Selection Sunday is just six days away, with a bevy of conference basketball tournaments this week inching us closer to March Madness. Last year an estimated $15.5 billion was wagered on the men’s NCAA tournament, according to the American Gaming Association.

That gargantuan number should only grow this year. Since the UConn men’s team cut down the nets last April, several more states have launched mobile sports betting, and, Monday, nearly 11 million more people in North Carolina will be allowed to try their luck as legal sports wagering goes live in the Tar Heel State. While that’s certainly welcome news for Duke and UNC fans hoping to cash in on potential Final Four runs, the debut also greenlights the biggest test yet for perhaps the most intriguing sportsbook challenger to the U.S. duopoly of DraftKings and FanDuel.