DETROIT — Seattle running back Shaun Alexander was asked at an interview session what would be a great Super Bowl for him.

"I carry the ball 20 times and score 20 touchdowns," the NFL's MVP said with a smile.

Hopefully, Pittsburgh linebacker Joey Porter won't hear about that. Porter is already steamed because Seahawks tight end Jerramy Stevens had the gall to intimate his team would win Super Bowl XL.

Easy, Joey. Alexander wasn't predicting a 20-touchdown game. He was just kidding around. You don't have to try and maim him Sunday. OK?

Besides, everyone knows you can't possibly score 20 touchdowns in a Super Bowl unless, of course, you are playing the Denver Broncos from the 1980s or the Buffalo Bills from the 1990s.

It's improbable enough that Alexander scored an NFL-record 28 touchdowns this season. And he made it look easy.

Alexander's every carry looks like a slow-motion replay. You watch him puttering along behind his blockers and think there's time to get a snack before he gets to the line of scrimmage.

He's the David Copperfield of running backs. He's more of an illusion than elusive.

Although his teammates know his act, they still get fooled.

"We'll be finishing our blocks, see him running up the field and we'll be saying, 'Run, run faster,' " Seahawks offensive guard Chris Gray said. "But nobody's catching him.

"I've talked to defensive guys on other teams. They say when they watch Shaun on film, it doesn't seem like he's running that fast."

They find out differently on game day.

Seahawks wide receivers coach Nolan Cromwell knows something about speed and running backs. He was a champion hurdler at the University of Kansas, where he rushed for 294 yards in a single game, and later won the NFC Defensive Player of the year award as a defensive back with the Los Angeles Rams in 1980. He played with Eric Dickerson and against Marcus Allen and Tony Dorsett.

"In flat-out speed, Eric was faster," Cromwell said. "Vision-wise, they're very similar.

"Shaun has great vision. And he understands where everybody is on the field."

Great vision alone won't get you 1,880 yards — Alexander's league-leading rushing total for the regular season. And you don't just slowpoke your way to 7,817 yards in six NFL seasons.

"Great running backs have patience," Cromwell said. "But when they see that crease — boom! — they burst through the hole. That's how Shaun is.

"You look at him and say he's not that fast. But all of a sudden, he makes that cut and he's gone."

Catching up to Alexander is only half the battle. At 5-foot-11, 225 pounds, he's a handful; his balance is as good as his vision.

"His sense of balance is tremendous," Steelers defensive coordinator Dick LeBeau said. "He just does not go down."

He doesn't stay down long, either. That's why the Seahawks were surprised when Alexander didn't bounce back up after a first-quarter carry in their playoff game with the Washington Redskins.

Alexander suffered a concussion on the play and didn't return to the game. A week later, he rushed for 132 yards on 34 carries in the NFC title game against Carolina.

Durability is another of his attributes. He rushed for 6,657 yards in his All-American high school days in Boone County, Ky., and set University of Alabama records for yards rushing, carries and touchdowns. Yet he has never had a serious injury.

"He knows how to avoid the big hit," Cromwell said. "You think you're going to have a good hit at him, then all of a sudden he turns his shoulders. You just never get a punishing hit on him."

Alexander is successful, healthy — and just as important to him — eligible for free agency after this season.

Seahawks coach Mike Holmgren is optimistic the team can re-sign him. But given the reality of the salary cap, the Seahawks might find out what opposing defenses already know: It's not easy holding on to Alexander.

Sports editor John Adams may be reached at 865-342-6284 or adamsj@knews.com.