John Thompson feels like a painter who has almost finished the masterpiece of a lifetime, but still has one last vital stroke remaining; thus, he is both exhilarated and terrified.

For the next 24 hours, the Georgetown coach will hold his breath. He, and almost everyone else, assumes that a 7-foot diamond of basketball hope named Patrick Ewing sits squarely in the Hoyas' palm. If only they don't drop him. Or have him snatched away.

Ewing, an 18-year-old at Cambridge Rindge and Latin School, already bears the marks of becoming one of the great centers in history. He has told Coach Mike Jarvis he will pick his college on Thursday. Jarvis and Cambridge Latin officials, who have established new standards of stringency for protecting a player from the hype and harassment of both recruiters and media, claim they plan to keep the decision secret until an oficial announcement Monday.

If Ewing says any other name that "Georgetown," he will slam-dunk the whole hoop world into stunned silence. Georgetown has led the Ewing derby more than a year. However, there is a vast difference between being in front and winning the race. That is why Thompson, as he sat in the bleachers here Tuesday night watching Ewing play, resembled a 300-pound mass of suppressed worry.

By halftime in the tiny, hot bandbox, Thompson was sweating like a refrigerator on the fritz. A generous student, taking pity, went across the street at intermission and bought Thompson a quart bottle of ice-cold soda pop Thompson grasped the precious gift, then looked above his head and saw a sign: t"No Food of Drink Allowed in the Gym." Suddenly, Thompson looked at the innocent soda as though it were arsenic hand-delivered by the devil. Or perhaps by Boston College Coach Tom Davis sitting only 10 yards away. Or for that matter, by one of the representatives of the other four schools in Ewing's final six -- North Carolina, Boston University, UCLA and Vilanova. All were in the bleachers.

"Does anybody have a brown bag?" Thompson asked.

One appeared. Thompson slipped the bottle inside, then stopped. "What if the principal sees me and throws me out of the gym?" he muttered. "Lord, I'd hate to lose this kid over a bottle of soda."

Summoning his courage, Thompson took the bottle out of the bag. "If It's in a brown bag, nobody'll believe it's pop," he said.

Slowly, the tempting bottle began its long assent toward the peak of the 6-foot-10 Mount Thompson. But, again, the mission was aborted.

To the constnat question, "Just how good is Pat Ewing?" perhaps this anecdote is the perfect answer. He is good enough to make John Thompson, a man of principles, worry about principals.

"It's great to hear that Patrick is expected to make a decision this week," Thompson said after watching Ewing get 21 points, 20 rebounds, 10 assists and 12 blocked shots, while playing less than 20 minutes in a 50-point victory. "That's very good news. The longer he waits, the more gray hair I get."

Whenever Ewing makes his final decision, whenever it is announced, one thing is certain: Nothing about Ewing is going to be secret or serene much longer. This is the player whom Jarvis decribes as "part Bill Walton, a bit of Abdul-Jabbar, a whole lot of Bill Russell and even more Patrick Ewing."

By that hyperbole, he means that Ewing can become as versatile a scorer, passer and all-round team player as Walton, as fluidly graceful a giant as Abdul-Jabbar and as intensely motivated a rebounder, shot-blocker and winner as Russell. In addition, Ewing is a power-game player who loves to sprint base line to base line and is a natural transition player. That opens the possibility that he may bring his skills to more parts of the court, more of the time than such players as Walton and Moses Malone, with whom he is being exicitedly compared. "I wouln't disagree with that assessment," Thompson said.

What part of Ewing's game would Thompson work on first?

"Catching the ball."

Why?

"Because if I get him," Thompson said, "he's going to be doing a lot of it."

Ewing may not be as tall as Ralph Sampson, or as quick and fierce around the basket as Malone but, all in all, he has the qualities that make coaches drool. Above all, this temperament shows in every gesture on the court. He is intense, self-motivated and obviously driven by vastly higher standards than the modest necessity that he crush high school players.

On defense, he looks like a wide-roaming hockey goalie who wants a shutout. He is that oh-so-rare player who obviously considers defense, total intimidating control of the defensive backboard and the quick, long outlet pass as his primary duties. He considers all five offensive players as "his," yet is so agile that he seldom fouls -- certainly not the clumsy kind usually associated with youngsters.

"The first thing that opened my eyes," Thompson said, "was when I saw him fire an outlet pass, then get down and stuff in a quick miss at the other end. The other great big men wouldn't have gotten to midcourt by then. He does everything well, but his trademark may be that no big man has enjoyed running or been able to run so well and so much.The key to beating a Chamberlain or Jabbar is to be where they aren't."

"I hate to see a big man walk," said Jarvis, once an assistant coach at Harvard under Satch Sanders.

On offense, Ewing can do the flashy things -- fancy dribble, shot a soft jumper, spin for finger rolls. He's a natural athlete and would be a fine forward at 6-6. But, unlike so many big men, he knows he's 7 feet and is determined to use every bit of his crushing natural advantage.

His whole offensive game is like a practice session for some higher league.

He demonstrates early, to please the crowd, that he can do the cute stuff. Then he heads for the hole and spends the rest of the night polishing the thankless skills -- fighting for position, spinning from one post to the other, timing his break for the lob pass, trying to get, or at least keep alive, every offensive rebound.

Most surprising of all, Ewing is both greedy and unselfish. He is greedy in the sense that, even when his team is far ahead, he is bearing down more than any other player, trying to exhaust himself by gobbling every rebound, being a part of every fast break. Yet, after the game, he said: "I just enjoy the game. The coach takes me out and rest me so much (out of pity for the opponent) that I can't wait to get back in. I just hate to miss the fun."

By contrast, Ewing is unselfish in that he practically has a phobia about being singled out as better than his teammates. He always tries to pass before he shoots and takes more satisfaction in the "showtime" of his mates than his own.

This freshness, which Thompson calls almost an innocence, probably should credited to Javis.

"This has been the most unusual recruiting of any player of this magnitude in history," Thompson said. "For once, the player is recruiting the schools, instead of them recruiting him. Patrick takes the initiatives and has the controls.

"For instance -- and nobody will believe this -- I could't find the gym tonight. I've never been here. I've never seen him play a high school game. tbefore. And I've never called him on the phone at home.

"If it weren't for the way Jarvis has run this, I wouldn't have had a chance. With Wilt, Moses, Sampson -- any of them -- to have a shot, I'd have had to spend more time in this gym than in my own. And I'd have had to be on the phone every night.

"For once, a player has been recruited without anybody feeling they've prostituted themselves. Ewing hasn't solicited flattery. In fact, the whole thing has been done at such a high level that it almost frightens me. tIt's at the point where you think you must have forgotten something."

That's not to say that Boston hasn't been pleading with Ewing to stay home. On Monday night, Ewing's whole team was at the Boston College-Villanova game and the capacity Boston College crowd began several spontaneous chants of "We Want Ewing."

After the game, Ewing was in the Eagle locker room where he had what the NCAA calls a "bump" with Coach Davis. That means the player and the prospective coach just happen to be in the same place at the same time -- bump into each other, don't you know? -- and exchange a minimum of pleasantries, before running in opposite directions like a pair of Caeser's wives. Davis, rightfully gun shy since his program has become tied up in the middle of an alleged point-shaving scandal, didn't say a word to Ewing, merely walking through his sphere of influence, casting a wholesome smile in his direction, and nodding imperceptibly.?

The style of his recruitment may be part of Ewing's legacy. "He hasn't been wined and dined and supercalled," Thompson said. "The reason is entirely Ewing and Jarvis. No matter what anybody says, it's the kid and those around him who set the tone . . .

"Every year at GU. I've felt that we lost at least one recruit because he though we weren't really interested in him when, in fact, we were. Every year, I practically plead with the kid, saying, 'Don't judge me by how many telephone calls and visits I make. Judge my intentions, not my attentions. How can I do justice to the 12 players on my team if I'm spending all my time pampering you'"?

Thompson recalls a story about Seton Hall Coach Bill Raftery, whose team was trailing by 30 points in a game last year. "He wrote a note on a slip of paper and sent it to the other team's coach by his manager. It said: 'I surrender.'

"I think," Thompson said, "that Cambridge Latin has probably been getting a lot of notes like that."

And starting very soon, Thompson may be getting them, too. But that won't be known until Monday and Ewing, when he talks to the press, isn't giving any hints.

"I've talked to a couple of other guys who've been recruited," said Ewing, "and it's hard to believe what they say -- being called on the phone 25 times a day. To tell the truth, Ive barely noticed it."

The total number of calls from coaches that Ewing has received has been zero. Breaking this rule means expulsion from consideration.

"When I think about college," said Ewing, "I just think about how much fun it will be. Most of all, I want to see if I'm as good as everybody says I am."

Whatever Ewing's final place in basketball history, he already has one distinction. No player of megatalents has ever come through the pernicious American recruiting system with so little damage. "Guys say to me, 'Aren't people always bothering you?'" said Ewing with genuine perplexity. "I just say, 'No.'"

On the issue of the college of his heart's desire, Ewing just says, "I'm not saying nothin' until Monday."

And, if that is Georgetown, the Hoyas, who have everyone back next season except 7-foot backup center Mike Frazier, surely will be ranked in the preseason top 10, and would have a strong shot at the NCAA championship if they also landed Anthony Jones, a 6-7 forward from Dunbar High in Washington. But no one in official rank at Georgetown wants to speculate on what the addition of Ewing would do to the program or the effort to build a new on-campus arena, for fear of offending Ewing -- or breaking sticky NCAA rules.

It's all part of an absolutely unparalleled situation that has been created where a hermetically sealed star actually exists. "I'm gonna love this weekend, says Jarvis. "The papers have been guessing all along, but now they're getting desperate. I think it's hilarious. One paper that covers Georgetown has already said that Patrick is going there. Today, the Boston Globe called up and told me they were prepared to write a story, based on unnamed sources, that Ewing was definitely going to North Carolina. They just wanted my comment.

"That kills me. They've got sources. I'm his damn coach and I don't know where he's going."