INDIANAPOLIS — Patrick Chung and Rulon Davis arrived at this week's NFL scouting combine with wildly different perspectives.

Chung, the 21-year-old safety from Oregon, describes himself as cocky and ready to conquer the world.

Davis, the 25-year-old defensive end from California, knows better. After spending more than three years in the Marines, including six months in Iraq, and surviving a serious motorcycle accident in California, he's just happy to be alive.

"It's a miracle, man," Davis said Sunday. "I should be dead."

By all accounts, Davis is right.

In July 2005, he was rear-ended on a California highway, thrown off his motorcycle and into the path of an oncoming semitrailer, which ran over both his legs. Somehow, Davis survived with no broken bones and no ligament damage, though he couldn't walk for a month and had to retrain his legs.

Miraculously, the kid with no scholarship offers out of high school, made it back to the football field and less than four years later is here in Indy, surrounded by some of the biggest names in college football.

"I had to learn how to walk again. The year after that I went to Cal, that's why I redshirted in '05," Davis said. "Today, there's no pain. I got a little bit of numbness here and there, but structurally it's sound."

In a league that tries to balance experience with youthfulness, Chung and Davis come from opposite worlds.

Chung, the No. 2 rated safety, always expected to be here. Davis did not.

Chung could be the youngest fifth-year senior selected in this year's draft, while Davis is projected to go in the middle rounds and likely to be the oldest player chosen in April.

But the two players with such divergent backgrounds and vastly different expectations do have one thing in common — they've beaten the odds.

Chung jumped onto the college football field at age 16, with a team full of older players ready to embrace him as more of a punch line than a teammate.

"They were a bunch of grown men, and the guys were picking on me," he recalled. "They called me 'Little Man.' "

Not for long.

Chung reported to freshman practice at an already comfortable safety-size of 5-foot-10, 188 pounds, played on special teams and emerged as one of Oregon's top practice players during his redshirt season. In Year 2, he was the Ducks' No. 2 tackler and on the way to starting 51 consecutive games.

Since then, Chung has grown in size and stature, overcoming the challenges his teammates placed on him.

"The older guys were showing me the ropes, and I was trying to be the best player I could," he said. "I'm kind of cocky, so you just keep going and going till you get that goal."

The biggest question, initially, for Chung was how he got to college at age 16.

The short answer: He was born in Jamaica, where he enrolled in school at a younger age than most Americans, then moved to Florida and eventually California where he was always tagged as the youngest in his class.

He was so young that he was the youngest player on the team for two straight years.

But by 2005, the teasing stopped when Chung emerged as a key player on the Oregon defense.

"When I got there as a freshman, he had redshirted, so he was starting as a redshirt freshman," said teammate Jairus Byrd, also a combine invitee. "At 17, he had a lot of people looking up to him."

Now, at 5-foot-11, 212 pounds, he has the resume and body frame to keep pro scouts interested.

Chung and Davis aren't the only ones in Indy who have overcome struggles.

Oregon State cornerback Keen Lewis was attending college when Hurricane Katrina struck his hometown of New Orleans. His family was evacuated to Houston, and Lewis still doesn't like to talk about it.

"I just put it in the Lord's hands and went on with that, making sure that everybody was fine," Lewis said.

Davis understands because of his military experience. When asked about his time in the Marines, he declined to answer.

But when asked for the details of his motorcycle accident, Davis opened up.

"I was trying to crawl from underneath the semi and the semi ran over both my legs," he said. "I had some swelling in my legs that wouldn't go down. They had to do some surgery to release the pressure, but no broken bones, nothing."

As Davis figures it, the second chance has given him a new opportunity.

NFL scouts have lowered his grade, in part because of a long list of injuries, but like colleges who offered him no scholarships out of high school, Davis believes he's undervalued.

After all, he is a survivor.

"I know I'm a high draft pick, but I know won't get that opportunity because of my injury history," he said. "But we're going to see what happens."