After 3 1/2 months of upsets leading to that new sports dance, the Ratings Shuffle, college basketball's best teams today start trying to bring some sanity to this mad season.

The occasion is the opening round of the NCAA tournament, which has such bang-up match-ups as San Francisco-Nevada Las Vegas, UCLA-Louisville, Tennessee-Syracuse and North Carolina-Purdue.

The games to be televised today in the Washington area by WRC-TV-4 are Cincinnati-Marquette at 2 p.m. and UCLA-Louisville at 4.

Sowe of the major questions that should be answered this weekend include:

Is San Francisco, rated No. 1 for two months before losing to Notre Dame last Saturday, a fluke or a legitimate championship contender?

Is Gene Bartow capable of guiding the legendary Bruins of UCLA to yet another national title or are his many critics correct about his coaching weaknesses?

Is Eastern basketball making a comeback, or are schools like Porovidence and Syracuse overrated?

This is a unique tournament. No school is an overwhelming favorite to win the national title, and as many as six teams (No. 1 Michigan, UCLA, Kentucky, San Francisco, North Carolina, Tennessee) have valid reasons for thinking they will be the champion when everything ends March 28 in Atlanta.

"There are 25 teams in the NCAA tournament that can win five straight games," Purdue coach Fred Schaus said. "I have to think that Purdue and North Carolina are two of them."

Purdue and North Carolina meet in Reynolds Coliseum on the State campus for a first-round game at 9:37 p.m. Purdue is the Big 10's at-large representative, North Carolina the Atlantic Coast Conference champion. Duquesne and Virginia Military Institute, two teams even Schaus would deem incapable of five straight wins at this level, open the doubleheader at 7:07 p.m.

North Carolina forward Walter Davis, who underwent surgery on his hand Sunday following an ACC tourney injury is out. If the Tar Heel's 6-foot-10 center, Tommy LaGarde, can get back from a knee injury, it will be mostly an inspirational appearance. Purdue's playmaker guard, Bruce Parkinson, sprained his ankle in practice Wednesday and may not play.

Steve Wagner, VMI's top reserve guard, was left home with the measles. Kelly Lombard, the point guard, sprained his right ankle in practice Thursday. He sat out yesterday's drills but said he will play today "no matter what." Duquesne has no injuries, but on the other hand also showed little talent during a 15-14 season.

North Carolina takes an 11-game winning streak and a 24-4 record into its game against Purdue, which finished third in the Big 10 with a 19-8 record but earned an at-large bid because of its tough nonconference schedule and because second-place Minnesota is on NCAA probation and thus ineligible for tourney play.

Carolina's defense will be based on different looks and a number of traps designed to steal the ball and trigger the fast break, which becomes more important that usual with Davis out.

Carolina coach Dean Smith said he would start Bruce Buckley, a 6-6 senior forward from Bladensburg, Md., and move 6-7 freshman Mike O'Koren, the normal big forward, over to Davis' position.

Duquesne's game plan revolves around the perimeter shooting of guard Morm Nixon and the offensive rebounding of 6-7 Rich Cotton and 6p8 Dan Gambridge. Ironically, Ron Carter, VMI's most spectacular player, is a Pittsburg product who has improved tremendously since high school when Duquesne wasn't interested in him.

If the keydets win their next problem could be measles. All the VMI players were exposed and incubation period is about 7 to 10 days, or just about in time for next week's Eastern Regional semifinals at College Park, Md.

Most of the nation's attention will be focused on the West Regional, where two teams ranked in the top 10 for most of the season will be eliminated this weekend.

The most intriguing of today's matchups is that of San Francisco (29-1) against Las Vegas (25-2) in Tucson, Ariz. Neither coach is delighted with the pairing, especially the Rebels' Jerry Tarkanian, who is convinced the NCAA never will give him a break it if has a choice.

"We sure didn't want them (San Francisco) in the first round," said Tarkanian, who has gotten six previous teams into the NCAA tournament but has yet to get to the Final Four. "We have a tough time matching up against them physically. What makes USF so good is that they're so big, but they're also quick.

"Their forwards are bigger than ours and are quicker, too."

The Rebels, who average 106 points a game, rely on accurate shooting off a nonstop fast break. But they can be hindered by two things: weak rebounding and cold outside shooting. And usually they don't play well away from Las Vegas, where they won 19 straight this year.

For the Dons' sophomore-dominated team, this will be a major test of their ability to deal with adversity. "We've lost before, we remember what it's like," said coach Bob Gaillard. "I don't think losing helps. I'd rather have a close win and say, 'You almost blow that one.'"

At Pocatello, Idaho, most of the talk about the UCLA-Louisville game centers around injuries. Gig Sims, the Bruins' freshman center, has a bad ankle and Bartow isn't sure if he can play - or who would start in his spot, Brett Vroman or freshman Kiki Vandeweghe.

UCLA ended the year in the midst of a disturbing habit, disturbing at last to Bartow. The Bruins were depending almost completely on the multitalents of Marques Johnson, the sport's player of the year, to pull out victories. Johnson responded with 262 points in the last seven contests, but Bartow would like better balance.

Larry Williams, Louisville's best rebounder, is recovering from a broken foot, but is expected to see action. How well he can hold up in a fast tempo game is another question.