Examining the Seven Most Famous Sports Gamblers
By
Richard Janvrin
Contributor Updated: 31 January 2025
Richard Janvrin Contributor
Richard has been writing about sports since he was a teenager. Still, his first professional role came in 2015, covering all things NFL and fantasy football-related. From there, in December 2018, he started in the sports betting industry, covering sportsbook reviews before arriving to where he is today.
Most Famous Sports Gamblers
In May 2018, the Professional and Amateur Sports Protection Act was overturned, allowing each state to pass legal sports betting legislation. Before that, many took to Las Vegas to wager on sports and, hopefully, make a living doing so.
Today, well over half of the states in the United States can bet at the best online betting sites, but back then, it was contained mostly to Vegas.
Over the years, there’s been endless amounts of lore surrounding the most famous sports gamblers.
Below, I’ll detail some of the most notable, including those that are strictly known for gambling and celebrities that have also had a hand in sports betting and have had reported success.
Billy Walters
When it comes to the most famous sports gamblers, Walters, 78, is often atop that list. His sports betting began when he was nine years old. According to the story, he wagered money he earned from his paper route and bet it on the New York Yankees to beat the Brooklyn Dodgers in the 1955 World Series.
The Dodgers beat the Yankees, and Walters lost his first-ever bet.
Despite the loss, he continued trying his hand at betting, but it didn’t really go all too well for a while.
By 22 years old, he lost $50,000 on betting and even lost his house in a game of pitching pennies. Thankfully, he instead paid the debt over 18 months as opposed to giving up his house.
Walters luck would begin to change in the 1980s, though.
He joined Computer Group, an outfit that used computers to analyze sports data. From there, Walters reportedly had just one losing year betting over the next 39. He even had a 30-year winning streak.
Walters primarily focused on basketball, college football, and the NFL.
One notable win came in Super Bowl XLIV when he bet on the underdog New Orleans Saints. He won $3.5 million.
In 2011, Walters told The Wall Street Journal that he would make between $50 and $60 million from betting on a good year.
Walters is enshrined in the Sports Betting Hall of Fame at the Circa Hotel and Casino in Las Vegas.
His plague at the Hall of Fame reads: “Billy Walters is known for being the greatest sports bettor of all time. He commands respect from every prominent bookmaker in the world and is known for contributing as a philanthropist to many causes,” per Men’s Health.
To me, of the most famous sports bettors, nobody tops Walters.
Floyd Mayweather Jr.
While many know Mayweather for his sensational 50-0 professional boxing record, which includes 27 wins by KO, he’s also one of the most famous sports gamblers. Mayweather has always been a businessman at heart, including boxing Connor McGregor, and, of course, his sports betting ventures.
In a report by the Daily Mail in 2022, they detailed Mayweather’s betting successes.
These included wins in college basketball, NFL, NBA, boxing, and MMA.
In 2014, he won $75,000 on March Madness. He won these wagers while he was in camp preparing for a bout against Marcos Maidana.
The Daily Mail also detailed that, in 2014, Mayweather won nearly $5 million in one month from NFL betting. He was also wagering up to $800,000 per wager.
Also, in 2015, he took to Instagram to detail his winnings on the Gennady Golovkin and Willy Monroe Jr. bout.
“The last 4 days have been great. I’m getting paid while watching others entertain and perform. I don’t (do) anything for free. I bet $350,000 and walked away with $827,272.73,” Mayweather wrote on the social media platform.
It’s unclear what his sports betting habits are like today or if he’s in the red or black historically, but either way, a person with his statute openly betting this much certainly makes him one of the most famous sports bettors.
Frank “Lefty” Rosenthal
Frank Rosenthal, also known as Lefty, passed away in 2008 but left behind quite a legacy in sports betting, making him one of the most famous professional sports gamblers.
For some additional backstory, he was a Las Vegas casino executive involved with organized crime and an FBI informant.
He had a colorful life.
Also, the movie Casino, directed by Martin Scorsese, is loosely based on him. If that doesn’t place you among famous sports bettors, I don’t know what will.
Rosenthal began to understand sports betting as a kid sitting in the bleachers at Wrigley Field in Chicago, Illinois, where he was born.
Additionally, his father had racehorses and became familiar with betting odds and lingo through that.
Rosenthal got involved in organized crime involving sports betting in the 1950s with the Chicago Outfit, a branch of the Mafia based in the city.
Because of his sports betting acumen, he headed up the biggest illegal bookmaking unit in the United States. Again, this was on behalf of the Mafia.
To go even further, the Chicago Outfit positioned itself as a moving company to keep a low profile.
The Chicago Outfit was involved with fixing sports matches, and Rosenthal was eventually indicted for sports bribery.
Further, when he was 40, Rosenthal began working for Stardust, a casino in Las Vegas, and was eventually named CEO of Argent Corporation.
The Chicago Outfit controlled Stardust, Fremont, Marin, and Hacienda.
In 1982, Rosenthal survived an assassination attempt.
Later in life, he moved to Florida and ran a sports bar and a sports betting website, where he worked as a consultant for multiple offshore sports betting outfits.
He was revealed to be an FBI informant after his death.
Rosenthal has the most colorful past among the famous sports bettors named thus far.
Michael “Roxy” Roxborough
Michael Roxborough, also known as Roxy, is still alive today and in his 70s.
He also has an intriguing past, serving as an oddsmaker, columnist, teacher, and author.
He’s the founder of Las Vegas Sports Consultants, an internal odds-making outfit licensed by the Nevada Gaming Control Board.
He was involved with the company from 1982 to 1999, and it was revolutionary in introducing math into the sports betting industry.
Roxborough also co-founded American Wagering Inc., the first sports betting company listed on the stock exchange.
Roxborough was also involved with founding “America’s Line,” a daily newspaper. He co-authored a book with Mike Rhoden titled “Sports Book Management: A Guide to the Legal Bookmaker.”
He and Rosenthal were both involved in sports betting at the highest levels but typically on opposite sides of the law.
Roxborough was inducted into the Sports Gambling Hall of Fame in 2023. Additionally, he’s considered one of the top 50 Greatest Sports Figures in Nevada History, the top 50 Most Important People in Sports, and the top 10 Most Influential People in Gaming.
