SAN FRANCISCO - By the time he graduated from MIT, Jeff Ma already had led a life many guys dream about. His card-counting prowess at blackjack tables during wild weekends in Las Vegas and Atlantic City won him and his college buddies millions of dollars, inspiring a best-selling book and the recent movie "21."

Now 35 years old, Ma thinks he can hit his next jackpot in a different fantasy land -- the fanciful football leagues that will preoccupy millions of people during the next four months as they accumulate points based on the statistics of NFL players picked for their imaginary teams.

Hoping to introduce a younger generation to the game of fantasy football, Ma and his primary business partner, Mike Kerns, have launched a program that enables the leagues to be managed within the popular Internet hangout Facebook.

Ma and Kerns, who run Citizen Sports Inc., reason that fantasy sports are ideally suited for online social networks like Facebook because the leagues are typically formed by groups of friends looking to deepen their bonds.

The idea was compelling enough to persuade Sports Illustrated to stamp its name on the program, its first fantasy football venture. The magazine spent the past decade on the sidelines watching Yahoo, ESPN and CBS build popular Web sites to help manage the leagues.

The 54-year-old magazine, owned by Time Warner Inc., is providing content for Citizen Sports' fantasy football program, handling all the advertising sales and promoting the service in its print edition and Web site.

"We think this can change the fantasy landscape," said Jeff Price, president of Sports Illustrated's digital operations.

Still, the odds appear to be stacked against San Francisco-based Citizen Sports because the most rabid fantasy football fans are entrenched in leagues that have been running for years on other Web sites.

"The switching costs for people to leave a league to come over to another site is a significant hurdle," Price said. But he believes it will be easier for Citizen Sports because having its program run on Facebook, where millions of people already spend hours every day, "brings fantasy football to the player instead of having the player come to you."

The field is led by Yahoo Inc., whose fantasy football site drew 6.6 million U.S. visitors in the opening month of the season last year, followed by ESPN.com at 2.6 million visitors, according to comScore Inc.

And Yahoo isn't taking its advantage for granted. The company has developed even more tools for its fantasy football service, including more graphics and audio alerts, while making it easier to play on mobile phones.

"It's a daunting task," Ma said of the challenge facing Citizen Sports. "Do you look at what Yahoo has been able to do and say, 'It's just not worth taking a chance?' Or do you look at the advent of social networks and say, 'Let's give it a shot."'

Ma struck it rich at a young age by taking an unusual risk while attending the Massachusetts Institute of Technology. Working with friends who also had a way with numbers, Ma developed a card-counting system that identified when blackjack decks had a higher percentage of face cards remaining, increasing the odds of being dealt a winning hand.

The formula paid off in spades, spawning the 2002 book "Bringing Down The House." The book was turned into the movie "21" last year. Ma, though, wasn't named in either one - his character was named Kevin Lewis in the book and Ben Campbell in the movie (in which he made a cameo as a blackjack dealer).

Kerns read "Bringing Down the House" in one night after learning through a mutual friend that he had been invited to a friendly poker game that would include the real-life Kevin Lewis. By the time he put the book down, Kerns decided to recruit Ma as a business partner.

Ma wants a piece of the fantasy football action because, as frivolous as it may seem to those that have never participated, the concept has turned into a lucrative market for the Web sites that help run the leagues.

While some sites charge small fees for special service, most of the money in fantasy football pours in from advertisers eager to connect with a mostly male audience that spends a lot of time online managing and tracking teams. The demographic is especially appealing to marketers because these guys tend to have above-average incomes and consume lots of beer, fast food and technology.

"It's a rich and robust audience," said Clay Walker, founder of the Fantasy Sports Association.

Privately held Citizen Sports is projecting at least a sevenfold increase in revenue this year, bolstered by the new fantasy football program along with other existing social network applications built to help people follow their favorite professional, college and high school teams in a variety of sports.

Sports Illustrated already has sold season-long sponsorships for Citizen Sports' Facebook fantasy program to AT&T Inc. and the sporting goods chain Finish Line Inc. The magazine's sales force is hoping at least 250,000 people participate in the Facebook fantasy league during the first season, Price said.

Nearly 100,000 people had downloaded the program through Aug. 6 after just a few weeks on Facebook. Interest is expected to intensify this month as more fantasy football players hold their drafts before the NFL season starts Sept. 4.

Citizen Sports' financial backers include former venture capitalist Kevin Compton, who owns the National Hockey League's San Jose Sharks, and Jeff Moorad, a former sports agent who owns Major League Baseball's Arizona Diamondbacks.

But that pedigree and some celebrity endorsements weren't enough to turn Citizen Sports' first fantasy foray into a smash success. Hoping to put a new twist on the fantasy sports concept, Ma and Kerns in 2005 introduced an electronic trading market called ProTrade that used sophisticated computer models to appraise the value of professional athletes as if they were shares in a publicly held company.

ProTrade still is around, though it never caught on like Ma and Kerns envisioned.

"It's just a little too obtuse for most people," Walker said.

This time, Ma and Kerns seem to understand that getting people to switch their fantasy sports program isn't a sure bet either.

"It's just us, with a slingshot, going against the big guys," Kerns said.