In the world of illegal gambling, sporting events are far and away the biggest money maker. Literally hundreds of billions of dollars are wagered illegally in the United States on sporting events every year — from the bar-room bookie deals for hundreds, even thousands, of dollars at a time, to the simple Super Bowl office pool (yes, buying that $5 square is illegal in almost every corner of the country), millions of people are in on the action.
Click ahead to see the top sports for illegal gambling.
Illegal wagers: $80-$100 billion
It's no surprise football is at the top of the illegal gambling heap according to professional sports handicapper and gambling strategy author Wayne Allyn Root.
"There's no coincidence that the No. 1 sport to watch is the No. 1 sport to bet on," the founder & CEO of WinningEDGE.com says. "The betting literally drives the viewership, and the heavy betting on football is driven by the fact that it's on television. They are synergistic. And what drives all of it? The pointspread. Without the pointspread, no one is betting or watching.
"The reason no one watches women's volleyball isn't because it's not interesting, it's because no one bets on it," Root says. "And no one's betting on it because there's no pointspread."
Illegal wagers: $6-$10 billion
Of the total wagered illegally on football each year, roughly 10 percent is spent on the Super Bowl.
"The Super Bowl has become an American national holiday — a betting holiday," Root says. "That is why it is the most-watched television event of each year. Take away the money, and it's just another sporting event. But with $6 to $10 billion changing hands, it's a life-changing event. The NFL is definitely the king of gambling and the Super Bowl is the crowning event of the football season."
Illegal wagers: $60-$70 billion
"The NFL used to be a dominant No. 1 in the betting world. Not anymore," Root says. "College football is a close No. 2 and gaining fast. Betting is driven by college graduates who learned to bet on sports while attending colleges with great football rivalries like Michigan, Ohio State, Florida, Georgia, Tennessee, Texas, Notre Dame, USC, etc. If you attended those colleges, and you enjoy gambling, it's natural for you to bet college football for the rest of your life."
Illegal wagers: Roughly $50 billion
"Just like college football, the excitement of college rivalries drives the popularity and growth of betting on college basketball," Root says.
Illegal wagers: $6-$12 billion
As much as 25 percent of illegal wagers placed on college basketball games each year comes from the three-week March Madness tournament.
"March Madness is the perfect betting vehicle," Root says. "Instead of one great televised game like the Super Bowl, here sports bettors get three weeks of great games in a Playoff format, and all on television. It's a bettors dream."
Illegal wagers: $35-$40 billion
"I think the NBA lags behind college basketball (in wagers) because the season is too long, and the players often just don't seem to care," Root says. "You don't have the intensity or tradition of college basketball. If you attended basketball powerhouses like Duke, Kansas or UCLA, you learn to love (and wager on) college basketball for the rest of your life. The NBA doesn't have that going for it. But the NBA Playoffs attracts big betting — just like March Madness."
Illegal wagers: $30-$40 billion
"Baseball is not a big betting sport like football or basketball because of the lack of pointspreads," Root explains. "In baseball you have odds, thereby producing big favorites and big underdogs. Without the 'handicap' of pointspreads that makes football so competitive, you just lose the betting excitement. But there is big money bet on the baseball playoffs and World Series."
Illegal wagers: $1-$3 billion combined
If there's a sporting competition, there's a bet to be made, but very little of the total illegal wagers placed in the United States each year goes to the "other sports" including boxing, horseracing, hockey and golf. Once again, it has a lot to do with pointspreads, Root says.
Illegal wagers: Nominal
It's the No. 1 sport in the world and the No. 1 international betting sport. So why is soccer at the bottom of our list? Simply put, there's not much interest in the US, and most of the rest of the world bets on the sport legally.
"Soccer does not feature the action, scoring or pointspread parity of a sport like NFL football," Root says. "It is just too slow for American TV viewers or bettors. And there's not enough scoring — who wants to bet on a 1-0 game?"