The sports landscape evolved at warp speed over the last six and half months of 2018, a dramatic shift fueled by none other than "The American Sports Gambler."

SportsBusiness Journal on Monday released its annual list of the most influential people in sports business for 2018. At the top of the list sits "The American Sports Gambler," a nod to the massive new consumer base that for decades had been mostly off limits to U.S. companies in every state but Nevada. Not anymore.

The American Sports Gambler beat out NBA commissioner Adam Silver (No. 2) and NFL commissioner Roger Goodell (No. 3) as the most influential in sports business for the year. LeBron James was the most influential athlete, coming in at No. 15, just behind Dallas Cowboys owner Jerry Jones (No. 13) and New England Patriots owner Robert Kraft (No. 14).

"We made [sports bettors] No. 1 on our most influential list, and we also think it's the biggest story of the year," SportsBusiness Journal senior writer Bill King said. "I'm sure we're not alone in that."

On May 14, the U.S. Supreme Court struck down the Professional and Amateur Sports Protection Act of 1992, a federal statute that had prohibited state-sponsored sports betting to a handful of states, primarily Nevada. Since the ruling, states have been rushing to get into the bookmaking game and sports leagues have been lobbying for their share.

Legal sportsbooks -- capable of offering Las Vegas-style sports betting -- have popped up in Delaware, Mississippi, New Jersey, New Mexico, Pennsylvania, Rhode Island and West Virginia in the past six months. More than a dozen states are lined up to take a look at sports betting in 2019 too.

New Jersey, which beat the NCAA and major professional sports leagues in a six-year legal battle over sports betting that ended with the Supreme Court decision, began taking bets in early June. The Garden State will eclipse the $1 billion mark in wagers this month, with more than 70 percent of the action having been placed online.

"The American Sports Gambler has been the most influential person in sports biz for decades," said retired New Jersey state senator Raymond Lesniak, who spearheaded the state's quest to allow its casinos and racetracks to offer sports betting. "It just took a United States Supreme Court decision to recognize it."

The American Gaming Association estimated that Americans bet more than $150 billion on sports in 2017, with only a small percentage of those wagers made with legal sportsbooks. Nevada sportsbooks, for example, took $4.8 billion in sports bets in 2017.

Jim Murren, chairman and CEO of MGM Resorts International, one of the largest sportsbook operators in the U.S., came in at No. 23 on the list. Under Murren's direction, MGM has landed sports betting partnerships with the NBA, NHL and Major League Baseball.

Joe Asher, CEO of the U.S. branch of bookmaker William Hill, is No. 47.

"The legalization of sports betting has been great," Asher said. "It's created lots of jobs, given fans new ways to engage with sports and customers an alternative to their illegal bookies; it's generated new revenues for sports leagues, the teams, media companies and countless small businesses, not to mention the much needed new tax revenue that is being raised in the states that have chosen to legalize sports betting. Basically, what we've been saying all along is being proven out. So, it's an incredibly exciting time in our industry and we are thrilled to be a part of it."

In addition to operating sportsbooks in several new states, William Hill has teamed with the Prudential Center, home of the New Jersey Devils, to open an in-stadium lounge, where employees are on hand to help customers download the company's bookmaking mobile app.

"[Sports betting] touches every sport," King told ESPN. "It touches teams, leagues, networks, facilities. And it's a great unknown, a major change, so that means people are spending a lot of time, a lot of energy to try to figure it out."