LIKE countless other baseball fans, Steve Knopf devours box scores with breakfast."My wife used to say that what woke me up in the morning was the sound of the newspaper hitting the driveway," says Mr. Knopf, a regional manager for a Minneapolis packaging company. For the past 11 years he's funneled his passion for the sport into Rotisserie baseball, the odd-sounding statistical "fantasy" baseball game hatched by a group of writers in a New York City restaurant, La Rotisserie Francaise [see story at left]. Knopf early discovered the joys of Rotisserie play, in which fans act as general managers to "paper" teams that rise and fall in the standings depending on the performance of actual major leaguers. "If you play Rotisserie," says Glen Waggoner, a member of the first Rotisserie league, "you can in effect put your money where your mouth is. It lets you evaluate baseball talent; it lets you wheel and deal; it lets you do everything a big-league general manager does, only you don't have to put up $75 million to buy a team to do it." The original Rotisserie players, in fact, put up $260 per team, or what Mr. Waggoner calls "sort of the rough equivalent of the Wednesday night poker game spread over a season." Prize money is divided based on final placement in the standings, but Waggoner scoffs at calling Rotisserie gambling "because we don't wager on the outcome of games." Today there are many variations on the "fantasy baseball" theme, some with little or nothing at stake except pride or a trophy. In pure Rotisserie, teams are "scored" by combined roster performance in four offensive categories and four pitching categories. [See story at right.] For example, the club with the most home runs in a 10-team league receives 10 points, the team with the next highest number nine points, and so forth. Rotisserie has become a "phenom" in its own right, captivating dyed-in-the-wool fans across the country. One might even classify it as a subculture. By most estimates, there are 1 to 2 million fantasy-ball players. There are books and at least one magazine devoted to these statistical games within a game. A number of newspapers run "fantasy baseball" columns. ESPN carries a nightly show that caters to fantasy-leaguers. And a cottage industry of computerized statistical services have sprung up to organize raw data, keep track of trades by fantasy players, and provide scouting reports. In all, the hobby generates between $20 million and $50 million, says Greg Ambrosius, managing editor of Fantasy Baseball magazine. The league in which Knopf competes is not tied in to a computer service, but he takes a laptop computer with him on business trips. ve got all my rosters and the other guys' rosters on it, and I use it to ponder trades and roster moves back at the hotel," he says. "It beats watching the same old TV shows night after night." Of course, there might be a ball game on - even several - and extensive TV baseball coverage is a boon to fantasy enthusiasts. OU can turn the channel and watch the Braves, switch and watch the Cubs, switch again and watch the Brewers; your guys are all over," Mr. Ambrosius says. "We feel this is one of the reasons [fantasy ball] is going to really take off in the '90s." Bill James, the noted baseball statistician and the author of number of books on the subject, also sees a rosy future. "I think [Rotisserie] will continue to grow for another 20 or 30 years," he says. "It's a way of giving people a handle on the game, a way of establishing a direct connection." The fantasy concept has also been adapted for competition in football, basketball, hockey, and golf. At times, fantasy players go overboard in their pursuit of the game. Domestic conflicts can arise over the amount of time devoted to fantasy ball (an average of three hours a week, according to Ambrosius) and also over the expense of participation, since some players rack up sizable long-distance phone bills communicating with league members in other cities. And then there are the white-collar cheats who use office time and equipment to pursue their passion. "I think a lot of people dial us up during the day on the boss's dime," says Harvey Laney, who handles USA Today's Rotisserie leagues. "There's a charge each time they punch up the computer to see how their team is doing and check out the [player] injury report." "It's the yuppie hobby right now," says Ambrosius. The typical fantasy player, a Fantasy Baseball readership survey showed, is male, 33.5 years of age, college educated, and has a household income of $48,000. New York Gov. Mario Cuomo, "Today" show co-host Bryant Gumbel, and hockey star Wayne Gretzky are among the better-known fantasy players. People who compete in fantasy leagues may also evolve different rooting interests and ways of viewing baseball. Steve Knopf remembers the confusion he once caused at Cincinnati's Riverfront Stadium. While wearing the cap of the hometown Reds, he says he "jumped up and began cheering a home run by Mike Marshall, who was then with the Dodgers." Marshall, of course, was on Knopf's fantasy team.