CLEMSON — Dabo Swinney said his team is competing against more than the defending national champion today when Auburn visits Memorial Stadium. Clemson’s head football coach said the Tigers are also battling a shapeless, immeasurable force:

Momentum.

Swinney said Clemson rode a confidence wave after defeating Miami in overtime in 2009, winning four straight games en route to an Atlantic Division title.

Swinney says momentum appears to be driving No. 21 Auburn, a team riding a 17-game winning streak. Swinney said momentum matters and says Auburn (2-0) has it after two close wins against Utah State and Mississippi State to open the season.

“Win that many games and a belief, a swagger, a confidence comes about,” Swinney said. “You believe you are going to make a play. You believe you are going to win.

“You never panic.”

But is momentum a real force or a word we use to explain an outcome?

Clemson sports communication professor Bryan Denham said the idea of momentum can affect athletes.

“Statistically, many of the streaks and ‘runs’ that we hear about are no greater than what we would expect to occur,” Denham wrote in an email. “But momentum can be useful psychologically. ... If an athlete believes (he) has momentum based on recent successes, then the athlete may have more confidence when competing. If an athlete senses a lack of momentum, (he) may essentially create a reason to continue that pattern and prove detractors correct.

“It can become a self-fulfilling prophecy.”

Other factors played into Clemson’s losing season last year, including quarterback Kyle Parker’s rib injury. But Clemson opened poised and confident at Auburn last September, taking a 17-0 lead before Parker was injured and Auburn’s Cam Newton began his Heisman campaign in the second half.

Swinney thinks Auburn gained its confidence in the overtime win against Clemson last season while Clemson is still searching to regain a confidence lost.

The Tigers faced a difficult three-game stretch early last season, losing to Miami and at North Carolina after losing at Auburn. This season, Florida State and Virginia Tech follow Auburn.

Clemson tight end Dwayne Allen said the Tigers suffered from a hangover they couldn’t shake last fall.

“Let’s say we (beat Auburn),” Allen said. “Just the confidence boost you would get ... then maybe we come back home maybe we take care of business against Miami maybe we don’t have mental busts. Then we go against North Carolina, against a depleted team, we go up there and take care of business.

“I do believe the (Auburn) game was a turning point.”

In the press conference following the loss to South Florida in December, Swinney said “We lost our confidence somewhere along the way.”

Perhaps it was at Auburn.

Perhaps Clemson can get it back today.