KANSAS CITY, Mo. — They want a breakthrough. They want to dig deep enough to scratch a nerve, break it down and tear through the protective layers of toughness and ambition.

Here's the scene: A stranger taps you on the shoulder, pointing the way toward a room or a hallway or a corridor, and that's where he'll ask questions about your childhood or your past or your parents. You met this person two minutes ago, and you trust the stranger because — why? He's working for a NFL team at the league's scouting combine, yet another of a hundred questioning gatekeepers, like the man who measures the vertical jump or the other who initiates the bench-press display.

This stranger is giving a test, and with the right answers, you may pass through his gate and hear your name called at next weekend's NFL draft. The right combination of answers, and entrance could be worth $40 million.

What if your father is in prison? Or you busted your roommate's nose at the beginning of sophomore year? Or skipped class for three weeks straight? Or told your coach once to take his playbook and shove it? Or tried Ecstasy once, or was it twice? Or don't especially enjoy playing football?

"Questions about yourself, nitpicking at your character," says Chiefs offensive tackle Branden Albert, a first-round pick last year. "You've got to be honest."

He'll ask those questions and make notes. He'll measure your words, your tone, your body language. When he's finished, you'll head toward another test, and the sports psychologist will begin compiling a report to share with more strangers, and they'll determine not just whether you're worth millions, but if you can handle the reality of being worth that kind of money.

As pro football races to adapt to its next generation — with its growing salaries, refined branding and sharper scrutiny — there is a disturbing byproduct that the league is now trying to curb: Some men are just not mentally prepared for the NFL's demands.

Former first-round draft picks such as Vince Young, Matt Jones and Plaxico Burress have, within the past year, allegedly displayed regrettable judgment and signs of perhaps questionable mental health, and teams are trying to figure out whether to help players with psychological problems or simply avoid them. They're trying to settle that debate by examining draft prospects' minds in the same exhaustive way that, for years, teams have tested players' bodies.

The combine used to measure height and weight, and that was about it. But that was when an entire team could be paid what a lower-rung player makes today. They might have missed some things back then, and that might not have always been a bad thing.

"There's got to be some sort of psychological problems with me," says Joe DeLamielleure, a Hall of Fame guard who was drafted in 1973. Joe was undersized, and the Buffalo Bills overlooked that. They also overlooked that before Joe finished Michigan State, his mother was the educated one in the house, having completed eighth grade, and Joe was one of 10 children and a bed wetter and a kid who woke up at 2 a.m. on weeknights to clean his dad's bar in downtown Detroit, and then he'd climb back into bed for two good hours before it was time to dress for school.

"Teacher told my mother that nobody yawned as much as me," Joe says now. "These days, they'd have looked at all those issues and said, 'Nah, I don't think this kid can do it."'

NFL teams want the whole truth, and that means digging deeper than ever. Whether it is the best or worst new habit by NFL teams, it is difficult to argue that some don't yet know how to appropriately gather and digest this information.

According to two well-known doctors, sports psychology in the NFL is held back by intimidation and soiled by inexperience. The problem with all that is teams have never placed as much emphasis on players' mental framework as they are doing now.

Teams want to eliminate risk, and they have embraced psychological evaluations as a worthy research tool. It's a start, but some teams' commitment, comfort and expertise in the science remain in their infancy.

"We're still in the dark ages," sports psychologist John Murray says. "There are going to be a lot of mistakes as people stumble around."

That was made clear in February, when Georgia quarterback Matthew Stafford, the likely No. 1 overall draft pick, was evaluated at the scouting combine. A psychologist affiliated with the San Francisco 49ers reportedly prodded Stafford, 21, about lingering issues related to his parents' divorce. Stafford bristled, and that made him look evasive; bottled up. The psychologist compiled a report and delivered it to team officials. Stafford's reaction to the probing compelled a testy but resolute Mike Singletary, the 49ers coach, to say on a radio show that Stafford had failed an essential test — and as a result, Singletary's team wasn't planning to draft Stafford.

"Maybe he doesn't belong here," Singletary told Bay Area radio station KNBR.

Singletary's comments underscored that NFL teams are no longer muting the importance of mental health. But Stafford's case also raised concerns about the unpolished manner in which the player was evaluated, worries that the details of a confidential meeting with a psychologist had been discussed and judged publicly, and the reality that some teams view this delicate and complicated science through a black-and-white lens: that a player is either fit or unfit to play professional football.

"You have something that people don't understand," says Jack Stark, a clinical psychologist who conducted player evaluations during the combine in 1996. "They don't know what they want."

Here's the scene: It's late January 2003, and Barret Robbins is gone again. He's the Oakland Raiders' Pro Bowl center, and he has picked Super Bowl week as the time to disappear, wandering San Diego's streets at night and heading across the border to Tijuana, Mexico. He'll say later that he drank himself into a stupor and even considered suicide — all because he's uncertain he can handle the expectations and pressure of playing in the Super Bowl.

After nearly a week of wandering, Robbins is incoherent at the team's Saturday night meeting. The Raiders suspend Robbins for the Super Bowl, which the team loses, and Robbins' teammates are furious. A year later, Oakland gives up on him, and Robbins won't play football again. It is revealed too late that Robbins suffered from bipolar disorder and severe depression. A more haunting fact emerges: Robbins' problems could have been treated years earlier, possibly preventing his Super Bowl breakdown and a chain reaction that killed his career.

"There were some signs," says Robbins' agent, Drew Pittman. "It's a brutal, brutal thing. My awareness of it was changed forever by ... seeing the things that happened to him.

"Society in general is not very sympathetic. Over the last five years, society has changed dramatically. The same thing is happening in the NFL."

With Robbins in mind, and last year's mysterious one-day disappearance of Tennessee Titans quarterback Young, the league is setting foot on unfamiliar ground. The principle of mental evaluations is decades old, but the emphasis is new. Until recently, teams haven't ruled out prospects because of their psychological profiles.

"If Jeffrey Dahmer could run a 4.2 40," Stark says of the old way, "somebody would go after him."

Today's standard is driven by the hope that, one way or another, episodes similar to Robbins' can be avoided — for players' sake and so that teams' high-stakes gambles are more likely to pay off. With many examples of breakdowns still fresh, teams are finely tuned to erratic behavior, and they're no longer burying mental-health concerns under a sea of toughness and machismo, a pair of elements that might have made players reluctant to seek help or admit they needed it.

Most NFL teams do not employ team psychologists. Some keep doctors on retainer or contract them as consultants, such as the time Stark evaluated players for the Miami Dolphins in 1996. Stark says he interviewed two or three players at a time, making notes of the players' traits — self-promoter, team player, violent history, introverted, etc. — and submitted a single-spaced, one-page report on about 75 prospects. But he also noticed that some team psychologists were not qualified to assess players.

"People would call themselves doctors who weren't doctors," he says. "The owner will hire somebody they knew or because they did marriage counseling with their kids. It's not like they go and look for the top 10 guys in the country."

Stark says one "psychologist" at that combine held no doctoral degree and possessed no sports psychology experience. He was, in fact, a counselor at a prison in Louisiana.

"An old boys' network," Murray says. "Legitimacy is ignored. They're going to get what they paid for."

Greg Aiello, the NFL's senior vice president of public relations, says the league doesn't regulate how teams conduct evaluations, enforce a standard for teams to follow, or suggest whom a team should choose to analyze prospects.

More unsettling, Stark says, is that some haven't acknowledged that psychology begins, and doesn't end, at an evaluation. As teams struggle to understand what their observations mean, players with perceived problems are being shunned.

"There's a stigma," Pittman says.

Here's the scene: At the same combine that Stafford was questioned, scouts were eager to watch another potential No. 1 pick, former Alabama offensive tackle Andre Smith. He is big, strong and athletic — the prototype NFL lineman. Earlier this year, Smith had been rated by ESPN's scouting service as the most talented prospect in the 2009 draft class. But there was a problem when it was Smith's turn to face the gatekeepers: He had disappeared.

Last month at Alabama's pro day, Smith, a 332-pound lineman, stunned observers by removing his shirt before lumbering down a track. Last week, he fired his agent. All this after Smith was suspended for January's Sugar Bowl.

Smith's episodes of unpredictable behavior have added up, and he's seen as a risky player. Now, ESPN ranks Smith as the No. 14 prospect, and he might fall from the draft's top 10, perhaps costing him millions. Alabama coach Nick Saban, a former NFL coach, has tried to slow Smith's fall by explaining to league officials that he simply received and followed bad advice.

"Andre Smith is a good person, a good guy," Saban says. "This is a little bit of a lesson for maybe all players to learn."

Stark says he has recommended to coaches that they hire full-time sports psychologists to help players who display erratic behavior, sometimes an early signal of a disorder. That way, the team that drafts a player such as Smith can determine whether he is among the 40 percent of the United States population that, according to Stark, suffers from mental illness.

"It could be a red flag," he says of Smith's behavior, "but it could be a normal reaction to being scared. Some of these kids have nobody to talk to.

"If I'm going to pay 25 million for this guy, I need to know if he's going to walk out of camp if my coach yells at him. But let's get him some help from the day he gets here."

Stark says at least three teams — the Indianapolis Colts, Carolina Panthers and New York Giants — acknowledge the value of thorough evaluations conducted by qualified doctors. He says their examinations are comprehensive and as thorough as time constraints allow.

"They know what they're doing," he says.

But some executives and coaches remain skeptical. He says some have told him it is the coach's job to manage players' moods, and in the event of a crisis beyond the coach's expertise or patience, players are directed to the team chaplain.

Stark says he would be surprised if Stafford ever trusts a therapist after his combine interview. Worse, the episode might have stifled the NFL's progress toward taking mental health seriously. Stafford was, in a way, punished for being honest — and Stark says Stafford, and others who paid attention, might have taken from that experience that it's better to deny or ignore problems than to address them. Stark says that contradicts what psychology is meant to accomplish.

"It's a mess," he says.

Murray says that players' inevitable hesitation will not ease until teams invest in licensed, legitimate doctors and understand that a player's mind cannot be disassembled and understood in the 30-minute blocks afforded each team at the combine. San Francisco 49ers director of public relations Bob Lange would neither identify the psychologist who interviewed Stafford, whether he or she is licensed, or reveal whether he or she was a team employee. Lange says that as a matter of policy, the team doesn't discuss any part of the team's medical approach.

"For too long," Murray says, "they've tried to sweep it under the rug and say it's not important. But now that they've embraced it, they're doing it awkwardly.

"It's a complex, mysterious thing, the mind. It's a very delicate thing you have to deal with. You get all this training and you get all geared up to go, ready to help some team, and they're afraid of it."

Murray says that teams haven't mastered how to retrieve information or find a suitable avenue to use it, but he admits it is encouraging that the NFL has begun to acknowledge the mind as a pathway to success or failure.

The mind, after all, might be the last natural frontier of predicting the difference between Peyton Manning and Ryan Leaf, players who look the same on film but are far different in how they approach success and handle it. An informed, educated opinion might win a Super Bowl, and a wrong decision might set in motion a $40 million mistake.

"That decision is so critical," Stark says. "Any little edge is huge. They're looking at you and saying, 'Jack, I can't be wrong on this one. I'll lose my job.' There's just too much money involved. You can't afford to guess wrong."