In real life, Patti Hirano is a 41-year-old self-employed bookkeeping servicer and devoted San Francisco 49ers fan.

But from September to January each year, mundane reality gives way to sublime fantasy as Hirano assumes the life of a cold-blooded NFL franchise owner, building contending teams from the ground up and executing daring deals throughout the season to earn a shot at a league championship.

Hirano, a Waikele resident, is one of 12 million Americans expected to participate in so-called fantasy football leagues this year.

The game uses the statistical performances of real-life NFL players as the basis of virtual competitions between competing fantasy teams.

Before the the start of each season, "owners" like Hirano typically get together online or in person to conduct "drafts" in which they select real players for their teams. Points are awarded for the players' week-to-week performance in key statistical categories.

In some leagues, the overall winner is determined by the total number of points accumulated during the season. In other leagues, teams square off head-to-head each week, vying for the best overall record or attempting to qualify for a league play-offs.

"It's just a lot of fun," says Hirano. "It makes the game more interesting to watch."

According to the Fantasy Sports Trade Association, the average fantasy football player participates in two to three different leagues and spends more than $150 per season on magazines, Internet scouting reports and other fantasy-related media. The overall value of the fantasy football industry has been estimated at anywhere between $2 billion and $4 billion a year.

While many trace the origin of fantasy sports to a similar game, rotisserie baseball, which was developed in the late 1970s, a form of fantasy football actually existed as early as 1962. That was the year Wilfred Winkenbach, a limited partner with the Oakland Raiders, formed the Greater Oakland Professional Pigskin Prognosticators League with Scotty Sirling and George Ross of the Oakland Tribune.

Hirano started playing fantasy football with a group of work friends 13 years ago. A longtime football fan, she says tracking the performances of individual players from different teams has only enhanced her enjoyment of the game.

Hirano spends most Sundays in front of the TV, watching players she and co-owner Scott Hirai selected for their weekly starting lineup rack up the rushing, passing and receiving points. During the week, she watches ESPN and scans the Internet for injury updates, trade reports and other useful information.

Hirano and Hirai enter the new fantasy season as marked people. Their team, "Stacked," won the league title last year.

Repeat championships are difficult in so-called re-draft leagues (in which owners have to assemble their teams from scratch each season), especially when, like Hirano and Hirai, you're drafting at the bottom of the order in a 10-league team.

Still, the duo studied diligently and drafted wisely, picking up Philadelphia running back Brian Westbrook, Oakland wide receiver Randy Moss and Minnesota quarterback Daunte Culpepper.

"He's the brains," Hirano says of Hirai. "I'm the luck!"

NET GAIN

While "paper" leagues are still popular, many fantasy players now prefer the conveniences of online fantasy sports play available through scores of different hosts — from yahoo.com to the sportingnews.com. These online leagues automatically compile and crunch statistical data to determine week-to-week outcomes for each team. Many pay sites include elaborate extras like customized team logos, weekly e-mail updates and individual performance graphs.

Andrew Pak, 47, belongs to three different fantasy football leagues. He also rounds out the year by playing fantasy baseball and basketball.

"In Hawai'i we don't have a hometown (NFL) team to root for," says Pak, a mathematics professor at Kapi'olani Community College. "Fantasy sports make it more interesting, because you can root for your players."

Pak says he's not fanatical about tracking statistics or researching individual match-ups. The fun, for him, comes from interacting with his fellow players.

Pak, a longtime sports card collector, participates in one online league with a group of fellow collectors. One is from Taiwan, another from Seattle, a couple more from the East Coast.

"There are 10 of us, and I've only actually met six in person," Pak says. "Still, we're all friends. For me, fantasy sports is more about interacting with other people."

Pak says that while fantasy football can heighten one's overall awareness of the game — "you get a better feel for who the better players are on less publicized teams," he says — the emphasis on individual statistical performances can shift the focus from the forest to the trees.

"You find yourself watching a game where your team is up by 20 in the third quarter; when they take out your quarterback you going, 'Awww!' " Pak says, laughing. "It sort of gives you a distorted view of the game."

ALL IN FUN

Kawika Hasegawa, 43, has been playing fantasy football on and off (mostly on) for the last eight years. Like Pak, he'll spend this season juggling three different fantasy league teams.

Over the years, Hasegawa has gleaned lessons from experiences in several different league configurations. He's asserted self-determination with live drafts and surrendered to predestination with online leagues that make selections for you. He's second-guessed himself to death by reading too many magazines and rebounded from wobbly beginnings with savvy second-half acquisitions.

"The first year I played I didn't know there were so many rounds," he says, laughing. "I only had 30 or 40 players on my list. After three rounds, I was dangling."

Hasegawa says he prefers live drafts because they give owner's a chance "to show their prowess."

"You get an opportunity to out-think and out-maneuver the other players," he says. "Sometimes the draft is what sets you apart."

Hasegawa is also a diligent researcher. Each week he evaluates how his players are performing, looks for trends, and tries to identify variables that could affect the way the real-life games are played.

Yet, while Hasegawa would love to see his Vegas Viceroys knock the snot out of the rest of the league, he says he is always mindful of the real reason he plays.

"It's all in fun," Hasegawa says. "Nobody is betting the house. We take everything with a grain of salt. It's a game, and that's all it is."

To that end, Hasegawa says he doesn't make side bets on the weekly games ("You don't want to ruin the friendships by making it all about money," he says) and he makes sure the trash talking never crosses the line.

Hasegawa and his league buddies get together a few times a season to hang out, watch games, talk football and share some food. That, he says, is an end to itself.

"It's like tailgating at UH football games," he says. "You're just having fun with your friends and meeting new people. You want to win, but if not, there's always next season."

Fantasy football gear: Magazines, Internet research and charts to organize your dream draft.

Reach Michael Tsai at mtsai@honoluluadvertiser.com.