Ralph Sampson ended months of speculation today by declaring that the University of Virginia and Coach Terry Holland held the winning ticket in the sweepstakes for high school basketball's most sought-after prize.

"It's been a hard decision for me," began the 7-foot-4 Harrisonburg High School senior, who had been courted by nearly 200 colleges. "I didn't know what to do the last two days. I changed my mind at least 50 times.

"It came down to between Kentucky and Virginia. And, I think I'm going to Virginia next season."

That statement at a news conference elicted cheers from the pro-Virginia contingent among the 100-odd members of the media, Sampson's family and colse friends gathered in the Harrisonburg High gym.

Sampson said he probably will go to college for only two years, then turn pro. He said all the schools knew of his intent.

He said he had not yet signed a letter of intent with Virginia. Asked whether it was possible he could change his mind, Sampson replied, "It could happen."

Harrisonburg Coach Roger Bergey said that Cavalier Coach Holland likely would arrive in Harrisonburg Firday afternoon for the signing of the letter.

"I still can't believe he's made the choice . . . I think he made a great choice. I can't imagine a better combination as far as the school and the educational program involved," Holland said from Charlottesville.

"What we're thinking about now is winning the national championship. That has to be our goal," said Holland, who returns starters Jeff Lamp, Lee Raker, Mike Owens and Jeff Jones from the 1978-79 team that went 19-10.

On the national letter of intent, Holland said, "I'm not worried about running over there and getting his signature. This youngster made his own decision . . . and I'm not worried about it . . . He's just a super young man."

Holland said Sampson "controls every aspect of the game. He's a very fine defensive player. At the offensive end of the floor, he's obviously going to score and he'll rebound at either end."

He also predicted Sampson will make his other players better and said he wouldn't be surprised if he led the team in assists.

In Chapel Hill, N.C., North Carolina Coach Dean Smith said, "We're disappointed Ralph did not select the University of North Carolina but wish him every success. He undoubtedly will go on to become one of the greatest college and professional players of all time."

"'Maybe' and 'probably' are Raplh's favorite words," the player's mother, Sarah Sampson, said. "I think he'll go to Virginia unless something drastic happens, like Terry Holland doing something to turn Ralph off. He felt he would play more at Virginia than at Kentucky: 40 minutes unless he gets into foul trouble."

Sampson said he chose Virginia from a pool of Virginia Tech, North Carolina, Virginia and Kentucky because of the school's membership in a "tough conference" (the Atlantic Coast Conference) and because Charlottesville "is a small city, like Harrisonburg. I like the surrounding area and the people."

Sampson arrived at the gym half an hour before the scheduled 1 p.m. press conference and immediately informed Bergey of his choice. Bergey and an assistant coach then called the head coaches of the final four schools to inform them of Sampson's decision.

Averaging 29.5 points and 20.4 rebounds last season, Sampson led the Blue Streaks to their second straight Virginia state AA title. Sampson compiled 1,699 points, 1,299 rebounds and 475 blocked shots in 83 games during his four years in high school.

Bergey recently discussed an assistant-coaching job at the University of Maryland with Terapin Coach Lefty Driesell. However, he said, he had planned to save any decision until after Sampson picked a school.

"Ralph Sampson and I have never discussed a package deal, nor have I discussed one with any university," Bergey said.

"I was trying to see the recruitment of Ralph all the way through. Then, if anybody was interested in me, we'd talk." CAPTION: Picture, Ralph Sampson