March Madness and the Super Bowl, the two biggest sporting events for office pools and if your co-workers are doing some friendly wagering, you're not alone.

FOX's Chris Hoenig reports:

The American Gaming Association estimates that $4.7 billion will be wagered, equivalent to the money spent on between Thanksgiving and cyber Monday last year.

But, 97-percent of that will be wagered illegally, because yes, even those office box pools are technically illegal.

Only Nevada allows sports betting on single events and there, you can bet on more than just the winner:

(Goldman) "The quick and easy is the coin toss. You can bet heads or tails. Which team is going to win the coin toss."

Mark Goldman is the one-time sports-book director at Cantor Gaming.

That coin toss prop bet has been a bit of an issue in Vegas this year. The Patriots are the designated away team, so they get to call the toss. And every away game for the past two seasons, the Patriots have called heads.

Chris Hoenig, FOX News.

Follow Chris Hoenig on Twitter: @Chris_Hoenig