There has never been an American sports weekend like this one, and there may never be another one like it again. That’s exciting for sports fans and big business for U.S. sportsbooks. 

The pandemic has pushed the National Hockey League and National Basketball Association playoffs to September, overlapping with Week 1 of the National Football League season for the first time ever. The U.S. Open men’s tennis final and a slate of Major League Baseball games will make Sunday one of the biggest sports betting days ever, according to Patrick Keane, chief executive officer of The Action Network, the sports betting research company.

“It’s going to be explosively big,” said Keane, who said his company converted more of its users to sportsbook signups on Thursday than any other day “by several orders of magnitude” in preparation for the weekend. 

The NFL’s Week 1 typically overlaps with MLB’s end of the regular season and the U.S. Open final, but it has never occurred simultaneously with professional basketball and hockey playoffs. It’ll be a boon for sportsbooks, but could have a depressing effect on TV ratings if American eyeballs are split between events, said Vince Wladika, a sports media communications consultant. 

“I wonder if it will fragment the audience,” said Wladika. “Or, will it actually bring more people to their TVs and they will be flipping back and forth between all these sports, like a rising tide lifts all ships?”

The NFL’s 2020 Kickoff game Thursday between the Kansas City Chiefs and the Houston Texans drew 19.3 million viewers — down 12% from last year. Still, the game was easily the most watched sporting event since the pandemic’s start in March. The U.S. Open men’s and women’s finals will likely draw lower ratings than usual with the absence of stars Roger Federer, Rafael Nadal, Novak Djokovic, and Serena Williams. 

Whether or not people watch on TV, betting action should be be robust. FanDuel is expecting one of the biggest betting weekends of the year, according to a company spokesperson. Total “Thursday Night Football” gambling increased about 300% year-over-year, the company said, in part because FanDuel is now legal and operational in several states for the first time, including Colorado and Illinois.

DraftKings, which has shared dominance of New Jersey’s betting market with FanDuel, saw “record engagement across our DraftKings sportsbook and daily fantasy products” on Thursday for the NFL’s opening Kansas City Chiefs-Houston Texans game. CEO Jason Robins said both the “coverging sports equinox” and “pent-up demand among fans” should create a perfect storm for weekend betting. 

WATCH: Sports betting is on the rise during the pandemic — here’s what you need to know