ROGERS, Ark. -- Under an enormous tent in a Wal-Mart parking lot earlier this year, some of the country's top fishermen hoisted their freshly caught largemouth bass. Fans and television cameras looked on as the anglers competed for a $200,000 check.

Standing near the back was another fishing champion, Bob Fowler. But the contest he won didn't require him to land any fish or even get anywhere near the water. Mr. Fowler is among the growing number of Americans hooked on a pastime known as "fantasy fishing."

Before each professional fishing tournament, Mr. Fowler spends hours on the Internet researching the pro anglers and considering factors such as weather forecasts and the depth of lakes where they're competing. Mr. Fowler, 46, then picks the fishermen he believes will catch the biggest fish in real-life. He enters his picks on a free fantasy-fishing Web site owned by pro fishing organizer FLW Outdoors and competes for prizes based on his predictions.

"It's harder to pick a top-five finisher here than it is to pick the winner of a football or baseball game," says Mr. Fowler, a sales representative for makers of furniture and lamps. In 2004, he won a model boat valued at $200 for a first-place finish in a fantasy-fishing contest. "My wife thought it was ridiculous until I won that one tournament," he says. "She still thinks it's ridiculous, but she respects it a little more."

First came fantasy baseball, in which enthusiasts put together make-believe dream teams of real-life players and compete based on those players' performances. Fantasy football and other variations followed. Now fantasy fishing is one of the more unlikely extensions of the concept. ESPN runs a fantasy-fishing league with prizes that include an $11,900 outboard boat motor. It says it has tens of thousands of participants. FLW Outdoors has about 40,000 fantasy players this year and a $5,000 prize for the top fantasy finisher in each of its seven tour events.

Like other fantasy sports players, fantasy fishermen put together virtual teams of professional anglers and earn points based on their team members' real-life performances. Exact rules vary by contest, but fantasy fishermen can win points each time an angler they've picked catches the heaviest bass; points can be lost each time a team member goes home with no fish.

Players scrutinize statistics from anglers' past showings, trying to assess whether an individual fisherman might do better in shallow or deep-water lakes, for example. They look for anglers on a roll and for previous victories on any given body of water. They also factor in other minutiae and myths, such as the "home-lake curse" said to afflict pros on water they know best.

Fantasy fishing is drawing on the increasing popularity of the professional fishing circuit, a series of multiday tournaments where anglers compete to land the biggest fish. Cable networks ESPN2 and Fox Sports Net each now broadcast several hours of fishing programming weekly, covering bass and other species. Cash prizes in the real-life-fishing contests FLW organizes will approach $40 million this year, thanks to corporate sponsorship. George Cochran, 56, of Hot Springs, Ark., was the FLW tournaments' top earner last year, raking in $547,250, the company says. Pro angler Mike Iaconelli says Fox Studios recently optioned the rights to make a film or TV series about his life.

Despite the surging fan and corporate interest, many in the pro-fishing industry believe it remains misunderstood. "People think of fishing as a guy with a six-pack of beer," says Irwin Jacobs, owner of FLW and chairman of Genmar Holdings Inc., a large motor-boat manufacturer. Fantasy fishing, with its focus on elite anglers and statistics, is one of the ways tournament organizers and their backers hope to deepen fan involvement.

Margie Ellis of Joplin, Mo., says she works on her fantasy-fishing picks every night. The 63-year-old convenience-store manager got into the hobby because her nephew, Randy Blaukat, is a pro angler. She pores over statistics online, looking for fishermen on winning streaks. Ms. Ellis, who doesn't fish, also watches weather forecasts on the Internet, guessing which fishermen might do better in sunshine or rain.

Earlier this year, she won a $5,000 prize from FLW for her picks in a tournament on Lake Murray in Columbia, S.C. "People who don't fish think that I'm crazy," says Ms. Ellis. But after she won the prize, about 10 friends and coworkers began playing fantasy fishing too.

Carl Herschbach had played fantasy football and basketball when he was lured by an ad for fantasy fishing on ESPN's Web site a few years ago. Mr. Herschbach, a 34-year-old farmer in Constantine, Mich., didn't follow pro fishing at the time, and he's never fished in his life. Since he began playing the fantasy-fishing contests, he now watches bass tournaments on TV.

Mark Zona, a host for several of ESPN's bass-fishing programs, says he initially thought fantasy fishing "was like Dungeons & Dragons or something." Now he believes there's a science to it. He starts by dividing pro anglers into two groups: those who excel in shallow water and those who excel in deep water. Mr. Zona, 33, compares it to golf. "There are certain golfers that will excel where the drive is more important than your putting," he says. "As in golf, certain fishermen will excel on one body of water."

Others counsel would-be fantasy-fishing champs to weigh less tangible, personal information about the anglers in assembling fantasy teams. One example is pro Brent Chapman, whose performance improved noticeably after his wife began traveling with him on the tour. Mr. Chapman agrees that his fishing got better after his spouse started handling the "behind-the-scenes stuff."

Some of the fantasy-fishing organizers aim to expand the statistics, a nod to the culture of numbers around fantasy baseball. The fantasy-fishing leagues' sites already provide detailed records of anglers' performance in past tournaments. Now FLW is starting to provide a series of other stats about anglers, including "average weight per fish over careers," "largest margin of victory" in pounds and "consecutive limits caught," which tracks anglers' streaks of hitting their five-fish daily quota, with data going back to 1996 when the FLW Tour started.

Remote Knowledge Inc. of Houston has ambitions of providing ever-more-sophisticated data. It makes computer systems for the boats used by TV crews following the 10 finalists of each FLW tournament. The equipment can record information such as latitude and longitude, water depth and temperature each time a bass is landed and relay that by cellular and satellite links.

Professional fishermen, who often spend days and weeks scouting out fishing spots in advance of tournaments, have some qualms about making public all of the available data about prized fishing holes and techniques. They also know how fickle fish can be. Mr. Blaukat, a pro angler since 1989, says "a fish is a creature you cannot predict."