March Madness starts today with the first two play-in games, but don't panic, you still have until Thursday to fill out your bracket.

A new survey found one in five Americans will gamble on the tournament this year... which is about 47 million of us, and 40 million of those people will be filling out at least one bracket. Here are four more stats about betting on March Madness:

  1. We'll gamble about $8.5 BILLION this year, and $4.6 billion of that will be on brackets. So, that's 54% of all the money we'll be wagering.
  2. We'll fill out a total of 149 million brackets. So a lot of us will be doing more than one. The average is just under four brackets per person.
  3. Another 18 million people will place bets in other ways. 4.1 million will place a bet through casinos, or a legal gambling app. 2.4 million will gamble illegally through a bookie, or a friend. And 5.2 million will gamble online through illegal offshore websites.
  4. Who's going to WIN the tournament this year? Well, Duke is the favorite among gamblers with 29% of the vote. The rest of the top five are Gonzaga, 9% . . . North Carolina, 8% . . . Kentucky, 7% . . . and Virginia and the University of Michigan at 5% each.

Read more at the American Gaming Association.