can figure it out faster than you can think of the person's name.

The clip is from last year, but got new-found attention today after it was posted to reddit videos and skyrocketed to the top of the category.

Jennings is famous just for being a contestant - he hold the record for wins on Jeopardy, where he won 74 games in a row, clocking up more than three million dollars in prize money.