Jennifer Munro has an educated idea of what makes Vijay Singh, Tiger Woods, Ernie Els and Phil Mickelson tick on the golf course. That knowledge, she said, helps explain why Woods, Singh and Mickelson have won green jackets and Els has had an arm in a couple of them.

Munro, who heads the Golf Digest Schools' neuro golf program, is an expert in determining a golfer's mental relationship with golf and how it affects his game.

The president of corporate sales for the school at PGA National in Palm Beach Gardens, Fla., Munro uses behavioral technology to place golfers into one of four profiles - challenger, social, traditional and technical.

Once Munro comes up with one of the profiles for a golfer through a written test, she can enhance the mental aspects of golf for a more rewarding experience.

Munro has been helping golfers recognize their profile for 25 years, the past two with the Golf Digest Schools, where she incorporated her knowledge into the neuro golf program. She has done more than 30,000 profiles in her career, and more than 2,000 since arriving at the Golf Digest Schools, of which there are nine around the country.

Though Munro has worked with Champions Tour golfer Peter Jacobsen, the program focuses on amateurs, mainly corporate sales groups and executives.

What she knows about the top PGA Tour golfers is based on her observations.

"My job is to create a golf experience that enhances business skills and golf skills and rewards people and builds strong relationships (by understanding their profile)," Munro said. "People will do anything to play golf. I wanted to give people a greater excuse to enjoy golf more."

Woods, Singh, Els and Mickelson have never taken one of Munro's tests, but she says she knows what categories they would fall in.

Woods and Mickelson, she said, are challenger golfers.

A challenger's central temperament trait is dominance. They have a drive to control their environment, destiny and outcome.

Above all, they want to face a challenge, she said.

"If they play an easy golf course or play with people who aren't competitive, they don't play well," Munro said. "If they're playing in that situation and they get behind where they think they ought to be, they will then start competing against themselves. They play well from behind, and they play their best when something big is at stake."

The most famous challenger, Munro said, is Arnold Palmer.

She said only about 10 percent of the general population falls into the challenger category, and she estimates that only 3 percent of players on the PGA Tour are challengers.

Though Mickelson and Woods are both challengers, there are some differences between them.

"Phil and Tiger both have this inability to take a conservative shot, but Phil is more into what people think than Tiger is," she said. "Phil hates the conflict around him. He has two traits that are in conflict with each other: one that wants to win no matter what, and the other that wants to keep calm and harmony around him. But a challenger can't be at peace. He wants to be challenging something. He wants to be slaying something and bringing it back to the cave."

Munro said Singh "has some strong technical-golfer profile components," which makes sense since his work ethic that has carried him to the top of the golf world at age 42. A technical golfer is a conformist who follows processes and systems and has a technical orientation and expertise.

Other characteristics of a technical golfer fit Singh to a T: suspicious, guarded, accurate, precise, systematic.

"He's certainly an introspective person," Munro said. "He's very methodical and patient. He moves at the same speed. I've never seen him at any speed but the one he's on. I think he's such a perfectionist, and a technical golfer is a perfectionist. You see a real internal drive for perfection; not an internal drive to win, but to perfection."

Munro said Nick Faldo is another technical golfer.

Els is a traditional golfer, Munro said. A traditional golfer's main trait is patience. They are easy-going, relaxed, stable, persistent, unselfish, dependable, cooperative and agreeable.

"He's totally traditional," Munro said of Els. "He's smooth, even, fluid and never gets ruffled. He's totally laid back, totally introspective and totally undistracted by anything around him. He's just in his own world. He repeats that beautiful swing. Everybody knows Ernie Els' swing. All you have to do is see it from a distance and you recognize the swing."

Munro said about 50 percent of the population and 85 percent of the PGA Tour are traditional golfers.

While her program is for amateurs, Munro said pros would benefit from knowing their personality profiles.

"I don't think they understand (their profile)," Munro said. "I think they do what the professor tells them to do. They do what has been proven and statistically shown how they are supposed to act. I don't think most of them are in touch; I guarantee you Tiger is in touch with who he is. I don't think most of the guys have a clue."

There aren't many successful pros who fit the fourth personalty profile - the social golfer. They are extroverts who are sociable, outgoing, fun, cheerful and communicative.

Munro said Jacobsen is one of the few social golfers to make an impact on the PGA or Champions tours.

"The social is the person who really does play for fun," she said. "Only about 20 percent of the golfers play for fun. Social golfers are externally impacted; they are easily distracted by external factors such as the mood their partners are in or what their partner is doing or the mood of the crowd. They have a hard time focusing internally because they are external people."

Munro said other social golfers include Lee Trevino and Chi Chi Rodriguez, both of the Champions Tour.

"It's easy for a social to get so caught up in what's going on around them that they lose focus on their game," she said.

"If they don't have interaction, they can play the best game of their life and not have a good time and think it wasn't a good day. There is no joy in it. It's like making a hole-in-one when nobody's watching."

So, of the Big Four (Singh, Woods, Els and Mickelson), who does Munro like this week?

"I can see any of these guys winning it," she said. "The Masters is a lot of emotion, and it helps to have the passion of the crowd behind you."

Munro said it could come down to Woods and Mickelson in Sunday's final pairing, as was the case in March's Ford Championship at Doral. Woods edged Mickelson by a shot in a classic battle of challenger golfers.

"They were like dueling titans out there, fighting to the death like gladiators," Munro said.