The Atlantic Coast Conference basketball tournament is an alluring fraud, a three-day rite filled with enough characters and conflict to excite some of us to the marrow. But it usually fails to keep an essential promise: that bad teams can beat good ones.

Anyone who bothers to check the record, and Ron Morris did in Eastern Basketball magazine, discovers that the higher-seeded team has won nearly 75 percent of the time, that the top-seeded team has never lost in the first round and that a lower-seeded team has not won a first-round game since 1979.

The top-seeded team has won the tournament 16 times and reached the final 22 times in 28 years. Sixth-place Virginia's championship in 1976, after upsets of third-seeded North Carolina State, second-seeded Maryland and first-seeded North Carolina, was the last major tournament freak.

Objective thinkers pray for form to prevail again, for the only two teams that deserve to be in the championship game Sunday are North Carolina and Virginia. Few seasons have produced more imbalance in the ACC; none would end more appropriately, if the Heels and Hoos go after each other for top seeding in the NCAA East Regional.

They split this season, each winning at home, and helped camouflage the fact that the ACC is only the third-best conference, from top to bottom, in the country, behind the Big East and the Big Ten.

The most pressure is on North Carolina State and Wake Forest in Friday's first round. They need to beat Maryland and Duke, respectively, to be assured a spot in the NCAA tournament. Virginia and Carolina are in the NCAAs even if they get shut out.

Omen seekers figure Virginia will emerge the champion, because this is an even year. Carolina has won the title in '75, '77, '79 and '81. Virginia has been playing scared, as though it wants to lose, for about a month. And Maryland was more than willing to accommodate.

Coach Terry Holland may have been playing mind games late in the season, not anxious to enter the postseason ranked No. 1 in the nation. Or the Cavaliers might have been in the boredom phase every fine team experiences as each season gets longer and longer.

They were embarrassed by the Terrapins in the ACC semifinals last year, then rallied and finished third in the NCAA tournament. If they remind themselves to emphasize the best college player alive on both offense and defense, Ralph Sampson, the Cavaliers can run by anyone.

Virginia has been devastating enough this season to dominate a potential final-four team, Carolina; it also has been dreadful enough to make Maryland seem marvelous. Who are these Hoos?

Carolina had its confidence shaken in Charlottesville but has been playing well lately. Even though Coach Dean Smith could convince a mule it had a chance to win the Kentucky Derby, Tar Heel shooters are vulnerable against tight, tough zone defenses.

If Michael Jordan has not recovered from tonsil problems that hospitalized him earlier in the week and kept him from practice until today, the Heels will have more trouble with Georgia Tech than casual fans believe.

The familiar bluster of Charles G. Driesell is blowing here again, thankfully. Until his Turtles beat Virginia Saturday in Cole Field House, much of basketball was starting to dismiss the Lefthander as a major factor in the sport, a hurricane that had run its course.

Not quite.

For the better part of a month, Driesell had been working one of his better cons, arguing that an ordinary team was awesome, that guys who lost twice to Georgia Tech ought to be among the NCAA tournament elite. Can't blame the man for trying. But after those boasts he lost to cloddish Clemson, sleepy Wake Forest and a State team slower than his own.

Still, Lefty's lucky. Just when he seems doomed, just when his program seems about to collapse, just when apathetic fans don't even bother to yawn, he pulls off something stupendous. Such as being victorious in a game Virginia lost more than the Terrapins won. Now a 15-11 team that probably should struggle to make the NIT field is being touted for the NCAA once again by its coach.

It's good to have him running rampant once more. A man who puts so much of himself into his every act, whether it helps or hinders him, and is so open about it enriches sport. But some basketball handicappers thought he should have won 17 games before Charles Pittman suffered that foot injury about a month ago.

So let Lefty leap for the heavens after vanquishing Virginia; let him sass and bluff in his special way; don't let him into the NCAA tournament without winning this one. Unless they stomp State, upset either North Carolina or the yellow horde from Georgia Tech that beat them home and home this season, and then grab Sunday what has eluded them every one of Driesell's years, the Terrapins no more belong in the NCAA than white socks belong with a tux.