You’re in Las Vegas. You’ve got money in your pocket. And you’ve got a strong opinion on the “Monday Night Football” match-up.

You wander into a sports book, where virtually every athletic contest in America has a price on it. You scan the boards, skipping over college football and a World Series game, searching for tonight’s NFL line.

There it is: The Giants are favored by 13½ points over the Bears. You like the Giants, playing at home. However, even though you’re certain the Giants will win the game, 13½ points seems like a lot to spot the Bears. That’s almost two touchdowns, you think, fingering the money in your pocket. You hesitate, weighing the pros and cons. Can the Giants win by two touchdowns? Well, on paper New York should dominate. … Of course, Chicago might get a lucky last-minute break. … On the other hand, the Giants usually play well at home on Monday night. … Hmmm.

Finally, you convince yourself the Giants are a good bet at 13½. You approach the window, minutes before the kick-off, ready to slide your stack of hundreds across the counter.

And then it happens: The 13½ changes to 14½.

“Wait a minute,” you tell the clerk. “I wanted to bet the Giants at thirteen and a half.”

“Too late,” he says, shrugging. “The line just moved. Should have bet five minutes ago.”

Indeed. Now the Giants don’t look so attractive. Now they have to win by more than two touchdowns. Now you might even bet the Bears.

“What happened?” you ask the clerk. “What happened to the odds?”

“Sir,” the clerk says, smiling, “you just got stung by the Line Mover.”

Welcome to the club.

The Line Mover is the most powerful—and successful—bettor in all of sports. He and his organization, a syndicate of approximately two dozen well-capitalized gamblers, exert the kind of influence over America’s sports betting odds that, were it occurring on Wall Street, would be called manipulating the market. Regularly wagering as much as $500,000 per football game, the Line Mover inspires fear in bookmakers, confusion in those who would try to piggy-back on his expertise, and hope in millions of casual sports bettors around the world who would like to think that there’s someone out there who really can consistently beat the game.

Speaking on the condition of anonymity, the Line Mover sat down with me and revealed how America’s biggest sports betting syndicate operates.

“It’s pretty simple,” he says flatly. “We find situations where we have way the best of it, and then we bet a whole lot of money. Do that enough and you end up with a nice little profit.”

How nice? He won’t say exactly. But the Line Mover does volunteer that over the past five years he has paid on average $3 million in taxes on his winnings. “We do pretty well,” he deadpans, nodding contentedly.

Of the Line Mover, Michael “Roxy” Roxborough, who for many years ran the company that produces the Las Vegas line, says, “Anybody can walk into a Nevada sports book and bet on a game. The truth is, we don’t worry about the average gambler. We worry about [the Line Mover]. There’s only four or five guys we’re really concerned about. We design the line with these guys in mind. Sports betting is a game of skill. Give a really skillful sports bettor a big bankroll and he’s dangerous. A guy like [the Line Mover] is the reason we have limits. He’s the reason we have to be so careful.”

Of Roxy Roxborough, the man who spends each working day trying to take his money, the Line Mover says, “The man has a very difficult job. He’s trying to make a line for the casinos to get two-sided action [equal bets on both teams], and he does a good job at that. But he can’t keep up with me, because I’m the tenth of one percent that consistently wins. If Roxy ever does catch up, I’ll quit tomorrow. In the meantime, even though I think Roxy is a good and admirable opponent, I know I’m going to beat him year in and year out.”

America’s biggest sports bettor accomplishes this feat by identifying games where the line is “off,” or, by his calculations, slightly mistaken. By his reckoning, a football line that is incorrect by a half point gives him close to a 7% advantage, depending on the number in question. A line that’s off by three points—well, that’s a monstrous edge. The trick, of course, is finding games in which the Las Vegas line is wrong.

Enter the computers. The Line Mover is famous in the gambling world for using up to a half-dozen sophisticated computer programs, custom-designed to evaluate past performance and predict future results. He won’t say what the computers are searching for—”That would be like the magician telling you how he cuts the girl in half,” he jokes—but he does reveal that the criteria, when processed properly, yield a chillingly accurate “power rating” that reduces every college and NFL football team to a quantifiable number. Employing a full-time team of handicappers, statistics-obsessed computer junkies who generate a series of daily reports, the Line Mover considers his analysts’ data and decides where his organization’s money will be invested. “My talent isn’t handicapping the games,” he admits. “My expertise is handicapping the handicappers—and knowing the best time to bet.”

The Line Mover’s sense of timing, his nearly extrasensory understanding of how—and when—the public will bet a sporting contest, is perhaps his greatest attribute. “I can’t emphasize how important timing is in my business. A half-point either way can make or break my profit. So some games we’ll bet early Monday morning, some five minutes before the kick-off. All depends what kind of price we think we can get.”

Casino sports books constantly adjust their lines based on the amount of money coming in. If, for example, everyone in Nevada seems to be favoring the Giants, the price on them will go up, making a bet on their counterpart, the Bears, more attractive. By offering odds that encourage two-way betting, the bookmakers can keep their accounts fairly balanced, avoiding big swings and virtually guaranteeing a profit. (Since the bookies charge $11 to win $10, $1 million bet on both sides of a game ensures them a $50,000 profit.) When the Line Mover makes his plays, an enormous amount of money comes in on one side, so the bookmakers quickly change their odds to dissuade other gamblers from taking the heavily bet side and encourage them to wager on the lightly bet side. The trick for the Line Mover is to get his money down before the bookmakers adjust their lines.

Every time the Line Mover bets a game, hundreds of bettors try to jump on his action. If “the middlers,” as the Line Mover calls them, get their bets down at various casinos before the Line Mover does, the odds change, fluctuating by the precious half-point (or more) that makes or breaks his profit.

Also, since no single casino will accept the $250,000-and-up bets that the Line Mover makes, in order to get all their money in play, he and his people are forced to make dozens of smaller bets with dozens of bookies around the world.

This is a sore subject with the Line Mover. He denies that he and his organization bet with illegal bookies, but knowledgeable sources say that the Line Mover would be incapable of plying his trade if he didn’t use bookies in, for instance, Dallas, Atlanta, New York, and Chicago. “Try betting three hundred thousand on a regular-season college football game,” one professional sports bettor explains. “The local casinos here in Vegas just aren’t going to fade [take] that kind of action. And even if they would, you could never get a fair price. By the time you bet your first fifty-thousand, they would start moving the line on you.”

Thus, a typical play by the Line Mover works like this. He and his analysts find a game that’s “off.” Using a pre-determined formula—a half-point warrants a $50,000 bet, two points warrant $250,000, and in rare cases, some lines inspire bets of $1 million—the Line Mover selects his best plays of the day. Some weekends he’ll bet as many as 25 college and NFL games; sometimes he’ll only bet a handful. “I gamble for value, not action,” he says. “I bet by a strict formula. So there’s no ‘get-even’ or ‘get-rich’ bets. If the numbers don’t look good, I pass.”

After deciding which contests his organization will bet on, the Line Mover sends out instructions to his associates, via a numerical pager. When the signal goes out to make a play, the Line Mover’s team members attempt to make their bet immediately and simultaneously, before the illegal bookies and legal Nevada sports books can adjust their lines unfavorably. Smart bookmakers, recognizing the source of the large bets, often bet with the Line Mover, “laying off” or hedging their money with another, unsuspecting, bookmaker. (Others merely try to avoid taking his bets.) Within minutes, bookmakers in every region of America—and often offshore—are flooded with fresh money, all on one team. Within a few more minutes, the official Las Vegas line moves to reflect the imbalance.

That’s why they call him the Line Mover.

He wasn’t always the king of the sports bettors. The man who is now widely regarded as one of the most powerful forces in all of gambling was, twenty years ago, indistinguishable from thousands of other wishful thinkers. “I bet on everything at the start and, like everybody else, I lost,” the Line Mover remembers. A successful businessman with a chain of appliance stores throughout the Midwest, the Line Mover blew off hundreds of thousands of dollars to local bookies. “It took me a long time to figure out that just reading the morning sports paper wouldn’t cut it. Just studying the box scores doesn’t work.” Instead, he sought out the best minds in the game, the brilliant computer programmers and data analysts who would revolutionize the way we bet on sports. He made them a deal: You provide me with the best information and I’ll provide you with the money to do something with it. “And that’s how our team was born.”

While the Line Mover professes to still love sports, he says, “If my life depended on it, I couldn’t tell you who’s leading the divisions. I don’t even look at the sports pages much. I’m a money manager, not an action-hungry sports fan. Your average sports bettor reads something in the paper or hears something on television and figures he’s got some kind of insider information.”

Indeed, the professional touts, so-called “experts” who sell their opinions to gullible gamblers via expensive 900 lines, help the Line Mover win his yearly millions. “People follow these touts blindly, like they’re in a cult. Ninety percent of the time I bet against the tout’s opinion. See, by promoting one side of a game so vigorously, they can sometimes move the line four, five, six points. That,” he says, smiling broadly, “tends to create some very profitable situations.”

The Super Bowl, according to the Line Mover, is a prime example. For five of the past six years, he says, the line has been dramatically off. Wildly off. “Only problem is, the public’s been right. I’ve bet on every loser.”

He says this with a grin, looking very much like a man who is used to being right far more often than he is wrong, a man who can afford to lose a sports bet now and again—a man who is accustomed to knowing before the rest of the world which way the line is going to move.