When the Giants open the World Series against Detroit, they will be riding a zip line of adrenaline that all sports teams hope to experience, but very few ever do. After falling behind Cincinnati 2-0, and St. Louis 3-1 in the playoffs, the Giants made history reeling off three straight wins -- twice. Fending off elimination six times, San Francisco rallied around an unseen force that was discussed as often as any vital player in their clubhouse: Big Mo.

"We just got a lot of momentum going our way," explained winning pitcher Matt Cain following the team's National League Championship Series victory Monday night over the Cardinals. And St. Louis manager Mike Matheny agreed the Giants had the magical mojo. "You have to acknowledge that when a team gets rolling," he said, "it's sometimes hard to stop them."

Ya think?

But wait a minute. The American League champs, the Detroit Tigers, have won five games in a row -- their clincher against Oakland in the first round, then four straight from the once mighty New York Yankees. So it's mathematically, terrifyingly possible that the Tigers have even more momentum than the Giants. Experts in the science of momentumology insist, however, that the Tigers' momentum has been sapped by the six days they were forced to wait for the Series to begin.

Seeing patterns

While athletes and their fans consider it a near-mystical force, there actually is some science

surrounding the study of momentum. But most of the conclusions drawn in a series of academic studies and books like "Scorecasting: The Hidden Influences Behind How Sports Are Played and Games Are Won" suggest that momentum in sports is a myth, a voodoo religion based on finding patterns among life's randomness.

In other words, there is no such thing as momentum in baseball. And yet, both teams in this year's World Series are certain they have it -- and are counting on it tonight.

"Just because we feel it, doesn't mean it exists," says Michael J. Fry, whose article in the current issue of the Journal of Quantitative Analysis in Sports, "Searching For Momentum in the NFL," didn't find any. Fry and a co-author studied fourth-down conversion attempts, turnovers and what happened after teams allowed their opponents to score for five seasons, and concluded that what players and coaches took for momentum was usually just wishful play-calling.

"Humans are very, very good at seeing patterns," Fry says. "In fact, we're so good at seeing patterns, we see them where they don't exist."

In physics, an object's momentum is the result of Mass multiplied by Velocity. But in sports, momentum is constantly darting back and forth, from sideline to sideline, which is why coaches often refer to turning points in a game, or a series. For the Giants, trailing the defending world champion Cardinals 3 games to 1, momentum shifted when Barry Zito pitched an unexpected shutout in Game 5. Zito's galvanizing performance wasn't a logical predictor of a change in the Giants' fortunes -- his won-loss record with the team suggested it was a fluke -- but it didn't matter. Zito's teammates believed he seized momentum from St. Louis and altered their collective fate.

Off the schneid

"It's something that most certainly has a role in sports because the athletes on the field believe it does," says Harry Edwards, professor emeritus of sociology at UC Berkeley, and a sports psychologist who once worked with the San Francisco 49ers. "Momentum. Destiny. It's part of the lexicon that keeps people moving forward, even when there's no rational reason for them to believe they have a chance." It may have been momentum that propelled Elizabeth Taylor to accept her eighth marriage proposal, even with a career matrimonial record of 0-7. Unlike Zito, Liz never did get off the schneid.

An athlete on a hot streak confers momentum on his team, and coaching decisions often are based on which player has the hot hand. But the laws of probability suggest that's usually a mistake. "If you want a big hit in a game," says L. Jon Wertheim, author of "Scorecasting" and a senior writer at Sports Illustrated, "you'd rather have the guy who's .310 for his career at the plate, not the guy who's gone 6 for his last 8 but hits .210 for his career."

Wertheim's book dismisses momentum as a "myth," but he acknowledges it's nearly impossible to find an athlete at any level who agrees -- including the basketball jock in the Oval Office. "We have it on reasonably good authority that Obama has read the book," Wertheim says, "and apparently said he enjoyed it. Until he got to the part about momentum, at which point he said, 'And then those guys totally lost me.' "

Despite their work debunking momentum, Wertheim and Fry both have intuitive doubts about their own findings. "Even though I've done research on this," Fry admits, "I cannot say momentum doesn't exist. I've played enough sports that I know what the feeling feels like."

The Giants know what the feeling feels like, too. And all they want now is mo', mo', mo'.

Contact Bruce Newman at 408-920-5004; follow him at Twitter.com/BruceNewmanTwit.