All season, whenever someone asked Buck Williams about the possibility that he might pass up his final year of college basketball to turn pro, he gave the same answer.

If, he said, "someone made me an outrageous offer like drafting me one, two or three, I wouldn't even think about coming back."

Lefty Driesell, Williams' coach at Maryland, also had a stock answer when question about his 6-foot-8 junior star came up. If he can get a guaranteed contract for big dollars I would tell him to go," Driesell said. "But only with a guarantee."

Late Saturday night, Buck Williams got that gurantee from both the Detroit Pistons and New Jersey Nets, in the form of assurances that he would receive a contract worth about $1.5 million over the next four years. And so, he decided to forgo his last year at Maryland in favor of the NBA.

Both Williams and Driesell never really thought that was going to happen. But two weeks ago, Williams decided he had an obligation to himself and his family to at least find out what the pros thought of him.

It started when Lerry Diedrich, an attorney in Williams' hometown, Rocky Mount, N.C., a friend of the Williams family, contacted Donald Dell and David Falk, a memeber of Dell's law firm. Dell and Falk were already familiar with Williams -- and interested in representing him. Dell had been seen frequently in the Maryland locker room the past two seasons and had represented such Maryland players as Tom McMillen and John Lucas.

Diedrich asked Falk and Dell to find out where n Williams stood with the NBA. They made some phone calls and came back with a startling answer: Buck could be the first player chosen if Ralph Sampson opted to remain in school.

"I was shocked," Williams said yesterday. "In fact, I was completely astounded. I thought because I had never made first team all-ACC that my potential was kind of hush-hush."

Now, suddenly, the situation went well beyond mere testing of the NBA waters. Last Tuesday, Williams, who has a genuine affection for Driesell, went to see his coach. He told him that he had asked the Dell people to check on his value and had found it was much higher than he had imagined.

Driesell, stunned by the news, said little except, "Don't do anything without a guarantee."

Williams also talked to his family. Since high school when he first began to find out that he had enormous talent on a basketball court, Charles Linwood Williams Jr. has had one dream: to build his family a house. That dream drives him, makes him the intensely competitive player he is.

Buck Williams' mother has had a different dream for her son. She watched Buck's older sister drop out of school to get married and never go back. Now, with her son one year from a college degree, she listened and told him to do what he thought best.

"But underneath I knew she wanted me to stay in school," Williams said. "That's the way mothers are."

Unlike many athletes of his caliber, Williams wants a degree in the worst way. Many college coaches, including North Carolina's Dean Smith, shied away from him when he was in high school because he had been a poor student through his junior year.

But at Maryland he has worked had to remain on schedule to graduate in four years. He is on schedule now.One of his goals this year was a 3.0 grade point average. He will reach that goal.

"I will definitely get my degree," Williams said. "I'm going to go to summer school this year and I'll go back to summer school next year. It's important to me that people, kids, realize I wasn't just talking when I said the degree was important to me. It is and if I had any doubts about getting it, I wouldn't go."

The question then was money. How much was Williams worth and could he get it guaranteed before midnight Saturday, the deadline for declaring eligibilty?

Falk spent most of the day Friday on the phone with NBA teams. Primarily, he talked with the Dallas Mavericks.

By this time the word was out that Sampson would stay at Virginia. The word also was out that Isiah Thomas of Indiana was going to come out.

The Detroit Pistons, who will flip a coin with Dallas for the first pick Thursday, coveted Thomas. They would take Thomas if they won the flip.

Would Dallas, Falk wanted to know, then pick Williams? "We told them we really liked Buck a lot," Dallas President Norm Sonju said. "But we had made a decision earlier that we would not make any guarantees to undergraduates because we didn't want to entice them."

Falk also knew that Detroit was negotiating with Georgia sophomore Dominique Williams. Saturday morning when Williams arrived at Dell's Connecticut Avenue offices, nothing had been decided.

By now, Driesell was panicked. Losing Williams was becoming more and more of a possibility. Saturday he woke up too depressed to go to the office as he had planned. Instead, he sat by his phone. And waited.

Driesell's assistants, Tom Abatemarco and John Kochran, who had done their recruiting this season assuming Williams would return, were just as stunned at their boss. Kochan had been selling Uwe. Blab, the 7-3 West German living in Effingham, Ill., on the idea that he would play next to a great rebounder, Williams, if he came to Maryland.

Both assistants went to the office Saturday afternoon and tried to find work to do. Finally, they went back to Kochan's house to wait.

Downtown, Falk was working about five different phones at the same time while Williams sweated. Falk called Sonju again, looking for a guarantee. Sonju wouldn't, couldn't, change his position. But he did give Falk a number to reach Dallas owner Donald J. Carter.

Falk reached Carter at about 4 p.m. Carter was on a retreat with friends and was about to fry some fish. He and Falk talked -- at length. Carter, knowing his coach, Dick Motta, would love to have Williams, was encouraging, telling Falk how highly he thought of Williams. But he would not change his positing on financial guarantees.

It was scramble time. Word was beginning to drift in that Wilkins was having second thoughts, that the money Detroit was offering was not enought. Falk went back to the phones. He called Detroit and he called the New Jersey Nets, the team with the third pick in the draft.

At about 9 p.m., exhausted to uncertain, Williams and Falk went to dinner at the Hyatt-Regency. During the meal, Williams asked Falk if he made a habit of working 15 hours on Saturday.

Back at the office, with the deadline approaching, things began to move. Shortly before 11 p.m. Falk confirmed that Wilkins was staying at Georgia. That left Detroit without a guaranteed player if Dallas won the coin flip. At the same time new Net Coach Larry Brown, who coached Williams last summer with the olympic team, was encouraging his management to guarantee Williams a contract.

While Falk negotiated, Driesell and his assistants talked back and forth by phone, speculating on what was happening, wondering what they could do. Driesell spoke to Red Auerback, who told him he didn't think there was time for a guarantee to be worked out and that Williams might go as low as seventh in the draft.

Shortly after 11 p.m. things began to fall into place. Detroit would draft Williams second if Dallas won the flip and took Thomas. If Detroit won the flip and took Thomas and Dallas didn't pick Williams, New Jersey would. The Pistons and Nets came up with the guarantee Williams was looking for; a four-year contract worth about $1.5 million.

There was a conference call, Williams and Falk one one end, Reggie Henderson, Williams' high school coach, on another and Diedrich on another line. "The decision was left up to me," Williams said.

"It was," he said, "without question the toughest decision I've had to make in my 21 years."

Finally, at 11:50 p.m., Williams told Falk, "Let's do it."

Minutes before the deadline, the deal was sealed.

Then, they called Driesell. He picked up the phone on the first ring. "I think I would have rather have jumped off a 10-story building than tell him," Williams said. "I felt like I was a child that had gone astray, like I had done wrong."

Driesell still was worried about the lack of a guarantee from Dallas. Falk's reassurances did not comfort him. He hung up angry and called Abatemarco and Kochran.

"He's gone," he told them, his voice is a whisper.

Williams finally went home at about 1 a.m. "My mind is like a crossword puzzle that hasn't been put together yet," he said yesterday after a few hours sleep. "It still hasn't sunk in that I've played my last game for Maryland.

"That part is hard to take because playing here has been the best thing that ever happened to me. Everyone treated my royally. But in the end, even if it offends a few people, I had to do what I thought was best for me."

The bottom line was that Williams was able to get a guarantee. Staying another year would have been a maybe. And, Williams had watched his close friend Albert King struggle this year after turning down big money a year ago. He and king talked about that during the week. Still, that was not the reason for his decision.

"What it came down to finally was my dream," Williams said. "I've had this dream all my life and suddenly, last night, there it was put right in front of me. I just couldn't say no to it."