THERE'S A RUMOR going around that Bob Davis, BYU's hard-headed all-conference inside linebacker, is no longer a wild and crazy guy. OK, so he gave the earrings to his wife, and the hair is shorter and he even shaves, occasionally; he gave up the Red Man, and he spends his weekday nights studying instead of partying, carousing or fighting.

The word out is that marriage and the family scene have caused Davis to settle down. "Oh, yeah, Bob's settled down," says his wife of a year, Julie, echoing the expressed sentiment of teammates and coaches.Yep, anyone can see that Davis is mellowing, all right. This is the same guy who regularly engages in head-butting contests, in which the contestants ram each other repeatedly, head-to-head, just above the forehead, until one of them surrenders or is knocked out. They don't wear helmets.

If that doesn't knock the spunk out of Davis, and it never does, there is always his weekly wrestling match with fellow linebacker Chad Robinson, a ritual that's beginning to draw a regular group of specta-tors.

Heaven knows what he'd do without the football field, where he's his usual mild, quiet self. Why just last fall, head coach LaVell Edwards kicked him off the practice field for making full-out tackles in what was supposed to be a half-speed drill. Davis knows only one speed.

If Davis isn't doing outrageous things, he's probably saying them.

- On Miami quarterback Steve Walsh, whom he will face Saturday in the Orange Bowl: "I want to hit Walsh. I don't like the guy. I want a sack. He's arrogant. He's always pointing and flaunting it and talking - he's kind of like me."

- On his prep football career: "I played linebacker, but I was also a tight end. I caught nearly 50 passes, but I couldn't wait 'til defense. The only time I liked offense is when I had the ball and could run over someone."

- On his behavior in general: "I love pain. I love hitting bodies."

Could anyone possibly doubt him?

Davis gets a lot of practice at hitting bodies. Few players in BYU history have hit more bodies than Davis has this season. With one game remaining in the regular season, he leads the team with 274 defensive points. If that means nothing to you, consider that Robinson is second in defensive scoring - with 177 points. On Saturday Davis has an outside chance of surpassing Kyle Whittingham's seven-year-old school record of 308 points.

What's most remarkable about Davis' point total is that he has few sacks (4.5), interceptions (one) and fumbles caused (zero), which are worth five points each in the BYU scoring system. Most of his points have come from making tons of tackles, which are worth fewer points (two for unassisted tackles, one for assisted). Davis has 137 tackles - 77 unassisted (13 short of the school record set by Dan Hansen and Larry Carr in 1972) and 60 assisted (well off the school record of 131 set by Rod Wood in 1978).

"To be a great athlete, you've got to have certain size and speed, but you also have to have a sixth sense, the ability to feel for the ball and know what to do, how to react," says Edwards. "Bob has a great knack for that. And then he's just a very physical kid. He's got a defensive player's mentality."

This is what Edwards says now. Two years ago he was ready to tell Davis to take a hike. As a freshman, Davis was anything but a model BYU student. "I was doing everything opposite of what you should do at BYU," he recalls.

He went to class with a diamond stud earring in one ear and a plug of tobacco in his unshaven cheek, resplendent in shorts or sweats. That is, when he went to class at all. He finished the year on academic suspension.

Davis also did the partying and drinking circuit, and once paid a visit to a fraternity at the University of Utah, of all places. There, well, one thing led to another and he wound up beating up two fraternity boys, who later filed suit (and then dropped it).

"It was a bad year all the way around," says Davis, who wasn't winning any friends in football, either. He was kicked out of practice "eight or nine times" for fighting and tackling the quarterback. The coup de grace came when he missed the plane to the Air Force game. "I stayed with some friends and I didn't wake up in time," he says.

When the season was finished, Edwards called Davis into his office for a chat. "Bob, we really want you to stay here," said Edwards, "but if you don't like BYU, I'll help you go somewhere else."

Davis, motivated by a chance to play the following year, vowed to change. He became a starter last year, but was erratic. More than once he was seen turning to a teammate to ask what he was supposed to do on a particular play. Worse, he missed several games with a shoulder injury.

During the off-season he cut 15 pounds and lived in the weightroom. This season Davis, a junior, came from nowhere to become a finalist for the Butkus Award, which is presented annually to the nation's top linebacker. As the season progressed, Davis' reputation grew - and finally caught up with him. "The last two or three games I had two or three guys keying on me and it was hard to make big plays," he says.

How good is Davis? "Bob Davis is an all-timer," says linebacker coach Claude Bassett.

Defensive coordinator Dick Felt is more conservative. "I'm not ready yet to say he's the best linebacker we've had. But he's a very good player. He's come a long ways and he can go a lot further."

Provided he doesn't mellow out too much, Davis' future does look bright. At 6-foot-11/2, 235 pounds, he can run like a halfback - 4.6 and some change for 40 yards - and he's a no-slip, no-nonsense tackler. "I saw him hit one guy - he stood him right up - and then take the ball away from him at the same time," says linebacker Regan Hansen. "I was amazed."

And to think, Davis is only 19 years old.

*** "Some people are just born with a wild streak," says Davis, clearly including himself in that category. When he was just 4 years old, his parents packed him off to school, because "I drove them crazy. I was a little wild guy. They wanted to give me something to do." A year later, he found football and his life's calling - as a linebacker.

The family, after stays in Florida, and Ohio, eventually settled in Mesa, Ariz., where Bob's notoriety grew on and off the football field. Let Davis give you his M.O. "I was into different stuff in high school. I had long hair and an earring, and I chewed tobacco . . . Everybody knew me as a wild guy. I got in a lot of fights. I've been sued two or three times. I was known in the Mesa area. If I was out, people were intrigued to see if they could take me."

So naturally Bob came to BYU, refusing scholarships from San Diego State and Arizona State, among others. "I knew BYU was strict, but not that strict," says Davis, who, despite the jarring inconsistencies, joined the Mormon Church as a prep senior.

Marriage to his high school sweetheart in July 1987, the talk with Edwards and a three-hour lecture from Bassett seemed to awaken Davis to what he calls "different responsibilities." The truth is, he has changed. He no longer drinks or chews, and Julie is the only one in the family who wears earrings. He can be found at the library at least two or three nights a week, which accounts for his 3.0 GPA the last couple of semesters.

One thing hasn't changed: Davis' single-mindedness and intensity. Last fall, he temporarily left his wife and moved into the dorms so he could concentrate on two-a-day practices. They part company at times during the season, as well. The night before a game, Julie visits friends. "She doesn't like to be around me," says Davis, who broods about the game during two-hour long walks. On game day Davis refuses to eat even a bite of food, which often means, if it's a night game, a fast of 24 hours or longer. "I like being hungry," he explains. "When I eat, I feel slow."

When Davis does relax, football is rarely far from his mind. If he's not watching televised football games he's watching videos of the great linebackers in action - Lambert, Nitchke, Butkus - and drooling. "I love to see hits where the helmets fly off," he says.

Ah, yes, his real passion - violence, in all its forms. When camp opened last fall, Davis was on the mend from a shoulder injury that had forced him to miss spring practice. He was itching for a hit, having gone without one for eight months, but Edwards, fearing injury, told him not to tackle. Davis did anyway and Edwards repeated his order. When Davis delivered another hard tackle, Edwards kicked him off the field. "I was so anxious to hit," says Davis. "I hadn't hit in so long. I missed it."

Not even football satisfies this urge for hitting, so he's found some extracurricular contact. Last fall he initiated heralded freshman Rocky Biegel into the Linebacker Club with a head-butting contest in the dorms. They ran at each other from five yards back and rammed each other at the top of the forehead. Repeatedly. Biegel finally collapsed and nearly went unconscious.

On the civilized scale, this ranks somewhere between boxing and cockfights, but Davis apparently has started a new sport. "Yeah, we do it all the time. I've done it against John Hunter and Mike O'Brien and the whole defense. We call it bonking."

That started another primal rite. In the huddle before the start of each game, Davis rams heads with each member of the defense, but with his helmet on. "Or, if the other team is driving, I'll say, `Hey, give me a bonk,' and we'll bang heads. Now everyone says `Give me a bonk."'

Or give me a show. On the road or at home, Davis and Robinson name the site for their Friday wrestling match, which is drawing a regular crowd of spectators. Many a hotel room has been trashed while 445 pounds worth of linebacker tumble and rumble.

"When you think of the typical football player you have Bob Davis," says Hansen. "He's a little crazy, and he's big, strong and fast."

"I'm still a wild guy in some ways," says Davis himself. "I think you have to be a little wild to be a linebacker."

The taming of Bob Davis goes on . . . .