Personnel directors want to see athletes get bigger and more experienced. They want an extra year to scout before making that million-dollar draft choice.
Still, for players wanting to leave early, the NFL's College Advisory Committee -- composed of two scouting experts and personnel executives from 12 teams -- will provide an estimate of where they might be selected.
The number of underclassmen seeking this information has grown from 53 in 1994 to 101 last year, the league says. Of the 759 players who have been evaluated, 63% chose to stay in school.
Because the NFL collective bargaining agreement has shifted dollars from rookies to veteran players, "only those draft choices at the very top now have an incentive to leave school," the league states.
But for some talented juniors, "it's really scary to stay," said Haagen, the law professor.
Injury is a big concern. Running backs are especially vulnerable, and no one has forgotten that Miami star Willis McGahee tore knee ligaments in the 2003 Fiesta Bowl, minutes before the end of his college career.
Tatupu ultimately decided to turn pro to help his family. He realizes this decision might have cost him millions.
Selected in the second round, higher than predicted, he received less than $2 million guaranteed. Some NFL experts believe that had he played his senior season, he would have been a first-round selection and earned twice as much.
Tatupu might squeeze another NFL year into his shelf life as a player, which could mean an extra contract renegotiation down the line. But, as Brandt points out, underclassmen drafted down the board probably won't recoup the guaranteed money they might have lost by coming out early.
Tatupu, a rookie star for the Seattle Seahawks, has no regrets. "I had accomplished everything I wanted to in college," he said. "Here, you're playing against the best. It's fun."
The same cannot be said for Williams, who tried to join the NFL as a sophomore but saw the courts uphold a league rule that players must wait until three years after high school. After sitting out a year, he is now a rookie with the Detroit Lions.
Williams recently told The Times that he reminisces about his days hanging around with his college teammates. "I miss that," he said.
On the flip side of this regret stands Matt Leinart. Last winter, after winning the Heisman Trophy and guiding his team to a national title, the quarterback chose to stay for his senior season. His decision was widely criticized in the media and, more quietly, among some in the game. After all, he was a probable top-five pick -- if not No. 1 -- with nowhere to go but down.
But Leinart was nervous about entering the draft with an elbow and groin injury that have now healed. He also insists that he wanted to have fun -- a few more of those days that Williams misses -- before leaving school.
Brandt praised his choice, saying that no matter what happens with the NFL's collective bargaining agreement, guaranteed money continually rises for top draft picks. Tennessee's Reese went back to the issue of maturity and experience.
"Just the Notre Dame game alone," he said, referring to USC's last-second 34-31 victory, "is worth staying an extra year."