The 100th season of the NFL begins Thursday night with its oldest rivalry. The Green Bay Packers visit the Chicago Bears for the first regular season game of the season. That's bringing people into race and sports books to place their wagers.

"The first week is always fun," John Haines, Director of the Peppermill Race & Sports Book said. "It's when all the parlay cards come out. It's when all our contests start up and everyone's been just kind of waiting for football all summer."

Bob Moffett is visiting Reno for the night. He decided to put some money down on the weekend's games.

"I'm pretty excited," Moffett said. "It's going to be a good season, different. Hopefully, the Patriots aren't in the Super Bowl."

Others are excited for tonight's game, including Bears fan, George Chicvara.

"I just think the Bears are a better team and they're at home," Chicvara, Coconut Creek, Florida resident said. "So, I don't know, I've always felt that home field advantage is worth something. So I took the Bears."

Carl Vinci is a Reno resident who mainly focuses on college football. He says he still plans on putting a little wager on the NFL opener, but he's not picking a winner.

"I'm looking at an over-and-under on the game but I may stay away from this one, Vinci said. "Everybody is saying to go with the Packers but the Bears are supposed to be really good this year."

The American Gaming Association (AGA) expects more 38 million American adults to bet on the NFL this year. Only 7 million will bet at legal sports books. The AGA says football bets are on the rise, since 12 more states have legalized sports betting.

"I think it's crazy that it's taken the country this long to legalize sports betting and bring it in," Haines said.

Haines says football is the biggest sport for bettors, saying it makes up about 70 percent of its handle each year. How successful the season is for sports books can often depend on the early weeks of the season.

"If they have a good first three, four, five weeks then we're just slammed all the way to the playoffs. If they get beat a couple times, it makes them a little reluctant to keep betting as much but they're still here watching the games," Haines said.

Haines says people often come in at 7 a.m. or 8 a.m. on Sunday mornings for a 10 a.m. NFL game. Some of them stay through the afternoon, spending money throughout the casino.

"People come in to watch the first weekend of football and if we get beat and they make a bunch of money, they just go to the restaurants and go to the table games and keep the fun going," Haines said.

"There's a bunch of old coaches that come down together and we get together, play slots, have lunch, have some coffee, bet the horses," Vinci said. "We love the horses."

Vinci says he enjoys the football season a lot more when he has money on the games. 

"I like to have a little action on it," Vinci said. "I always do. I've been betting it for 45 years, so it's a natural thing."

People are betting parlays, single games, over-unders, and futures, including who they think will win the Super Bowl.

"Possibly the LA Chargers or the Kansas City Chiefs," Moffett said. "I just thought they were close last year and if they can improve a little bit, I think it's an AFC team besides the Patriots."