The sports gambling business — legal and illegal — is worth several hundred billion dollars worldwide. Of that, only $2.6 billion is wagered legitimately in the U.S. through the sports desks at Las Vegas casinos. According to 24/7 Wall St. research, most of the bets are placed on just 22 of the 122 teams in the four major leagues.

The NFL seems to be the gamblers’ favorite, with 65% of the total $2.6 billion bet on football teams, according to data gathered by 24/7 Wall St. as well as interviews conducted with people in the sports gambling industry. Most of the balance goes to wagers on college football and teams in the MLB, NHL, and NBA.

Read: The Five NFL Teams Americans Bet On The Most
Read: The Six NBA Teams Americans Bet On The Most
Read: The Six MLB Teams Americans Bet On The Most
Read: The Five NHL Teams Americans Bet On The Most 

The amount and number of these bets is a closely kept secret. Even the Nevada State Gaming Control Board, which regulates betting in the state, has only partial figures on major league sports gambling. 24/7 Wall St interviewed regulators, casino sports desk management, and people in the online bookmaking and Internet gambling businesses to find out which professional teams drew the most gambling action in the last full season of the four major leagues. Jay Rood, VP of Race and Sports at the MGM Resorts Intl, was a particularly helpful source.

Football betting action is bigger than the three other sports combined for several reasons. First, many of the league’s games are nationally televised. Second, the Super Bowl is broadcast around the world and was seen by 109 million U.S. viewers last year. The event draws nearly $100 million in legal bets through Las Vegas alone. Football is also a larger sport financially than the others based on ticket prices and television contracts. Finally, a number of teams, such as the Dallas Cowboys, Green Bay Packers, and New England Patriots, have significant national fan bases.

The four major leagues have 122 teams among them. Sporting desk managers define gambling action based on the total volume of bets made for or against any given team. They do not track illegal sports gambling and there are no reasonable estimates of illegal betting amounts. 24/7 was able to compile a list of the major league teams Americans bet on most: five NFL teams, five NBA teams, six NHL teams and six MLB teams.

24/7 Wall St. also wanted to see if there is a correlation between the level of betting on a team and any other statistics about the organization. Betting action was most correlated with team valuations, which came from Forbes, win-loss records, and attendance trends, which came from the leagues and each of the teams. The teams that draw the most gambling are, in almost all cases, organizations that have high revenue within their sports, teams with decade-long track records of winning, and, in some cases, several years of improvements in attendance.

Most of the teams that have highest betting activity are iconic organizations. The New York Yankees are at the top of the baseball list. The Los Angeles Lakers, and the Minneapolis Lakers, have the most impressive championship record in the NBA. Tradition and excellence, it seems, even extend to the interests of gamblers.